On Sept. 28, the CLARITY-BPA program released two resources, while work continues toward completing the final report in the fall of 2019.

• 1. Data sets from the CLARITY-BPA grantee studies.
  2. The report from the CLARITY-BPA core study, which was reviewed by a panel of external scientific experts in April 2018.

CLARITY-BPA stands for the Consortium Linking Academic and Regulatory Insights on Bisphenol-A Toxicity, which was designed to identify potential health effects over a wide range of exposures to BPA.

Grantee data released for transparency

The National Toxicology Program (NTP) released the primary data from the grantee studies without summarizing or analyzing it in any way, so other researchers can do their own analyses.

Nigel Walker, Ph.D., chief of the NTP Toxicology Branch, worked closely with a team of NTP staff and contract support personnel on the painstaking process of standardizing formats and then combining data from 13 different projects into the Chemical Effects in Biological Systems online database.

BPA is produced in large quantities and used mainly in epoxy resins that coat some metal food cans and water supply pipes, as well as polycarbonate plastics like water bottles.

“Releasing primary data from both the grantee studies and the core study online to the public is an essential element in the transparency of the NTP process,” said Walker. “They are critical steps towards supporting the next phase of the CLARITY-BPA project, where all the information will be integrated.”

Grantees publish their findings separately in scientific journals, and NTP posts links to those publications on the CLARITY-BPA website.

Core study portion now final

The authors of the core study reported observed changes in rat pituitary and reproductive tissues at the highest BPA doses administered, but these exposure levels were many times higher than what people typically receive. They also saw some health effects at lower doses, but it was uncertain whether the changes were related to BPA exposures.

“To fully understand the core study results, we need to compare these traditional guideline studies with results from the grantee studies, which looked at a broader range of health conditions,” said John Bucher, Ph.D., NTP senior scientist. “This will be done in the final integrated report next year.”

Blending regulatory and academic studies

CLARITY-BPA was designed by NIEHS, NTP, and the U.S. Food and Drug Administration (FDA) to integrate two distinct, but complimentary, approaches to studying the potential health effects in rats from BPA exposure.

The core study component, which was conducted by FDA’s National Center for Toxicological Research, involved research that followed international guidelines for toxicity testing.

The grantee studies, which were conducted by university researchers, used animals and tissues from the core study. These researchers tested a broader range of health endpoints, including genetic impacts, cardiovascular disease, reproductive effects, obesity, and behavior.

(Virginia Guidry, Ph.D., is a technical writer and public information specialist in the NIEHS Office of Communications and Public Liaison, and a regular contributor to Environmental Factor.)