Brent Collett already had some inklings about the pervasiveness of hormone-mimicking chemicals such as phthalates and Bisphenol-A (BPA).
He knew, for example, that salmon in the Puget Sound near his Seattle-area home were showing signs of exposure to the chemicals, including feminization and intersex traits. And Collett knew the chemicals had been linked to an increasing number of health problems in humans as well, especially in developing babies and children.
But he still couldn't have predicted the test results that came back after his family, including his two kids, restricted themselves for five days to a diet of organic foods that never touched plastic between the farm and their plates. The milk, for example, came in glass bottles from a local dairy with grass-fed cows.
"We were really surprised," said Collett, recalling when his family got the news that their levels of these chemicals, commonly used to soften and harden plastics, had actually gone up by the end of their participation in the small study, published in February. On average, members of the five local families who received the catered foods saw their BPA levels double and levels of one common phthalate, DEHP, rise by nearly 24-fold. Further tests revealed heavy doses of the chemicals in the milk and coriander spice.
"Even if you go to extremes, it's really hard for a consumer to limit exposure to some of these things," said Collett. "It's probably impossible."
In the last few weeks, we've learned that the stealth chemicals may harm the brain, raise the risk of asthma and obesity, and slow down the growth of a developing baby. That's on top of a list that already includes diabetes, infertility and certain cancers. Meanwhile, experts from the United Nations and the World Health Organization declared in February that endocrine disruptors -- so-called because they disrupt proper hormone functioning -- were "a global threat."
Dr. Sheela Sathyanarayana, the lead author of the study and an environmental health pediatrician at the University of Washington in Seattle, has been studying the chemicals for about a decade -- during which time we've seen BPA banned from baby bottles and phthalates banned from kids' toys. "We used to say that plastic bottles, makeup or other consumer plastics were the major source of exposure," she said. "Now we know it's most likely diet."
The results of the new study suggest that while avoiding plastics when storing, cooking and eating foods can help reduce exposures, it may not be enough. Experts suggest that government and industry need to better track the source of these chemicals in order to start eliminating them from the food chain.
"The hardest part is that we just don't know where the contamination is coming from," said Sathyanarayana. "This could be a wake-up call for food manufacturers."
Some makers of the chemicals don't necessarily see their products as culpable, however. ExxonMobil, a major manufacturer of phthalates, told The Huffington Post that their products have been "thoroughly tested," and that "evaluations by multiple government agencies in the U.S. and Europe show they are safe in their current applications."
Shanna Swan, a toxic chemical expert at Mount Sinai Hospital in New York, suggested that part of the problem is simply that "people want these products."
"We can make them with alternative chemicals," she said. "But switching over is difficult and expensive for companies."
What's more, without proper testing, the substitutes can be just as risky, as HuffPost has reported with the exchange of polychlorinated biphenyls (PCBs) for polybrominated diphenyl ether (PBDE), and more recently, swapping out BPA for Bisphenol-S (BPS).
Overall, some 80,000 chemicals are currently on the market, with only a small portion tested for safety. Even fewer have been evaluated for specific effects, such as the scrambling of hormone signals.
Sathyanarayana noted the great lengths her team went to in order to ensure that they were delivering uncontaminated food to the study volunteers. In addition to storing the milk in glass bottles, they had produce delivered in wood crates, and all meals were cooked without the use of plastic utensils.
How such high levels of chemicals ended up in the coriander spice, no one is sure. "I hope that is a fluke, in the sense that it just happened to be this one manufacturer and this one spice," said Sathyanarayana.
As for the milk, Sathyanarayana suggested that the most likely source was the flexible plastic tubing used by dairies to milk the cows. The soil might be another possibility. Pesticides, too, can contain endocrine disruptors.
"We just don't milk a cow with our hands anymore," said Swan. "Whenever food is processed through a tube, whether it's milk in a milking machine, or tomato sauce going into the bottle, it's going to pick up phthalates. We see that very dramatically in the neonatal intensive care nursery."
Kelli Ludlum, director of congressional relations at the American Farm Bureau Federation, noted that her industry group is unaware of how milk might become tainted before going into packaging. She added that they are aware, however, about chemical compounds leaching from packaging, although she said this isn’t so much a concern for dairy products given their short shelf life. “It’s more an issue if you rinse out a milk carton and reuse or reheat it,” said Ludlum.
Tine Fierens, of the Flemish Institute for Technological Research in Belgium, has been looking into these alternative avenues of contamination. In his research, Fierens has found higher levels of DEHP, a common phthalate, in raw cow's milk that came from outside of Europe as compared to European dairies. The difference, he told HuffPost in an email, is likely due to the differences in legislation. DEHP is no longer allowed to be used in milk tubings in Europe.
Fierens' research has also found that plastics are just the tip of the iceberg. Because phthalates and BPA are also used as adhesives and coatings, he said, foods and drinks packed in printed cardboard or cans may actually contain more contaminants than those encased in plastic.
While much is out of a consumer's control, Swan did note that there are some communities that seem to naturally steer clear of the hormone hazard. She recently studied a Mennonite community that ate mostly fresh, unprocessed foods that were farmed without pesticides, and generally avoided personal care products. She found their bodies carried very little BPA or phthalates.
Swan recalled that one woman had used hairspray -- evidence of which appeared as detectable phthalates in her urine.
For those not willing to go to such extremes, there are still many exposure-limiting steps to take, such as choosing personal care products carefully, not microwaving meals in plastic, and eating fresh, local foods low in fat. Fierens also emphasized eating a diet that is as varied as possible. "Don't always buy food from the same brand, that is packed in the same packaging material, from the same shop," he said.
Sathyanarayana suggested that the repetitive diet of the study likely contributed to the elevated exposure. This is reassuring -- but only to a point.
"We need more information," she said. "When it comes to our food supply, we just don't know a lot about it."