Environmentally caused learning disorders

Recent studies have shown the effects of persistant organic pollutants in the environment on human health. These effects, passed on through the mother to children are also now appearing as learning disorders, behavioral problems and attention problems in children at school. Further effects include abnormal reflexes, shorter attention span, intolerance to stress, lowered IQ and reduced memory.

Although the emissions of some of these substances are falling, concentrations in the environment are of concern, both near highly contaminated areas and as a result of widespread distribution through the food chain (UNEP 1996a).

Concern over the impact of POPs on the environment and human health has increased further with the emergence of scientific findings that suggest that certain POPs (and also some organo-metallic compounds) – called endocrine disrupters because they interact with the endocrine, or hormone system – may be playing a role in a range of problems from reproductive and developmental abnormalities to neurological and immunological defects in humans and other animals (Colborn and others 1996).

Researchers at Wayne State University in the United States have documented significant learning and attention problems in children exposed prenatally to PCBs and other persistant organic pollutants passed on by mothers who had eaten Lake Michigan fish in the six years prior to pregnancy. Eleven year old children who had been most exposed, displayed poor short and long term memory, attention disorders, IQ levels three times below the norm, and were twice as likely to be two years behind in reading comprehension. A further study at the State University of New York (Oswego) showed neurobehavioral deficits in the newborn children of mothers who had eaten fish from Lake Ontario. The Oswego study was the first to document temperament effects from prenatal exposure to pollutants.