B.C. researchers seek immigrant women for heavy metals study

May 20, 2015

By Pamela Fayerman, Vancouver Sun |

Women who’ve moved to the Lower Mainland from certain South and East Asian areas are being sought for a major study measuring their levels of heavy metals and environmental toxins.

Those who are aged 19 to 45 and have moved to Vancouver (or Toronto, the second site of the research) in the last five years from India, China, Hong Kong and Taiwan can enrol. Principal investigator Dr. Tom Kosatsky, head of environmental health services at the BC Centre for Disease Control (BCCDC), said participants will be told the levels of such contaminants in their blood or urine and will also learn how to reduce their exposures and concentrations if they are too high.

Kosatsky said this is especially useful information for women who intend to become pregnant.

Co-investigator Linda Dix-Cooper said since toxicants such as lead and mercury are known to be transmitted from pregnant mothers to their fetuses, there is concern that high levels could affect fetal development and growth.

The study builds on previous, smaller studies which indicated that foreign-born women had levels of some metals and organic pollutants that were as much as twice as high as levels in Canadian-born women. High levels of pollutants and industrial contaminants, pesticides and heavy metals like cadmium, lead, mercury, cobalt, nickel and selenium are linked to an array of adverse health effects including cancer and immune system abnormalities, besides reproductive and developmental disorders.

Canada has stricter regulations on contaminant use, which may explain why blood levels of toxins are generally lower in women born in Canada.

A pivotal study published in 2012 and led by McMaster University’s Warren Foster concluded that because of the differences in foreign-born vs. Canadian-born pregnant women, “place of birth” should be considered in future studies. Hence, the current study, a collaboration between Fraser Health, Vancouver Coastal Health, Toronto Public Health and the University of Toronto. It is being sponsored by Health Canada, BCCDC and the BC Ministry of Health.

Researchers are recruiting 300 women locally — and another 150 in Toronto — from now until January 2016.

Women could potentially be exposed to such contaminants through vermilion or sindoor, a scarlet red powder pigment derived from Cinnabar, which can contain high levels of mercury (traditionally applied by married Hindu and Sikh women to indicate married status). Other sources include imported Ayurvedic treatments, traditional Chinese medicines and herbs, imported candies, cosmetics (Kohl eye liner which may contain lead), occupations (like metal work, welding or furniture refinishing), glazed cookware or those made of copper or bronze, and diet, including animal organs and shellfish or large predatory ocean fish like Ahi tuna, grouper, tilefish, King mackerel, shark, marlin and swordfish.

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