Conserving Our Coastal Environment
I. Endocrine Disruptor Pollution in Asia and the Pacific
II. Coastal Management and Sustainable Development
III. Marine Ecology and Environment
8-10 July 2002, Field Excursion: 11-13 July 2002
Status and results of EDC
Monitoring in Malaysia
Mustafa
A.M. Department of Pharmacology, Faculty of Medicine, University of Malaya
For a long time now,
awareness has been growing about the threats posed to human health and the
global environment by the ever-increasing release of synthesized chemicals.
Mounting evidence of damage to human health and the environment has focused the
attention of many developed and underdeveloped countries on several classes of
compounds, which include a group of compounds classed as endocrine disruptors or
EDCs. Most pesticides, PCB, dioxins, phytoestrogens, phthalates and alkylphenols
are endocrine-disrupting chemicals (EDCs), causing biological effects, with
modes of action mimicking that of the female hormone, estrogen.
In Malaysia, monitoring
of EDCs has been actively going on for many years, especially for the
agricultural chemicals or pesticides group. Recently, more specific monitoring
of EDCs is becoming increasingly important and has been given special attention.
The new approach by the Ministry of Health in conducting surveys and monitoring
of EDC chemicals leaching from domestic materials and utensils has opened
avenues for researchers and other government agencies to embark on similar
activities. Some of the chemicals recently incorporated into these activities
are phthalates, bisphenol A , nonylphenols,dioxins, pesticides and
phytoestrogens.
Some of the matrix or
materials used for these monitoring activities include population blood samples,
drinking water, bottled drinks, babies feeding bottles, food containers, fatty
food, rice, plastic containers and packing materials, sweets and candies and
various others.
In this presentation,
discussions will be based on some of these screening and monitoring results.
Seven pesticides and eight alkylphenols were monitored in human plasma using the
GCMS method. The pesticides are lindane, diazinon, a-endosulfan, b-endosulfan,
endosulfan sulfate, chlorpyrifos and endrin; while the alkylphenols are
4-n-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol, 4-t-octylphenol,
4-n-heptylphenol, nonylphenol, 4-n-octylphenol and bisphenol A. 130 babies'
bottles, including both new and old bottles, were collected to test for the
leaching of bisphenol A in water at 30°C and 80°C. Bisphenol A was extracted
using a liquid-liquid extraction and analyzed with a GCMS. This study revealed
that more bisphenol A leached from used or old babies' bottles compared to the
new babies' bottles. EDCs found in the cord blood ranged from trace levels to
15.17ng/ml.
A nationwide assessment
of phytoestrogens levels in cord blood was also started. A total of 250 samples
of cord blood were sampled to assay for phytoestrogens, diadzein and genistein,
in the population. As Malaysia is not a soya consuming country, in contrast to
Japan, the baseline level of phytoestrogens were not expected to be high.
577 schoolchildren in 60
schools throughout Peninsular Malaysia were investigated for pesticide residues
levels in a cross-sectional study. The results of this monitoring survey
revealed the following range of concentrations of pesticide residues in blood (ng
per gram): aldrin, nd-47.6; dieldrin, nd; endrin, nd; alpha-endosulfan, nd-0.6;
beta-endosulfan, nd; endosulfan sulfate, nd; heptachlor, nd-3.8; lindane, nd-5.7;
p,p'-DDT, nd-3.4; o,p'-DDE, nd-1.4; p,p'-DDE, nd; chlorpyrifos, nd-10.3;
diazinon, nd-103.0. There was a statistically significant relationship between
the contaminated children and ethnic as well as site distribution. The results
of this study underline the importance for government and public health
authorities to evaluate the magnitude of exposure to environmental contaminants
in humans in the future. There is also a need to evaluate the possible means of
contamination and sources as some of the detected pesticides were banned or not
legally available in Malaysia. This study also has managed to initiate a
preliminary baseline establishment in the levels of these chemicals in the
population.
Acknowledgement: SUCXeS
(Shimadzu-UMMC Centre for Xenobiotic Studies) University of Malaya, Japan
Chemical Industry Association, Ministry of Health Malaysia, Government of
Malaysia (for IRPA grant granted to HeRDU), University of Malaya Endocrine
disruptors research group.
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