WORLD Environment Day is commemorated each year on June 5 as one of the principal vehicles through which the United Nations stimulates worldwide awareness of the environment and enhances political attention and action.

The commemoration tomorrow is to deepen public participation on the need to preserve and enhance the environment.

It is also about promoting health, which is now increasingly dependent on the environment. Without a healthy environment, our health will invariably be affected sooner or later.

World Environment Day is, therefore, about us, about how we can co- exist with our environment for the mutual benefit.

On this day, too, nations of the world come together and learn from one another in meeting the challenges of a viable and equitable balance between environment and development.

This challenge is not limited to only physical or socio-economic ones, but more so our intellectual development, as we forge forward into the era of “intellectual capital”.

Recent review of evidence carried out in the UK reiterated that “pollution and other environmental threats are harming the intelligence of millions of people across the world”.

This is based on a report by Dr Chris Williams of the Institute of Education, University of London, who is also a fellow of the Global Environmental Change Programme, social science initiative of the Economic and Social Research Council.

He undertook a global review of science-based research into the impact of environmental factors on intelligence, and observed that among the causes listed are poisonous chemicals such as lead, fluoride, PCBs (polychlorinated biphenyls, synthetic compounds used in electrical equipment), and also radiation.

Lead for example has long been identified as a threat to health and IQ especially among children. This issue has been dealt with a number of times (Poison Control, NST, Jan 23).

In the UK, one child in 10 is reported to have blood-lead level high enough for intelligence to be affected. While in some developing countries, the proportion could be as high as nine children in 10.

In Malaysia preliminary investigations by the Centre and other local institutions suggest that some sectors of the population may also face similar risks. And it is heartening to note that the Malaysian government is now planning a surveillance programme nationwide.

The other well-established environmental threat to the development of intelligence is the exposure to PCBs. In fact, studies carried out in Holland and America show that PCBs can damage the intelligence even of unborn babies.

It has been suggested that children born to mothers with high PCB levels can have their IQ reduced by up to six points compared with those born to women with low PCB levels.

Even the intelligence of Inuit children in the Arctic is not spared from being damaged by PCBs which allegedly originate in the tropics. In the case of Malaysia, where PCBs is still very much in use, little has been done in this area.

Of late, the director of experimental toxicology at the US Environmental Protection Agency, reiterated, “We’re not seeing kids without arms and legs, but we are seeing children who get ill more easily or who would have had a higher IQ without that exposure”.

Latest evidence published in the journal, Science, suggests that even these low levels of PCBs may affect development in young children. For that reason, most developed countries have taken steps to restrict or eliminate the use of such poisons.

Despite that, they can still be found, often in minute quantities, in the body of most people examined.

This is because the substance can accumulate in the food chain and once consumed will stay in the body for a very long time causing a variety of chronic ill-effects.

At this juncture it is worthwhile quoting Dr Williams when he categorically states “the human brain is now at risk from its own behaviour, and nothing else in the ecosystem is harming itself in the same way”.

This is made worst if one takes into consideration other phenomenons like soil erosion due to deforestation for example.

Collectively these can result in the loss of micronutrients like iron and iodine. Such nutrients are essential in the human diet and are usually instrumental in enriching food crops for improved health status.

Moreover, children deficient in nutrients such as iron, have been known to be more vulnerable to lead poisoning threatening their IQ even further.

In South-east Asia alone, an estimated 1.5 billion people are said to be affected by the iron deficiency, partly due to impoverished crops.

One other disturbing finding is Dr Williams’s observation, in some Indian villages where “the wells have been poisoned with fluoride, causing a loss in intelligence”.

Interestingly enough, a study published in a recent International Journal of Environmental Studies describes a fluoride-related factor that is correlated with higher lead levels in children.

Analysing a survey of over 280,000 Massachusetts children, the investigators found that silicofluorides chemicals widely used in treating public water supplies in the area of study are associated with an increase in children’s absorption of lead.

From the analysis, the study found that levels of lead in children’s blood was significantly higher in Massachusetts communities using the silicofluorides: fluosilicic acid and sodium silicofluoride, than in towns where water is treated with sodium fluoride or not fluoridated at all.

Compared to a matched group of 30 towns that do not use silicofluorides, children in 30 communities that use these chemicals were over twice as likely to exceed the so-called “safe” limits accepted internationally, at 10 microgramme per 100 millilitre of blood lead.

In fact earlier in 1997 the Natick Fluoridation Study Committee, after conducting “a thorough review of the scientific literature” states that the developmental neurotoxicity of fluoride would manifest as lower IQ and behavioural changes.

These are is not all. Epidemiologists have also detected a statistically significant increase in the birth of children with Down’s Syndrome which is linked to radiation from the explosion of the Chernobyl nuclear reactor.

The increase was dependent on rainfall in the period following the explosion whereby excess Down’s Syndrome births were recorded in some parts of Europe, just nine months after the disaster.

And since one of its four reactors in Chernobyl is still in operation, experts regard this as a ticking bomb.

All these has led to the director of the Global Environmental Change Programme, Dr Frans Berkhout, to remark: “This issue reveals a wider problem that science has when faced with complex and uncertain environmental issues.

“Some of the most difficult environmental challenges are not being adequately addressed simply because of the difficulties of collecting the necessary evidence and establishing cause and effect.”

Although in some cases it is hard to know the full extent of some of the impending problems, the public must be made aware of their possibilities, and not to dismiss them offhand or to be taken lightly.

We need to act smart, rather than falling back on knee-jerk type of responses when confronted with such complex findings. As such let us stay smart by showing our commitment against the use of chemicals that would not only hurt our environment, but also insult our intelligence.