Margaret Munro, CanWest News Service
Industrial chemicals have impaired the brain development of children, knocked down IQs, shortened attention spans and triggered behaviour problems, says a new report that is calling for better regulation of 201 chemicals with neurotoxic effects.
In a report warning of ''a silent pandemic in modern society,'' a team from the Harvard School of Public Health says millions of children may already have been affected.
''About half of the 201 chemicals that we list are high-volume production chemicals,'' says lead author Dr. Philippe Grandjean. The list includes aluminum and tin compounds, solvents like acetone and benzene, many organic substances and dozens of pesticides.
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The report takes a global view of the problem, but Grandjean says there is no question Canadians are exposed and affected.
''Most of these chemicals occur in Canadian chemical production, in the environment, in consumer goods,'' he says. He also says Canada stands out for exposure to the neurotoxin manganese, which has been used as an anti-knock agent in gasoline.
Health Canada declined to comment on the report, published Wednesday in the Lancet, or say how widely used the compounds are in Canada. But the department is promising action on thousands of chemicals that were introduced into use in Canada without adequate toxicity testing.
''We will have something in the very near future,'' says Erik Waddell, press secretary for Health Minister Tony Clement.
Critics doubt the government will go far enough, and predict it will be decades before the toxins are off the market.
''We're moving toward the George Bush model,'' says Bruce Campbell, executive director of the Canadian Centre for Policy Alternatives, which recently issued a report harshly critical of the way the government has moved towards deregulation and cut funding for enforcement and testing.
The Lancet report says one in six children now has a developmental disability, many of them learning problems, sensory deficits and developmental delays that affect the nervous system. Mounting evidence has linked industrial chemicals to such neurological disorders, and the report deplores the way the chemicals are ''not regulated to protect children.''
There are ''great gaps'' in testing of the chemicals, and regulators will only restrict compounds if there is a ''high level'' of proof of damage and problems, the report says, adding this puts vulnerable developing brains at unacceptable risk.
In nine months, the fetal brain grows into ''a complex organ consisting of billions of precisely located, highly interconnected and specialized cells,'' the report says.
The growth occurs within ''a tightly controlled time frame, in which each developmental stage has to be reached on schedule and in the correct sequence.''
This creates ''windows of unique susceptibility to toxic interference'' that can have permanent consequences, say Grandjean and co-author Philip J. Landrigan, a professor at Mount Sinai School of Medicine.
The researchers compiled the list of 201 chemicals toxic to the human brain based on available data and studies. They say there are likely many more.
"Even if substantial documentation on their toxicity is available, most chemicals are not regulated to protect the developing brain," says Grandjean. Only a few substances, such as lead and mercury, are controlled with the purpose of protecting children.
''The 200 other chemicals that are known to be toxic to the human brain are not regulated to prevent adverse effects on the fetus or a small child."
The report concludes, ''the combined evidence suggests that neurodevelopmental disorders caused by industrial chemicals has created a silent pandemic in modern society.''
As evidence of the scale of the problem, they note that virtually everyone born in industrialized countries between 1960 and 1980 was exposed to lead, which was used as a gasoline additive. That exposure may have reduced IQ scores above 130 (considered superior intelligence) by more than half and increased the number of scores less than 70, says the report, noting that lead was banned only after there was proof it could shorten attention spans and slow motor co-ordination.
The researchers warn the lingering affect of lead exposure may increase the risk of Parkinson's disease and other neurodegenerative diseases.
While lead and mercury are perhaps the best known neurotoxins, the reports points to evidence many pesticides and solvents can affect the brain. It describes manganese, fluoride, and perchlorate as ''emerging neurotoxic substances.''
Health Canada and Environment Canada have recently completed the ''categorization'' of 23,000 chemicals in use in Canada and are now working on a plan to manage those deemed a priority.
The departments are promising a ''chemical management strategy to better protect human health and the environment while maintaining the economic viability of industries,'' says Jason Bouzanis, media relations officer at Health Canada.
He says Health Canada is concerned about the links between industrial chemicals and brain development, and has already taken steps to reduce exposure to lead, mercury and PCBs.
''However there is much we don't know about the effects of many industrial chemicals and at what levels effects may be observed,'' says Bouzanis.
He said controlling substances that pose a risk to children will be a ''priority'' in the government's long-promised management strategy.
Campbell, of the Canadian Centre for Policy Alternatives, said it could be decades before substances thought to be toxic, but not proven conclusively in a scientific sense, are banned or even restricted.
''It will make it more difficult to get these toxic chemicals out of the environment to protect our children,'' says Campbell.
Like the authors of the Lancet report, Campbell favours Europe's move towards tighter control and regulation of toxins.
The idea is to take a precautionary approach and introduce strong regulation, which could later be relaxed if the hazard turned out to be less than anticipated, says Grandjean.