The National Toxicology Program (NTP) released a draft report Feb. 23 from one of two distinct but complimentary arms of a study called the Consortium Linking Academic and Regulatory Insights on BPA Toxicity, or CLARITY-BPA. This research initiative is studying the full range of potential health effects in rats from exposure to bisphenol A (BPA, see sidebar).
The federal study was conducted by the National Center for Toxicological Research (NCTR) at the U.S. Food and Drug Administration (FDA), with guidance from a CLARITY-BPA steering committee. The committee included members from NTP, NIEHS, NCTR, the FDA Center for Food Safety and Applied Nutrition, and academic researchers. The NCTR researchers who conducted the study followed standard regulatory and statutory guidelines for toxicity testing.
Using the CLARITY-BPA model, these findings will ultimately be paired with academic research that is testing a broad range of health endpoints, including mammary cancer, prostate development, cardiovascular disease, obesity, and behavior. A final integrated report from this collaboration between NIEHS, NTP, FDA, and academic researchers is expected in 2019.
“CLARITY-BPA aims to create a mutually beneficial partnership that unites standard regulatory research practices with innovative studies conducted at universities, to help expand the kinds of studies considered by regulatory agencies,” said Linda Birnbaum, Ph.D., director of NIEHS and NTP.
Findings part of a bigger picture
According to FDA, the researchers observed minimal effects of BPA on the health endpoints studied, including growth, body weight, and tumor development. However, FDA acknowledged that some findings may merit further research, such as an increase in the occurrence of mammary gland tumors at the lowest BPA dose in one of the groups studied.
“What really remains to be seen is how these findings fit together with observations from the academic research,” said John Bucher, Ph.D., NTP senior scientist. “The coordination of both components is what makes the CLARITY-BPA study design unique.”
The federal study provided the animals and tissues that the academic researchers are using. This ensured that both arms of CLARITY-BPA used specimens raised in the same laboratory conditions and exposed to the same carefully controlled BPA doses. The academic researchers received the animals and tissues in a blinded fashion, without knowing if they were dosed with BPA or how much they were dosed.
Opportunity for public comment
A public comment period is part of the standard NTP process for external scientific review. The NTP draft report is available for public comment until April 12. A review by external experts will take place at NIEHS on April 26.
The review is open to the public, either in-person or via webcast, but registration is required. The draft report, registration, and other information are available on the NTP website.
(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 the Environmental Factor.)