Findings come from Health Canada and the first results from the Maternal-Infant Research on Environmental Chemicals (MIREC) study that examined phthalate and BPA exposure among pregnant Canadian women.
The study measured BPA and phthalate metabolites in first trimester urine samples collected in a national-scale pregnancy cohort study and identified predictors of exposure.
It recruited 2,000 women in the first trimester of pregnancy from ten sites across Canada.
A questionnaire obtained demographic and socio-economic data on participants and a spot urine sample was collected and analyzed for BPA (GC-MS/MS) and 11 phthalate metabolites (LC–MS/MS).
BPA concentrations
Maternal urinary concentrations of BPA ranged from non-detectable (<0.02 μg/L) to 140 μg/L, uncorrected for specific gravity, with almost 88% of the women having detectable concentrations.
Women in the MIREC study, who were younger, smoked, had fasted, were born in Canada, had lower income and education level and provided their urine sample later in the day had significantly higher urinary concentrations of BPA.
Dr John M Rost, chairman, North American Metal Packaging Alliance (NAMPA) said the study is critically important to the discussion of the safety of BPA, and should be given appropriate weight.
“This study continues the work of regulatory agencies around the globe that are conducting high quality research to determine the safety of products on the market, including those made with BPA,” he told FoodQualityNews.com.
“In contrast, many academic researchers continue to publish more hypothetical research that tries to show some possible mechanism that BPA "may" have to causing harm, but often has no relevance to what is actually happening in the human body.”
Rost said the studylooks at real life human exposures to food packaging.
“It is a biomonitoring study that demonstrates clearly that typical exposure to BPA for pregnant women is more than a thousand times lower than established safe levels,” he said.
“Its direct relevancy to people makes it a far different kind of study, with far greater importance than studies where chemicals are injected at high levels into test animals, with authors then drawing some conclusion to human health.”
The government of Canada determined that BPA is toxic to human health in 2010 and a provisional tolerable daily intake of 25μg/kg body weight from food packaging was established.
Current dietary exposure to BPA through food packaging uses does not pose a health risk to the population, including newborns and young children, said Health Canada in 2008 and 2012.
One limitation was that only one spot urine sample was collected in assessing an individual's exposure per woman during the 1st trimester. As the chemicals have a short half-life (hours) and there are multiple sources and routes of exposure, intra-individual variability in results are expected, said the researchers.
ACC: Results reaffirm safety
Steven G. Hentges, of American Chemistry Council’s Polycarbonate/BPA Global Group, said the results reaffirm the safety of BPA from Health Canada’s perspective.
“While acknowledging that exposure to BPA is expected, the Health Canada study found BPA at lower average levels and in a lower percentage of women, compared to the overall Canadian population,” he said.
“These results indicate that typical exposure to BPA for pregnant women is more than a thousand times lower than the safe intake level established by Health Canada.
“The results are consistent with similar studies conducted in the US by the Centers for Disease Control and Prevention, and Health Canada’s current perspective on BPA is very consistent with the US Food and Drug Administration (FDA).”
Source: Environment International, Volume 68, July 2014, Pages 55–65
Online ahead of print, DOI:10.1016/j.envint.2014.02.010
“Phthalate and bisphenol A exposure among pregnant women in Canada — Results from the MIREC study”
Authors: Tye E. Arbuckle, Karelyn Davis, Leonora Marro, Mandy Fisher, Melissa Legrand, Alain LeBlanc, Eric Gaudreau, Warren G. Foster, Voleak Choeurng, William D. Fraser, the MIREC Study Group.