Common Household Chemical Could Raise Breast Cancer Risk

By Steven Reinberg
HealthDay Reporter
Friday, December 7, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

THURSDAY, Dec. 6 (HealthDay News) -- A chemical found in many plastic products used in households caused accelerated breast development and genetic changes in newborn female lab rats, a condition that might predispose the animals to breast cancer later in life, a new study says.

Butyl benzyl phthalate (BBP) is commonly used to soften polymers and plastics. It's found in everything from plastic pipes, vinyl floor tiles and carpet backing to lipstick. BBP has also been found to be an endocrine disruptor, which mimics the effect of hormones. Endocrine disruptors are known to damage wildlife and have also been implicated in reduced sperm counts and neurological problems in humans, the researchers said.

"Our study is the first one demonstrating that exposure to this compound (BBP) soon after birth results in alterations in the expression of genes present in the mammary gland," said lead researcher Dr. Jose Russo, a breast cancer expert at the Fox Chase Cancer Center, in Philadelphia.

The findings are important, Russo said, because the researchers are studying the lifetime effect of BBP on the mammary gland, long before it starts developing under the influence of the hormones of puberty, and the potential implications on humans.

Because of lasting genetic changes in the breast, exposure to BBP could increase the risk for developing breast cancer later in life, Russo said.

"To prevent breast cancer in adulthood, it is necessary to protect both the newborn child and the mother from exposure to this compound that has an estrogenic effect and could act as an endocrine disruptor," he added.

For the study, Russo's team fed lactating rats BBP, which their offspring absorbed through breast milk. The rat pups received levels of the chemical equivalent to the U.S. Environmental Protection Agency's safe dose limit for humans, according to the report in the Dec. 5 online issue of BMC Genomics.

The researchers found that BBP affected characteristics of the female offspring of the rats, such as more rapid breast development and changes in the genetic profile of the mammary glands. While these effects wore off after exposure to BBP was stopped, the changes caused by the chemical might have an effect later in life, the researchers said.