Technology & Science

Contaminant test part of StatsCan's latest health survey

Statistics Canada will test 5,000 Canadians for everything from toxic contaminants in the blood to physical fitness in what it's calling the most comprehensive survey of our overall health.

Statistics Canada will test 5,000 Canadians for everything from toxic contaminants in the blood to physical fitness in what it's calling the most comprehensive survey of our overall health.

The Canadian Health Measures Survey will test blood and urine samples of Canadians agessix to 79 to measure diabetes, cardiovascular health, infectious diseases, nutrition and environmental exposure to contaminants such as lead.

It will also measure height, weight, waist circumference and physical fitness, and will rely on actual measurement as opposed to self-reporting from individuals to provide a more accurate assessment.

Jeanine Bustros, the director of the physical health measures division of Statistics Canada running the survey, told CBC News Online the test will put Canada in line with countries like the United States, Australia and New Zealand, which have run similar health studies.

"We've done testing of some physical measures, but we've never done a comprehensive survey like this before," said Bustros.

The testing for toxic contaminants has been of particular interest to researchers after studies in the United States provided the first evidence that Americans had too much lead in their blood. Those results led the government to phase out lead as an additive in gasoline.

Earlier this year federal cabinet ministers Tony Clement and Rona Ambrose, and NDP Leader Jack Layton volunteered to donate their blood as part of an awareness campaign by Toronto non-governmental organization Environmental Defence.

The CHMS will test for 69 known contaminants, many of which have had consumer and industrial use in this country for decades. Among the contaminants the tests will search for are:

  • Eleven types of phthalates, the plastic softeners used in many cosmetics. Research has linked the substances to the interference of male hormones.
  • Organic contaminants like polychlorinated biphenyls (PCBs). The study will test for 15 kinds of PCBs to see if the substances— banned in 1977— are still present. Another banned organic contaminant, DDT, will also be tested for.
  • Bisphenol A, a component of polycarbonate, used to make hard-plastic water bottles. It is known to mimic the female sex hormone estrogen.
  • Potentially hazardous elements such as lead, nickel, uranium, arsenic and mercury.

Bustros said the blood and urine samples would be frozen, with the permission of participants, for potential future use in testing for substances not currently on the list of tested contaminants.

Direct physical assessment

But toxic contaminant testing is just one aspect of the comprehensive health survey, which begins in March 2007 and should finish in June 2009.

Direct physical assessments and blood testing for diseases such as diabetes also allow researchers to get a more accurate portrait of how Canadians are doing physically.

"What we've found is more and more evidence cannot be collected from self-reporting," said Bustros. "People will underestimate things like their weight or overestimate their height. And in other cases like lung function there is no way for people to know that information."

The difference between self-reporting and actual assessment can lead to startlingly different results. In Australia, a similar survey conducted from 1999 to 2001 found that for every known case of diabetes, there was one undiagnosed case.

Bustros said the tests haven't been done in Canada because of cost concerns and a lack of infrastructure to track the data. The cost to run the toxic contaminant test alone is about $1,000 per person. Federal funding will cover this survey, though funding has yet to be secured for followup studies, said Bustros.

She said it's important for Canadians to conduct their own research and not rely on the findings from other countries such as the U.S., because differences in legislation and even the ingredients of common products could lead to different results.