Scientists have documented for the first time that several phthalates – controversial chemicals used to make vinyl and fragrances – are declining in people while several others are rising. The study, published today, is the first comprehensive, nationwide attempt to document trends in exposure to these widely used chemicals over the past decade.
The researchers said the results suggest that manufacturers may be reformulating products in the wake of a federal regulation and environmental groups’ campaigns.
Three compounds banned in U.S. toys and other children's products in 2008 have declined. But since other phthalates are increasing, it's possible that industries have substituted them in some products.
“Our findings suggest that interventions may be working, though legislation didn’t entirely predict which levels went up or down,” said Ami Zota, a George Washington University assistant professor of environmental and occupational health who led the research when she was at the University of California, San Francisco.
Phthalates have been linked to a variety of health effects in animal tests and some human studies, including hormone disruption, altered male genital development, diabetes, asthma, attention disorders, learning disabilities and obesity.
Chemical industry representatives said that the traces found in most products are small, and not likely to cause harm.
“Despite the fact that phthalates are used in many products, exposure is extremely low – much lower than the levels considered safe by regulatory agencies,” said Liz Bowman, a spokesperson for the American Chemistry Council, which represents manufacturers of phthalates and other chemicals.
The researchers analyzed the urine of more than 11,000 American adults and children between 2001 and 2010. They discovered that people are still widely exposed to phthalates; some were found in 98 percent of people tested.
Breakdown products of three phthalates that Congress banned from toys and other children’s products were significantly lower in 2010 than in 2001. One of the compounds, known as DEHP, found in some toys, blood bags and medical tubing, decreased 37 percent.
While DEHP remained higher in children than adults, the levels dropped faster in children, narrowing the gap over time, according to the study, which was published online in the journal Environmental Health Perspectives. The study did not look at children under 6, who may be more highly exposed to phthalates and more susceptible to adverse health effects.
“Today phthalate usage is virtually nonexistent in toys. They have been replaced by non-phthalate substitutes,” said Alan Kaufman, senior vice president of technical affairs for the Toy Industry Association. He added that the toy industry began to transition away from phthalates years ago, but that the trend has been accelerated by regulatory actions in the U.S. and European Union.
However, three other phthalates used in some children’s products increased between 2001 and 2010. DiNP rose 149 percent, while DnOP increased 25 percent and DiDP rose 15 percent. The three were temporarily banned in 2008 in U.S. toys and childcare products that could be put in a child’s mouth. The Consumer Product Safety Commission is currently debating whether to lift the restrictions or make them permanent.
In addition, last month, California added DiNP to a list of chemicals known by the state to cause cancer. That could lead to warning labels on consumer products sold in the state.
DBP, which dropped 17 percent in people in the decade studied, was used in nail polish until a few years ago, when most major manufacturers eliminated it. Benzylbutyl phthalate, used in vinyl tiles and sealants, decreased 32 percent. Both compounds were part of the 2008 ban for children's products.
A phthalate used primarily for fragrance – diethyl phthalate or DEP – decreased 42 percent. While it is not subject to U.S. bans, advocacy groups have pressured the cosmetics industry to remove it from products with initiatives such as the Campaign for Safe Cosmetics.
The study authors saw a steeper decline in DEP in adults and adolescents than in children, who may be less likely to use personal care products.
Joe Braun, an epidemiologist at Brown University who was not involved in the study, said “the age-dependent patterns confirm what we suspect about where these exposures are coming from.”
“These findings are not as reassuring as they could be,” Braun added.
For instance, DiBP, used in some nail polishes and personal care products, increased 206 percent in the decade studied.
Manufacturers may be using some phthalates as substitutes for the ones that declined, the researchers said. But it’s hard to know because they aren’t required to list ingredients on many consumer products.
"We are not confident that cosmetics manufacturers are replacing toxic phthalates with safer alternatives," said Janet Nudelman, co-founder of the Campaign for Safe Cosmetics.
The Personal Care Products Council, a Washington D.C.-based trade group, did not respond to requests for comment on the findings.
“There’s a clear need for better data reporting on ingredient composition of everyday consumer products so that we can fully understand the impacts of legislation and consumer pressure,” said Zota, who co-authored the study with UC San Francisco Professor Tracey Woodruff and Centers for Disease Control and Prevention scientist Antonia Calafat.
This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.