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Climate change is an incessant global phenomenon and has turned contentious in the present century. Malaysia, a developing Asian country, has also undergone significant vicissitudes in climate, which has been projected with significant deviations in forthcoming decades. As per the available studies, climate changes may impact on the fertility, either via direct effects on the gonadal functions and neuroendocrine regulations or via several indirect effects on health, socioeconomic status, demeaning the quality of food and water. Malaysia is already observing a declining trend in the Total fertility rate (TFR) over the past few decades and is currently recorded below the replacement level of 2.1 which is insufficient to replace the present population. Moreover, climate changes reportedly play a role in the emergence and cessation of various infectious diseases. Besides its immediate effects, the long-term effects on health and fertility await to be unveiled. Despite the huge magnitude of the repercussion of climate changes in Malaysia, research that can explain the exact cause of the present reduction in fertility parameters in Malaysia or any measures to preserve the national population is surprisingly very scarce. Thus, the present review aims to elucidate the possible missing links by which climate changes are impairing fertility status in Malaysia.
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Review
Ravindran Jegasothy*, Pallav Sengupta, Sulagna Dutta and Ravichandran Jeganathan
Climate change and declining fertility rate in
Malaysia: the possible connexions
https://doi.org/10.1515/jbcpp-2020-0236
Received July 26, 2020; accepted October 4, 2020;
published online December 14, 2020
Abstract: Climate change is an incessant global phenom-
enon and has turned contentious in the present century.
Malaysia, a developing Asian country, has also undergone
significant vicissitudes in climate, which has been pro-
jected with significant deviations in forthcoming decades.
As per the available studies, climate changes may impact
on the fertility, either via direct effects on the gonadal
functions and neuroendocrine regulations or via several
indirect effects on health, socioeconomic status,
demeaning the quality of food and water. Malaysia is
already observing a declining trend in the Total fertility rate
(TFR) over the past few decades and is currently recorded
below the replacement level of 2.1 which is insufficient to
replace the present population. Moreover, climate changes
reportedly play a role in the emergence and cessation of
various infectious diseases. Besides its immediate effects,
the long-term effects on health and fertility await to be
unveiled. Despite the huge magnitude of the repercussion
of climate changes in Malaysia, research that can explain
the exact cause of the present reduction in fertility pa-
rameters in Malaysia or any measures to preserve the na-
tional population is surprisingly very scarce. Thus, the
present review aims to elucidate the possible missing links
by which climate changes are impairing fertility status in
Malaysia.
Keywords: climate change; fertility; global warming;
infectious disease; pregnancy.
Background
Global climate change is the biggest threat to biodiversity
and is severely affecting natural population of species via
various mechanisms [1, 2]. It has both direct and indirect
impacts on human health as all the physiological adapta-
tion strategies are failing in the face of shifting environ-
mental phenomena [3, 4]. Climate change may directly
affect health by disrupting physiological functions or
indirectly by impairing the overall environmental and
sociodemographic factors indispensable for health, such
as degradation of air and water quality, causing insecurity
of food and shelter etc. [4]. The major climate change is
attained by global warming that induce high risk of disease
outbreaks, sensitive to changes in weather, for example,
cholera, malaria, malnutrition and natural disasters com-
bined [57]. Malaysia is also experiencing distubances of
annual rainfall and gradual increase in surface warming,
mainly since the past two decades [8]. Moreover, Malaysia
is also suffering from increasing trends of altered sea level,
surface temperatures, and extreme weather events [8, 9].
Therefore, changes in climate and their consequences
should be paid research attentions.
The long-term effects of climate change on health and
fertility of a population often get ignored while several
factors independently or in combinations, are silently
declining the overall fertility rate in Malaysia. Malaysia has
observed a declining trend in the Total fertility rate (TFR)
over the last three decades. In women, within the age range
of 1549 years, TFR is showing a decline from 4.9 babies
per woman in 1970 to 1.8 babies in 2018 [10].
Considering high importance of reproductive health in
persistence of a nations population, it is crucial in the
present scenario to apprehend how climate change is
affecting fertility parameters. This article is the first ever
published review to present the possible impacts of climate
changes in Malaysia over the fertility parameters. The article
has individually addressed the most essential factors
*Corresponding author: Professor DatoDr. Ravindran Jegasothy
Adjunct Professor, Department of Obstetrics & Gynaecology, and
Former Dean, Faculty of Medicine, Bioscience and Nursing, MAHSA
University, Kuala Lumpur, Malaysia, Phone: +6012 610 7997,
E-mail: rjegasothy@yahoo.com
Pallav Sengupta, Department of Physiology, Faculty of Medicine,
Bioscience and Nursing, MAHSA University, Kuala Lumpur, Malaysia.
https://orcid.org/0000-0002-1928-5048
Sulagna Dutta, Department of Oral Biology & Biomedical Sciences,
Faculty of Dentistry, MAHSA University, Kuala Lumpur, Malaysia.
https://orcid.org/0000-0002-7893-5282
Ravichandran Jeganathan, Department of Obstetrics & Gynaecology,
Hospital Sultanah Aminah, Johor Bahru, Malaysia
J Basic Clin Physiol Pharmacol 2020; ▪▪▪(▪▪▪): 20200236
associated with climate change and carved out the possible
pathways by which they may affect male and female
reproduction. It provides a predictive outlook of the extent
to which climate changes can modulate fertility status in
Malaysia and aid preventive measures to be taken with
adequate perception of the magnitude of this scenario.
Fertility status of Malaysia: current
scenario
Malaysia is suffering from a gradual decline in fertility rate
most prominently over the past 30 years. This is evidenced
from the report depicting a reduction in TFR in Malaysia
from 4.9 babies in 1970 to 1.8 babies in 2018 (per woman
within the reproductive age) [10]. In fact, since 2013, the
recorded national TFR is below the replacement level of 2.1
which is denitely alarming. This suggests that the average
number of babies born per woman in the country do not
sufce the number required to replace herself and her
partner in the population [10]. The number of live births
was 501,945 in 2018, a decrease of 1.3 percent as compared
to 508,685 in 2017. The crude birth rate (CBR) declined from
15.9 (2017) to 15.5 (2018) per 1,000 population [10]. To
regulate the long-term effects of climate change on a
population, the nation urgently needs strong predictive
models that can effectively unveil the current impacts on
the fertility status in both men and women as well as
project future scenario of climate-change-mediated fertility
modulations.
Malaysian government demographic reports of 2016
show the distribution of Malaysian population in the
country with 80% living in Peninsular Malaysia, 11% in
Sabah, while only 9% in Sarawak. Distribution of popula-
tion according to ethnicity shows that population in
Peninsular Malaysia bears about 61.8% Malays, 21.4%
Chinese and 6.4% Indians and others make up the rest
0.9% [11].
Even before the implementation of the National Family
Planning Program in 1966, fertility transformation in
Peninsular Malaysia had already started. In 1960, Indians
had 7.3 babies per woman, the highest TFR, followed by
Chinese (6.3) and Malay (5.8) [12]. However, the trend of
TFR among the ethnic groups in Malaysia changed over
time with Malays having highest fertility rate followed by
the Chinese and then Indians since 1965. In Malaysia, the
TFR declined from 5.7, in 1965, to 3.6, between 1966 and
1985, the TFR in Peninsular Malaysia declined from 5.7, in
1965, to 3.6, in 1985, and this was associated with high
increase in use of contraceptive or the contraceptive
prevalence rate (CPR) from 8 to 50%. CPR determines the
proportion of married women using some form of contra-
ception. CPR is dened as the percentage of currently
married women using any contraceptive method[13]. The
prevalence of contraception stagnated over the next two
decades and even decreased, but the overall fertility rate
decreased signicantly through 3.0 in 2000, 2.5 in 2005 and
further decreased to 2.3 in 2008.
The predicted TFR in Peninsular Malaysia, which is
adequate to replace the current population, would be 3.8,
based on the regression equation (TFR=7.270.07 CPR)
from a study by Tsui (2001). The observed TFR of 1.8 in 2018
is below the expected value by 2.0, given a moderate CPR of
about 50% [13]. Such statistics pose a threat as Malaysia
becomes an ageing nation with increased elderly popula-
tion by 2030, with circumstances the increasing costs of
health care and reduced youth force. As for the discrep-
ancies in the association of TFR with CPR, it is reported for
various other countries as well [14, 15]. However, the lower
than anticipated TFR has led to speculation that abortion
and sterility are on the rise, along with increasing concern
in understanding the reasons for this phenomenon.
Based on the statistics given by the Department of
Statistics, Malaysia, in 1957, Chinese population contrib-
uted to 37.4% of the whole Malaysian population with TFR
of 7.4 which declined to about 1.1 in 2018. The Malay and
Indian population in Malaysia are facing similar drop in
their TFR from 6.1 in 1957 to 2.4 in 2018 for Malay, and 8.0 in
1957 to 1.25 in 2018 for Indians. The overall TFR of Malay-
sian population declined from 2.1 in 2014, to 2.0 in 2015 and
1.8 in 2018 in women aged between 15 and 49 (Figure 1)
[16, 17]. Previous couple of studies in Malaysia had put
forth links among the socioeconomic factors, ethnicity and
fertility rate [18, 19]. While intermediate variables are
important to explain differences and reduction in fertility
status in Malaysia, there is a serious lack of research on the
subject.
How climate change may impact
fertility?
To date, multiple studies have reported that climate
change is the greatest threat to global health in the 21st
century[20, 21]. Climate change poses an urgent and sig-
nicant risk to human health and human survival world-
wide. Everyone is at danger, whether affected via
heatwaves, severe weather events, drought, starvation,
altered illnesses and water pollution leading to diarrhoea,
hunger, mass migration or any subsequent issues [22].
2Jegasothy et al.: Climate change and fertility in Malaysia
Developing countries are likely to be most heavily affected
by climate change, with women bearing the greatest toll.
In Malaysia, very little work has been done on pro-
jecting potential impacts of climate change on health
burdens. Climate change affects human health through a
range of direct or indirect exposures. In tandem with
obvious and visible extreme events of floods, forest fires
and heat waves, there exist certain silent factors like global
warming having chronic effects on health and fertility [23].
The reproductive tissues function only within a range of
temperature. Thus, when the ambient temperature exceeds
that critical temperature, it adversely affects reproductive
functions via common mechanisms of gonadal heat shock,
oxidative stress (OS) and alterations in endocrine milieu.
Heat stress can be an environmental as well as an occu-
pational hazard that can lead to chronic illnesses and even
death, from the after effects of heat stroke [24, 25]. Besides
temperature changes, accumulation of toxic contaminants
in air also contribute to various reproductive disorders and
can also induce OS. These environmental cues can induce
unregulated production of free radicals, reactive oxygen
species (ROS) and reactive nitrogen species (RNS). The
chain of oxidative damage severely affects gonadal func-
tions such as impairment of gametogenesis, gamete chro-
matin integrity, mitochondrial functions as well as
increased germ cell apoptosis. This leads to decreased
semen quality in men and reduced oocyte quality and
uterine receptivity in females. The disruption in the hypo-
thalamicpituitarygonadal (HPG) axis alter the release of
gonadotropin releasing hormone (GnRH) and subsequent
tropic hormones, luteinizing hormone (LH) and follicle
stimulating hormone (FSH), thereby leading to decreased
testosterone levels in males, oestrogenic and progesterone
in females, impairing gonadal functions (Figure 2). Natural
calamities like storms, oods, draught and changes in
rainfall pattern can affect socioeconomic status of a nation
inicting malnutrition, poor sanitation, increased food and
water-borne diseases, emergence and spread of infectious
diseases affecting overall health and thereby indirectly
posing threat to fertility.
Climate change in Malaysia and its
impacts on fertility
Temperature change and reproductive
health
Climate change adversely affects global thermal environ-
ment and will continue to increase local temperature as
well as frequency of heat waves [26]. The set-point tem-
perature in humans is 37 °C and potentially lethal effects
associated with hyperthermia are usual at body tempera-
tures above 4041 °C [27]. Regulation of core body tem-
perature is, therefore, not surprisingly a priority over
several other physiological functions.
In Malaysia, the approximate rate of increase in mean
temperature has been reported to be 0.25 °C per decade in
the peninsular Malaysia, 0.20 °C per decade in Sabah and
0.14 °C per decade in Sarawak [28]. The high spikes in
ambient temperature in 1972, 1972, 1991, 19971998 and
20152016 were suggested owing to El Nino which was
probably the strongest in the 20152016 [8]. Intergovern-
mental Panel on Climate Change (IPCC) had reported that
global mean surface temperature has increased 0.74 °C
between 1905 and 2005 and predicts an increase of 24.5 °C
over the next 100 years. In Malaysia, surface temperature of
last four decades has increased between 2.7 and 4.0 °C per
century [29]. Tang (2019) has reported that the yearly
moving average of mean daily temperature shows an up-
trend in different parts of Malaysia, including, Kota Kin-
abalu, Kuching, Malacca, Kuantan and Subang Jaya.
Increase in the annual moving average of mean daily
temperature, was shown to be lowest in magnitude for
Kuching, followed by slightly higher in Kota Kinabalu,
Malacca, Kuantan and Subang Jaya [8]. The information
here is in line with the reports put forth by the Malaysian
Meteorological Department (2009) which also depicted
that Kuching has the least rise in temperature owing to its
slower development pace [30].
There is available literature that emphasizes the impact
of environmental temperature on the viability of a popula-
tion. The lethal limit of temperature is termed as the critical
thermal limit(CTL). But a sublethal level of ambient
Figure 1: Declining trend of Malaysian total fertility rate (TFR) based
on ethnicity
TFR of Malaysian population presented in greybars; TFR of Malay,
Chinese and Indian ethnicities are denoted in green,redand
blue, respectively.
Jegasothy et al.: Climate change and fertility in Malaysia 3
temperature can impair the reproductive functions rendering
a population with compromised fecundity [31].
Temperature change and male reproductive
functions
Reproductive functions in both the genders are immensely
affected by temperature changes [32]. Data on the alter-
ations in Malaysian men reproductive functions due to
temperature changes are not available. However, studies
on animal shows that high ambient temperature impairs
spermatogenesis, effects the quality of sperm, leads to
abnormal sperm morphology and reduces sperm motility
[33, 34]. In most of the animals including human, testes are
suspended outside the body cavity in a scrotum such that
the intratesticular temperature is much lower than the core
body temperature. In the testis, there is a complex ther-
moregulatory mechanism that is mediated by counter-
current heat exchange between blood with higher
temperature that enters testes and the ones with lower
temperature exiting testes via the pampiniform plexus [35].
Therefore, the scrotum is so built because of the need for
low temperatures for either spermatogenesis, sperm stor-
age or for reducing mutations in gamete DNA [36]. An in-
crease in testicular temperature in mammals with external
testes result in decreased sperm production, decreased
sperm motility and increased morphologically abnormal
sperm in the ejaculate [35]. Two muscles further monitor
this degree of cooling: the scrotums tunica dartos that
Figure 2: Overview of the impact of climate
changes on male and female reproductive
functions
ROS, reactive oxygen species; GnRH,
gonadotropin releasing hormone; LH,
luteinizing hormone; FSH, follicle
stimulating hormone; HPG axis,
hypothalamic-pituitary gonadal axis; E2,
oestradiol.
4Jegasothy et al.: Climate change and fertility in Malaysia
regulate the area of the scrotum and the muscle of the
cremaster that regulates the location of the scrotum
compared with the body. The testicular cells that are
reportedly most vulnerable to get damaged by increase in
ambient temperature are primary spermatocytes and early
spermatids, but effects on spermatogonia and Sertoli cells
have also been observed [37]. Among the major causes of
thermal damage to sperm, oxidative stress (OS) plays a
pivotal role inducing lipid peroxidation of sperm mem-
brane, apoptosis of germ cells, disruption of mitochondrial
functions as well as sperm chromatin disintegration by
DNA fragmentation [3844].
The developmental competency of the resulting em-
bryo can also be impaired if the fertilization is attained via
spermatozoon affected by heat stress [45]. These include
epigenetic alterations in embryonic development. A recent
study reported the effects of increased environmental
temperature on sperm quality and embryo development in
Holstein bulls. It has showed reduced rates of blastocyst
formation on insemination sperm exposed to high tem-
perature [46].
In another context, it is significant to put forth that
Malaysia is a highly epidemic region for dengue, malaria,
chikungunya and other vector borne diseases [4749]. It is
reported that prevalence of these diseases increases with
increased ambient temperature [50]. Thus, an indirect pre-
diction can be made on these infection-induced alterations
in semen quality and male fertility status. Reports have
shown the effects of various microorganisms on semen
quality deterioration and altered male fertility [42, 5154].
Though, studies reporting direct relations of these infection-
induced male sub- or infertility in Malaysian peninsula are
scanty, this could be presumed that these may impact
signicantly in reproductive health of Malaysian men.
Temperature change in female reproduction
and pregnancy outcomes
As discussed earlier, overall TFR of Malaysia is declining in
a significant rate and is below the replacement level of 2.1
(1.8 in 2018) implying that offspring produced by each
women in reproductive age do not suffice the number
required to replace herself and her male counterpart in the
Malaysian population [10]. Both male and female factors
contribute to this decline in fertility rate. Amongst various
factors affecting fertility parameters, ambient temperature
changes do play critical role [55]. The ovarian follicle pool
and the enclosed oocytes are very susceptible to hyper-
thermia among the components of the female reproductive
tract. Heat-induced changes within small antral follicles
can later be expressed as impaired maturation and devel-
opmental capabilities of the ovulating oocyte [56]. The
recent climate changes and exposure to elevated ambient
temperatures are curbing normal oogenesis, menstrual
cycle, impregnation rates, pregnancy outcomes as well as
offspring development [35, 55, 57]. Heat stress can disrupt
the production and function of the oocyte for female
gametes. The ability of oocyte to get fertilized and grow in
lactating cows has been shown to deteriorate during the
periods of the year in conjunct with heat stress [58]. There is
plenty of evidence that heat stress can affect the oocyte and
follicle encasing it [59].
Extreme ambient temperatures also affect embryonic
development. Study on cow model shows that hyperther-
mia at day-1 of pregnancy impairs early embryonic devel-
opment. In mice, high ambient temperatures for one day
following mating disrupted normal embryonic develop-
ment [60]. Elevated temperatures during mid-gestation
also reduced foetal weights [61]. An animal study con-
ducted by Hamid et al. (2012) in Universiti Putra Malaysia
has reported the effects of elevated ambient temperature
on reproductive outcomes during different stages of preg-
nancy and the prenatal heat stress on offspring growth.
They have reported from that exposure to elevated ambient
temperature during pre- and peri-implantation has stron-
ger adverse effects on reproductive outcomes and offspring
growth than post-implantation exposure [55].
Temperature and reproductive hormones
Reproductive hormones and their crosstalk with other
hormones intricately regulate the male and female repro-
ductive functions. Few studies are available, although
none from Malaysia, on the effects of elevated environ-
mental temperature on the secretion of reproductive hor-
mones. Initially studies performed in bulls and boars have
put forth that heat stress leads to an initial reduction in the
levels of testosterone concentrations [62, 63]. Recent
studies have shown that extreme heat can lead to
compromised levels of luteinizing hormone, follicle-
stimulating hormone besides diminished levels of testos-
terone. These in turn cause damage to the spermatogenic
cell lineage, reduced semen quality and sperm DNA frag-
mentation in males [64, 65]. In females, the reproductive
hormones are associated intricately with endogenous
temperature regulation of the autonomic nervous system,
such that, oestradiol and progesterone have both central
and peripheral inuence on thermoregulation, where
oestradiol is used to facilitate heat dissipation and pro-
gesterone mediates heat storage and increased body
Jegasothy et al.: Climate change and fertility in Malaysia 5
temperatures [66]. High ambient temperature affects the
secretion of both gonadotropins (LH and FSH) and
gonadotrophin-releasing hormone (GnRH) which disrupt
development and maturation of oocyte, early embryonic
development, fetal and placental growth as well as lacta-
tion. Such deleterious effects of heat stress are either the
result of heat stress hyperthermia or the physiological
changes made to regulate body temperature by heat-
stressed animals [35].
Thus, we need effective research on the effects of
ambient temperature changes on Malaysian population
with particular emphasis to exposure-time adversely
affecting male and female fertility.
Haze, air pollution and its impact on
fertility
Episodes of haze in Southeast Asia in 1983, 1984, 1991, 1994
and 1997 caught the attention of the environmental man-
agement of Malaysia and began to enhance awareness of
air pollution owing to climate change [67]. This followed
the establishment of Malaysian Air Quality Guidelines, the
Air Pollution Index, and the Haze Action Plan to improve
air quality [67]. The predominant air pollutants in Malaysia
include carbon monoxide (CO), sulphur dioxide (SO
2
), ni-
trogen dioxide (NO
2
), ozone (O
3
) and Suspended Particu-
late Matter (SPM). Several big cities in Malaysia also
possess high levels of CO, O
x
,SO
2
and Pb [67]. A very
concerning factor for diminished air quality in Malaysia is
the frequent high amounts of smoke and haze that drift into
Malaysia for the past 40 years, caused by the uncontrolled
res across Indonesia. The haze negatively correlates with
human health, climate and economy [68]. Reports from a
wildlife rescue centre in Borneo on orangutans depicted
that haze results in respiratory tract infection, dehydration,
malnourishment and it is predicted that the long-term ef-
fects can lead to birth defects and reproductive failure. A
recent study by Tajudin et al. (2019) on the health effects of
air pollution of Kuala Lumpur city has reported that
exposure to air pollutants and trace gases can lead to both
immediate and delayed effects on cardiovascular, respi-
ratory and other health issues. Not adequate number of
studies are available that depicted the impact of air
pollution upon health of Malaysian population, thereby
making it arduous to postulate the impact of air pollution
over reproductive health in Malaysia [69]. However, there
are few studies that can be mentioned, such as the one
analysing the health impact of the forest re of 1997.
Another study had showed that at the peak time of smoke
haze, there is many fold increase in outpatients mainly
suffering from respiratory diseases, in the hospitals of
Sarawak, Kuching as well as in the Kuala Lumpur General
Hospital [70]. There is also evidence of air-pollution
madiated increased cases of acute respiratory infection,
conjuctivitis and asthma, in hospitals in Kuala Lumpur,
between AugustSeptember, 1997 [71].
It is high time to generate extensive evidences on the
actual impacts of haze of reproductive health of Malaysian
population that is crucial for population persistence.
Female reproductive system has a unique way to
respond to toxic exposure, particularly towards the pol-
lutants with oestrogenic potential [72] such as, polycyclic
aromatic hydrocarbons, which mimic natural hormone
activities and varying regulation and function of the endo-
crine system [73]. Impacts of air pollutants on reproductive
health often result from short-term exposure during the
vulnerable phases of ovulation or foetal organogenesis. Ef-
fects of certain toxicants can remain hidden for years due to
accumulation in parental tissues and later may be during
pregnancy, lactation or even post-natal development [74]. It
is shown that particulate matter of size less than 10 μmcan
affect pregnant women mainly at the rst trimester of preg-
nancy and affect pregnancy duration, impaired foetal growth
as well as negative or undesired pregnancy outcome [75]. The
knowledge about mechanisms of these phenomena is
limited. Menstrual disturbances, most prominently luteal
phase shortening, have been documented as a common
health hazard from fossil fuel combustion [76].
In terms of sperm production, motility and/or
morphology, numerous animal- and human-based
research on exposure to environmental toxins indicate a
negative impact on the semen quality [7779]. Such toxins
can have oestrogenic and/or anti-androgenic effects,
which in turn modify the hypothalamicpituitarygonadal
(HPG) axis, trigger damage to sperm DNA or cause epige-
netic changes in sperms [8082].
Heavy rainfall, flood and its impact
on fertility
Heavy rain and runoff may contribute to surface water
pollution and may again endanger the supply of clean
water. After floods, the risk of disease outbreaks such as
hepatitis-E, gastrointestinal disease and leptospirosis was
found to increase, particularly in areas with poor hygiene
and displaced populations [83]. Malaysia has witnessed
several major oods in the last two decades [8, 8488]
(Table 1).
6Jegasothy et al.: Climate change and fertility in Malaysia
There is no direct Malaysian report elucidating the
impact of flood and water quality on male and female
reproductive health. However, flood causes decreased
water quality [89], which affects reproductive health in
both [90]. Floods can affect the health of new-borns by
affecting the pregnanat women in terms of both mental
and physical health and diminishing their capability to
avail health services. Studies of women with prenatal
disaster exposure have revealed that high levels of pre-
natal stress positively correlate with poor pregnancy
outcomes [91] and poor health outcomes in offspring, that
include their behavioural and psychiatric features [92].
The risk of adverse effects on birth outcomes and childs
health increase with magnitude and duration of disaster
exposure within the gestational period [83]. Floods and
changes in rainfall pattern severely creek into socioeco-
nomic status of the population inicting malnutrition,
poor sanitation, food- and water-borne infectious dis-
eases, which individually or as combined factors exert
their toll on fertility.
Climate change, infectious
diseases and infertility
Increasing global temperatures will shorten the length of
winter, facilitating potential disease-carrying agents and
aid further spread of diseases [6]. Climate change may
render the habitats unsuited for animals, compelling them
to migrate more to urban areas and thus enhancing the risk
of transmission of zoonotic diseases [6]. The World Health
Organization (WHO) warned in 2007 that emerging infec-
tious diseases are becoming a growing threat in the face of
increasing urbanization, resistance to antimicrobials and
climate change [93].
Dengue is a prevalent disease in Malaysia. It was
projected that climate changes have great influence over
the dengue prevalence in Malaysia [94]. The inuence of
climate change on monsoon seasons bring about variation
in transmission of dengue in Malaysia [50, 94]. Institute for
Medical Research (IMR) model depicted that high rainfall
leads to higher dengue transmission. The vector-borne
diseases, mainly dengue and malaria also increase with
temperature uctuations due to increased availability of
the vector breeding habitats. For example, between
January 1 and August 20, 2016, a total of 71,590 dengue
cases were reported in Malaysia with 162 deaths. The bulk
of the cases were in the states of Selangor, Kelantan, Johor
and Kuala Lumpur. Climate change would have a direct
effect on vector distribution and consequently in diseases,
Table :Major oods and other extreme weather events in past two
decades in Malaysia.
Occurrence Description and consequences
 December  Tropical Storm Vamei was a tropical Pacic
cyclone developed closer to the equator than
any other tropical cyclone. Vamei (also known
as the Typhoon Vamei) originated in the
South China Sea at .°Non December as
the last storm in  during the Pacic
typhoon season. This was called as a typhoon
as it had sustained wind speed of  km/h
( mph) and appeared like an eye. It caused
landslides and severe ooding in eastern
Peninsular Malaysia, with ve deaths and a
huge economic damage of $.million
().
December 
January 
Typhoon Utor passed across the central
Philippines in December , while its re-
sidual moisture indirectly led to immense
ooding in Malaysia. This series of oods
affected the region for a long duration till it
ceased in February  []. The tropical
moisture together with high velocity monsoon
winds continued to persistent precipitation
over Malaysia, especially the states of Johor,
Pahang and Malacca. Peak rainfall of
.mm (. in) was recorded in Bandar
Muadzam Shah with almost similar records in
surrounding region, over a four-day period of
the rainfall spree []. Segamat and Kota
Tinggi were adversely affected by the oods
and turned inaccessible by land. There were
eight deaths recorded from this historical
ooding.
OctoberNovember

A devastating ood series was observed in
Thailand and Malaysia in , due to
abnormal late arrival of monsoon moisture
over the Bay of Bengal. This development led
to overow of Chao Phraya, the meeting zone
of rivers and affected Bangkok, and subse-
quently after two weeks, it induced a tropical
depression in the further south causing
oods in Malaysian states of Kedah and Per-
lis. These ash oods severely affected
health, food supply, education sectors,
transportation and overall economy in
Malaysia. This contaminated water supply in
Kedah and Perlis, which compelled these
states to thrive on water supplies from the
neighbouring Perak state. As per the reports
from the federal government, the oods
damaged over , ha of rice elds in
Kedah alone, for which the government
pledged a compensation of  million ringgit
to the farmers []. Almost , people
were evacuated, and four deaths were recor-
ded as the consequence of this ood series
[].
Jegasothy et al.: Climate change and fertility in Malaysia 7
such as, dengue, malaria, lariasis and Japanese en-
cephalitis (JE) as well [5, 48]. Food and water-borne dis-
eases also are predominant in tropical and subtropical
countries which may be the indirect health impacts of
climate change. These include: (i) diarrhoeal diseases
caused by a variety of organisms (such as, Escherichia
coli,Vibrio cholera, salmonellae and viruses), (ii) other
viral diseases (such as, hepatitis A and poliomyelitis) and
(iii) protozoan diseases (such as giardiasis and amoebic
dysentery) [29].
Dengue may significantly contribute in impairment of
reproductive parameters [95, 96]. A single centred study
was conducted to analyse the patterns and outcomes of
dengue infection amongst pregnant women in Malaysia. It
suggested that dengue infection during pregnancy may
result in maternal morbidity and death, particularly in
Table :(continued)
Occurrence Description and consequences
JanuaryFebruary

Various regions of Sabah including Mengga-
tal, Penampang and Tuaran were ooded due
to heavy rainfall and ash ooding. As of 
February , more than , people had
been evacuated to  relief centres in Beau-
fort and Tenom. There were two reported
deaths and property damage scored to mil-
lions of ringgits [].
OctoberNovember

The Peninsular Malaysia tornado outbreak of
 is a natural phenomenon that took
place in the state of Kedah and Selangor,
Malaysia from  October to  November
. Kedah and Selangor were hit by epi-
sodes of EFtornado, each lasting for 
 min with wind speed up to  km/h. The
frequent tornado formation was speculated to
have been due to changes in monsoon. This
calamity rendered , homeless (,
homes destroyed) and economic damage of
about $.billion (USD) (as per the currency
rate of the time in ).
December 
January 
The series of oods in affected most of the
Southeast Asian countries and reportedly
caused by the northeast monsoon, affecting
more than , people and at least 
reported deaths. Malaysian East Coast were
severely affected by the ooding, the regions
included Pahang, Terengganu and Kelantan
states. Moreover, states in Peninsular
Malaysia including Johor, Perak, Selangor
and Perlis and a state in East Malaysia, Sabah
also experienced the oods due to the heavy
rainfalls with peak of  mm. These oods
have been described as the most severe
oods in past few decades [].
JanuaryFebruary

Heavy intensity rainfall from  January 
till the end of February, led to ooding across
the Eastern Malaysia, mainly in Sarawak and
Sabah. The number of evacuated people were
estimated to be around , people, with
property damage of almost $. billion
(USD) and one casualty of a teenage girl was
reported, a teenage girl [].
FebruaryMarch  Heavy rainfall occurring in the rst half of
February , led to immense ood in
Malaysian states including Bau, Samarahan
and Serian in Sarawak, Tangkak, Ledang and
Segamat in Johor and Alor Gajah, Central
Malacca and Jasin in Malacca and parts of
Negeri Sembilan. Three casualties were re-
ported, and property damage were estimated
to be $ million (USD) [].
December early

Flooding that occurred in southern Thailand
had signicant effects on Malaysian states of
Kelantan and Terengganu. Changes in the
annual monsoon season was the major cause
Table :(continued)
Occurrence Description and consequences
of this ood and led to an estimated loss of
USD billion, contributing to severe damage
in agriculture, infrastructure and tourism [].
October  Typhoon Paolo, originated from a tropical
cyclone, stroked across Sabah. It was char-
acterised by strong wind and heavy rain. It
had dreadful consequence rendering 
deaths, more than  missing cases and
about , people became homeless [].
November  A sudden ood in Penang lead to evacuation
of approximately  people. The calamity
was accompanied by strong winds and long
duration torrential rain and was reportedly
developed from tropical cyclone. This calam-
ity resulted in at least deaths and over
, after oods swept through the
northern states of Penang and Kedah in
peninsular Malaysia [].
December  Strong wind blew across the west coast of
Sarawak, Sabah and Labuan at  km/h
and was caused by Tropical Storm Kai-Tak
that originated in the Western Pacic Ocean
[].
Jan  The annual northeast monsoon caused high
intensity rainfall that led to oods in Malaysia
particularly in the states of Terengganu,
Johor, Pahang and Sabah. The ood killed two
in Pahang and caused about , people to
be displaced nationwide. Kuantan and Rom-
pin districts in Pahang were the most affected
regions. Malaysias National Disaster Man-
agement Agency (NDMA) reported that relief
centres were set in two districts, which shel-
tered more than , displaced people [].
8Jegasothy et al.: Climate change and fertility in Malaysia
premature baby delivery. In the case of febrile pregnant
women, dengue infection should be strongly suspected
[95].
The recently emerged novel coronavirus, SARS-CoV-2
causing the disease COVID-19, has raised waves of fear
across the globe and Malaysia is one of the countries
moderately affected by the same. A correlation between
metrological parameters and COVID-19 cases has already
been reported [97]. As reported till 23 July 2020, a total of
15.1 million people around the world have been infected
with COVID-19 since the coronavirus outbreak began over a
couple of months ago. The Ministry of Health (MoH) of
Malaysia has conrmed that COVID-19 cases in Malaysia
have increased to 8,831 (as per reports on 23 July 2020) [98].
This is not the rst time in recent history that the world has
struggled with a global epidemicthere was the severe
acute respiratory syndrome (SARS) in 2003, the Middle East
coronavirus respiratory syndrome (MERS) rst identied in
2012 and the Zika virus in 20152016and this coronavirus
is unlikely to be the last [50]. However, unlike coronavirus
infections in pregnant women caused by SARS and MERS,
COVID-19 have not yet posed threat to maternal survival. At
this point in the global pandemic of COVID-19 infection,
there is no evidence that SARS-CoV-2 undergoes intra-
uterine or transplacental transmission from infected
pregnant women to their foetus. A very recent study has
suggested that the SARS-CoV-2 might directly bind to re-
ceptors in the reproductive tissues of patients [99] and may
impair gonadal functions. The study encourages long-term
interventions and follow up over the COVID-19 affected
men, to unveil the exact effects of this virus on male fertility
[99103].
Climate changes, socioeconomic
and demographic factors and
infertility
Malaysia is a fast-growing developing country. So, there
are scopes of regular shifts in economic variables that
would impact food security. There is a wide range of eco-
nomic channels through which climate change can affect
fertility rate of a nation, that includes sectoral reallocation,
wage inequalities among gender, longevity and child
mortality [104]. Through its economic effects, climate
change could have a substantial impact on population
growth, primarily by inuencing behaviour of people to-
wards increasing family size. It inuences their decision on
whether to devote more time and money for child-rearing,
or channelize those to have more children [104]. The cross-
relations among climate change-sociodemographic fac-
tors-infertility are subject for detailed interventions at
different strata in Malaysian population which is presently
lacking. However, a recent study on 300 men attending the
Fertility Clinic, International Islamic University Malaysia
(IIUM), demonstrated signicant associations between
critical sociodemographic factors, such as household in-
come, educational attainment and others, with levels of
seminal abnormalities in the subjects [105].
The climate conditions in Malaysia are evolving very
rapidly and have had adverse effects on food production
[106]. Even that, food insecurity in households is not only
related to social and economic factors, but also linked
signicantly to the direct and indirect effects of climate
factors [107]. Previous studies have shown that 50% or
more of the rural low-income households face certain food
insecurity. A recent study showed that 23.3% of poor and
low-income households are poorly food-insecure, 14.3%
are moderately food-insecure and 9.6% are seriously food-
insecure in Malaysia [108]. The global food supply system
faces serious new threats from economic and related crises
and climate change, which have a direct effect on poor
peoples nutritional well-being by reducing their access to
nutritious food. In deal with this, vulnerable populations
prefer calorie-rich, but nutrient-poor, food consumption.
The consequence is a decrease in dietary quality and ul-
timately in quantity, rising micronutrient malnutrition
(or secret hunger) and exacerbating pre-existing in-
equalities that contribute to poorer health, lower incomes
and decreased physical and intellectual ability [109].
Inadequate nutritional intake is undeniably associated
with poor reproductive health in both men and women. In
men, it correlates with increased testicular and seminal
oxidative stress and associated sperm DNA fragmenta-
tionandimpairedchromatincondensation. Epigenetic
modulation has been reported, with transmission to the
offspring [110]. However, direct causality has not been
demonstrated.
Inadequate nutrition is closely linked to female
reproductive pathophysiology [111]. Decient food intake,
insufcient nutritional diets, extreme dietary restrictions
and general lack of nutrients result in loss of both body
weight and physical performance, delayed puberty, post-
partum time lengthening to pregnancy, lower levels of
gonadotropin secretion with hormonal cyclicity changes
and increased infertility. Poor intakes of proteins, micro-
and macro-minerals and vitamins are associated with
reduced reproductive efciency, as the altered energy
balance is directly correlated with reduced ovulatory
maturation in women. It was reported that maternal
malnutrition adversely affects foetal health, resulting in
Jegasothy et al.: Climate change and fertility in Malaysia 9
poor development and altered body composition with low
muscle mass, poor brain development and metabolism
[112, 113], modulations at the hormonal crosstalk, receptor
expressions as well as genetic and epigenetic constitutions
[113, 114]. In the long term, these alterations will result in
low cognitive development, incompetency in education,
low immunity, inadequate working potential and an
increased risk of several chronic diseases [112]. It was also
proposed that there exist proximal leversto facilitate
positive attitudes and measures to ensure optimal foetal,
infant and childhood nutrition [115].
Future perspectives and conclusion
The projections of climate change in Malaysia over the next
few decades are worrying enough with speculation of
extreme variations in rainfall, increase in ambient tem-
perature and lack of clean water (Table 2: [116120]). These,
even at less than extreme levels may affect the fertility
parameters of Malaysian population which is already
following a declining trend and the climate change may be
an essential role player in the process, either directly or
indirectly. The direct impact of climate change on repro-
ductive functions may involve heat-induced physiological
alterations that impair the structure and functions at the
tissue or cellular levels or disrupt the orchestration of
hormones regulating the reproductive functions. There are
number of indirect means by which climate change can
affect fertility. Flood, drought or even uctuations in
ambient temperature may facilitate emergence of novel
infectious micro-organisms that can cause and spread both
systemic and reproductive infections leading to subfertility
or infertility. In addition, climate changes, national socio-
economic status and food supply are closely linked, and
sociodemographic or economic alterations are in turn
important determinants of fertility rate in a population.
Moreover, deterioration in quality or quantity of food in
any region, may severely affect overall health as well as
fecundity of the population. Since, Malaysia lacks proper
research to support the possible effects of climate change
on fertility, the present report provides a probable scenario
based on worldwide evidence of the mechanism by which
Malaysian fertility is and will fall victim of the ongoing
climate changes, and thereby, further studies should be
encouraged in this direction.
Research funding: None declared.
Author contributions: R Jegasothy: Conceptualization,
Manuscript editing and review. P Sengupta: Literature
search, Manuscript writing, Manuscript editing and review.
S Dutta: Literature search, Manuscript writing, Manuscript
editing and review. R Jeganathan: Manuscript editing and
review. All authors have accepted responsibility for the
entire content of this manuscript and approved its
submission.
Competing interests: Authors state no conict of interest.
Table :Predictions of future climate change.
Source Prediction
Malaysian Meteorological
Department ()[]
The estimated rise in temperature till  is between .and .°C for East Malaysia and between .°C and
.°C for the Peninsular Malaysia. Owing to its highly variable precipitation-modulating factor, no certain
precipitation pattern was reported. During the st century, the precipitation on the West Coast increased and
precipitation on the East Coast of the Peninsular Malaysia decreased. Until the end of st century, major rises
in precipitation were expected over west Sarawak.
Kwan et al. [] Between  and , increased probability of intense rains on the west coast of Malaysia was expected in
September to November. In some areas of Malaysian Borneo, early monsoon rainfall was predicted. Higher
frequency of extreme warm temperatures and small decreases in cold extremes were forecast.
Loh et al. [] The rise in temperature between .and .°C, ..°C and ..°C was projected at the national level by
the end of the st century in three different emission scenarios (A,AB and B). For drier months from
December to May, and rain months from June to November, a high rainfall variability was expected.
Syafrina et al. [] RCP .scenarios were used to predict increase in rainfall in hours and  h from the year , with a
wider spatial distribution.
Amin et al. [] In November from  to , and also in November and December from  to , the simulation
showed a substantial increase in mean monthly ows in the Dungun watershed. The rise in ow from April to
May and July to October has been projected between  and  for Muda Watershed. (GCM for climate
projection and watershed hydrology model (WEHY) for hydrologic simulations over Muda and Dungun
watershed in the Peninsular Malaysia)
10 Jegasothy et al.: Climate change and fertility in Malaysia
References
1. Cheeseman J. Food security in the face of salinity, drought,
climate change, and population growth. Halophytes for food
security in dry lands. Elsevier; 2016:11123 pp.
2. Hoffmann AA, Sgro CM. Climate change and evolutionary
adaptation. Nature 2011;470:47985.
3. Somero G. The physiology of climate change: how potentials for
acclimatization and genetic adaptation will determine winners
and losers. J Exp Biol 2010;213:91220.
4. Grace K. Considering climate in studies of fertility and
reproductive health in poor countries. Nat Clim Change 2017;7:
47985.
5. Zell R. Global climate change and the emergence/re-emergence
of infectious diseases. Int J Med Microbiol Suppl 2004;293:
1626.
6. Borroto RJ. Global warming, rising sea level, and growing risk of
cholera incidence: a review of the literature and evidence.
GeoJournal 1998;44:11120.
7. Lindsay SW, Thomas CJ. Global warming and risk of vivax malaria
in Great Britain. Global Change Hum Health 2001;2:804.
https://doi.org/10.1023/a:1011995115713.
8. Tang KHD. Climate change in Malaysia: trends, contributors,
impacts, mitigation and adaptations. Sci Total Environ 2019;650:
185871.
9. Tangang F, Juneng L, Ahmad S. Trend and interannual variability
of temperature in Malaysia: 19612002. Theor Appl Climatol
2007;89:12741.
10. Mahidin MU. Vital statistics, Malaysia, 2019. Department of
Statistics, Malaysia Ofcial Portal; 2019.
11. MyGovernment. Demography of population Malaysia:
Department of Information, Government of Malaysia; 2016.
Available from: https://www.malaysia.gov.my/portal/content/
30114 [Accessed 26 July 2020].
12. Tey NP, Ng ST, Yew SY. Proximate determinants of fertility
in Peninsular Malaysia. Asia Pac J Publ Health 2012;24:
495505.
13. Tsui AO. Population policies, family planning programs, and
fertility: the record. Popul Dev Rev 2001;27:184204.
14. Curtis SL, Diamond I. When fertility seems too high for
contraceptive prevalence: an analysis of northeast Brazil. Int Fam
Plann Perspect 1995;21:5863.
15. Saha UR, Bairagi R. Inconsistencies in the relationship between
contraceptive use and fertility in Bangladesh. Int Fam Plann
Perspect 2007;33:317.
16. The Star Online TS. Malaysias shrinking families Malaysia; 2019.
Available from: https://www.thestar.com.my/news/nation/
2019/11/10/malaysia039s-shrinking-families [Accessed 26 July
2020].
17. Department of Statistics, Malaysia.Malaysia: Vital statistics;2015.
18. Govindasamy P, DaVanzo J. Ethnicity and fertility differentials in
Peninsular Malaysia: do policies matter? Popul Dev Rev 1992;18:
24367.
19. Tey N. Fertility trends and differentials in Peninsular Malaysia:
four decades of change. Women in development: two decades of
change Kuala Lumpur. Malaysia: MPH; 2009:293310 pp.
20. Scott J, Stephenson J, Twigg J, Wolff J, Patterson C. Managing the
health effects of climate change. Lancet 2009;373:1693733.
21. The L. Sexual and reproductive health and climate change. Lancet
2009;374:949.
22. Costello A, Abbas M, Allen A, Ball S, Bell S, Bellamy R, et al.
Managing the health effects of climate change: lancet and
University College London Institute for Global Health
Commission. Lancet 2009;373:1693733.
23. Hanna EG, Spickett JT. Climate change and human health:
building Australias adaptation capacity. Los Angeles, CA: SAGE
Publications Sage CA; 2011.
24. Thonneau P, Bujan L, Multigner L, Mieusset R. Occupational heat
exposure and male fertility: a review. Hum Reprod 1998;13:
21225.
25. Mackay A. Climate change 2007: impacts, adaptation and
vulnerability. Contribution of working group II to the fourth
assessment report of the intergovernmental panel on climate
change. J Environ Qual 2008;37:2407.
26. Kwok AG, Rajkovich NB. Addressing climate change in comfort
standards. Build Environ 2010;45:1822.
27. Jardine DS. Heat illness and heat stroke. Pediatr Rev 2007;28:
249.
28. Malaysia Biennial Update Report to the UNFCC. Putrajaya,
Malaysia: Ministry of Natural Resources and Environment
Malaysia; 2015.
29. Hassan NA, Hashim JH, Johar Z, Faisal MS. The implications of
climatic changes on food and water-borne diseases in Malaysia:
a case study of Kelantan, Terengganu, Johor and Melaka. BMC
Publ Health 2014;14:P22.
30. Malaysian Meteorological Department. Climate change
scenarios for Malaysia 20012099. Malaysia: Malaysian
Meteorological Department; 2009.
31. Walsh BS, Parratt SR, Hoffmann AA, Atkinson D, Snook RR,
Bretman A, et al. The impact of climate change on fertility. Trends
Ecol Evol 2019;34:24959.
32. Bronson FH. Seasonal variation in human reproduction:
environmental factors. Quarty Rev Biol 1995;70:14164.
33. Hansen P, Drost M, Rivera R, Paula-Lopes F, Al-Katanani Y,
Krininger C III, et al. Adverse impact of heat stress on embryo
production: causes and strategies for mitigation. Theriogenology
2001;55:91103.
34. David J, Araripe L, Chakir M, Legout H, Lemos B, Petavy G, et al.
Male sterility at extreme temperatures: a signicant but
neglected phenomenon for understanding Drosophila climatic
adaptations. J Evol Biol 2005;18:83846.
35. Hansen PJ. Effects of heat stress on mammalian reproduction.
Phil Trans Roy Soc B Biol Sci 2009;364:334150.
36. Werdelin L, Nilsonne Å. The evolution of the scrotum and
testicular descent in mammals: a phylogenetic view. J Theor Biol
1999;196:6172.
37. Setchell B. The effects of heat on the testes of mammals. Anim
Reprod 2018;3:8191.
38. Shiraishi K. Heat and oxidative stress in the germ line. Studies on
mens health and fertility. Springer; 2012:14978 pp.
39. Dutta S, Majzoub A, Agarwal A. Oxidative stress and sperm
function: a systematic review on evaluation and management.
Arab J Urol 2019;17:8797.
40. Alahmar AT, Calogero AE, Sengupta P, Dutta S. Coenzyme Q10
improves sperm parameters, oxidative stress markers and sperm
DNA fragmentation in infertile patients with idiopathic
oligoasthenozoospermia. World J Mens Health 2020;38:16.
Jegasothy et al.: Climate change and fertility in Malaysia 11
41. Agarwal A, Sengupta P. Oxidative stress and its association with
male infertility. In Male infertility. Springer; 2020:5768 pp.
42. Agarwal A, Leisegang K, Sengupta P. Oxidative stress in
pathologies of male reproductive disorders. In Pathology.
Elsevier; 2020:1527 pp.
43. Dutta S, Henkel R, Sengupta P, Agarwal A. Physiological role of
ROS in sperm function. In Male infertility. Springer; 2020:33745
pp.
44. Selvam MKP, Sengupta P, Agarwal A. Sperm DNA fragmentation
and male infertility. In Genetics of male infertility. Springer;
2020:15572 pp.
45. Paul C, Murray AA, Spears N, Saunders PT. A single, mild,
transient scrotal heat stress causes DNA damage, subfertility and
impairs formation of blastocysts in mice. Reproduction 2008;
136:73.
46. Luceño NL, Van Pou cke M, Perez MB, Szymanska K, Ang rimani D,
Van Soom A. 154 Exposure of bulls to heat stress had
deleterious effects on embryo development. Reprod Fertil Dev
2019;31:202.
47. Hussin N, Lim YA-L, Goh PP, William T, Jelip J, Mudin RN. Updates
on malaria incidence and prole in Malaysia from 2013 to 2017.
Malar J 2020;19:55.
48. Chrostek E, Hurst GD, McGraw EA. Infectious diseases:
antiviral Wolbachia limits dengue in Malaysia. Curr Biol 2020;
30:R30-2.
49. Woon YL, Lim MF, Rashid TRTA, Thayan R, Chidambaram SK,
Rahim SSSA, et al. Zika virus infection in Malaysia: an
epidemiological, clinical and virological analysis. BMC Infect Dis
2019;19:152.
50. Mordecai EA, Cohen JM, Evans MV, Gudapati P, Johnson LR, Lippi
CA, et al. Detecting the impact of temperature on transmission of
Zika, dengue, and chikungunya using mechanistic models. PLoS
Neglected Trop Dis 2017;11:e0005568.
51. Wilder-Smith A. Can dengue virus be sexually transmitted? J Trav
Med 2019;26:tay157.
52. Mansuy JM, Dutertre M, Mengelle C, Fourcade C, Marchou B,
Delobel P, et al. Zika virus: high infectious viral load in semen, a
new sexually transmitted pathogen? Lancet Infect Dis 2016;16:
405.
53. Dutta S, Sengupta P, Izuka E, Menuba I, Jegasothy R, Nwagha U.
Staphylococcal infections and infertility: mechanisms and
management. Mol Cell Biochem 2020;474:5772.
54. Sengupta P, Dutta S, Alahmar AT, Dsouza UJA. Reproductive tract
infection, inammation and male infertility. Chem Biol Lett 2020;
7:7584.
55. Hamid HY, Zakaria AB, Zuki M, Yong Meng G, Haron A,
Mohamed Mustapha N. Effects of elevated ambient temperature
on reproductive outcomes and offspring growth depend on
exposure time. Sci World J 2012;2012:359134.
56. Roth Z. Effect of heat stress on reproduction in dairy cows:
insights into the cellular and molecular responses of the oocyte.
Ann Rev Anim Biosci 2017;5:15170.
57. Roy M, Gauvreau D, Bilodeau J-F. Expression of superoxide
dismutases in the bovine oviduct during the estrous cycle.
Theriogenology 2008;70:83642.
58. Sartori R, Sartor-Bergfelt R, Mertens S, Guenther J, Parrish J,
Wiltbank M. Fertilization and early embryonic development in
heifers and lactating cows in summer and lactating and dry cows
in winter. J Dairy Sci 2002;85:280312.
59. Chinchilla-Vargas J, Jahnke MM, Dohlman TM, Rothschild MF,
Gunn PJ. Climatic factors affecting quantity and quality grade of
in vivo derived embryos of cattle. Anim Reprod Sci 2018;192:
5360.
60. Matsuzuka T, Ozawa M, Nakamura A, Ushitani A, Hirabayashi M,
Kanai Y. Effects of heat stress on the redox status in the oviduct
and early embryonic development in mice. J Reprod Dev 2005;51:
2817.
61. Wallace JM, Regnault T, Limesand SW, Hay W Jr., Anthony R.
Investigating the causes of low birth weight in contrasting ovine
paradigms. J Physiol 2005;565:1926.
62. Wettemann R, Desjardins C. Testicular function in boars
exposed to elev ated ambient temperatur e. Biol Reprod 1979;20:
23541.
63. Rhynes W, Ewing L. Testicular endocrine function in Hereford
bulls exposed to high ambient temperature. Endocrinology 1973;
92:50915.
64. Zhang MH, Zhai LP, Fang ZY, Li AN, Xiao W, Qiu Y. Effect of scrotal
heating on sperm quality, seminal biochemical substances, and
reproductive hormones in human fertile men. J Cell Biochem
2018;119:1022838.
65. Li Z, Li Y, Ren Y, Li C. High ambient temperature disrupted the
circadian rhythm of reproductive hormones and changed the
testicular expression of steroidogenesis genes and clock genes
in male mice. Mol Cell Endocrinol 2020;500:110639.
66. Charkoudian N, Hart EC, Barnes JN, Joyner MJ. Autonomic control
of body temperature and blood pressure: inuences of female sex
hormones. Clin Auton Res 2017;27:14955.
67. Afroz R, Hassan MN, Ibrahim NA. Review of air pollution and
health impacts in Malaysia. Environ Res 2003;92:717.
68. Mahidin MU. Compendium of environment statistics, Malaysia
2019. Department of Statistics Ofcial Portal; 2019.
69. Tajudin MABA, Khan MF, Mahiyuddin WRW, Hod R, Latif MT,
Hamid AH, et al. Risk of concentrations of major air pollutants on
the prevalence of cardiovascular and respiratory diseases in
urbanized area of Kuala Lumpur, Malaysia. Ecotoxicol Environ Saf
2019;171:290300.
70. World Health Organization. Biregional workshop on health
impacts of haze-related air pollution, Kuala Lumpur, Malaysia,
14 June 1998: report. Manila: WHO Regional Ofce for the
Western Pacic; 1998.
71. Frankenberg E, McKee D, Thomas D. Health consequences of
forest res in Indonesia. Demography 2005;42:10929.
72. Mendola P, Messer LC, Rappazzo K. Science linking
environmental contaminant exposures with fertility and
reproductive health impacts in the adult female. Fertil Steril
2008;89:e81-94.
73. Sikka SC, Wang R. Endocrine disruptors and estrogenic effects on
male reproductive axis. Asian J Androl 2008;10:13445.
74. Hatch M, Goldman MB. Women and health. Gulf Professional
Publishing; 2000.
75. Merklinger-Gruchala A, Kapiszewska M. Association between
PM10 air pollution and birth weight after full-term pregnancy in
Krakow city 19952009trimester specicity. Ann Agric Environ
Med 2015;22:26570.
76. Merklinger-Gruchala A, Jasienska G, Kapiszewska M. Effect of air
pollution on menstrual cycle lengtha prognostic factor of
womens reproductive health. Int J Environ Res Publ Health 2017;
14:816.
12 Jegasothy et al.: Climate change and fertility in Malaysia
77. Sengupta P, Dutta S, Krajewska-Kulak E. The disappearing
sperms: analysis of reports published between 1980 and 2015.
Am J Mens Health 2017;11:1279304.
78. Sengupta P. Environmental and occupational exposure of metals
and their role in male reproductive functions. Drug Chem Toxicol
2013;36:35368.
79. Sengupta P, Dutta S, Tusimin MB, İrez T, Krajewska-Kulak E.
Sperm counts in Asian men: reviewing the trend of past 50 years.
Asian Pac J Reprod 2018;7:8792.
80. Mima M, Greenwald D, Ohlander S. Environmental toxins and
male fertility. Curr Urol Rep 2018;19:50.
81. Zhang J, Cai Z, Yang B, Li H. Association between outdoor air
pollution and semen quality: protocol for an updated systematic
review and meta-analysis. Medicine 2019;98:e15730.
82. Sengupta P, Banerjee R. Environmental toxins: alarming impacts
of pesticides on male fertility. Hum Exp Toxicol 2014;33:101739.
83. Alderman K, Turner LR, Tong S. Floods and human health: a
systematic review. Environ Int 2012;47:3747.
84. CFE-DM. Malaysia disaster management reference handbook
2016. Available from: https://reliefweb.int/sites/reliefweb.int/
les/resources/disaster-mgmt-ref-hdbk-Malaysia.pdf.pdf
[Accessed July 26, 2020].
85. Kusumastuti DI. Hydrology analysis for the Johor river using
synthetic unit hydrograph Gama I. Rekayasa J Ilm Fakultas Tek
Univ Lampung 2009;13:21928.
86. Suhaila J, Deni SM, Zin WW, Jemain AA. Trends in peninsular
Malaysia rainfall data during the southwest monsoon and
northeast monsoon seasons: 19752004. Sains Malays 2010;39:
53342.
87. Nora NM, Sibly S, Fizria FFA, Abdul A. Increasing knowledge and
awareness on oods in ood affected communities in Padang
Terap, Kedah. In: Kaneko N, Yoshiura S, Kobayashi M, editors.
Sustainable living with environmental risks. Springer Nature;
2014. https://doi.org/10.1007/978-4-431-54804-1_12.
88. FreeMalaysiaToday. Typhoon paolo wreaks havoc in Sabah;
2017. Available from: https://www.freemalaysiatoday.com/
category/nation/2017/10/18/typhoon-paolo-wreaks-havoc-in-
sabah/ [Accessed 26 July 2020].
89. Manale A. Flood and water quality management through
targeted, temporary restoration of landscape functions: paying
upland farmers to control runoff. J Soil Water Conserv 2000;55:
28595.
90. Burkhardt-Holm P. Endocrine disruptors and water quality: a
state-of-the-art review. Int J Water Resour Dev 2010;26:47793.
91. Tong VT, Zotti ME, Hsia J. Impact of the Red River catastrophic
ood on women giving birth in North Dakota, 19942000. Matern
Child Health J 2011;15:2818.
92. Kinney DK, Miller AM, Crowley DJ, Huang E, Gerber E. Autism
prevalence following prenatal exposure to hurricanes and
tropical storms in Louisiana. J Autism Dev Disord 2008;38:4818.
93. World Health Organization. The world health report 2007: a safer
future: global public health security in the 21st century. World
Health Organization; 2007.
94. Paul B, Tham WL. Interrelation between climate and dengue in
Malaysia. Health 2015;7:672.
95. Ismail NAM, Kampan N, Mahdy ZA, Jamil MA, Razi ZRM. Dengue
in pregnancy. Southeast Asian J Trop Med Publ Health 2006;37:
681.
96. Paixão ES, Teixeira MG, Maria da Conceição NC, Rodrigues LC.
Dengue during pregnancy and adverse fetal outcomes:
a systematic review and meta-analysis. Lancet Infect Dis 2016;
16:85765.
97. Iqbal MM, Abid I, Hussain S, Shahzad N, Waqas MS, Iqbal MJ.
The effects of regional climatic condition on the spread of
COVID-19 at global scale. Sci Total Environ 2020;739:140101.
98. Ministry of Health. Malaysia. COVID-19 (latest Updates)
Malaysia; 2020. Available from: http://www.moh.gov.my/
index.php/pages/view/2019-ncov-wuhan [Accessed 26 July
2020].
99. Fan C, Li K, Ding Y, Lu WL, Wang J. ACE2 expression in kidney and
testis may cause kidney and testis damage after 2019-nCoV
infection. medRxiv 2020. https://doi.org/10.1101/2020.02.12.
20022418.
100. Sengupta P, Dutta S. Does SARS-CoV-2 infection cause sperm
DNA fragmentation? Possible link with oxidative stress. Eur J
Contracept Reprod Health Care 2020;25:4056.
101. Dutta S, Sengupta P. SARS-CoV-2 and male infertility: possible
multifaceted pathology. Reprod Sci 2020;14. https://doi.org/
10.1007/s43032-020-00261-z.
102. Dutta S, Sengupta P. SARS-CoV-2 infection, oxidative stress and
male reproductive hormones: can testicular-adrenal crosstalk
be ruled-out? J Basic Clin Physiol Pharmacol 2020;31:14.
103. Anifandis G, Messini CI, Daponte A, Messinis IE. COVID-19 and
fertility: a virtual reality. Reprod Biomed Online 2020;41:1579.
104. Casey G, ShayeghS, Moreno-Cruz J, Bunzl M, Galor O, Caldeira K.
The impact of climate change on fertility. Environ Res Lett 2019;
14:054007.
105. Muhamad S, Sengupta P, Ramli R, Nasir A. Sociodemographic
factors associated with semen quality among Malaysian men
attending fertility clinic. Andrologia 2019;51:e13383.
106. Alam M, Siwar C, Al-Amin AQ. Climate change adaptation policy
guidelines for agricultural sector in Malaysia. Asian J Environ
Disas Manag 2010;2:4639.
107. Alam MM, Siwar C, Murad MW, Toriman M. Farm level
assessment of climate change, agriculture and food security
issues in Malaysia. World Appl Sci J 2011;14:43142.
108. Ibrahim A, Alam M. Climatic changes, government interventions,
and paddy production: an empirical study of the Muda
irrigation area in Malaysia. Int J Agric Resour Govern Ecol 2016:
292304.
109. Bloem MW, Semba RD, Kraemer K. Castel Gandolfo Workshop:
an introduction to the impact of climate change, the economic
crisis, and the increase in the food prices on malnutrition. J Nutr
2010;140:132S5S.
110. Mosley W. Nutrition and human reproduction. Springer Science
& Business Media; 2012.
111. Silvestris E, Lovero D, Palmirotta R. Nutrition and female fertility:
an interdependent correlation. Front Endocrinol 2019;10:346.
112. Rajagopalan S. Nutrition challenges in the next decade. Food
Nutr Bull 2003;24:27580.
113. van Hoek M, Langendonk JG, de Rooij SR, Sijbrands EJ,
Roseboom TJ. Genetic variant in the IGF2BP2 gene may interact
with fetal malnutrition to affect glucose metabolism. Diabetes
2009;58:14404.
114. Peter CJ, Fischer LK, Kundakovic M, Garg P, Jakovcevski M,
Dincer A, et al. DNA methylation signatures of early childhood
Jegasothy et al.: Climate change and fertility in Malaysia 13
malnutrition associated with impairments in attention and
cognition. Biol Psychiatr 2016;80:76574.
115. Solomons NW. Programme and policy issues related to
promoting positive early nutritional inuences to prevent
obesity, diabetes and cardiovascular disease in later life: a
developing countries view 1. Matern Child Nutr 2005;1:20415.
116. Malaysian Meteorological Department. Climate change
scenarios for Malaysia 20012099. Kuala Lumpur: Malaysia
Meteorological Department; 2009.
117. Kwan MS, Tangang FT, Juneng L. Projected changes of future
climate extremes in Malaysia. Sains Malays 2013;42:10519.
118. Le Loh J, Tangang F, Juneng L, Hein D, Lee D-I. Projected rainfall
and temperature changes over Malaysia at the end of the
21st century based on PRECIS modelling system. Asia Pac J
Atmos Sci 2016;52:191208.
119. Syafrina A, Zalina M, Norzaida A. Climate projections of future
extreme events in Malaysia. Am J Appl Sci 2017;14:392405.
120. Amin M, Shaaban A, Ercan A, Ishida K, Kavvas M, Chen Z, et al.
Future climate change impact assessment of watershed scale
hydrologic processes in Peninsular Malaysia by a regional
climate model coupled with a physically-based hydrology
modelo. Sci Total Environ 2017;575:1222.
14 Jegasothy et al.: Climate change and fertility in Malaysia
... 23 24 Extreme weather events such as heavy rainfall, floods and droughts, associated with climate change, can indirectly affect semen quality by impacting the overall health, nutrition and living conditions of individuals. 6 For instance, these conditions can lead to increased stress, changes in diet and exposure to contaminated water, all of which can impact semen quality. 25 26 Heat stress The scientific investigation into the impact of heat stress on semen quality reveals a multifaceted interaction between environmental temperatures and male fertility, both in humans and livestock. ...
... Role of education, healthcare and policy in addressing reproductive health and climate change The interplay between education, healthcare and policy plays a pivotal role in addressing the dual challenges of reproductive health and climate change, particularly in relation to declining male fertility and TFR. 6 This complex nexus demands a multifaceted approach to ensure a sustainable future. ...
Article
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Background Recent studies have reported a significant decline in human semen quality worldwide, raising concerns about climate change and its extensive effects on human health and biodiversity. Methods This article investigates the correlation between deteriorating semen quality and changing climate conditions, within the context of the United Nations Sustainable Development Goals (SDGs). It aims to explore the linkage between decreasing semen quality and climate change, and to understand its implications for population dynamics, reproductive health and sustainability. Results Integrating findings within the SDGs framework, the study emphasises SDG 3 (good health and well-being), SDG 13 (climate action) and SDG 15 (life on land). A multidisciplinary approach, incorporating data from environmental science, epidemiology and demography, is used to statistically analyse global and regional trends in semen quality against climate variability indicators, such as temperature fluctuations and pollution levels. Preliminary findings indicate a strong correlation between adverse climate conditions and reduced semen quality, suggesting potential impacts on fertility rates and population health. The research highlights the importance of climate action (SDG 13) in protecting human reproductive health and ensuring population stability (SDG 3), while emphasising the interconnectedness of ecosystem health and human well-being (SDG 15). Conclusion The article calls for integrated policy responses addressing climate change and reproductive health as interconnected challenges, advocating for enhanced cross-sectoral collaboration to achieve the SDGs through comprehensive strategies encompassing environmental protection, reproductive healthcare and population management for a sustainable future.
... Climate change is prominently transforming the global ecosystem, exerting profound effects on both natural and anthropogenic systems [33] (Figure 2). Such alterations exert both direct and indirect effects on the determinants of TFR, denoting the mean number of offspring a female is projected to produce during her lifespan [34]. Resource scarcity is one of the major challenges. ...
Article
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Sustainable Development Goals (SDGs) are paramount as the global community confronts the ramifications of climate alterations, especially its implications on population dynamics. Initial studies suggest an intricate relationship between environmental determinants and reproductive choices. This systematic review elucidates the complex interplay between climate-related challenges and observed global fertility rate variations. A comprehensive search and analysis of literature published in the last 10 years (2013–2023), available in the PubMed database, delineates the relationship between environmental changes and fertility patterns in both human and animal populations. The review highlighted significant effects of climatic fluctuations on reproductive health, manifested as either adaptive or maladaptive responses to environmental stressors. This relationship not only influences population trajectories but may also have complications for the SDGs, specifically those pertaining to health, well-being, and gender equality. The study emphasizes the importance of intertwining demographic insights with ecological considerations. A deeper understanding of the nexus between climate and fertility can augment strategies aimed at global sustainability. The synthesized evidence underscores the urgency for further research, which seeks to seamlessly incorporate eco-fertility perspectives into wider climate and sustainability discussions.
... Infertility caused by male factors affects approximately 4-6% of couples worldwide, with declining semen quality being a common cause [66]. Accelerating global climate change today, when ambient temperatures exceed critical temperatures, oxidative stress severely affects gonadal function, including impaired mitochondrial function and increased germ cell apoptosis, which leads to decreased male semen quality [67]. Our study demonstrates the inverted U exposure-response curves between TA and sperm quality, confirming the general adverse effects of TA on male sperm quality during the hot season, which has important public health significance. ...
Article
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Backgrounds Global fertility rates continue to decline and sperm quality is a prime factor affecting male fertility. Both extreme cold and heat have been demonstrated to be associated with decreased sperm quality, but no epidemiological studies have considered human adaptation to long-term temperature. Our aim was to conduct a multi-center retrospective cohort study to investigate exposure-response relationship between temperature anomaly (TA) that deviate from long-term climate patterns and sperm quality. Methods A total of 78,952 semen samples measured in 33,234 donors from 6 provincial human sperm banks in China were collected. This study considered heat and cold acclimatization to prolonged exposure in humans and explored the exposure-response relationship between TAs and sperm quality parameters (sperm concentrations, sperm count, progressive motility, progressive sperm count, total motility and total motile sperm count) during the hot and cold seasons, respectively. Linear mixed models and generalized linear models were built separately for specific centers to pool in a meta-analysis to obtain the pooled effect of TA on sperm quality, considering repeated measurements data structure and spatial heterogeneity. Results We identified an inverted U-shaped exposure-response relationship between TA and sperm quality during the hot season. Significant negative effect of anomalous cold on sperm quality during the hot season was found after additional adjustment for Body mass index, marital status and childbearing history. The heat-related TA in hot season was significantly negatively associated with sperm concentration, progressive sperm count and total motile sperm count (all P-values<0.05). After adjusting the relative humidity, the cold-related TA in cold season was negatively associated with the sperm total motility (P-values<0.05). Conclusions Our results suggest both heat-related and cold-related TAs are associated with decreased sperm quality. The findings highlight the importance of reducing exposure to anomalous temperatures to protect male fertility.
... Notwithstanding these experiences of pregnant women in the Caribbean, the reproductive health of all women, regardless of if she is pregnant or not, can be adversely affected by several climate change variables such as humidity, precipitation, and temperature of the environment, as well as changes in gonadal function and neuroendocrine regulation due to changes in health and socioeconomic status (Choudhari 2022;Jegasothy et al. 2020). ...
Chapter
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Maternal health concerns the well-being of women during pregnancy, childbirth, and the postpartum period. Climate change events often threaten maternal health because mothers and their offspring are more susceptible to environmental changes. In developing countries, 88% of children succumb to climate change-related deaths. The inherent vulnerability of mothers and their offspring to infections, illness, and malnourishment due to limited social services, healthcare, low household income, and dependency, are often to blame for the high mortality rate. Given that the literature on the impact of climate change events on maternal and child health in the Caribbean region is scarce, this chapter seeks to address this gap by using a secondary research approach. The impacts that climate change events in the Caribbean are likely to have on the maternal and child health of persons residing in flood-prone areas and coastal communities will be discussed. Like Nigeria, Ghana, and India, in the Caribbean, climate change events negatively impact the mortality of the mother and her child. The decline in the nutritional quality of food, amongst other health-related issues, also contributes to adverse pregnancy outcomes.
... Reproductive health is vital for the survival of all living things. However, the global deterioration of male reproductive health and fertility is a major concern when Malaysia has also shown a declining trend in the total fertility rate over the past few decades (Dutta & Sengupta 2018;Durairajanayagam 2018;Cariati et al. 2019;Mann et al. 2020;Jegasothy et al. 2021). The reproductive system of males is crucially essential for producing male gametes and their transportation to the female reproductive tract for successful fertilisation (Mohanty & Singh 2017). ...
Article
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Reproductive health and male fertility are closely related to dietary practices. In recent years, Malaysia has shown a lot of interest in using herbal plants as dietary supplements or in the treatment of numerous diseases. Aquilaria malaccensis, commonly known as karas or gaharu, has recently gained attention for its potential to cure many diseases due to its pharmacological properties. However, studies on its effect on male fertility and reproductive organs are very scarce. This study was conducted to determine the effect of A. malaccensis on male reproductive organs' weight (testis, epididymis, prostate gland and seminal vesicle) and sperm quality (sperm count, sperm morphology and sperm motility) in adult Sprague Dawley rats. Twenty-four male Sprague Dawley rats were allocated into four treatment groups; Control (C: 1 mL of distilled water, n = 6), Treatment 1 (T1: 1 g A. malaccensis/kg body weight, n = 6), Treatment 2 (T2: 2 g A. malaccensis/kg body weight, n = 6) and Treatment 3 (T3: 3 g A. malaccensis/kg body weight, n = 6), respectively. Distilled water and A. malaccensis were administered by oral gavage once daily for 28 days. The rats were euthanised on Day 29 for assessment of reproductive organs' weight and sperm quality. Result shows that weight of testis, epididymis, prostate gland, seminal vesicle and sperm motility did not differ (p > 0.05) among control and treated groups. A significant increase (p < 0.05) of sperm number (1.36 × 10-6) and a decrease (p < 0.05) in percentage of the abnormal sperm (8.17%) were observed in T1 group when compared to Control group. Incremental dosage of A. malaccensis seemed to decrease number of sperm (T3: 0.78 × 10-6 < T1: 1.36 × 10-6 with p < 0.05) and increase percentage of abnormal sperm (T3: 18.83% > T2: 12.17% > T1: 8.17% with p < 0.05). In conclusion, the administration of either 1, 2 or 3 grams of A. malaccensis did not alter the reproductive organs' weight and sperm motility. However, the higher concentration of A. malaccensis consumed by the rats seemed to have detrimental effects on the number and morphology of sperm.
... Over the last four decades, most areas of Malaysia have seen an increase in surface temperature of 2.7-4.0 o C (Jegasothy et al. 2021). Since the 1970s, precipitation in Peninsular Malaysia has also increased (Loo et al. 2015). ...
Article
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In recent years, palm oil production has grown rapidly as a result of rising demand. Oil palm plantations have been established on thousands of acres to meet this demand. The objective of this study is to assess the suitability of oil palm production as driven by soil, climate, and land use. The land suitability assessment (LSA) method was adopted in this study. We use geospatial techniques of overlay mapping as a suitable land suitability assessment method, in which the evaluation criteria are recorded as superimposed layers. A land suitability map is produced by integrating these layers into a single layer. The method is also applied to delineate available areas for growing oil palm in Peninsular Malaysia. The findings revealed that suitable soil areas for oil palm production are extensively found in the selected regions of Peninsular Malaysia, in states like Selangor and some parts of Kedah, Kelantan, and Terengganu with clay loam and sandy loam soil properties, while in the southern region like Melaka, moderate suitability for oil palm production was found due to the domination of clay soil in the area. Highly suitable areas were estimated (mean annual water deficit <150 mm) to be 3688254.00 ha (29.54%) of the total land area; suitable areas (mean annual water deficit <250 mm) were 6540669.00 ha (52.38%); moderately suitable areas were (mean annual water deficit <400 mm) 2227500.00 ha (17.84%), and unsuitable areas (mean annual water deficit >400mm) for oil palm production as a result of poor water availability was 31104.00ha (0.25%). The Land Use Land Cover Map of Peninsular Malaysia revealed the suitable areas to cover an average of 10885001.46 ha (82.45%), water bodies 1239505.58 ha (9.39%), built-up areas (unsuitable areas) 1051544.34 ha (7.96%), and bare surface areas are also not suitable areas for oil palm production at 26509.73 ha (0.20%). This study recommends that oil palm plantations be expanded into areas with highly suitable soils and climates.
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Due to its effect on weather and its propensity to cause catastrophic incidents, climate change has garnered considerable global attention. Depending on the area, the effects of climate change may vary. Rainfall is among the most significant meteorological factors associated with climate change. In Malaysia, changes in rainfall distribution pattern have led to many floods and droughts events which lead to La Nina and El Nino where Johor is one of the states in southern part that usually affected. Thus, rainfall trend analysis is important to identify changes in rainfall pattern as it gives an initial overview for future analysis. This research aims to evaluate historical rainfall data of Johor between 1991 and 2020. Normality and homogeneity tests were used to ensure the quality of data followed by Mann-Kendall and Sen's slope analysis to determine rainfall trend as the rainfall data is not normally distributed (p > 0.05). Standardized precipitation anomaly, coefficient of variation, precipitation concentration index and rainfall anomaly index were used to identify rainfall variability and intensity while standard precipitation index was used to evaluate drought severity. The lowest annual rainfall recorded was 1725.07 mm in 2016 and the highest was 2993.19 mm in 2007. Annual rainfall and seasonal rainfall showed a declining trend although it is not statistically significant (p > 0.05). Results reveal that Johor experienced extreme wet and dry years, leading to drought and flood incidents. Major floods arose in 2006, 2007, 2008, 2010 and 2011 while driest years occurred in 1997, 1998 and 2016 which led to El Nino phenomenon. March and April were identified as the driest months among all. Thus, the findings from this study would assist researchers and decision-makers in the development of applicable adaptation and mitigation strategies to reduce climate change impact. It is recommended that more data analysis from more stations should be done in the future research study to obtain a clearer view and more comprehensive results.
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Proceedings of the 4th International Conference on Economy, Education, Social Science, Supply Chain, Engineering, Technology and Tourism (ESSET23) It is my pleasure to welcome you to the 4th International Conference on Economy, Education, Social Science, Supply Chain, Engineering, Technology and Tourism (ESSET23). ESSET23 aims to provide a platform for connecting academic scholars and industry practitioners world-wide to share the research findings from various disciplines and create a space for intellectual discussion, exploration and reflection of key issues that are shaping the world today. This is a great opportunity for delegates to expand knowledge, plan and implement innovative strategies, overcome barriers and move forward with the initiatives that benefit the community. There will be potential opportunities for networking, informed dialogues and collaborations. Your participation and submission of research papers in this conferenc is greatly appreciated and on behalf of the Organizing Committee, I wish you all continued success and to keep up with the good work. The post-covid19 issues such as inflation, economic instability, job and food security are real and prevalent, however our research works must endure despite these challenges to continue contributing to the body of knowledge from new research ideas, methods and problem resolutions. Thank you. Dr. Safaie Mangir Conference Chairman
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Worldwide concern regarding the growing incidence of male infertility is taking a toll on research to unveil numerous factors affecting male reproductive functions. Infection or inflammation in the reproductive tract either via pathogenic intrusion or systemic diseases, reportedly are closely associated with deterioration in male fertility parameters. There are various proposed mechanisms to explain how reproductive tract infection or inflammation may curb male fecundity. One of the prominent mechanisms is via the over-production of reactive oxygen species (ROS) inducing testicular oxidative stress (OS). In normal conditions, testicular cells produce ROS at modest levels to maintain physiological functions. However, in inflammatory state, the surge of pro-inflammatory mediators, cytokines lead to infiltration of immune cells (as observed by increased seminal leukocytes number) and these leukocytes serve as major contributors in the increased seminal plasma ROS levels that overwhelms the testicular antioxidant capacities. This initiates oxidative damage to the testicular cells to impair sperm production, as well as sperm membrane damage, disruption of essential signalling cascades, sperm mitochondrial and nuclear DNA damage and thereby impairing overall sperm functions. There are number of studies reporting diversified hypothesis of infection/inflammation-induced male reproductive problems. This article aims to review the available information and present a precise overview of possible mechanisms relating male reproductive tract inflammation and male infertility.
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The pandemic outbreak of the novel coronavirus epidemic disease (COVID-19) is spreading like a diffusion-reaction in the world and almost 208 countries and territories are being affected around the globe. It became a sever health and socio-economic problem, while the world has no vaccine to combat this virus. This research aims to analyze the connection between the fast spread of COVID-19 and regional climate parameters over a global scale. In this research, we collected the data of COVID-19 cases from the time of 1st reported case to the 5th June 2020 in different affected countries and regional climatic parameters data from January 2020 to 5th June 2020. It was found that most of the countries located in the relatively lower temperature region show a rapid increase in the COVID-19 cases than the countries locating in the warmer climatic regions despite their better socio-economic conditions. A correlation between metrological parameters and COVID-19 cases was observed. Average daylight hours are correlated to total the COVID-19 cases with a coefficient of determination of 0.42, while average high-temperature shows a correlation of 0.59 and 0.42 with total COVID-19 cases and death cases respectively. The finding of the study will help international health organizations and local administrations to combat and well manage the spread of COVID-19.
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The COVID-19 pandemic is an extraordinary global situation and all Countries have adopted their own strategies to diminish and eliminate the spread of the virus. All measures are in line with the recommendations provided by WHO. Scientific societies, such as ESHRE and ASRM, have provided recommendations and guidance to overcome and flatten the growing curve of infection in patients that undergo IVF treatments. Although there is no evidence yet that the virus causing COVID-19 may exert negative effects on IVF outcome, fertility treatments have been postponed in order to support the healthcare systems by avoiding additional stress contribution. The possibility of the virus affecting sperm function and egg performance cannot be excluded. Also, an indirect effect of the virus on gametes and embryos during their manipulation cannot be ruled out. This commentary aims to provide some ideas on the possible effect of the virus on gametes and embryos as well as how it can affect the normal functioning of the embryology laboratory.
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• ROS are important physiological mediators of male fertility, sperm maturation, and fertilization. • Excessive ROS disrupts spermatogenesis, semen quality, steroidogenesis, and sexual functions. • Endogenous ROS in the male reproductive tract predominantly arises through immature spermatozoa and leukocytes. • Exogenous ROS resulting in reproductive track OS and male infertility include exposure to various endocrine disruptors, radiation, a disturbed lifestyle, and micronutrient deficiencies. • Male reproductive pathology causing infertility through OS includes varicocele, cryptorchidism and genital tract infections (including prostatitis). • Systemic pathology causing infertility through OS include visceral adiposity, diabetes, systemic inflammatory disease, and autoimmunity. • Antioxidant therapy showed evidence of improving reproductive tract OS and fertility outcomes.
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Sperm DNA fragmentation (SDF) is associated with male infertility, and it adversely affects reproductive outcomes. Both chromatin integrity and protamination status determine the extent of DNA damage. Oxidative stress due to increased levels of reactive oxygen species in the seminal fluid damages sperm DNA. Several tests have been introduced into the clinical laboratory settings to assess the sperm chromatin integrity and the extent of SDF. This chapter elucidates the molecular changes, specifically proteomic alterations, caused due to SDF. Moreover, the factors affecting sperm DNA integrity and the consequences of increased SDF are highlighted. It also focusses on the importance of SDF testing and its impact on reproductive outcomes.