The New Straits Times, December 3, 2000
By Dzulkifli Abdul Razak
AS the world continued to express its concern about AIDS on World AIDS Day, December 1, another issue, equally threatening, is being brought to focus tomorrow. Then until December 9, the fifth and final round of talks on the United Nations treaty to control persistent organic pollutants will take place in South Africa.
POPs first include pesticides such as DDT and chlordane. Secondly, industrial chemicals including PCBs (polychlorinated biphenyls) come under this umbrella, and third, those by-products that are created "unintentionally", notably dioxins and furans, through industrial processes such as paper bleaching. In all there are at least a dozen (better known as "Dirty Dozen") substances that persist in the environment.
The POPs are both widespread and persistent and the executive director of the UN Environment Program (UNEP), Klaus Tpfer, put it succinctly: "Now they are in the air, water, and soil around the planet _ and in us all _ and they last for generations".
The need for controls on the use and availability of these substances is vital if health hazards are to be avoided, apart from the long-term impact on the environment.
As long as they persist in the environment, the substances will enter the human body, primarily through the food that we eat. Many of us are being poisoned insidiously over a long-term period (see Poison Control, NST, Oct. 12, 1998).
In fact, statisticians at the US Environmental Protection Agency (EPA) have recently finished a new evaluation of accidental exposure, for instance, people breathing in more than they should _ and incidents of poisoning related to pesticides.
One such example of exposure involves chlorpyrifos, a key ingredient in a variety of products like pet flea collars, ant sprays, and especially for termite control. Chlorpyrifos belongs to yet another class of 37 persistent pesticides known as organo-phosphates. They attack the nervous system, and were developed initially as nerve gases in World War II by the German company I.G. Farben.
Recent studies at Rutgers University indicate that chlorpyrifos persists much longer indoors than had been previously recognised. Carpets, soft furniture and plush toys are especially likely to absorb chlorpyrifos, to retain it for longer periods of time and then release vapours into the air, increasing the possibility of over-exposure to children. Children are especially susceptible because their brains and nervous systems are still developing.
The increased concern about chlorpyrifos emerged after studies _ some conducted by its manufacturer _ showing that the compound causes brain damage in foetal rats, whose mothers were given the pesticide.
The results of the animal tests are considered serious enough to indicate that the pesticide should not be used where there are children, although the direct link to humans is yet to be established.
Another study reports that it can cause increases in auto-immune antibodies among people exposed to it. Auto-antibodies are "renegade" immune system components which mistakenly attack the person's own self; linked in some cases of male and female infertility to auto-immune disorders in which the immune cells attack either the sperm or egg.
The EPA has announced that products containing chlorpyrifos will be phased out for home and garden use (http://www.bandursban.org/) .
It has concluded that safety levels for exposure to the substance are inadequate. Similarly, last year, EPA banned the use of other pesticides with organo-phosphates _ methyl parathion on fruits and many vegetables,and restricted the use of azinphos-methyl.
But without financial aid to help them get rid of POPs the result will be unimpressive. Even then exactly how such aid will work and how much money will be involved still remain uncertain. Financial assistance goes a long way in helping towards the disposal of POPs and other pesticides.
It is also important for technological improvements to prevent the "unintentional" formation and release of dioxins and furans. But it continues to be a sticking point in the South African talks as it is expected to colour negotiations on all other issues.
Whatever the merit of the case, governments should act to prevent the use of pesticides like POPs. The goal should be to use as little toxic chemical as possible as soon as possible.
Thus, recent reports that local agro-chemical use is growing, from RM262 million in 1993 to RM392 million last year, despite ample evidence of the perils, is of grave concern (NST, Nov 28). Without doubt POPs and OP are included in this figure as they are available as pesticides in the country.
More alarming still, according to a Mardi (Malaysian Agriculture Research and Development Institute) researcher, one of the two commonly pesticides used (endosulfan, a POP) is beginning to contaminate water bodies as a result of agricultural use. Studies previous to this showed that pesticide contamination was also evident in rice, vegetable and tobacco.
In other words, the Malaysian Government must initiate a thorough-going review of the use and availability of some of the chemicals now known to threaten public health.
Industrialised countries are already controlling pesticides such as POPs under a regional pact _ the Convention on Long-Range Transboundary Air Pollution, for example.
But developing countries such as Malaysia lag far behind even in controlling them within their own borders, something that needs to be improved.
