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Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
Introduction
An analysis in 2011 indicated that
mercury was added to about 16% of
skin-whitening creams in Cambodia to
block the formation of melanin. e
maximum concentration of mercury
found in a cream in Cambodia was
35,000 μg/g. None of the product labels
indicated the addition of mercury. e
half-life of inorganic mercury in the
body is approximately 30–60 days, and
mercury levels in the body increase
with daily application of a mercury
cream. Inorganic mercury commonly
causes kidney damage and also results
in neurological toxicity and skin
disorders.- Although chelation therapy
Background. In Cambodia, there is widespread use of skin-whitening creams containing
levels of mercury that exceed Association of Southeast Asian Nations (ASEAN) guidelines by
up to 35,000 times. Mercury in skin-whitening creams threatens to compromise the health of
Cambodians.
Objectives. It is important to provide essential information on sources of mercury so that
Cambodians can avoid exposure to elevated levels of mercury and to support informed
management of consumer goods.
Methods. Students were directed to buy selected skin-whitening creams that were then
sampled with replication in 2011 and 2015 and processed with X-ray uorescence (XRF) at
the University of Health Science (UHS), Phnom Penh, Cambodia.
Discussion. e analysis of skin-whitening creams in Phnom Penh in 2015 was compared
to analyses in 2008 and 2011 and showed that several creams produced in Asia no longer
contain mercury. However, skin creams produced in Phnom Penh continue to use mercury
and counterfeit products also are contaminated with mercury. Vendors occasionally identied
Vietnam as a source of counterfeit products, but oen the source was unknown. Mercury
continues to be the metal of greatest concern in skin creams. Creams with more than 1,000
μg/g of mercury are a common cause of dermatitis (27% of cases). A new XRF analyzer was
also able to detect more lead and arsenic than that used in analyses performed in 2011, and
these two metals also exceeded ASEAN guidelines. Arsenic contamination also reected the
presence of bismuth in creams.
Conclusion. Some producers of skin-whitening creams in ailand, China and Taiwan
appear to be aware of the risks of mercury contamination and have modied their products.
However, other producers of skin-whitening creams continue to use mercury. XRF analysis
allows for rapid screening of mercury in cosmetics and should be used to gather additional
information on mercury content in cosmetics in support of public health eorts to stem the
import, export and sales of skin creams containing mercury.
Competing Interests. e authors declare no competing nancial interests.
Keywords. Toxicity, mercury, skin-whitening cream, Cambodia
J Health Pollution 9: 33-46 (2015)
Mercury Contamination of Skin-whitening Creams
in Phnom Penh, Cambodia
omas Murphy1,2, Sothea Kim2,
Prean Chanra2, Sereyrath Lim1,
Kenneth Wilson3,4, Kim N. Irvine5,
Darell G. Slotton6, Lori Allen7
1 Bualo State, State University of New
York, NY
2 University of Health Sciences, Phnom
Penh, Cambodia
3 Texas State University, San Marcos, TX,
USA
4 Royal University of Phnom Penh,
Cambodia
5 Nanyang Technological University,
National Institute of Education, Singapore
6 University of California, Davis,
California
7 University of Wisconsin, Parkside, USA
Corresponding Author:
omas Murphy
Tel: (855)179-02023
tompatmurphy@gmail.com
Murphy et al
has health risks, at times it has been
used to expedite recovery from the use
of skin creams with mercury.- Usually
the body recovers once use of such
creams is stopped; however at times,
neurological and kidney damage can be
long term or even permanent.,
Unfortunately, use of mercury in
skin creams is common.- Social
pressure to appear pale is centuries
old and persists today. Reducing
the use of mercury requires both
education of users of cosmetics and
rapid detection of mercury to facilitate
enforcement and suppression of
sales. is paper reviews the use of
educational clinics in Cambodia and
X-ray uorescence (XRF) analysis
to detect and discourage the use of
mercury-containing creams. e
Minamata Convention has addressed
the issue of mercury in skin-whitening
creams in order to reduce the use and
availability of mercury (http://www.
mercuryconvention.org/).
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
As
ASEAN
Ba
Bi
Br
CBC
Cd
Cl
Cr
Cu
CVAAS
EU
Fe
Hg
ICPMS
ICP-OES
ND
Ni
Pb
ROS
Sb
SD
Se
Sn
Ti
UHS
UV
V
XRF
Zn
Arsenic
Association of
Southeast Asian Nations
Barium
Bismuth
Bromine
Complete blood count
Cadmium
Chlorine
Chromium
Copper
Cold vapor-atomic absorption
spectrophotometry
European Union
Iron
Mercury
Inductively coupled
plasma mass spectrometry
Inductively coupled plasma
optical emission spectroscopy
Non detect
Nickel
Lead
Reactive oxygen species
Antimony
Standard deviation
Selenium
Tin
Titanium
University of Health Science
Ultraviolet
Vanadium
X-ray uorescence
Zinc
is paper reports previously
unreported aspects of our educational
clinics conducted in 2011. e
collection of creams focused on strong
replication in 2011 and 2015 to allow
for analysis of changes in mercury use
in creams. e main objectives were
to: 1) determine if the mercury content
of creams with a history of high levels
of mercury in 2008 and 2011 has
changed and 2) evaluate the presence
of other metals in creams.
Methods
Educational Clinics
Sampling protocols were approved
by the Ethical Review Committee of
the Cambodian Ministry of Health.
Students from the University of
Health Sciences and two Don Bosco
Institutes in Phnom Penh, garment
factory workers and women in the
service industry, were invited to bring
skin creams that they were currently
using for evaluation of their mercury
content. Don Bosco Institutes are
training schools run by the Catholic
Church. More than 90% of the study
participants were women between
18 and 22 years old. e analysis was
preceded by short lectures in Khmer
on the risks of mercury and were
augmented whenever a toxic cream
was discovered. e students asked
questions and some returned later for
more discussion. Students were given
interview forms and direction prior to
measurement of the creams (Table 1 ).
An important aspect of the clinics was
having students see the measurements
directly using a Niton XL3t handheld
x-ray XRF analyzer (ermo Fisher
Scientic, Waltham, MA).
e sampling methods in 2011 were
presented in Murphy et al. 2012. In
2014, eight products that had been
kept from the collection in 2011 for
displays were analyzed with a Niton
XL3T970 handheld XRF analyzer
with a sample holder. In 2015, sixty
cosmetic samples from 21 products
were purchased from April to May
from six dierent local markets such
as Oreusey market, Old market, Psar
om Toul Sanke, Kilo4 market
and Beong Keng Kong market and
analyzed using a Niton XL3T970
handheld XRF analyzer with a sample
holder.
In addition, examples of creams with
mercury were displayed as part of the
clinic. Most students took pictures
of the displays to show their friends
and families. e results of the x-ray
analysis of the creams were used to
select students to donate samples urine
or hair. Selection of samples included
some without mercury exposure
as controls, but most students had
used a cream with high mercury
levels. Analysis of urine was done
at Central Laboratories, Bangkok
using inductively coupled plasma
mass spectrometry (ICPMS) and wet
digestion. Hair samples were as long
as 70 cm and as short as 20 cm. ey
were cut into segments of no less
Murphy et al
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Abbreviations
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
dimethyl sulfoxide, which assists in
the mixing of mercury and reduced
sampling errors, but for safety, was
conducted only in the laboratory, not
with students. We had previously
conrmed the skin cream analysis
method with independent laboratories
using inductively coupled plasma
optical emission spectroscopy (ICP-
OES) and spiking. e analyses of
other metals in the present study
should be considered preliminary and
require verication. Our study using
XRF analysis of sediments found that
XRF results deviated from certied
reference materials as follows: iron (Fe)
3%, arsenic (As) 4%, copper (Cu) 6%,
zinc (Zn) 32% and lead (Pb) 57%. In
2015, the XRF mercury (Hg) results
were within 1% of a certied reference
material supplied by ermo Fisher Inc.
Statistical analysis
Microso Excel 2013 was used for the
basic statistical analysis. To determine
the signicance of r2 values in linear
regression the following website
was used for Pearson’s correlation
coecient: http://www.gied.uconn.
edu/siegle/research/correlation/
corrchrt.htm. To compare the means
of creams collected in 2011 to the
same products in 2015, we used the
Mann-Whitney U test calculator at
the Vassar University website http://
vassarstats.net/utest.html. To compare
the three ai cream products that
were measured in 2008 to the analyses
in 2011 and 2015 we combined the
three products into a ai data set and
compared the years using the Mann-
Whitney U test. For a Cambodian
producer of skin creams (pseudonym
Khmer1) we also combined creams
in groups by year. To compare the
signicance of the proportion of rashes
produced by skin creams, we used the
Vassar University calculator.
Results
e thin lm method allowed the
educational clinics to proceed quickly
so that the students’ attention was
maintained. Students were very
concerned to see if their cream
contained mercury. Most were worried
about their health and planned to
avoid using any creams with mercury.
For screening purposes, the thin layer
method is much faster than the sample
cup method. In Figure 1, the relative
standard deviation for the thin lms in
triplicate analysis was 3.98%, whereas
with the sample cups it was 2.48%. e
samples in Figure 1 were all uid-type
creams with some water (Vaseline). By
comparison with more viscous creams
(counterfeit Lemon Herbal Cream
from Vietnam) the relative standard
deviation was 1.69% with thin lm and
9.24% for the sample cups. For viscous
creams, which are common, the
sample cups produced more variable
than 10 cm. Hair analysis was done
at the University of California, Davis
using cold vapor-atomic absorption
spectrophotometry (CVAAS),
following digestion under pressure
at 95o C in a mixture of concentrated
nitric and sulfuric acids with
potassium permanganate.
XRF Calibration
For most of the analyses presented in
this paper, about 0.3 g of cream was
placed on Mylar lm which was then
folded over the cream and placed in
front of the XRF analyzer in a sample
stand. For a subset of samples, 5 g of
cream was placed into sample cups.
Calibration of the XRF unit was done
by adding mercuric chloride to sample
creams for both the sample cup and
the thin lm method. Calibration used
Date
Name
Age
Phone number
Email
Approval to send results by email Signature____________________________
Weight (used to estimate skin surface and thus assimilation of mercury)
Skin cream product name
Bought where
Cost
Size
How long does it last the user?
How long have you been using it?
Do you mix the product with anything else and if yes what?
Times a day used?
Face only, or % of rest of body covered?
Does it lighten your skin as desired?
Have you noticed any changes other than lighter skin?
Did you know that some skin whiteners contain mercury?
Table 1 — Interview Questions
Murphy et al
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
data. For screening purposes, this
degree of variability was not a concern.
e response with the sample cups
was more curvilinear than was seen
in the thin lm layer in Figure 1, but
by itself, this was not a signicant
concern. With higher concentrations
of mercury, the response was more
curvilinear (data not shown).
Because of the greater adsorption
of uorescent x-rays by mercury at
high concentrations, XRF analysis is
fundamentally curvilinear. Likely
this self-adsorption of mercury at
higher concentrations is also greater
in thicker samples. For screening
purposes, this small deviation causing
a curvilinear response is not a concern.
In Figure 1, the detection of mercury
was virtually 1:1. Recoveries of
mercury were close to 100% and never
more than 110% or less than 98%.
e cream used in Figure 1 contained
about 6.5% titanium, but this had
no apparent eect on the mercury
analysis. However, the mercury greatly
impeded the measurement of titanium.
e degree of suppression varied
with the mercury concentration:
5,000 μg/g Hg suppressed titanium
measurement by 90%. e variability
of the XRF analysis of titanium (Ti)
was much greater than for other
metals. For example, in a set of 6
products analyzed in triplicate, the
average coecients of variation for
titanium and mercury were 33.9% and
7.4%, respectively. Each of the tested
products had more than 1000 μg Ti/g
or 600 μg Hg/g. e subsampling of
viscous creams is awkward, but even
with a uid sunblock and use of a
Vortex stirrer immediately before
subsampling, the variability in Ti
analysis was high with both the thin
lm and cup methods.
Eect of Sample Depth on
XRF Analysis
e ermo Niton manual suggests
using deep samples, which is not
optimal for screening skin creams.
When the depth of cream (or plastic)
varies, the depth of the samples
should be recorded in the analyzer.
e algorithm is then able to make
accommodations for depth. If the
sample cups were used, another
variable was added to the analysis
because the volume of cream was
oen less than 5 ml and an attempt
should be made to measure the height
of the sample. Without correction for
height, the error could be as much as
40%. With the thin lm method, all
triplicates had coecients of variation
less than 9%. As can be seen in Figure
2, the curve appears to be the attest
(least variable) with cream sample
thicknesses of 0.2 to 0.7 mm. Veried
by testing on multiple days, spiked
samples within this range of depths
produced an average of 99% recovery.
Note that in Figure 2, we kept the
sample thickness setting on the
analyzer at 0.3 mm. is was done to
evaluate whether sample thickness had
an important eect on the thickness
used for the thin sample method. It
is easy to work within the desired
thickness of 0.2 to 0.7 mm. For routine
analysis it is unnecessary to measure
the sample thickness.
Mercury Analysis with a in
Film Method
e procedure recommended in the
ermo manual uses sample cups, but
this is awkward for screening of skin
creams. e manual is mainly written
to guide the preparation of geological
powders and soil samples. Many
skin creams are too viscous to ll the
sample cups well. For viscous creams it
is dicult to avoid having air bubbles
at the bottom of the sample cup, which
reduces the apparent concentration
of mercury. Moreover, the ermo
manual’s suggestion of samples of at
least 5 g is impossible for many of
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Murphy et al
0
1000
2000
3000
4000
5000
6000
7000
01000 2000 3000 4000 5000 6000 7000
Measured Hg μg/g
Spiked Hg μg/g
Thin Layer
Cups
Expected
response
Figure 1 — Comparison of in Layer and Sample Cup Methods
For linear regression analysis, the thin lm method had a slightly better r2 (0.9911) vs the
cup method (0.9888). e standard deviations were slightly larger in the thin lms (mean
3.98%) vs sample cups (mean 2.48%), but were only larger than the sample dots, with one
sample spiked with 6000 μg/g mercury.
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
the creams which are oen sold in 3
ml jars. For screening purposes, it
is not necessary to have a 5 g sample.
Students did not mind donating 0.3 g
of their cream, but may have had an
issue with donating the entire cream.
Creams could be removed from the
sample cups, but this would take
time, and handling of these products
should be kept to a minimum or be
done in a fume hood, which is not
conducive to a live demonstration.
Our demonstrations were typically
done in simple classrooms with over
30 students.
Advantages of in Film vs Sample
Cup Method
1) No need for cups, which reduces
costs and amount of toxic wastes.
2) Much smaller mass of sample
needed (~0. 3 g vs >5 g).
3) Much faster, which is important
when screening many samples in front
of students.
4) With viscous creams there is
better reproducibility due to fewer air
bubbles produced by sample transfer
to the sample and which are resistant
to release by Vortex agitation.
Comparison of Samples from 2015 to
Earlier Sampling in 2008 and 2011
In 2015, mercury was detected in
41% of samples. In 2011, 16% of
581 creams collected in non-biased
clinics contained detectable mercury.
For simplicity, the same detection
level of 20 μg/g as was determined
in 2011 was used for both, i.e. results
lower than 20 μg/g in 2015 were
considered non-detects. In this case,
the dierences in sample processing
and smaller sample size in 2015 (n=60)
did not warrant discussion of the
signicance of the apparent increase
in the proportion of samples in which
mercury was detected. e highest
mercury concentration found in 2015
was 6,305 μg/g, whereas it was 35,000
μg/g in 2011. Table 2 illustrates that
in 2015, mercury was found at much
higher concentrations than arsenic or
lead, the only other toxic metals above
the Association of Southeast Asian
Nations (ASEAN) guidelines.
Other Metals
In 2015, the XRF analysis was done
with a newer model and appeared
to detect more arsenic and lead.
ese results should be considered
preliminary and qualitative, but could
guide future sampling. Lead is able to
suppress detection of arsenic in XRF
analysis and these results might mask
the signicance of arsenic in skin
creams. In 2011, the XRF analyzer
results of As and Pb in soils were
Murphy et al
Figure 2 — Eect of Sample Depth on Mercury Measurement
All samples in
Figure 2 used
the same skin
cream (“Lemon
Cream” from
Vietnam)
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
conrmed with certied reference
materials and detection levels were
about 9 μg/g for Pb and 13 μg/g for
As. In 2015, the detection levels were
about 5 μg/g for both Pb and As.
By ignoring detected values lower
than the 2011 detection level, the
increases in arsenic and lead in skin
creams were signicant (α = 0.05) in a
Mann-Whitney analysis. No lead was
observed in creams in 2011, whereas
it was detected in 22% of creams in
2015. Only 6% of creams in 2011
appeared to contain arsenic, whereas
in 2015, 22% of creams appeared to
contain arsenic. In 2015, two samples
of Rojzy Jiali appeared to exceed the
ASEAN guideline for arsenic by a
factor of about 9 times. In 2015, Qian
Mei exceeded the ASEAN guideline
for arsenic by up to three-fold. e
Chinese cream Qian Mei contained
bismuth that was contaminated with
arsenic. Figure 3 illustrates a highly
signicant relationship between
bismuth and arsenic (r2 = 0.858, p
< .0.01, four of the 17 points were
superimposed). A set of 8 samples
from the 2011 collection were kept
for display and analyzed in 2014. e
relationship between bismuth (Bi)
and arsenic was y = 0.0144x - 8.0129,
r2 = 0.99, n = 8. e relationship
Sample
Guideline
As ± SD (n)
5
Comments
Pb ± SD (n)
10
Hg ± SD (n)
1
ailand 2008 3 products ND (3) ND (3) 4600 ± 3608 (3)
ailand 2011 3 products ND (9) ND (9) ND (3) Signicant p <0.01
ailand 2015 3 products ND (9) ND (9) ND (3) Signicant p <0.1
Taiwan 2011 Rojzy Jiali ND (6) ND (6) 4333 ± 4791 (6)
Taiwan 2015 Rojzy Jiali ND (9) 32 ± 28 (4) 28 ± 30 (4) Signicant p <0.01
China 2011 Hua u Li ND (10) ND (10) 6401 ± 7397 (10)
China 2015 Hua u Li ND (5) ND (5) 0 ± 0 (5) Signicant p < 0.01
China 2011 Qian Mei ND (10) ND (10) 3779 ± 1926 (10)
China 2015 Qian Mei ND (12) 9 ± 4 (12) 17 ± 31 (12) Signicant p < 0.01
Cambodia 2011 3 products* ND (4) ND (4) 2599 ± 2320 (4)
Cambodia 2015 13 products 9 ± 31 (13) ND (13) 2022 ± 2232 (13) Not Signicant
USA 2011 “Enjoy” ND (6) ND (6) 12947 ± 826 (6)
USA 2015 “Enjoy” 52 ± 9 (6) ND (6) 5989 ± 252 (6) Signicant p < 0.01
Vietnam 2015 “Lemon” 5 ± 5 (6) ND (6) 3649 ± 229 (6) Reported bootleg
Country/year
ASEAN
Table 2 — Metals in Skin Whitening Creams 2008, 2011 and 2015
ai Creams: Ninatop, Me One, Ucare All values are µg/g
*Khmer1 “Lemon” is fake Lemon Herbal ND = non-detect
± SD (n) is standard deviation ± (number of samples)
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Murphy et al
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
between Bi (x) and As (y) in 2011 and
2014 was similar (2011: y = 0.0093 x
-0.1884), but any statistical analysis of
limited data is inappropriate. e one
extreme sample of Rojzy Jiali analyzed
in 2014 exceeded ASEAN guidelines
for arsenic by 86 times. e trend in
the 2014 data was dominated by one
sample of Rojzy Jiali that contained
433 μg/g of arsenic, and 30,270 μg/g
of bismuth. Of the eight samples
reprocessed in 2014, ve contained
more than 39 μg/g of arsenic, which
conrms that the newer analyzer was
more sensitive for arsenic analysis.
Some other creams such as fake
Lemon Herbal contained similar
concentrations of bismuth, but had
undetectable levels of arsenic. Clearly
if one producer can nd a supply of
bismuth without arsenic, all could.
Another interesting relationship is
the signicant correlation between
tin and mercury in Khmer1 cream
products in 2015 (r2 = 0.7006, n =
14 p<0.01, Figure 4). Mercury and
tin are found together in geological
deposits. Mercury in other products
such as fake Lemon Herbal had no
tin and presumably got their mercury
from another source. e set of ve
samples of the fake cream “Enjoy”
had two samples with high tin and
high mercury, but three with high
mercury and low tin, so there was
no signicant relationship in “Enjoy”
creams between tin and mercury.
We commonly detected the following
15 elements: Arsenic (As), barium
(Ba), Bismuth (Bi), bromine (Br),
chlorine (Cl), chromium (Cr), copper
(Cu), iron (Fe), mercury (Hg),
nickel (Ni), lead (Pb), antimony
(Sb), tin (Sn), titanium (Ti) and
zinc (Zn). Moreover cadmium (Cd),
selenium (Se), and vanadium (V)
were occasionally detected. Analysis
of these 18 elements might at times
ngerprint producers of bootleg
creams. However, this is likely
done with a simpler analysis. Some
bootleg products are obvious. Figure
5 shows “Enjoy” cream packaging
that was purchased at markets. Note
the obvious worn appearance of the
packaging. e label claims that this
Enjoy cream is produced in the USA.
With “Lemon Herbal” and other
creams a vendor said that they were
produced in Vietnam and placed into
packaging that was recycled. is
vendor oered a discount for recycled
cream containers and packaging.
e labeling on the “Lemon Herbal”
package said it was produced in
ailand. Not all use of mercury is
hidden by bootlegging. Eight of 13
products of Khmer1 creams contained
mercury. is producer in Phnom
Penh operates outlet stores. In 2011,
a third of such small companies
including beauty shops produced
whitening creams with mercury and
there is no reason to believe that this
has changed. We sampled Khmer1
creams only as an example, but believe
mercury is as common now in beauty
shops in Phnom Penh as it was in
2011.
Dermatitis
e improved sensitivity of the
new XRF analyzer could better
support more detailed assessment
of dermatitis in relation to other
ingredients contained within the
creams. In interviews in 2011,
students using creams with more than
1,000 μg/g mercury were signicantly
(P < 0.0002, two tailed) more likely
to develop a skin rash. Of 30 students
using a cream with more than 1,000
μg/g of mercury, eight reported having
a rash. In the set of students (n = 274)
using a cream with less than 1,000
μg/g of mercury, only ve reported
having a rash. ese 5 creams did not
contain mercury. ere were
30 creams with less than 1,000 μg/g,
but with detectible concentrations of
mercury (20–100 μg/g. n = 12; 100-
500 μg/g, n = 12; 500-1,000 μg/g,
n = 6).
Two cases of allergic reaction were
associated with commercial creams
containing 8,000 μg/g and 13,000 μg/g
of titanium, a common ingredient in
Murphy et al
R² = 0.858
0
2
4
6
8
10
12
14
16
18
0 500 1000 1500 2000
Arsenic µg/g
Bismuth µg/g
Arsenic and Bismuth in Qian Mei Cream
Figure 3 — Arsenic contamination signicantly related to bismuth
in Qian Mei Cream
In the linear regression analysis, the r2 of 0.858 was highly signicant, P < 0.01, n = 17
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
sunblock. e three other reported
cases of allergic reaction without
mercury were from beauty shop
creams, and they contained no major
concentrations of metals. In 2011,
one unique cream had 878 μg/g of
cadmium, and three women in the
service industry who had used this
cream complained of dermatitis. at
level is almost 300-fold the Canadian
guideline of 3 μg Cd/g. Cadmium
was undetected in 2015. ASEAN is
apparently evaluating a guideline of
1-3 μg Cd/g in skin creams.
Two samples of fake Enjoy appeared
to have 500 μg/g of antimony, which
is 100-fold the Canadian guideline.
Otherwise, it was rarely found and
had no obvious relationship to
other contaminants. e Canadian
review states “Dermal absorption
of antimony has not been well
studied.” Antimony in skin creams
is not currently regulated in ASEAN
guidelines. We are uncertain of the
validity of the XRF measurements
of antimony, but any substance that
exceeds a guideline by as much as a
hundredfold warrants some concern
and validation. e antimony and lead
in fake Enjoy are of academic interest.
Because of the extreme concentration
of mercury (mean 5,989 ± 250 μg/g,
n = 6), we recommend that this
bootlegged version of Enjoy skin
cream be taken o the market.
In 2015 we detected four creams with
more than 30 μg/g of nickel. Cobalt
and chromium are also known to
initiate allergic skin responses. We
did not detect cobalt in skin creams.
However, in 2015, two samples of
creams appeared to contain more
than 150 μg/g of chromium, a known
essential micronutrient which is toxic
at high concentrations.
Assessments of Mercury
Bioaccumulation
Five of 15 samples of urine had higher
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Murphy et al
R² = 0.7006
0
1000
2000
3000
4000
5000
6000
7000
0 20 40 60 80
Hg µg/g
Sn µg/g
Mercury and Tin in Khmer1 Creams
Figure 4 — Tin contamination signicantly related to mercury
in Khmer1 Creams
Figure 5 — Image of “Enjoy” cream packaging
In linear regression analysis, the r2 of 0.7006 was highly signicant, P < 0.01, n = 14
Note the worn packaging reecting recycling and relling with bootleg cream.
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
levels than the warning level of 20
μg/L Hg required for physicians to
report to the New York Department
of Health (Tab le 3 ). However, one
of the subjects with 25 μg/L Hg in
urine claimed she was not using a
cream with mercury. Interviews are
not always accurate and the data
on urine in the present study is not
strong. e lab detection level of
18 μg/L is barely adequate. ere
was no signicant relationship
between the mercury in creams and
mercury in urine. It would have
been better to calculate the exposure
of mercury via the interviews, but
the experimental design did not
anticipate the frequent inability of
students to ll out the questionnaires.
is area needs considerably more
analysis, including blood analysis, to
gather more information on mercury
bioaccumulation and potential
relationships between mercury and
cases of infection and anemia.
e concentrations of mercury in hair
in our study (Figure 6) were similar
to what Agusa et al. observed in hair
samples in Phnom Penh. e pattern
of mercury in student hair samples
in Figure 6 is quite strong. However,
three of the subjects in Figure 6 had
been using a cream with mercury
for less than two months. No hair
sample represented a growth period
of less than 20 months. Since hair
grows at approximately 1 cm a month,
the longest hair sample represented
growth of about 70 months and no
subjects had used a cream for more
than 24 months. e samples farthest
from the scalp were all beyond the
time frame that students had been
using skin creams. e patterns
observed in mercury concentration do
not represent absorption of mercury
through the skin and excretion into
hair. Rather, it represents surface
contamination that presumably takes
place when the subjects are lying on
their hair while sleeping.
Student Interviews
e most consistent data in the
interviews was the reporting of the
whitening of subjects’ skin, and
presence of rashes or other skin
irritations. We chose to ignore pimples
because they are common and some
organic whitening agents are used
professionally to treat pimples. We
also ignored reports of being tired and
having itchy skin which might warrant
specic questions in interviews. e
new XRF is more sensitive and could
produce a more detailed assessment
of dermatitis. e biggest issues
with interviews were inaccurate and
incomplete data entry. ese mistakes
may possibly reect the concentration
of mercury in creams. In one subset (n
= 72) of the best recorded interviews
on use of the 16 creams with detectable
mercury, 87.5% of respondents made
mistakes in the questionnaire form
responses. For those students using
creams without mercury (n = 55),
only 32.7% made mistakes on the
questionnaire form responses. Any
conclusion that this might reect the
eects of mercury toxicity might be
compromised by students quickly
learning from a display that their
cream was toxic and having their
attention disrupted or intentionally
biasing their report.
Discussion
Producers of Me One, Ninatop, UCare,
Rojzy Jiali, Hua u Li, and Qian Mei
appear to have stopped using mercury
in their skin-whitening creams.
Interviews with students using the
ai creams in 2011 indicated that the
creams without mercury still whitened
skin. Likely a less toxic organic
whitening agent had been added
or whitening could have reected
use of one of the following white
colouring agents: titanium dioxide,
zinc oxide, barium oxide and bismuth-
oxychloride which were detected
(> 1,000 μg/g) in 75% of creams.
Evaluation of organic whitening
agents that block melanin production
like hydroquinone, retinoic acid or
betamethasone was not possible in
this study. ere are up to 50 such
organic compounds that can suppress
melanin production to whiten skin
and full resolution is not practical for
developing countries.
Murphy et al
Control
< 18
980
33
Control
< 18
980
33
0
25
1,020
< 18
29
< 18
1,189
< 18
219
< 18
1223
< 18
351
22
6,000
< 18
588
< 18
6,518
54
588
33
6,700
< 18
11,501
< 18
Cream Hg µg/g
Urine Hg µg/L
Cream Hg µg/g
Urine Hg µg/L
Table 3 — Mercury in Skin Creams and Urine of Cream Users
e control samples were urine from non-users of skin creams. A urine sample spiked with 246 µg/L of Hg measured as 219 µg/L of Hg.
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
Mercury was the only metal in our
study that was commonly associated
with dermatitis. One Korean face
cream with 878 μg/g of cadmium
produced dermatitis in three
Cambodian users of this cream.
is cream was purchased in Korea
by a tourist and does not represent
most creams in Cambodia. e main
concern with the bootleg Enjoy
product was the high concentration
of mercury, but strangely two samples
of Enjoy had 500 μg/g of Sb while the
mean content of lead in Enjoy was 32
μg/g, which is 100-fold and ve-fold,
respectively, the Canadian guideline.
e linkage with dermatitis was
not assessed in 2015 as the data set
was too small in 2015. A subset of
individuals will be more sensitive and
such responses cannot be assessed in
small samples. For example, 10-20% of
Americans are reported to be allergic
to nickel. In general we found much
higher levels of metals in creams than
a recent study sponsored by the US
Food and Drug Administration.
Further evaluations of dermatitis
with respect to arsenic are warranted.
Unfortunately, in the larger survey,
the XRF analyser was less sensitive
than the second XRF analyzer and
exceedence of guidelines detected in
the second smaller study of arsenic
was not evaluated with respect
to dermatitis. In 2015, three ai
products (UCare, Ninatop, Me
One) and Qian Mei had arsenic
levels that were twice the arsenic
guidelines, while Rojzy Jiali had
six-fold the arsenic guidelines (Tabl e
2). Furthermore, one sample of
Rojzy Jiali in 2014 had 86-times the
guideline for arsenic. Arsenic can
induce reactive oxygen species (ROS)
and overproduction of ROS within
tissues can damage DNA and promote
cancer.
With respect to ROS generation,
two common major ingredients in
skin creams, zinc oxide and titanium
dioxide, likely have more potential
to induce photo-oxidation than trace
contaminants. Titanium dioxide and
zinc oxide are added to creams to
block ultraviolet (UV) rays by physical
scattering. Some creams in our earlier
analysis contained up to 100,000 μg/g
of zinc and 165,000 μg/g of titanium.
e guidelines in Canada for both
zinc oxide and titanium dioxide are
250,000 μg/g. e European Union
(EU) also allows titanium dioxide at
250,000 μg/g, but currently does not
allow zinc oxide. At times both zinc
oxide and titanium dioxide are also
added without dispersants so that a
whitening eect is achieved (white
coloring, not suppression of melanin
production). Titanium dioxide has
been shown to induce production of
ROS., Similarly, ROS production
has been observed with zinc oxide.
Recently, because of the fear associated
with ROS and cancer, some products
containing titanium dioxide were
voluntarily removed from stores in
California. Cosmetic producers have
used various materials such as silicon
dioxide to coat titanium dioxide, in
part to reduce ROS., However,
it is not clear if titanium dioxide in
South East Asia is modied or if XRF
analysis could detect this dierence.
e production of ROS by titanium
dioxide might have special relevance
to the arsenic zone in Cambodia where
more than 100,000 people are at risk
of arsenic poisoning. e use of
titanium dioxide should be evaluated
with respect to potentially greater risks
in people with added arsenic burden.
e same situation with enhanced
arsenic exposure and skin cream use
exists in Vietnam, Bangladesh, India
and other countries. e poorest
people do not use skin creams, but
some farmers have other jobs and in
farming families with money, women
may use such creams. Even though
in the present study titanium dioxide
was not a strong inducer of dermatitis,
in the long-term it could have the
potential to promote skin cancer in
individuals who already have ROS
production due to arsenic exposure.
Any analysis of titanium dioxide in
cosmetic creams in South East Asia
should start with clarication of the
apparent interference of titanium
dioxide by mercury in XRF analysis,
resolution of the high variability
of titanium in XRF analysis, and
assessment of the preparation of
nanoparticles of titanium oxide.
Current Situation
In 2011, only 15% of Cambodians
interviewed knew what mercury was.
Informal interviews in 2015 suggest
little has changed with regard to
mercury awareness. Moreover, some of
the potential health eects of mercury
remain unresolved. Agusa et al. did not
believe that mercury levels measured
in Cambodian sh could be the source
of the high levels in human hair and
that there was an unknown source of
me rcur y. If Agusa’s hair data reected
skin cream use, their hair data likely
reected surface contamination,
but their blood analyses showing
high levels of mercury must reect
bioaccumulation. e observation of
estrone enhancement associated with
mercury may also indicate a toxic
response, i.e. endocrine disruption.
New problems have also developed.
Sampling via the Internet estimated
that 6% of skin-lightening products
globally contain more than 1,000 μg/g
me rcur y. e ability to purchase
products on the Internet opens up
new opportunities for producers of
toxic skin-whitening creams. e
chances of buying a counterfeit item
on the Internet is high. e situation
in Cambodia is similar to that in
many developing countries in that
counterfeiting of products including
face creams is common. A survey of
870 retail outlets found more than half
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Murphy et al
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
had at least one counterfeited article.
In 2006, 200 boxes of counterfeit Olay
and Dove cosmetics were found in
Indonesia. In 2010, seven tons of
Cambodian-made fake cosmetics were
discovered by the police in Phnom
Penh. In 2014, Interpol raided a
factory in China producing counterfeit
cosmetics with high levels of
me rcur y. Such formal conscations
of counterfeit consumer goods
have become more common, but
counterfeit products are still available.
e potential for such products to
be shipped overseas is high. It is
simple for bootleggers to create new
packaging and is not possible for the
average citizen to detect a bootleg
product. A website from Minnesota,
USA shows “Lemon Herbal” in new
packaging and with 10-times higher
levels of mercury (33,000 μg/g) than
found in the present study: http://
www.health.state.mn.us/topics/skin/.
Bootlegging of cosmetics is thus a
global problem.
Educational Clinic Benets
e students were very keen to learn
about this issue. ey oen came back
with other creams from their family
and friends, clearly demonstrating
that they had discussed what they had
learned with several people. Moreover,
most students took pictures of creams
with mercury to show their friends
and family. With regard to security,
operating in a university environment
provides some isolation from
producers and marketers of creams.
Directly interfering with the cosmetic
business in public markets might
become confrontational. e intent of
the present was to provide education,
not enforcement. In addition, by
processing products bought by
students, we avoided the problem
of vendors recognizing professional
buyers and selling legal products
instead of the counterfeit versions. We
observed such awareness by vendors
on a few occasions. Another benet
to holding the educational clinics at
the Don Bosco institutes was it was
very easy to get repeat interviews
with students for follow-up. In our
limited assessment of factory workers,
it was very dicult to make follow-up
appointments with clients.
Educational Clinic Limitations
ere were several limitations to the
present study. e students needed
greater supervision on their written
interviews. A greater number of sta
or fewer students may have improved
the output. Weak interviews limited
interpretation of mercury exposure.
Another limitation of the present
study involves incomplete sampling of
the population. It is possible women
working in bars, massage shops and
other occupations may be exposed
to additional types of contaminated
products. e present study was also
limited in its ability to detect a number
of potential toxins. Using any face
cream to whiten skin includes risks
from organic chemicals that cannot
be rapidly screened using XRF metal
analysis. In addition, medical and
Murphy et al
Figure 6 — Hair of users of mercury-contaminated face creams
e distal samples are farthest from the skin.
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
laboratory services in Cambodia
need further development. Ideally
the mercury content of urine or
blood would be analyzed shortly aer
collection. At the time of the present
study, rapid analysis was not possible
in Cambodia. e advantages of speed
are to minimize storage problems and
to facilitate data interpretation and
health management.
As has been observed with mercury-
containing soaps in Tanzania, the hair
of users of skin-whitening creams
is directly contaminated by surface
contact of the cream with hair. Hair
analysis is a very attractive technique
in that samples can be easily shipped
overseas. It is more dicult to ship
blood or urine. Cambodia currently
lacks the ability to measure metals in
blood. In part this reects political
barriers and fears associated with HIV.
In theory a few labs could measure
metals in blood and urine, but that
is not currently the case. In general,
laboratories in Cambodia suer from
inadequate facilities, poor training and
inadequate funding. For appropriate
management of other potential
sources of mercury, especially in the
oil and gas industry, gold mining,
and traditional Chinese medicines,
Cambodia needs to improve its
analytical capacity.
Cambodia has signed the
Minamata Convention and is
currently considering ratication
of this agreement (http://www.
mercuryconvention.org/). If it is
ratied, Cambodia will be required
to stop production of contaminated
skin creams by 2020. Furthermore,
the illegal importation of mercury
would be halted. As illustrated by
producers of Hua u Li, Ninatop, Me
One, Qian Mei, Rojzy Jiali and Ucare
skin-whitening creams, it is certainly
possible to adapt manufacturing
processes to avoid mercury. However,
currently, some Cambodian producers
of skin creams still use mercury and
bootleggers continues to produce fake
creams with mercury.
Recommendations
Based on the results of the present
study, we recommend that future
studies include specic questions in
interviews on rashes, colored skin
patches, itchy skin, headaches, and
tiredness and that interviews be closely
overseen. Data from groups that can
be interviewed a second time are
more useful for assessing relationships
between mercury exposure and
mercury bioaccumulation in urine
and blood. Assessments of simple
health indicators, such as hemoglobin/
complete blood count (CBC) analysis
would also be useful. Evaluations
of mercury in skin creams should
be conducted in as many regions of
Cambodia as possible to develop a
national database on mercury use in
skin creams.
In addition, eorts should be made
to provide education on the health
risks of unnaturally whitening skin in
pursuit of an articial social construct
of beauty. A lot of money is spent
on cosmetics and the health risks of
using contaminated products are very
serious.
Conclusions
Although several cream producers
in Asia appear to have removed
mercury from their creams, mercury
remains the metal of greatest concern
in skin creams. Mercury remains a
common problem in bootleg skin
whitening creams and is commonly
added to creams that are produced in
Cambodia. Mercury is the metal most
likely to induce a skin rash, and 27%
of users of creams with high mercury
content (> 1,000 μg/g) reported
developing a rash. Use of XRF
analysis allows for rapid screening
of mercury in cosmetics and enables
decisive police actions that could stop
the import, export and sales of skin
creams containing mercury.
Acknowledgments
Funding was supplied by the World
Bank Research Project on Analysis of
Mercury and other Toxic Compounds
in Skin-Whitening Creams Grant: No.
H607-KH to the University of Health
Sciences, Phnom Penh, Cambodia.
Mrs. Lynn Dudley of the Ministry of
Education provided useful advice on
the World Bank protocols. Ms. eng
Davy, Ms. Chhuon Ratana, Ms. Chin
He Kanika, and Ms. Chhin Sovanndan
of UHS provided assistance in the
laboratory and sample collection. Mr.
David Ford of the Royal University of
Phnom Penh and Dr. Swee Ngin Tan
of Nanyang Technological University
donated chemicals. For the earlier
work, Mr. Stephen Williams and
Mr. Adrian Smith of ermo Fisher
Scientic each loaned handheld X-ray
uorescence analyzers.
References
1. Murphy TP, Lim S, Huong SP, Irvine K, Bayen
S, Kelly B, Wilson K. Application of handheld
x-ray uorescence analyzers to identify mercury in
skin-whitening creams in cambodia. J Health Pollut
[Internet]. 2012 Jun [cited 2015 Nov 17];2(3):21-31.
Available from: http://www.journalhealthpollution.
org/doi/pdf/10.5696/2156-9614-2.3.21
2. Toxicological prole for mercury [Internet].
Atlanta, GA: Agency for Toxic Substances and Disease
Registry; 1999 Mar [cited 2015 Nov 17]. 676 p.
Available from: http://www.atsdr.cdc.gov/toxproles/
tp.asp?id=115&tid=24
3. Soo YO, Chow KM, Lam CW, Lai FM, Szeto
CC, Chan MH, Li PK. A whitened face woman with
nephrotic syndrome. Am J Kidney Dis [Internet]. 2003
Jan [cited 2015 Nov 17];41(1):250-3. Available from:
http://www.sciencedirect.com/science/article/pii/
S0272638603500336 Subscription required to view.
4. Chakera A, Lasserson D, Beck LH Jr, Roberts
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
Murphy et al
Journal of Health & Pollution Vol. 5, No.9 — December 2015
Research
IS, Winearls CG. Membranous nephropathy aer
use of UK-manufactured skin creams containing
mercury. QJM [Internet]. 2011 Oct [cited 2015 Nov
17];104(10):893-6. Available from: http://qjmed.
oxfordjournals.org/content/104/10/893.long
5. Weldon MM, Smolinski MS, Marou A, Hasty
BW, Gilliss DL, Boulanger LL, Balluz LS, Dutton RJ.
Mercury poisoning associated with a Mexican beauty
cream. West J Med [Internet]. 2000 Jul [cited 2015 Nov
17];173(1):15-8. Available from: http://www.ncbi.nlm.
nih.gov/pmc/articles/PMC1070961/
6. Olumide YM, Akinkugbe AO, Altraide
D, Mohammed T, Ahamefule N, Ayanlowo S,
Onyekonwu C, Essen N. Complications of chronic use
of skin lightening cosmetics. Int J Dermatol [Internet].
2008 Apr [cited 2015 Nov 17];47(4):344-53. Available
from: http://onlinelibrary.wiley.com/doi/10.1111/
j.1365-4632.2008.02719.x/abstract Subscription
required to view.
7. Risher JF, Rosa CT. Inorganic: the other mercury.
J Environ Health [Internet]. 2007 Nov [cited 2015 Nov
17];70(4):9-16. Available from: http://connection.
ebscohost.com/c/articles/27366168/inorganic-other-
mercury Subscription required to view.
8. Chan TY. Inorganic mercury poisoning
associated with skin-lightening cosmetic products.
Clin Toxicol (Phila) [Internet]. 2011 Dec [cited 2015
Nov 17];49(10):886-91. Available from: http://www.
tandfonline.com/doi/abs/10.3109/15563650.2011.626
425?journalCode=ictx20#.VksuJoRH1E4 Subscription
required to view.
9. Tang HL, Mak YF, Chu KH, Lee W, Fung
KS, Chan HW, Tong KL. Minimal change disease
following exposure to mercury-containing skin
lightening cream: A report of 4 cases. Clin Nephrol
[Internet]. 2013 Apr [cited 2015 Nov 17];79(4):326-
9. Available from: http://www.dustri.com/index.
php?id=98&artId=9577 Subscription required to view.
10. Mercury exposure among household users and
nonusers of skin-lightening creams produced in
Mexico — California and Virginia, 2010. Morbidity
Mortal Wkly Rep [Internet]. 2012 Jan 20 [cited 2015
Nov 17];61(2):33-6. Available from: http://www.cdc.
gov/mmwr/preview/mmwrhtml/mm6102a3.htm
11. Mercury in skin lightening products [Internet].
Geneva, Switzerland: World Health Organization;
2011 [cited 2015 Nov 17]. 6 p. Available from:
http://www.who.int/ipcs/assessment/public_health/
mercury_yer.pdf
12. McKelvey W, Jeery N, Clark N, Kass D,
Parsons PJ. Population-based inorganic mercury
biomonitoring and the identication of skin care
products as a source of exposure in New York City.
Environ Health Perspect [Internet]. 2011 Feb [cited
2015 Nov 17];119(2):203-9. Available from: http://
www.ncbi.nlm.nih.gov/pmc/articles/PMC3040607/
13. Fact sheet: mercury in skin lightening
cosmetics [Internet]. Montpelier, VT: Mercury
Policy Project; 2012 Jun [cited 2015 Nov 17]. 4 p.
Available from:http://mercurypolicy.org/wp-content/
uploads/2010/06/skincreamhgfactsheet_may31_nal.
pdf
14. Hamann CR, Boonchai W, Wen L, Sakanashi
EN, Chu CY, Hamann K, Hamann CP, Sinniah
K, Hamann D. Spectrometric analysis of mercury
content in 549 skin-lightening products: is mercury
toxicity a hidden global health hazard? J Am Acad
Dermatol [Internet]. 2014 Feb [cited 2015 Nov
17];70(2):281-7. Available from: http://www.jaad.org/
article/S0190-9622(13)01046-3/abstract Subscription
required to view.
15. Murphy T, Slotton D, Irvine K, Sukontason K,
Goldman C. Mercury contamination of skin whiteners
in Cambodia. Hum Ecol Risk Assess [Internet].
2009 Nov 6 [cited 2015 Nov 17];15(6):1286- 303.
Available from: http://www.tandfonline.com/ doi/
abs/10.1080/10807030903306877 Subscription
required to view.
16. Murphy T. Standard operating procedure for
XRF screening of mercury in skin creams [Internet].
Phnom Penh, Cambodia: University of Health Science;
2015 Jun 15 [cited 2015 Nov 17]. 15 p. Available from:
https://www.researchgate.net/publication/278244672_
Standard_Operating_Procedure_for_XRF_Screening_
of_Mercury_in_Skin_Creams
17. Lim S, Irvine K, Murphy TP, Wilson K.
Sediment-associated metals levels along the sewer-
natural treatment wetland continuum, Phnom Penh,
Cambodia. Urban Water J [Internet]. 2015 May 21
[cited 2015 Nov 17];2015:1-12. Available from: http://
www.researchgate.net/publication/277969504_
Sediment-associated_metals_levels_along_the_sewer-
natural_treatment_wetland_continuum_Phnom_
Penh_Cambodia
18. Lowr y R. e signicance of the dierence
between two independent proportions [Internet].
Poughkeepsie, NY: Vassar College; 2001 [updated
2015; cited 2015 Nov 17]. Available from: http://
vassarstats.net/propdi_ind.html
19. Piorek S. Feasibility of analysis and screening
of plastics for heavy metals with portable X-ray
uorescence analyzer with miniature X-ray tube
[Internet]. Billerica, MA: GPEC; 2004 [cited 2015
Nov 18] Available from: http://mie.esab.upc.es/ms/
informacio/miscellanea/Heavy%20metals%20in%20
plastics.pdf
20. ermo sher scientic niton analyzers XL3
analyzer version 8.0.0 user’s guide: abridged revision
A. Springeld Township, NJ: ermo Fisher Scientic;
2011 Nov. 254 p.
21. Be TY. Asia-Pacic update: ASEAN mirrors EU
regulation [Internet]. Carol Stream, IL: Cosmetics
& Toiletries; 2014 Aug 27 [cited 2015 Nov 18].
[about 3 screens]. Available from: http://www.
cosmeticsandtoiletries.com/regulatory/region/
asia/Asia-Pacic-Update-ASEAN-Mirrors-EU-
Regulation-272730691.html
22. Module 2: basic XRF concepts [Internet].
Wasington D.C.: United States Environmental
Protection Agency; 2008 Aug [cited 2015 Nov 18].
44 p. Available from: http://www.clu-in.org/conf/tio/
xrf_080408/prez/XRF_02pdf.pdf
23. Maslennikov VV. Geodynamic conditions for
formation of mercury, antimony and tin deposits.
Int Geol Rev [Internet]. 1989 [cited 2015 Nov
18];31(9):931-41. Available from: http://www.
tandfonline.com/doi/abs/10.1080/00206818909465946
?journalCode=tigr20 Subscription required to view.
24. Guidance on heavy metal impurities in cosmetics
[Internet]. Ottawa, Canada: Health Canada; 2012
[cited 2015 Nov 18]. 7 p. Available from: http://
www.hc-sc.gc.ca/cps-spc/pubs/indust/heavy_metals-
metaux_lourds/index-eng.php
25. Leighton J. DOHMH health alert #3: mercury
poisoning case linked to use of “skin- lightening”
cream [Internet]. New York, NY: New York County
Medical Society; 2005 Jan 27 [cited 2015 Nov 18].
[about 3 screens]. Available from: http://www.nycms.
org/article_view.php3?view=1102&part=1
26. Agusa T, Kunito T, Iwata H, Monirith I,
Chamnan C, Tana TS, Subramanian A, Tanabe S.
Mercury in hair and blood from residents of Phnom
Penh (Cambodia) and possible eect on serum
hormone levels. Chemosphere [Internet]. 2007 Jun
[cited 2015 Nov 18];68(3):590-6. Available from:
http://www.sciencedirect.com/science/article/pii/
S0045653507000185 Subscription required to view.
27. Nuttall KL. Interpreting hair mercury levels in
individual patients. Ann Clin Lab Sci [Internet]. 2006
Summer [cited 2015 Nov 18];36(3):248-61. Available
from: http://www.annclinlabsci.org/content/36/3/248.
full.pdf+html
28. Toxicological prole for nickel [Internet].
Atlanta, Georgia: Agency for Toxic Substances and
Disease Registry; 2005 Aug [cited 2015 Nov 18]. 397
p. Available at: http://www.atsdr.cdc.gov/toxproles/
Murphy et al
Journal of Health & Pollution Vol. 5, No. 9 — December 2015
Research
tp15.pdf
29. Hepp NH, Mindak WR, Gasper JW, ompson
CB, Barrows JN. 2014. Survey of cosmetics for
arsenic, cadmium, chromium, cobalt, lead, mercury,
and nickel content. J Cosmet Sci [Internet]. 2014 May-
Jun [cited 2015 Nov 18];65(3):125-45. Available from:
http://www.researchgate.net/publication/264091887_
Survey_of_cosmetics_for_arsenic_cadmium_
chromium_cobalt_lead_mercury_and_nickel_content
30. Flora SJ, Bhadauria S, Kannan G, Singh
N. Arsenic induced oxidative stress and role of
antioxidant supplementation during chelation: a
review. J Environ Biol [Internet]. 2007 Apr [cited 2015
Nov 18];28(2 Suppl):333-47. Available from: https://
www.researchgate.net/publication/5914958_Arsenic_
induced_oxidative_stress_and_role_of_antioxidant_
supplementation_during_chelation_A_Review
31. Sunscreen monograph [Internet]. Vancouver,
Canada: Health Canada; 2013 Jul 7 [cited 2015 Nov
18]. 15 p. Available from: http://webprod.hc-sc.gc.ca/
nhpid-bdipsn/atReq.do?atid=sunscreen-ecransolaire&
32. CosIng [Internet]. Brussels, Belgium: European
Commission. 1976 - [cited 2015 Nov 18]. Available
from: http://ec.europa.eu/growth/tools-databases/
cosing/index.cfm?fuseaction=search.simple
33. Tiano L, Armeni T, Venditti E, Barucca G,
Mincarelli L, Damiani E. Modied TiO(2) particles
dierentially aect human skin broblasts exposed to
UVA light. Free Radic Biol Med [Internet]. 2010 Aug
1 [cited 2015 Nov 18];49(3):408-15. Available from:
http://www.researchgate.net/publication/44581146_
Modied_TiO%282%29_particles_dierentially_
aect_human_skin_broblasts_exposed_to_UVA_
light
34. Shukla RK, Sharma V, Pande y AK, Singh S,
Sultana S, Dhawan A. ROS-mediated genotoxicity
induced by titanium dioxide nanoparticles in human
epidermal cells. Toxicol In Vitro [Internet]. 2011 Feb
[cited 2015 Nov 18];25(1):231-41. Available from:
http://www.sciencedirect.com/science/article/pii/
S0887233310003000 Subscription required to view.
35. Sharma V, Singh SK, Anderson D, Tobin
DJ, Dhawan A. Zinc oxide nanoparticle induced
genotoxicity in primary human epidermal
keratinocytes. J Nanosci Nanotechnol [Internet]. 2011
May [cited 2015 Nov 18];11(5):3782-8. Available from:
http://www.researchgate.net/publication/51512769_
Zinc_Oxide_Nanoparticle_Induced_Genotoxicity_in_
Primary_Human_Epidermal_Keratinocytes
36. Whitehouse L. Brands agree to pull titanium
dioxide amid calls for ‘more study’ [Internet].
Montpellier, France: Cosmetics Design; 2014 Jun 5
[cited 2015 Nov 18]. [about 3 screens]. Available from:
http://www.cosmeticsdesign.com/Regulation-Safety/
Brands-agree-to-pull-titanium-dioxide-amid-calls-
for-more-study
37. Burnett M, Wang SQ. Current sunscreen
controversies: a critical review. Photodermatol
Photoimmunol Photomed [Internet]. 2011 Apr
[cited 2015 Nov 18];27(2):58-67. Available from:
http://onlinelibrary.wiley.com/doi/10.1111/j.1600-
0781.2011.00557.x/epdf
38. Strobel C, Torrano AA, Herrmann R, Malissek
M, Brauchle C, Reller A, Treuel L, Hilger I. Eects
of the physicochemical properties of titanium
dioxide nanoparticles, commonly used as sun
protection agents, on microvascular endothelial cells.
J Nanopart Res [Internet]. 2014 Jan [cited 2015 Nov
18];16(1):2130-46. Available from: http://link.springer.
com/article/10.1007/s11051-013-2130-3
39. Sampson ML, Bostick B, Chiew H, Hagan JM,
Shantz A. Arsenicosis in Cambodia: case studies and
policy response. Appl Geochem [Internet]. 2008 Nov
[cited 2015 Nov 18]; 23(11):2977–86. Available from:
http://www.sciencedirect.com/science/article/pii/
S0883292708002333 Subscription required to view.
40. Survey of counterfeits in Cambodia [Internet].
Phnom Penh, Cambodia: BNG Legal; 2010 Jul [cited
2015 Nov 18]. 4 p. Available from: http://bnglegal.
com/sys-content/uploads/2013/04/Survey-of-
Counterfeits-in-Cambodia.pdf
41. Bender M. Mercury in cosmetics [Internet]. Paper
presented at: UNEP Mercury Products Meeting. 2007
May 18 [cited 2015 Nov 18]; Bangkok, ailand.
Available from: http://slideplayer.com/slide/4514647/
42. Soenthrith S. Seven tons of Cambodian-made
fake cosmetics uncovered [Internet]. Phnom Penh,
Cambodia: Cambodia Daily; 2010 Oct 10 [cited 2015
Nov 18]. [about 3 screens]. Available from: http://
www.cambodiadaily.com/stories-of-the-month/
seven-tons-of-cambodian-made-fake-cosmetics-
uncovered-358/
43. Nearly 700 held or probed in major Asia
counterfeit sweep [Internet]. Sunnyvale, California:
Yahoo News; 2014 Sep 22 [cited 2015 Sep 28]. [about
2 screens]. Available from: http://news.yahoo.com/
nearly-700-held-probed-major-asia-counterfeit-
sweep-231108969--nance.html
44. Harada M, Nakachi S, Cheu T, Hamada H,
Ono Y, Tsuda T, Yanagida K, Kizaki T, Ohno H.
Monitoring of mercury pollution in Tanzania:
relation between head hair mercury and health.
Sci Total Environ [Internet]. 1999 Mar 9 [cited
2015 Nov 18];227(2-3):249-56. Available from:
http://www.sciencedirect.com/science/article/pii/
S0048969799000315 Subscription required to view.
Murphy et al
Mercury Contamination of Skin-whitening Creams in Phnom Penh, Cambodia
