By Nneka Leiba, EWG Research Analyst
Exposure to butylparaben, an ingredient common in personal care products, has been associated with DNA damage in men's sperm, according to an important new study led by John Meeker of the University of Michigan School of Public Health.
The study, published Sept. 28 by the journal Environmental Health Perspectives, also found that the plastic chemical BPA, a synthetic estrogen, damaged DNA in sperm.
The research team, a collaboration of scientists from the University of Michigan, Harvard School of Public Health and the federal Centers for Disease Control and Prevention, called for further investigation of the implications for human health of butylparaben.
Biomonitoring shows these chemicals in our bodies One member of the team is the CDC's Antonia Calafat, a pioneer in the field of biomonitoring, in which blood and urine tests of thousands of Americans are analyzed to determine population-wide exposure to environmental chemicals. The CDC's Fourth National Report on Human Exposure to Environmental Chemicals, released last July, found parabens and BPA in more than 90 percent of Americans tested, with significantly higher concentrations of both chemicals in women compared to men.
Both substances are widespread pollutants in people. An EWG biomonitoring study released in September 2008 detected parabens in the urine of all of 20 teen girls tested. A 2009 EWG study of umbilical cord blood of minority newborns found BPA in 9 of 10 samples.
Ubiquitous chemicals These figures reflect the ubiquitous use of these chemicals in consumer products. Parabens are used to control bacteria and mold and extend the shelf lives of a wide variety of cosmetics and body care products, including moisturizers, face and skin cleansers, shampoos, conditioners, sunscreens, deodorants and antiperspirants, shaving gels, toothpastes and makeup. They also turn up in some foods and pharmaceuticals.
Skin Deep, EWG's cosmetics safety database, indicates that parabens are in almost half of the 60,000-plus products listed, and butylparaben is in almost 3,000 products. You can search the database for paraben-free products here.
What's so bad about parabens? Previous studies have found that parabens can cause skin irritation, allergic reactions, reproductive health problems and cancer, depending on the form of paraben. Public health experts have been particularly concerned about the longer chain parabens -- butylparaben, isopropylparaben, isobutylparaben and propylparaben -- because studies have shown that they can mimic the hormone estrogen and disrupt normal function of the hormone system.
Ethylparaben and methylparaben, the shorter chained parabens, appear to have few associated hazards and weaker endocrine disruption potency.
Parabens are also linked to ecological harm; low levels of butylparaben can kill coral, according to Roberto Danovaro and a team of researchers from Polytechnic University of the Marche in Italy.
So what's a cosmetics user to do? Some companies have already moved away from parabens. But they can still be found in some personal care products. Search Skin Deep to find products without them.
There is much that scientists DON'T know about how the body reacts to parabens. But consumers don't need to wait for definitive conclusions - you can (and should!) read labels carefully and vote with your pocketbook. That way, you'll protect your family and help shift the market towards safer products.