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Journal of Environmental Monitoring (JEM) issue 12, 2008, is focusing on the areas of Medical Geology &
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Medical Geology has seen immense growth and maturation allowing biomedical/health professionals and geoscientists to take strong
root in the international arena. The journal anticipates publishing many articles in this eld. The rst two reviews, included in this issue,
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The utility of mosquito-borne disease as an environmental monitoring tool in tropical ecosystems
Andrew Jardine, Angus Cook and Philip Weinstein
10th Anniversary Critical Review: Naturally occurring asbestos
Martin Harper
Air- and Biomonitoring
features six selected papers on exposure monitoring within the preventive framework of identifying
and controlling health hazards within the workplace and in the environment presented at AIRMON 2008, held at Geilo,
Norway, January 28-31, 2008.
Highlighted papers:
Three dimensional modeling of air ow, aerosol distribution and aerosol samplers for unsteady conditions
Albert Gilmutdinov and Ilya Zivilskii
Experimental methods to determine inhalability and personal sampler performance for aerosols in ultra-low
windspeed environments
Darrah K. Schmees, Yi-Hsuan Wu and James H. Vincent
A study of the bio-accessibility of welding fumes
Balázs Berlinger, Dag G. Ellingsen, Miklós Náray, Gyula Záray and Yngvar Thomassen
ISSN 1464-0325
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Cutting-Edge Research on Environmental Processes & Impacts
Volume 10 | Number 12 | December 2008 | Pages 000–000
Journal of
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Monitoring
10th Anniversary Review
Janice Lough
A changing climate for coral reefs
Editorial
Richard Pike
The way forward
Celebrating
10 years
1464-0325(2008)10:1;1-C
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Journal of
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www.rsc.org/jem Volume 11 | Number 3 | March 2009 | Pages 449–692
Cover
Röllin et al.
Toxic metals in maternal & cord blood
Hot Article
Button et al.
Toenails as arsenic biomarkers
Levels of toxic and essential metals in maternal and umbilical cord blood
from selected areas of South Africa—results of a pilot study†
Halina B. R
€
ollin,
*
abc
Cibele V. C. Rudge,
de
Yngvar Thomassen,
f
Angela Mathee
ac
and Jon Ø. Odland
dg
Received 16th September 2008, Accepted 9th January 2009
First published as an Advance Article on the web 12th February 2009
DOI: 10.1039/b816236k
This pilot study uses concentrations of metals in maternal and cord blood at delivery, in seven selected
geographical areas of South Africa, to determine prenatal environmental exposure to toxic metals.
Samples of maternal and cord whole blood were analysed for levels of cadmium, mercury, lead,
manganese, cobalt, copper, zinc, arsenic and selenium. Levels of some measured metals differed by site,
indicating different environmental pollution levels in the regions selected for the study. Mercury levels
were elevated in two coastal populations studied (Atlantic and Indian Ocean sites) with mothers from
the Atlantic site having the highest median concentration of 1.78 mg/L ranging from 0.44 to 8.82 mg/L,
which was found to be highly significant (p < 0.001) when compared to other sites, except the Indian
Ocean site. The highest concentration of cadmium was measured in maternal blood from the Atlantic
site with a median value of 0.25 mg/L (range 0.05–0.89 mg/L), and statistical significance of p < 0.032,
when compared to all other sites studied, and p < 0.001 and p < 0.004 when compared to rural and
industrial sites respectively, confounding factor for elevated cadmium levels was found to be cigarette
smoking. Levels of lead were highest in the urban site, with a median value of 32.9 mg/L (range 16–81.5
mg/L), and statistically significant when compared with other sites (p < 0.003). Levels of selenium were
highest in the Atlantic site reaching statistical significance (p < 0.001). All analysed metals were detected
in umbilical cord blood samples and differed between sites, with mercury being highest in the Atlantic
site (p < 0.001), lead being highest in the urban site (p < 0.004) and selenium in the Atlantic site (p <
0.001). To the best of our knowledge this pilot investigation is the first study performed in South Africa
that measured multiple metals in delivering mothers and umbilical cord blood samples. These results
will inform the selection of the geographical sites requiring further investigation in the main study.
Introduction
Human exposure to persistent toxic substances (PTS) in the
living environment, which include toxic metals and persistent
organic pollutants, can be from natural sources, anthropogenic
from current or past industrial activities, and from living activ-
ities of the population. PTS have the ability to exert negative
health effects that are often subtle, long-term, sometimes trans-
generational and difficult to measure, even in epidemiological
studies in large populations. Furthermore, the most vulnerable
periods for toxic impact of pollutants on human development are
the embryonic and foetal stages, followed by early childhood;
most PTS are known to affect reproductive health and pregnancy
outcomes, reduce disease defense mechanisms, impact on
children’s physical and mental development, and increase the
risk of cancer.
1–3
Several multidisciplinary international projects are currently
investigating firstly, the sources and levels of PTS in people
residing in different geographical regions and secondly, ascer-
taining the relationship between the levels of these compounds
and health. For example, the Arctic Monitoring and Assessment
Programme (AMAP) initiated in 1991 measured levels of
multiple contaminants and studied possible health effects and
birth outcomes of these in the indigenous and other populations
living in the Arctic and other areas of the Northern Hemi-
sphere.
4–6
Studies in Canada found elevated levels of methyl
mercury not only in indigenous Dene and Inuit populations, but
also in the general population residing in other areas of Canada.
7
Elevated levels of organochlorines and metals were also detected
in human fluids such as breast milk, in populations residing in
different areas within the polar region.
8–12
At present no comprehensive data exist on the levels of
contaminants in ecosystems and populations in the Southern
Hemisphere. To date, in South Africa, research linking envi-
ronmental exposures to human health outcomes in the general
population has been scarce. A number of South African studies
used animals as bio-indicators for environmental contamination;
examples are vanadium levels in cattle, cadmium levels in
terrestrial isopod (Porcellio laevis) and in the river crab, or the
arsenic resistance in species of multi-host ticks.
13–15
a
South African Medical Research Council, PO Box 87373, Houghton,
2041, South Africa. E-mail: hrollin@mrc.ac.za; Fax: +27 11 642 6832;
Tel: +27 11 274 6064
b
University of Pretoria, South Africa
c
University of the Witwatersrand, Johannesburg, South Africa
d
University of Tromsø, Tromsø, Norway
e
Sa˜o Paulo State University, Botucatu, Brazil
f
National Institute for Occupational Health, Oslo, Norway
g
University of Aarhus, Denmark
† Part of this study was presented at the Symposium held at the 19th
Conference of the International Society for Environmental
Epidemiology, ISEE 2007 in Mexico City, Mexico, 5–9 September 2007.
618 | J. Environ. Monit., 2009, 11, 618–627 This journal is ª The Royal Society of Chemistry 2009
PAPER www.rsc.org/jem | Journal of Environmental Monitoring
A limited number of community based studies performed in
South Africa indicate elevated environmental levels of metals
that may have detrimental effects on public health. For example,
environmental mercury pollution, fish contamination and health
problems in the community residing in the vicinity of a non
operational mercury processing plant have been reported.
16
Due
to the pervasive lead contamination in the country, a high
percentage of children residing in inner cities and informal
settlements, as well as peri-urban and rural areas, was found to
have unacceptably high blood lead levels.
17–20
Elevated levels of
blood manganese have been found in school children in some
areas of South Africa.
21,22
Although a number of South African studies report on expo-
sure to metals and possible health effects in occupationally
exposed subjects, little is known about exposures of the
communities residing in the vicinity of such operations.
23,24
South Africa, the southernmost part of Africa in the Southern
Hemisphere, and being both a developed and a developing
country, is of particular importance to the global research in the
science of environmental pollutants and human health outcomes.
Firstly, South Africa is rich in mineral deposits and econom-
ically important metals such as lead, manganese, platinum,
chromium, vanadium and gold, are being mined extensively. The
country is also a major producer of other metals such as
aluminium, zinc and copper, from enriched deposits; thus the
potential exists for emission of these metals into the environ-
ment. Though industries are constantly upgrading production
technologies to meet global standards and to comply with envi-
ronmental regulations, the use of outdated technologies in the
past may have contributed to toxic metal contamination around
certain industrial sites, particularly mining and smelting. South
Africa is also experiencing a rise in informal mining (especially
artisanal gold mining) and other uncontrolled informal indus-
trial activities that often take place within the living environ-
ments of the communities.
25
Secondly, increased population
migration and rapid urbanization, with its wide range of
anthropogenic activities, may further contribute to environ-
mental degradation and pollution. A high prevalence of infec-
tious diseases (lung diseases, TB, HIV/AIDS) and endemic
malaria present in parts of the country make South African and
other populations living in the developing countries of the
Southern Hemisphere more susceptible to the toxic effects of
pollutants in the living environment.
Within this context and in response to the lack of comprehen-
sive data on levels of PTS in populations residing in South Africa,
a pilot project was designed and carried out under the auspices of
AMAP, by the South African Medical Research Council and the
University of Tromsø, Norway during 2005–2006.
Although both metals and organic persistent pollutants were
measured in maternal and cord bloods in the pilot phase of the
study, this paper reports on the metal results only. The results for
the concurrently measured organic pollutants (polychlorinated
biphenyl congeners (PCBs), pesticides and their metabolites, and
perflourinated compounds) will be reported separately.
The present paper reports on the levels of cadmium (Cd),
mercury (Hg), lead (Pb), manganese (Mn), cobalt (Co), copper
(Cu), zinc (Zn), arsenic (As) and selenium (Se) found in maternal
and umbilical cord bloods drawn from random samples of deliv-
ering women in seven selected regions of South Africa that differ in
their degree of environmental pollution. Other parameters repor-
ted include socioeconomic factors of participants, self reported
health status, life style, diet and birth outcomes. The manuscript
that will assess in detail the placental permeability for metals
measured in paired maternal-cord blood samples is in preparation.
Materials and methods
Selection of study sites
All seven study sites were purposely selected to include a range of
different communities: rural, urban, industrial, fishing (situated
on the Atlantic Ocean), mining, coastal endemic malaria (situ-
ated on the Indian Ocean) and inland endemic malaria. Selected
sites differed in the type of environmental pollution and all had
a provincial delivery hospital serving the particular community.
The rural site is situated close to the Botswana border where no
agricultural and industrial activities take place with no major
roads or traffic in the area. The urban site is the large city of
Johannesburg with extensive gold mining and other industrial
activities in and surrounding areas and heavy traffic. The
industrial site selected is a coal mining and stainless steel
producing small town. The fishing site in the Western Cape is
situated on the Atlantic Ocean is known for its fishing and fish
processing industry. The mining site is a small town where
extensive gold mining takes place. The coastal village on the
Indian Ocean is only 8 km away from the Mozambique border
and in the vicinity of the world heritage site of Kosi Bay, where
only subsistence fishing is allowed. The inland site is a small town
with very little industrial activity that is about 70 km away from
the Indian Ocean coastal site, but also malaria endemic. The
choice of two malaria endemic sites was necessary for the
investigation on persistent organic pollutants which are also part
of this project. Fig. 1 shows the geographical location of each
study site within South Africa.
Recruitment of participants and informed consent
Ethics clearance certificate Protocol Number M040314 for the
study was granted by the Committee for Research on Human
Subjects of the University of the Witwatersrand, Johannesburg,
South Africa. In addition, informed written consent was obtained
from each participant prior to commencement of the study.
Potential participants were recruited from women who pre-
sented for delivery at the hospital. Recruitment was done by the
health worker on duty and trained research assistant who briefly
explained the objectives of the study and distributed a detailed
information sheet about the project, written in simple language.
About 95% of potential participants approached agreed to
participate. Women who volunteered to participate signed an
informed consent form and agreed to donate blood and urine
samples before delivery and cord blood samples post-partum and
they agreed to answer a socioeconomic questionnaire by inter-
view in the language of their choice and to grant the research
team access to hospital records, post-partum.
Data collection
A socioeconomic questionnaire that also included dietary, life
style and self reported health status questions was administered
This journal is ª The Royal Society of Chemistry 2009 J. Environ. Monit., 2009, 11, 618–627 | 619
by trained research assistants in English or in a language of the
participants’ choice. After delivery, the researchers extracted
records from patient hospital files that included date of delivery,
weight and length of the baby, head circumference, Naegele
term, Apgar score, gestational age, as well as noting any
congenital malformations and birth complications as per
comments of doctor or sister present at delivery.
Sampling procedures
For each mother, 30 ml of blood was drawn by venous puncture
into 3 Vacutainer tubes before delivery, and umbilical cord
blood was collected after delivery by a nursing sister, using the
sterile Vacutainer disposable system. Metal-free vessels were
used throughout and great care was taken to prevent contami-
nation of samples during collection and fractionation. All
samples were stored at 20
C and shipped in a frozen state to
the University of Tromsø, Norway, from where samples were
transferred in a frozen state to the analytical laboratories.
Measurements of metal content in whole blood were performed
by the National Institute for Occupational Health (NIOH),
Oslo, Norway.
Analytical methods
Samples of maternal and cord whole blood were analysed for
levels of Cd, Hg, Pb, Mn, Co, Cu, Zn, As and Se. Mn, Cu, Zn and
Se are considered to be essential metals, but are known to be
toxic at elevated levels. Chemical analyses were performed using
the inductively coupled plasma-mass spectrometry (ICP-MS)
technique. The required contamination elimination procedures
and validation of results by using certified standards were applied
throughout the analyses.
Sample preparation
For the measurements of elements in whole blood, 1.5 mL of 65%
ultrapure nitric acid (Chemscan Ltd., Elverum, Norway) was
added to 1 mL of whole blood in a polypropylene digestion tube.
The mixture was digested by heating the tube at 95
C for 1 hour.
The acid homogenization procedure using nitric acid was per-
formed in covered tubes at ambient pressure, and is a well
accepted and verified procedure for whole blood, with no losses
of e.g. Se or Hg. These procedures have been carefully studied
and are used extensively at NIOH, as well as by many other
international laboratories.
Fig. 1 Geographical positions of study sites within South Africa. Legend: Site 1 ¼ Rural; Site 2 ¼ Urban; Site 3 ¼ Industrial; Site 4 ¼ Atlantic Ocean;
Site 5 ¼ Mining; Site 6 ¼ Indian Ocean; Site 7 ¼ Inland malaria.
620 | J. Environ. Monit., 2009, 11, 618–627 This journal is ª The Royal Society of Chemistry 2009
The digest was cooled to room temperature and 200 mLofan
internal standard solution containing
72
Ge for
75
As and
77,78,82
Se,
115
In for
114
Cd,
204
Tl for
206,207,208
Pb and
200,201,202
Hg,
60
Ni for
55
Mn,
59
Co,
63,65
Cu and
64,66,68
Zn was added and diluted to a final volume
of 10 mL with ultrapure water.
Instrumental measurements
The digested blood was analysed by using an Element 2 mass
spectrometer (Thermo Electron, Bremen, Germany) calibrated
with the whole blood matched standard solutions. The instru-
ment was programmed to determine Cd by use of the
114
Cd
+
ion
with automatic mass correction caused by the
114
Sn
+
ionic
interference. Since the molybdenum (Mo) concentration in whole
blood is around 1ng/mL or lower, any mass interference at
114
Cd
+
from the
98
Mo
16
O
+
was not considered to contribute to the
overall signal. The following mass resolutions were used; low for
Cd, Hg, Pb, medium for Mn, Cu, Zn and high for As and Se. The
detection limits (three times standard deviation of all blank
samples) for metals in whole blood were as follows: As: 0.09 mg/
L, Cd: 0.01 mg/L, Co: 0.07 mg/L, Cu: 1 mg/L, Hg: 0,1 mg/L, Mn:
0.3 mg/L, Pb: 0.1 mg/L, Se: 1 mg/L, Zn: 20 mg/L. One aliquot of
each blood sample was analysed in triplicate. Seronorm Trace
Elements (Sero Ltd., Billingstad, Norway) human whole blood
quality control materials were used for quality assurance of all
element measurements; after every ten blood samples analysed,
a quality control sample at two different concentration levels was
also analysed.
The NIOH laboratory participates in the Wadsworth Center-
New York State Department of Health Proficiency (USA) trace
element testing schemes for whole blood and urine, with
consistently acceptable results and no indication of any system-
atic biases.
Statistical analysis
Statistical analyses were conducted using the statistical STATA
package, version 10 (Stata10 2007).
26
Descriptive statistics were calculated for metals, including
median, first and third quartiles. Comparisons between different
sites were made using Kruskal Wallis test and Dunn test for
multiple comparisons. A p value of less than 0.05 indicated
a significant difference.
Results
The pilot study took place in seven selected sites during 2005–
2006, and the analytical work was completed by mid 2007. In the
tables that follow, study sites are referred to according to their
characteristics and presented in a particular order: rural, urban,
industrial, Atlantic Ocean, mining, Indian Ocean malaria and
inland malaria. In total, 96 women participated in the pilot
study, 12 women each at five sites, with 20 and 16 women at rural
and urban sites respectively.
Socioeconomic and housing characteristics
Socioeconomic and housing characteristics for participants at
each site are summarized in Table 1 and Table 2. Questionnaire
data confirmed a similar socioeconomic status of participants at
Table 1 Socioeconomic characteristics of participants by site
Statistics
Rural Urban Industrial Atlantic Ocean Mining Indian Ocean malaria Inland malaria
N ¼ 20 N ¼ 16 N ¼ 12 N ¼ 12 N ¼ 12 N ¼ 12 N ¼ 12
Population group %
B ¼ African Black, C ¼ Coloured, W ¼ White B 100 B 94, C 6 B 92, W 8 B 27, C 73 B 100 B 100 B 100
Marital status (%)
M ¼ married, S ¼ single L/T ¼ living together,
D ¼ divorced
M 25, S 75 M 29, S 17, L/T 54 M 9, S 75, L/T 16 M 20, S 40, L/T 30, D 10 M 20, S 40, L/T 40 S 100 S 100
Home language (%)
E ¼ English, S ¼ Sotho, Z ¼ Zulu, X ¼ Xosa,
A ¼ Afrikaans, T ¼ Tswane, O ¼ Other
S 50, T 50 E 27, X 7, S 7 E 11, Z 67, O ¼ 23 E 18, A 55, X27 S 90, Z 10 Z 100 Z 100
Educational status (mean years)
W ¼ women, P ¼ partner/husband W 9.6, P 7.5 W 11.4, P 11 W 10.5, P 11.7 W 9.6, P 10.8 W 8.5, P 10 W 8.3, P 11.3 W 9.8, P 9.6
Mean monthly income
Rand (1US$ ¼ 7.2 R) 943 (445) 4166 (4440) No data 3286 (2276) 2250(1838) No data 968 (547)
Number of persons (%) employed per
household
1 (55%),
2 (27%), 3 (9%)
1 (54%),
2 (38%), 3 (7%)
1 (78%),
2 (22%), 3 (9%)
1 (28%),
2 (57%), 4 (14%)
1 (85%),
3 (14%)
1 (33%),
2 (67%)
1 (100%)
This journal is ª The Royal Society of Chemistry 2009 J. Environ. Monit., 2009, 11, 618–627 | 621
