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ISSN 2220-3389
A ChemicalBUET publication
ChE Chemical Engineering & Science Magazine
Thoughts
A Critical Analysis of Artificial Fruit Ripening: Scientific, Legislative and
Socio-Economic Aspects
Mehnaz Mursalat, Asif Hasan Rony, Abul Hasnat, Md. Sazedur Rahman, Md. Nazibul
Islam, Mohidus Samad Khan1*
Department of Chemical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka-
1000, Bangladesh
* Corresponding Author: mohidus.khan@mcgill.ca
Article received 21 February 2013; received in revised form 21 June 2013; accepted 24 June 2013; online published
24 June 2013
Abstract
Fruit ripening is a natural process which also can be stimulated using different artificial fruit ripening agents. In the
recent years, the effect of artificial ripening has become questionable because of various health related issues. There
are direct and indirect health hazards associated with artificial ripening agents and their impurities, which require
qualitative and quantitative analysis of chemical toxicity and their impact on fruit quality. To understand the possible
health hazards, it is important to analyze chemicals present within artificially-ripened fruits, and to analyze any
change in food value. This article sheds light on the usages of different chemical compounds as artificial fruit ripening
agents, their mechanisms, their effects on fruit quality, and possible health impacts. The existing laws and legislations
practiced in different countries are also reported here. The paper gives an overview of different aspects of artificial
ripening, and the key factors which should be borne in mind while choosing right fruits. The key objective of the paper
is to address the problems associated with artificial ripening and bring them to the notice of the scientific and non-
scientific communities.
Keyword: Artificial fruit ripening; ethylene; calcium carbide; ethephon; health hazards; legislations.
1. INTRODUCTION
Fruit ripening is a natural process in which the fruit
goes through various chemical changes and
gradually becomes sweet, colored, and gets soft
and palatable [1-5].With the advancement of
science and technology, various artificial methods
of fruit ripening has been observed mostly to meet
consumers’ demand and other economic factors.
However, in the recent years, artificial fruit ripening
has been considered a matter of concern and the
effect of artificial ripening has become questionable
because of various health related issues [6-9].
The need of artificial fruit ripening is often
encountered when the fruit-sellers offer fruits to the
customers before due season. It is easier to identify
artificially-ripened fruit during off season. However,
it is harder to find physical differences between
artificially ripened fruits and naturally ripened fruits
during the actual season of ripening. Fruit-sellers
artificially ripen green fruits even during the due
season to meet the high demand and make high
profit of seasonal fruits. They also ripen fruits
artificially to deal with the transportation and
distribution issues. Transporting and distributing
fruits from the farmers’ orchards to consumers’
baskets can take several days. In the distribution
process fruits are collected from farmers to the local
storage points. From local storages (or collection
points), fruits are transported to the warehouses of
the major cities and also to the remote parts of the
country, from where the retailers collect fruits and
sell to household customers. Besides, a wide range
of fruits are also exported to different parts of the
world. Therefore, it may take several days from
plucking fruit from the tree to reaching it to
consumer’s basket considering the transportation
Volume-4 Issue-1, December 2013
2 | P a g e
route and the availability of warehouses or cold
storage. During this time the naturally ripened fruits
can become over ripe and inedible. A part of
naturally ripened fruits can also be damaged during
harsh condition of transportation. It is an economic
loss for the fruit-sellers and therefore, to minimize
the loss, fruit-sellers sometimes prefer collecting
fruits before they are fully ripe, and artificially ripen
fruits before selling to the consumers.
Though the demands of the consumers is met to a
great extent with the help of these ripening agents,
it is important to investigate any possible health
hazards that are associated with them. Most of the
ripening agents are toxic and their consumption can
cause serious health problems, such as heart
disease, skin disease, lung failure and kidney
failure [6, 9-12]. Scientists have also reported that
regular consumption of artificial-ripened fruits may
cause dizziness, weakness, skin ulcer and heart
related diseases [6, 7, 13-15]. In addition, these
ripening agents may contain different chemicals as
impurities which are also toxic for human health. To
address the increasing health related concerns,
different countries have issued and implemented
different acts and laws to control or to prohibit the
production, sell and distribution of artificial fruit
ripening [11, 16-22]. It is important to perform
qualitative and quantitative analysis of the presence
of ripening agents within the fruit-skin and flesh to
understand the relevant health hazard. The
presence of artificial ripening agents is usually
encountered on the fruit skin. It is also important to
quantify the presence of chemicals within fruit-flesh
and to analyze the chemical impact on the food
value of artificially ripened fruits [12].
The purpose of this study is to address the
legislative, scientific and health related issues
associated with artificial ripening, to report current
research findings on the food value assessment of
artificially ripened fruits, and to make people aware
of choosing the right fruit. In order to perform the
study on artificial fruit ripening our research
explored different concerned places in Bangladesh
for information regarding the manufacturing,
distribution and application of artificial ripening
agents. Measures for qualitative and quantitative
analysis shall be taken up in future to proceed with
the study further.
2. ORIGIN OF FRUIT RIPENING
Unripe fruits often contain various types of organic
acids, namely citric acid, malic acid, ascorbic acid,
formic acid, tartaric acid etc [5]. These acids are
held responsible for the sour taste of fruits. After
certain chemical changes these acids are
transformed into sugars and the fruits turn sweet
[5]. In fruit ripening process, Chlorophyll is
produced and at the same time decomposed.
Starch is induced by Amylase usually produces
sugar. Pectin converts into pectinase and
decomposition of pectin, in this case unglues the
fruit cells. The cells being able to slip past one
another makes the fruit further soft [4].
Since many years people have been adopting
several ways to ripen fruits. Ancient Egyptian
harvesters used to cut figs in order to stimulate the
ripening process, while Chinese farmers used to
leave pears in confined chambers with added
heating [5]. Later on Researches showed that
treating of fruits with high temperature also triggers
fruit ripening [2].
In 1901 Russian scientist Dimitry Neljubow
observed that Ethylene gas emerging from larger
pipes influences ripening process of fruits [5]. After
almost three decades, researchers [5] observed
that the plants not only respond to ethylene but also
they produce ethylene all by themselves and hence
ripening process is accelerated in injured fruits or at
a temperature usually higher than the normal. As
the gas (ethylene) can diffuse and travel
spontaneously from cell to cell at a high pace in the
fruits which are cut than those which are uncut, the
rate of ripening accelerates [5].
3. CHEMICAL AGENTS USED FOR ARTIFICIAL
RIPENING
Ethylene is the major ripening agent produced
naturally within the fruits which initiates the process
of ripening [15]. There are multifarious uses of
many ripening agents to release ethylene in order
to speed up the ripening process. Chemicals like
ethanol, methanol, ethylene glycol, Ethephon,
calcium carbide are used to ripen fruits and
vegetables artificially [13, 15, 23]. The use of
calcium carbide is much widespread in many
regions of south Asia including India, Bangladesh,
Nepal and so forth for its cheaper market price
3 | P a g e
despite its ban due to its harmful feats [4, 9, 20, 21,
24].
Ethylene: A very small concentration (1 ppm) of
ethylene in air is sufficient to promote the fruit
ripening process [3]. Externally applied Ethylene is
likely to trigger or initiate the natural ripening
process of apple, avocado, banana, mango,
papaya, pineapple and guava, and therefore, can
be marketed before the predicted time.
Calcium Carbide: Calcium Carbide is widely used
in different parts of the world [10]. Once applied on
the fruits Calcium Carbide comes into the contact of
the moisture and releases acetylene, which has
fruit ripening characteristics similar to ethylene.
The reaction is [24]:
CaC2 + 2H2O = Ca (OH) 2 + C2H2
Industrial grade calcium carbide contains traces of
arsenic and phosphorus hydride, which are
hazardous for human health in direct contact [24].
Ethephon: Ethephon is another agent which is
used to artificially ripen fruits [25, 26]. Ethephon is
often considered better than calcium carbide
because pineapple, banana and tomato treated
with 1000 ppm of ethephon required less time for
ripening (48, 32 and 50 h, respectively) than other
treated fruits as well as compared with the non-
treated fruits. The fruits ripened with ethephone
have more acceptable colour than naturally ripened
fruits [31] and have longer shelf life than fruits
ripened with CaC2 [32]. Ethephon is decomposed
into ethylene, bi-phosphate ion and chloride ion in
aqueous solution [25]. The released ethylene
further fastens up the ripening process.
4. Possible Health Hazards
Calcium Carbide releases acetylene which almost
works like ethylene in terms of speeding up the
ripening process. Direct consumption of acetylene
has been found to be detrimental as it reduces
oxygen supply to the brain and can further cause
prolonged hypoxia [6].
Calcium Carbide is alkaline in nature and irritates
the mucosal tissue in the abdominal region. Cases
of stomach upset after eating carbide-ripened
mangoes has been reported recently [9]. Even
though eating the carbide-ripened fruit does not
lead to any allergic reaction instantly, seizure
headache, sleepiness may be faced while applying
these chemicals on the fruits. Impurities like arsenic
and phosphorus found in industrial grade calcium
carbide may cause serious health hazards when
workers are in direct contact with these chemicals
while applying the ripening agents. This may cause
dizziness, frequent thirst, irritation in mouth and
nose, weakness, permanent skin damage difficulty
in swallowing, vomiting, skin ulcer, and so forth [9].
Higher exposure may cause undesired fluid build-
up in lungs (pulmonary edema) [11].
5. NATIONAL AND INTERNATIONAL LAWS AND
LEGISLATIVES
To address the growing health related concerns,
developing and developed countries have issued
and implemented different acts and laws controlling
the usage of artificial fruit ripening agents. In
Bangladesh, the agencies and organizations
responsible ensuring the proper practice of
inspecting, examining and controlling harvesting,
ripening and marketing fruits are: Bangladesh
Ministry of Agriculture, Customs, Mobile court,
Ministry of health, Ministry of Science. These
agencies implement the following laws and acts in
order to maintain the quality of the home grown and
imported fruits: Pesticide law 2007, Pure food rules
and act 1967 and 2005, Quarantine rules 1968,
Mobil court act 2009, and Penal code 1860 [20, 21].
The above laws and acts prohibit using any
chemicals (such as calcium carbide, ethephon,
etc.) to ripen fruits and penalize any person who is
mixing, selling and/or using illegally ripened fruits.
In Sri Lanka, under the Food Act No 26, 1980, no
person can manufacture, sell or distribute any food
that contains any added detrimental substance,
which turns out to be injurious to human health [18].
In India, the usage of calcium carbide for fruit
ripening is prohibited under Rule 44 AA of the
Prevention of Food Adulteration Rules 1955 [16]. In
Nepal, the Nepal Food Regulation-2017 (Part 7,
rule no 19(d)) has strongly prohibited the use of
calcium carbide in ripening of fruits [9].
In USA, the United States’ NOSB recommends the
use of ethylene for post-harvest ripening of tropical
fruit and degreening of citrus, which is stated in the
‘Formal Recommendation by the National Organic
Standard Board (NOSB) to the Organic Program
(NOP)’ [22]. The United Kingdom's Soil Association
allows the use of ethylene to ripen bananas and
kiwi [Soil Association Organic Standards, rev 16.4,
4 | P a g e
June 2011] [27]. Besides, the International
Federation of Organic Agriculture Movements’
(IFOAM) also enlists ethylene gas as ‘Only for
ripening fruits’ in IFOAM Indicative List of
Substances for Organic Production and
Processing.
6. Critical Analysis on Fruit Quality and Nutrition
Values
Researchers from different disciplines are working
to assess the health hazards associated with fruit
ripening agents [1, 2, 9, 12, 13, 15, 23]. To evaluate
the relevant health hazard it is critical to quantify the
toxic concentration within the chemically-ripened
fruit-skin and flesh. In different studies, sample
fruits are collected from local market rinsed in water
and analyzed rinsed water to identify the presence
of ripening agent(s) on the fruit skin; this
methodology may not confirm or quantify the
presence of chemicals within fruit-flesh. There are
few studies reported the presence of chemicals
within fruit-flesh and have addressed the changes
of biochemical and nutritional properties of fruits
because of treating with fruit ripening agents [9, 12,
28]. Wills et al (2007) have reported the ethylene
concentration in a wide range of artificially ripened
fruits: apple, pear, peach, avocado, banana, lemon,
pineapple, orange, and lime [28]. Hakim et al (2012)
have collected Pineapple and Banana samples
from different Bangladeshi local markets and
compared to the naturally ripened and lab treated
(using Ethephone) Pineapples and Bananas. They
have found that chemically ripened Pineapples and
Bananas have higher sugar content than non-
treated samples; other fruit nutrition values like
Vitamin C and -carotene are higher in naturally
ripened fruits (Table 1). They also have reported
the presence of Lead (Pb) in chemically ripened
(market and lab treated) pineapples and bananas,
and Arsenic (As) in pineapples collected from
market) [12]. The daily permissible intakes of Pb
and As for adults are 600 μg/day and 16.7-129
μg/day, respectively [33, 34]. The average daily
consumption of fruits for an adult is in between 100
to 150 gm [35]. Therefore, the possible daily intake
of Pb and As from fruits would be 12-50 and 2.5-
3.75 μg/day respectively, which is within the
acceptable limit for an adult. Nonetheless, further
studies must be conducted regarding the effects of
long term consumption of such elements in fruits.
Besides, in many developing countries, the
potential sources of chemical contamination of
fruits and vegetables include the usage of
pesticides during harvesting process, preservatives
at post-harvesting process [29]. Therefore, to
correctly assess the health hazards related with
ripening agents, it is not only essential to consider
their effects on the fruit’s quality, but also the
qualitative and quantitative analysis of the
impurities associated with ripening agents, other
possible sources of chemical adulteration, and their
aftereffects on the nutrition value, taste and shelf-
life.
7. Choosing the Right Fruits to Consume
The external color and the texture are usually taken
under consideration when it comes to choose right
fruits. The naturally ripened fruits are often uneven
in color. It is advisable to choose fruits during the
season when it turns ripe naturally, since a ripe fruit
during off season may artificially ripen unless it is
genetically ripen [9]. For instance, in Bangladesh,
Table 1: Properties of Pineapple and Banana at different conditions [12]
5 | P a g e
June and July is the ideal period when naturally
ripened mangoes occupy the market. However,
ripening also induce the taste of the fruits and also
contributes to their weight loss.
8. Discussion
Ethylene is the major ripening agent produced
naturally within the fruits to instigate ripening
process. However, chemicals agents like ethephon
and calcium carbide are frequently used in
developing countries to activate fruit ripening
process due to cheaper price. Working with such
chemical agents without using appropriate
protective gears can be hazardous for the workers.
On the other hand, the consumers suffer from the
indirect consumption of ripening agents and their
contaminants. Researchers from Bangladesh
reported that the nutrition values like the protein
content, vitamin-C and beta-carotene decrease in
artificially ripened Pineapples and Bananas [12];
the critical finding was the presence of Arsenic (As)
and Lead (Pb) within artificially ripened Pineapples
and Bananas. The concentration of As and Pb were
within the daily permissible intake limit for an adult,
however, regular consumption of such fruits can
cause serious health hazards to human beings like
cancer, skin irritation, diarrhea, liver disease,
kidney disease, gastrointestinal irritation with
nausea, vomiting, diarrhea, cardiac disturbances,
central nervous system depression and cardiac
abnormalities etc. [12]. Ideally artificial ripening
agents release ethylene or acetylene to instigate
fruit ripening and should not contain metal or
metalloid. But practically industrial grade calcium
carbide and ethephon may contain a high
percentage of As, Pb and Phosphorus compounds
which are toxic for human health and can
contaminate artificially ripened fruits. Usage of high
grade ripening agents requires low dosing rate and
any metal/metalloid contamination must be
avoided.
It is interesting to note that the developed countries
like USA and UK allow using ethylene for post-
harvest ripening of selective fruits following specific
dosing protocols. In contrast, most of the
developing countries, including Bangladesh, India,
Pakistan and Sri Lanka, demonstrate zero
tolerance in preparing, selling or distributing
artificially ripened fruits. However, it is reported that
in spite of the strict laws and acts, fruit-sellers in
developing countries often use different fruit
ripening agents because of different socio-
economic factors, such as: high profit, high
demand, offsetting transportation and distribution
issues, etc. The law enforcement agencies also
take actions against artificial fruit ripening [10].
Contrariwise, the fruit-sellers seek guidelines to the
government agencies for the safer use of artificial
ripening agents [30]. Most of the ripening agents
used by the fruit-sellers are of industrial grade,
collected from unauthorized sources, and may
contain a high percentage of toxic impurities. These
chemical impurities also cause serious health
hazard. To compensate the transportation and
distribution issues in developing countries,
Government or local authorities can help fruit-
sellers and farmers facilitating convenient
transportation and adequate cold storage
especially for the seasonal fruits. In addition, the
government agencies and scientific communities
can investigate to develop safer, low concentration
and economically viable dosing protocols and
guidelines for fruit ripening. The consumers can
also play an important role in terms of selecting the
right fruit by keenly observing the variation of color
and buying seasonal fruits.
9. Conclusion
In recent years, different ripening agents are used
to artificially ripen fruits. These ripening agents
along with their chemical impurities are health
hazardous. To understand their health effect better,
it is important to study their chemical criteria,
mechanisms, effects on fruit quality and nutrition
value. In this article, different fruit ripening agents
are discussed along with their ripening mechanisms
and possible health hazard. The national and
international laws and regulations available to
prohibit or control artificial fruit ripening are also
reported. The socio-economic issues of artificial
fruit ripening were also addressed. Artificial fruit
ripening is a complex issue especially in developing
countries like Bangladesh and requires the
combined involvement of the government agencies,
policymakers, fruit-sellers, farmers, scientists and
consumers for an effective solution to this matter.
Instead of generalizing the issue, it is important to
assess different aspects of artificial fruit ripening,
investigate standard practices and carry out
extensive scientific studies to improve the situation.
10. Acknowledgment
Many thanks to Dr. Shaila Hossain and Dr. Md.
Ziaul Islam from National Institute of Preventive &
Social Medicine (NIPSOM), Dhaka, Bangladesh for
useful discussion.
11. REFERENCES
1. Prasanna, V., T.N. Prabha, and R.N. Tharanathan,
Fruit Ripening Phenomena–An Overview. Critical
6 | P a g e
Reviews in Food Science and Nutrition, 2007. 47(1):
p. 1-19.
2. Bouzayen, M., et al., Mechanism of Fruit Ripening, in
Plant Developmental Biology - Biotechnological
Perspectives, E.C. Pua and M.R. Davey, Editors. 2010,
Springer.
3. Brady, C.J., Fruit Ripening. Annual Review of Plant
Physiology and Plant Molecular Biology, 1987. 38: p.
155-178.
4. Koning, R.E. Fruit Ripening. Plant Physiology
Information Website. 1994; Available from:
http://plantphys.info/plants_human/fruitgrowripe.
shtml.Retrived: 2 June 2012
5. Kendrick, M., The Origin of Fruit Ripening, in
Scientific AmericanTM. 2009, Nature America, Inc.:
New York.Homepage: www.scientificamerican.com;
Retrived: 2 June 2012
6. Fattah, S.A. and M.Y. Ali, Carbide Ripened Fruits - A
Recent Health Hazard. Faridpur Medical College
Journal, 2010. 5(2): p. 37.
7. Jayan, T.V., Beware of These Fruits, in The Telegraph,
Calcutta. 2011, The Telegraph, India: Calcutta,
India.Homepage: www.telegraphindia.com;
Retrived: 2 June 2012.
8. Vila, R., et al., Biochemical Changes in Chaenomeles
Fruits and Fruit Juice During Ripening and Storage, in
Japanese Quince - Potential Fruit Crop for Northern
Europe, K. Rumpunen, Editor. 2003, Swedish
University of Agricultural Sciences: Uppsala,
Sweden. p. 159-168.
9. Siddiqui, M.W. and R.S. Dhua, Eating Artificial
Ripened Fruits is Harmful. Current Science, 2010.
99(12): p. 1664-1668.
10. Hoque, M.A., Action Against Unscrupulous Fruit
Ripeners, in The Financial Express. 2012,
International Publications Limited.: Dhaka,
Bangladesh.Homepage: www.thefinancialexpress-
bd.com; Retrived: 25 November 2012.
11. Description of a Hazardous Substance Fact Sheet,
S.o.N.J. Department of Health, USA, Editor. 2000,
Department of Health, State of New Jersy, USA:
Trenton, NJ. p. 1-4.
12. Hakim, M.A., et al., Role of Health Hazardous
Ethephone in Nutritive Values of Selected
Pineapple, Banana and Tomato Journal of Food,
Agriculture & Environment 2012. 10(2): p. 247-251.
13. Chace, E.M., Health Problems Connected with the
Ethylene Treatment of Fruits. American Journal of
Public Health and the Nation's Health, 1934. 24(11):
p. 1152-1156.
14. Gross, K.C., et al., Biochemical Changes Associated
with the Ripening of Hot Pepper Fruit Plant
Physiology, 1986. 66: p. 31-36.
15. Nagel, M.C., The Fruits of Ethylene. ChemMatters,
1989. 7(2): p. 11-13.
16. 16. The Prevention of Food Adultration Act & Rules
1955, F.S.a.S.A.o.I. (FSSAI), Editor. 1955, Ministry of
Health and Family Welfare: India.
17. 17. The Food Safety Act 1990 (Consequential
Modifications) (England and Wales) Order 1990:
The Preservatives in Food Regulations 1989,
H.M.s.S.O. (HMSO), Editor. 1990, The National
Archives, UK: UK.
18. 18. The Gazette of the Democratic Socialist
Republic of Sri Lanka: The Food Act, No. 26 of 1980.
1990, The Ministry of Health: Colombo, Srilanka.
19. 19. A Report Regarding a Proposed Amendment of
Certain Sections of the Bangladesh Pure Food
Ordinance, 1959 (Ordinance No. LXVIII of 1959),
L.C.o. Bangladesh, Editor. 2007, Law Commission of
Bangladesh, GoB: Dhaka, Bangladesh.
20. 20. Report on a Workshop on Food Inspection
Arrangements in Bangladesh, F.a.A.O.o.t.U.
Nations, Editor. 2010, Food and Agriculture
Organization of the United Nations: Dhaka,
Bangladesh. p. 1-27.
21. Review of Food Safety and Quality Related Policies
in Bangladesh, F.a.A.O.o.t.U. Nations, Editor. 2010,
Food and Agriculture Organization of the United
Nations: Dhaka, Bangladesh. p. 1-28.
22. Giacomini, D.G., Formal Recommendation by the
National organic Standard Board (NOSB) to the
National Organic Program (NOP). 2012, U.S.
Department of Agriculture: USA.
23. Goonatilake, R., Effects of Diluted Ethylene Glycol as
A Fruit-Ripening Agent. Global Journal of
Biotechnology & Biochemistry, 2008. 3(1): p. 8-13.
24. Ur-Rahman, A., F.R. Chowdhury, and M.B. Alam,
Artificial Ripening: What We are Eating. Journal of
Medicine, 2008. 9(1): p. 42-44.
25. Plant Growth Regulator, in Metabolic Pathways of
Agrochemicals: Part 1: Herbicides and Plant Growth
Regulators, T.R. Roberts, et al., Editors. 1998, The
Royal Society of Chemistry (RSC) Publication:
Cambridge, UK. p. 784-787.
26. Singal, S., M. Kumud, and S. Thakral, Application of
Apple as Ripening Agent for Banana. Indian Journal
of Natural Products and Resources, 2011. 3(1): p.
61-64.
27. Soil Association Organic Standards: Food and Drink.
2011, Soil Association. p. 77.
28. Wills, R., et al., Postharvest: An Introduction to the
Physiology and Handling of Fruit, Vegetables and
Ornamentals. 5th ed. 2007, Sydney, Australia:
UNSW Press.
29. Bhuiyan, M.H., M.S. Ali, and M.M. Molla, Effects of
Using Chemicals and Hormones for Cultivation and
Marketing of Vegetables and Banana. 2009,
7 | P a g e
National Food Policy Capacity Strengthening
Programme, Bangladesh: Dhaka, Bangladesh. p. 1-
66.
30. Ananth, M.K., Mango Growers and Traders Seek
Guidelines on Artificial Ripening of Fruits in The
Hindu. 2011, The Hindu: Chennai, India.Homepage:
www.hindu.com; Retrived: 25 November 2012.
31. Rahman, A., Chowdhury, F. R. and Alam, M. B. 2008.
Artificial ripening: what we are eating. J. Med.
9:42–44.
32. Medlicott, A. P., Sigrist, J. M., Reynolds, S. B. and
Thompson, K., Effects of Ethylene and acetylene on
Mango fruit ripening. Annals of Applied Biology,
1987, 111, 439-444.
33. WHO, Lead (Evaluation of Health Risk to Infants and
Children), in Toxicological evaluation of certain food
additives and contaminants. 1987, WHO Press:
Cambridge.
34. WHO, Arsenic in Drinking Water: Background
Document for Development of WHO Guidelines for
Drinking-Water Quality. 2011, World Health
Organization: Geneva, Switzerland. p. 24.
35. Agudo, A. Measuring Intake of Fruit and
Vegetables. World Health Organization, Kobe,
Japan, 2005; p 40.
