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Some phthalates fall in new exposure study, but others are rising in U.S.

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As I looked at list after list yesterday, it occurred to me that it might be quicker to list the categories of goods that don't contain phthalates.

A report published Wednesday on Americans' exposure to phthalates — the plasticizing agents linked in animal studies to a frightening array of health risks— concludes that federal bans on a handful of the chemicals may indeed be lowering their prevalence in our bodies.

However, the prevalence of other phthalates seems to be on the rise, indicating that manufacturers may be responding to the pressures of regulation and public-health campaigns by replacing the targeted chemicals with less infamous but equally worrisome alternatives.

First mention of the report I saw was in Wednesday's edition of Environmental Health News, which handles the topic of phthalate contamination with as much depth and consistency as anyone.

The study itself appears in Environmental Health Perspectives, a journal of the National Institute of Environmental Health Sciences (links at end).

Its lead author, Ami Zota, and her team at the University of California-San Francisco examined urine samples from more than 11,000 Americans during the decade that ended in 2010, measuring changes in prevalence of eight selected phthalates and producing what EHN calls "the first comprehensive, nationwide attempt to document trends in exposure to these widely used chemicals."

It's about time for a study like that, and it may be a measure of sheer ubiquity of phthalates that the results are so mixed. Also, that whatever initiatives by manufacturers or consumers are driving trends in two opposite directions remain somewhat murky.

Widespread applications

Phthalates are additives used to make plastics softer, shinier and silkier, more durable and more viscous, more flexible and long-lived — more wonderful in myriad ways than they already were.

They have been around since the 1920s, but only recently have they caused much concern, thanks to animal studies linking them to endocrine disruption that can show up as birth defects,  learning disabilities, asthma, obesity, diabetes, liver damage  and breast cancer.

And they are pretty much everywhere.

They are especially common in vinyls, particularly as an additive to polyvinyl chloride (PVC). We encounter them most commonly, still, in plastic coatings and packaging but they are also used increasingly in cosmetics, which is kind of a problem because they enter our bodies not only through the uptake of food, drink and airborne dust but also by absorption through the skin.

A highly incomplete listing of everyday products likely to contain phthalates goes like this:

Plastic bags and packaging, textiles and films, lubricants, dispersants, emulsifiers, detergents, waxes, paints, glues, floor tiles, printing inks, children's toys, sex toys, shower curtains, food-storage containers, cleaning products, hairspray, pharmaceutical coatings and even some food products, not to mention medical equipment such as IV tubing and surgical gloves.

As I looked at list after list yesterday, it occurred to me that it might be quicker to list the categories of goods that don't contain phthalates.

Releases into environment

Because phthalates are not chemically bonded to the plastic compounds they improve, but merely attached physically through the application of heat, they don't stay put.

They can also be detached through the application of heat, along with certain solvents and leaching agents, and can then attach themselves to other things. It is believed that one of the principal pathways carrying them into our bodies may be fatty food.

On the plus side, freed phthalates aren't as persistent in the environment as some other chemical nasties, but this does not keep them from accumulating in our bodies. Especially if we are children, still learning what's OK to put in our mouths and what isn't.

Then we excrete them in our urine. Among the 11,000 Americans whose urine was tested for this study between 2001 and 2010, 98 percent contained some phthalates. As in previous studies, prevalence was higher in children than in adults, in people of color and the poor.

Eight particular compounds were tested, including the three that were banned in children's toys by federal law after 2008. These are known as DEHP, DnBP and BBzP, and their prevalence declined, respectively, by 37%, 17% and 32%.

Three more were banned in toys so small that children might put them in their mouths, and in certain child-care items. Known as DiNP, DiDP and DnOP, these increased in prevalence, respectively, by 149%, 15% and  25%.

Two more, unaddressed by the bans and restrictions, rounded out the list: DEP, which declined by 42%, and DiPB, which increased by 206%.

Influence of anti-phthalate campaigns

What explains these trends? From the report, lightly condensed:

As expected, we observed declines in metabolites of those phthalates that have been the focus of legislative activities. However, legislative activity does not entirely explain the observed trends.

For example, among the phthalates in our study, we found the largest reductions in metabolite concentrations of DEP, a phthalate used in fragrances that is neither regulated in the US or the EU.

The success of advocacy efforts by public health and environmental organizations such as the Campaign for Safe Cosmetics, may partly explain some of our findings. Over the last decade, it has used a multi-prong strategy to reduce phthalate exposures from cosmetics by increasing consumer awareness of phthalate toxicity, creating a market for phthalate-free products, and pressuring the cosmetics industry to disclose chemical ingredients in their products.

There has been an increased consumer demand for alternative products making it the fastest growing sector of the cosmetics market.  Since 2004, over 1,000 companies have pledged to remove chemicals of concern from personal care products and increase transparency of chemical ingredients in their products.

{However,] the rise in metabolite concentrations of DiBP and some high molecular weight phthalates suggest that manufacturers may be using them as substitutes for other phthalates even though the U.S. Environmental Protection Agency has expressed concern about their use.

This is the kind of story that makes me glad my child-rearing years are behind me, that I don't wear makeup and that my tastes in toiletries are fairly spartan and traditional — not that this guarantees my choices to be phthalate-free.

Database of risky products

So, over the weekend, I may try looking up some of our household staples on a new product database launched this month  by California's Department of Health as part of its Safe Cosmetics Program.

Under California law, companies must report to the program if any of the products they sell there contain an ingredient the state considers a cause of cancer, birth defects or harm to reproductive health. The data can be searched by product type, product name, brand name or company name.

Not all manufacturers are covered — those with aggregate annual sales under $1 million for all  products get a pass — and the database won't tell you how much of, say, a particular phthalate is in your nail polish.

But it's a start, at least, and you can find it here.

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The EHN story can be read here, and the full study as published in Environmental Health Perspectives is available here.

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