WEDNESDAY, June 23 (HealthDay News) -- Exposure to common
chemicals during critical periods of breast development may affect
breast growth, the ability to breast-feed and breast cancer risk, a
new report contends.
Some of these chemicals are found in ordinary household products
such as certain types of plastic water bottles, canned foods and
laundry detergents, the researchers noted.
With this in mind, the study authors called for chemical test
guidelines for industry requiring that scientists test the
chemicals' effects on early mammary gland development.
Scientists from the U.S. National Institutes for Environmental
Health Sciences, the Environmental Protection Agency and the Silent
Spring Institute collaborated on the report, published online June
22 in the journal
Environmental Health Perspectives.
"If we try to figure out what causes breast cancer, we have to look at the breast when we do the chemical safety tests," said Ruthann Rudel, research director at Silent Spring.
Currently, protocols for testing don't require looking at
mammary tissues, Rudel said, so it is rarely done. "We could be
missing a lot," she said.
Experts believe these early disturbances in mammary glands due
to chemical exposure may boost the risk of harmful effects later in
life. These could include impaired lactation (secretion of breast
milk), abnormal breast growth in men and breast cancer.
One impetus for the study, in fact, was an increase in early
breast development in girls, which is linked to an increased risk
of breast cancer.
The report also noted that although experts recommend that all
infants be breast-fed exclusively for six months, some 3 million to
6 million women in the United States are unable to produce milk or
have difficulty breast-feeding each year.
The scientists interviewed 18 experts, reviewed research and
discussed the issue at a workshop in late 2009. They are submitting
a request to the Paris-based Organisation for Economic Co-Operation
and Development (OECD), asking it to add mammary tissue testing to
The international organization develops guidelines for testing
of chemicals for safety, human health effects and environmental
effects. "It's a call for government agencies that develop policy
to make sure mammary gland assessment is required," Rudel said.
Industry representatives said they welcomed the review.
"This workshop, which provided a forum for scientific discussion, did not produce data or outcomes relevant to consumers, and thus comments from the meeting should not cause undue concern," said Kathryn St. John, spokeswoman for the American Chemistry Council. "Based on their review of animal studies conducted by the participating scientists, the group considered ways to change chemicals safety testing, and discussed the relevance of potential scientific outcomes to human health."
According to Rudel, the three main findings of the review
- Rodents are a reasonable test models and should be used to test
for dangers to humans.
- The breast can be more sensitive to the chemical exposure than
other tissues, and in some cases the male mammary tissue was most
- Chemical exposure to the developing mammary gland can alter
susceptibility to cancer-causing agents.
In the report, the experts concluded that early life
environmental exposures can alter milk gland development, disrupt
the secretion of breast milk, and increase susceptibility to breast
cancer. "Assessment of mammary gland development should be
incorporated in chemical test guidelines and risk assessment," they
Among the chemicals known to affect breast development and
cancer susceptibility in animal studies, according to the report,
are pesticides such as atrazine, used in agriculture; dioxins, an
industrial pollutant found in some fatty foods; bisphenol A (BPA),
found in some water bottles and canned foods; polybrominated
diphenyl ether (PBDE) flame retardants, and nonylphenol (a
breakdown product found in certain laundry detergents).
While efforts are being made to curb some of these chemical
exposures, the experts said required testing is crucial. Rudel
speculated that women with genetic predispositions to breast cancer
might be at higher risk from these exposures.
The study authors declared no financial conflicts of
The review is "raising a necessary red flag," said Olga
Naidenko, a senior scientist at the Environmental Working Group, an
advocacy organization in Washington, D.C. She reviewed the report
but was not involved in it.
Naidenko agreed that there has been a gap in studying the effect
of chemical exposure on the mammary gland. "For many chemicals,
researchers have not looked at it."
Meanwhile, she said, while some exposures are difficult to
avoid, there are steps to take to minimize exposure.
Avoiding the plastic BPA in bottles (which some manufacturers
have discontinued using) is one step. Buying organic produce
whenever possible may also help consumers avoid the pesticide
Avoiding canned foods (which can also have BPA in the liners)
and the chemical DEHP by focusing on a fresh food diet can also
reduce the levels of those chemicals in the body, according to the
Silent Spring Institute.
To reduce your exposure to harmful chemicals, visit the
Silent Spring Institute.