PERSISTENT ORGANIC POLLUTANTS AND TOXICANTS (POPT) RESEARCH GROUP
What are Persistent Organic Pollutants and where does the POPT research group fit in?
Persistent organic pollutants (POPs) are chemical substances that are resistant to degradation and may therefore remain in the environment for long periods of time. These substances are capable of long-range transport, and therefore widely distributed geographically, even in places where it has never been used or produced. POPs bio-accumulate in the fatty tissues of organisms, and can bio-magnify in food chains, having the potential to cause adverse health effects in humans and animals. Health effects caused by POPs may include chloracne, hyperpigmentation, endocrine disruption, immune-, nervous- and reproductive system defects and even cancer.
These pollutants arouse global concern, and to curb the spreading of POPs, the United Nations Environment Programme (UNEP) initiated the Stockholm Convention on Persistent Organic Pollutants in May 1995. This Convention is an international treaty aimed at the reduction and elimination of the twelve most harmful POPs, known as the “dirty dozen”. These twelve groups of chemicals include the chlorinated pesticides: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex and toxaphene, two groups of industrial chemicals: hexachlorobenzene and polychlorinated biphenyls (PCBs), and unintentional combustion by-products generally known as dioxins and furans. As a signatory of the Convention, South Africa is legally obligated to abide by the objectives of the Stockholm Convention. In undertaking our research, the POPT research group are fulfilling a part of our responsibility to the Convention, in providing a better understanding of POPs, since very little is known about these substances in our country.
Our research group is well established in the biological analysis for the unintentionally produced dioxin-like substances, which include dioxins, furans and dioxin-like PCBs. More recently, we have added other persistent organic toxicants to the list, which includes chlorinated pesticides such as endosulphan, dicofol, methoxychlor, DDT and lindane, as well as industrial-related pollutants which include polycyclic aromatic hydrocarbons (PAHs), polychlorinated naphthalenes, PCBs, octachlorostyrene, short- and medium chained chlorinated paraffins, hexachlorobutadiene and tetrachlorobenzene. In doing so we are dignifying the acronym of our research group that stands for Persistent Organic Pollutants and Toxicants.
We have already analysed soils, sediments and fish tissue for the presence of some of the above-mentioned substances, and will be including chicken eggs, wild bird’s eggs and human breast milk soon. Knowing the concentration of these compounds bio-accumulation in food chains can be determined, and possible health risks associated with the consumption of contaminated food, may be calculated. In addition to the biological and chemical analysis of biotic and abiotic materials, morphological structures of snails, frogs and small mammals are also examined, to act as indicators of possible endocrine disruption. The POPT group is a very diverse and dynamic group of people, who aims at contributing towards a better understanding regarding POPs in South Africa.
Back to top
Contact details
School of Environmental Sciences and Development: Zoology
North-West University
Potchefstroom Campus
Private Bag X6001
Potchefstroom 2520
South Africa
Prof. Henk Bouwman
Tel: +27 18 299 2377
Fax: +27 18 299 2503
Email: henk.bouwman@nwu.ac.za
Dr. Rialet Pieters
Tel: +27 18 299 2379
Fax: +27 18 299 2503
Email: rialet.pieters@nwu.ac.za
Back to top
|
|
|
