Reporting on BPA fails to consider importance of dose.

Posted by Laura Vandenberg at Mar 10, 2010 07:45 AM |

A HealthDay News article reports a link between BPA exposure and asthma in mice but fails to indicate that the effects were observed at doses below what the U.S. Environmental Protection Agency has deemed safe.

An article in the online publication HealthDay News highlights a recent study that found exposing female mice to BPA before, during and after pregnancy led to asthma in their offspring. As mentioned in the article, this study suggests that events occurring during early development can contribute to the development of diseases later in life.
 
Missing from the article, however, is an indication of how the exposure levels used in the study compare to the levels considered safe for people.
 
Reporter Amanda Gardner correctly points out that early life exposure led to asthma in animals exposed to 10 micrograms of BPA per kilogram of weight per day (ug/kg/day). Effects were not seen in animals exposed to 0.1 or 1 microgram.
 
Based on risk assessments, the U.S. Environmental Protection Agency regards 50 ug/kg/day as a safe human exposure. Therefore, the dose of BPA that induces asthma in mice is below the level that is considered “safe”.
 
Animal studies that indicate harmful effects of BPA exposure do not always use irrelevant, high doses. To date, more than 130 animal studies have found harmful effects of BPA exposures at doses below what the EPA says are safe. Together, these studies provide evidence that exposure to low doses of BPA could be impacting many different aspects of human health, including asthma.
 
The public could have a greater perspective on the health risks of environmental chemicals if reporters would include how the doses used in research studies stack up against safe exposure limits set by regulatory agencies.