Environmental Health Risks

Math errors are the plague of the writing class. Reporters and editors are frequently flummoxed by simple slip-ups and held up to public ridicule. But scientists? They're expected to get it right.

Thus, it must be doubly embarrassing for the editors of the journal Chemosphere. They recently posted a correction to a study about toxic flame retardants in kitchen utensils made of black plastic.

The study had warned that these utensils might pose a significant health risk, leading to media reports advising people to replace their kitchen spatulas and spoons.

“We know for a fact that these toxic flame retardants can migrate out of the products that they’re in and into our environment,” said Megan Liu, who co-authored the study. Heat, she noted, can make it easier for these chemicals to leach out.

Just a few digits off

However, it turns out that the authors made a math error that overstated the risk.

The original study estimated that kitchen utensils could transfer 34,700 nanograms of a toxic flame retardant (BDE-209) per day, which they compared to the EPA's safe level of 420,000 nanograms per day.

But the authors mistakenly reported the EPA's safe limit as 42,000 nanograms per day, making the estimated exposure appear much closer to the safe limit than it actually was. After correcting the error, they clarified that the actual exposure was much lower than previously suggested.

Despite the error, the study's overall conclusion remains the same, the authors said. The corrected study still states that flame retardants in plastic products are a significant concern, but the risk to consumers is much lower than initially reported.

"This calculation error does not affect the overall conclusion of the paper," the correction reads. The corrected study still ends by saying that the flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."

“There’s really no safe level of exposure to these harmful toxic flame retardants,” Liu said, adding these substances can build up in the body.

The federal government is banning perchloroethylene (PCE or Perc), a chemical used in dry cleaning, adhesives, and industrial products, due to its link to cancer and other health risks.

While occasional exposure from wearing dry-cleaned clothes poses minimal risk to consumers, spills and leaks from dry cleaners can contaminate drinking water and air, posing greater risks for nearby residents.

“U.S. communities large and small have tap water with potentially harmful levels of TCE, and they may not be aware of this risk,” said Tasha Stoiber, Ph.D., senior scientist with the Environmental Working Group. 

“People can be exposed to this toxic solvent at home not just by drinking TCE-contaminated water but also by inhaling it when bathing and washing dishes. The EPA’s final rule will help to finally end most uses of this dangerous chemical,” added Stoiber.

The ban will phase out Perc in consumer and many commercial uses over the next 10 years. Some states and cities already restrict its use, and many dry cleaners have switched to safer alternatives. Workers in industries using Perc face the highest risks.

The EPA is also banning another harmful chemical, trichloroethylene (TCE), found in some cleaning products and linked to water contamination cases. Experts advise testing well water for such chemicals and using filters if needed.

For most people, occasional exposure to these chemicals is limited, and focusing on healthy habits like eating well and exercising is key to reducing overall health risks.