Ottawa (Canada) Citizen September 8, 2005 DOCTORS FEAR POLLUTION IS SKEWING BIRTH RATES Two girls for every boy born near chemical plants Tom Spears, The Ottawa Citizen Doctors were investigating the effects of pollution on an Ontario Chippewa community when some band members raised an odd point: Their community had enough girls for three softball teams, but only one boys' team. They were worried about the lack of baby boys. From that unexpected observation, health researchers from Ottawa and Sarnia tracked down a shocking fact: Today, nearly two baby girls are born for every baby boy at Aamjiwnaang First Nation, near Sarnia. Pollution from the petrochemical factories of nearby Chemical Valley is the likely -- though still unproven -- cause, the team argues. It's been known for more than a decade that many industrial pollutants mimic the action of the female sex hormone estrogen, and these can upset the reproductive systems of wildlife and humans alike. "You can't be anywhere on their land and not see a score of these things (chemical plants)," says Jim Brophy, director of the Occupational Health Clinic for Ontario Workers, a Sarnia clinic that focuses on health effects of industrial chemicals and asbestos. A University of Ottawa medical student, Constanze Mackenzie, started counting baby boys and baby girls born on the reserve since 1984. Until the early 1990s, an average of 54 per cent of the babies were male -- very close to the Canadian average of 51.2 per cent, she found. "But over the past 10 years that dropped to 41-per-cent male, and in the past five years it averaged 35-per-cent male," she said. The final years of the study, from 1999 and 2003, saw 86 baby girls and only 46 boys born. "We see, holy smokes, in the past 10 years we've got this huge drop" in male births, Mr. Brophy said. He noted it hasn't shown signs of levelling out. "We don't know what all the implications are for human health." The study appears in a science journal, Environmental Health Perspectives. There's no evidence that these babies have any unusual health problems. But the researchers know that in wildlife, upsetting the reproductive system with pollutants can cause long-term health problems in the next generation, such as behavioural problems, infertility and cancer. The reserve's soil is full of toxic metals such as arsenic, lead, chromium, and especially mercury, says Mr. Brophy, who has a PhD in occupational and environmental health. It's also close to factories that have air emissions such as benzene and its compounds. Mr. Brophy said other communities downwind of Chemical Valley -- places south and east such as Corunna and Chatham -- appear on the basis of preliminary analysis of Statistics Canada data to have more baby girls than boys as well. It's "nothing as significant as the First Nations, but it's in every single one of them," he said. To the north, away from prevailing winds, there are more boys born, Mr. Brophy said. "These are all puzzle pieces. We have no causal connection," he added. "But these are all parts of a larger picture." "It's difficult to prove cause and effect in science," adds Ms. Mackenzie, "but we feel there's enough evidence here that there should be some concern." No one has done blood tests in search of pollutants in Aamjiwnaang yet. Ms. Mackenzie said she hopes her work will be the first stage of a longer investigation.