The researchers from Switzerland added that the while the highest dose rate was “far below” the tolerable daily (TDI) intake of 50 µg/kg bw deemed safe, it was of “the same order of magnitude as recently reported concentrations that caused low-dose health effects in rodents”.
More research into overall exposure through food packaging was also flagged up – with an evaluation on canned food being especially important to gauge adult exposure to the chemical, said author Natalie von Goetz, Ph.D., senior scientist at the Swiss Federal Institute of Technology in Zurich.
The study, Bisphenol A: How the Most Relevant Exposure Sources Contribute to Total Consumer Exposure, examined multiple sources of potential exposure across nine age/gender groups in Swiss, German and Austrian populations.
It found that exposure to the chemical decreases as people become older, with highest exposure coming through canned foods. The research found the main exposure to BPA across all groups comes through food.
"In general humans in their developmental stages (foetus, infant, child) seem to be exposed more severely than adults," said the research published in the journal Risk Analysis.
The study examined 17 different sources so that an “overall risk assessment” could be based on the exposure from all relevant products and pathways – also known as the “total exposure”. The research found the most potentially exposed group is bottle-fed infants from 0-6 months of age. This group had estimated mean dose rates of nearly 0.8 micrograms per kilogram body weight per day, below the TDI of 50 µg/kg bw as set by both the European Food Safety Authority (EFSA) and the US Food and Drug Administration (FDA).
BPA exposure through food packaging
The group called for more research into exposure through food packaging as this constituted the greatest level of uncertainty with their evaluation - as the “consumption of packaged food is highly variable throughout the population and will depend on socioeconomic as well as regional factors”.
The study highlighted the need for greater investigation into BPA levels in food cans as this is “highly variable” and suggested that food processors standardise production practices to help cut adult exposure to the substance.
“By optimizing the production processes of cans, extreme high values such as those reported for canned soup and canned meat could possibly be avoided, which would reduce the high exposure dose rates of adults to the mean exposure dose rates presented,” said the researchers.
Bisphenol A: How the Most Relevant Exposure Sources Contribute to Total Consumer Exposure by Natalie von Goetz 1,Matthias Wormuth, Martin Scheringer, and Konrad Hungerbühler.
DOI 10.1111/j.1539-6924.2009.01345.x
Source: Risk Analysis: An International Journal