BPA contaminants found in most Canadians
Last Updated: Monday, August 16, 2010 | 10:13 AM ET Comments97Recommend93
About 91 per cent of Canadians have detectable levels of bisphenol A (BPA), a chemical used to make some hard plastic containers, bottles and toys, a new report suggests.
Statistics Canada released the finding Monday as part of the results of its survey measuring the levels of various contaminants in the urine of Canadians aged six to 79.
What is bisphenol A?
Bisphenol A is a chemical compound found in some hard, clear, lightweight plastics and resins. It’s used in the production of various types of food and drink containers, compact discs, electronics and automobile parts, and as a liner in some metal cans. Animal studies suggest that, once ingested, BPA may imitate estrogen and other hormones, according to the National Institutes of Health.
Bisphenol A is an industrial chemical used to make polycarbonate plastic for water bottles and food containers as well as the protective lining in metal cans. It does not occur naturally in the environment.
Some studies on animals suggest that low levels of exposure to BPA very early in life can affect brain development and behaviour, but scientists are unsure in interpreting how these findings might be relevant to human health, Statistics Canada said.
Animal studies suggest that, once ingested, BPA may imitate estrogen and other hormones, according to the U.S. National Institutes of Health.
Compared with children aged six to 11, those aged 12 to 19 had a higher concentration, while those aged 40 to 79 had lower concentrations, Statistics Canada said.
It is the first time the BPA levels of Canadians have been measured in a nationally representative sample of the population.
The findings are consistent with results from international studies, the agency said. BPA has been detected in 93 per cent of Americans aged six or older, and 99 per cent of Germans aged three to 14.
The Statistics Canada data “suggest continual widespread exposure in the Canadian population,” the report concluded.
Canadians’ average BPA level in their urine was 1.16 micrograms per litre.
In October 2008, Canada became the first country in the world to ban the import and sale of polycarbonate baby bottles containing bisphenol A, as a safety precaution. It is still used as a liner in food and beverage cans sold in Canada.
Lead levels fall
Researchers also looked at the levels of lead in the blood of Canadians, the first such national level measurement in 30 years.
Lead was detected in 100 per cent of the population, but concentrations have fallen dramatically over the past 30 years, the agency said.
Average lead concentration for people aged six to 79 measured by the survey between 2007 and 2009 was about one-third of the concentration measured in the 1978-79 Canada Health Survey for the same age group.
In 1978-79, about 27 per cent of Canadians aged six to 79 had blood lead concentrations at or above the intervention level, compared with less than one per cent from 2007-09.
Too much exposure to the metal can cause serious illness. In young children, it can impair neurological development.
The Canadian Health Measures Survey also looked at blood levels of mercury, which was found in 88 per cent of Canadians tested.
The average concentration was 0.69 micrograms per litre.
Mercury concentrations were lower for children and teens aged six to 19 than for adults aged 20 to 79, Statistics Canada found.
Health Canada has established a total mercury level in blood guidance of 20 micrograms per litre for the general adult population and eight micrograms per litre for for children, pregnant women and women of childbearing age.
Most people are exposed to mercury by eating fish and seafood.
Chronic exposure to high levels of mercury may cause a number of health effects, including:
- Numbness and tingling in the extremities.
- Blurred vision.
- Intellectual impairment.
Prenatal exposure to mercury may cause neurological and developmental delays, according to the agency.
Samples for the study were collected from March 2007 to February 2009 from a representative sample of about 5,600 Canadians aged six to 79 years at 15 sites across the country.