Embarrassing math mistake ‘scared people out of wearing pants’ because of toxic black kitchen utensils

Earlier this year, a study was conducted on people Throw their black spoons and other black kitchen utensils for fear of toxic chemicals, but it turns out the alarming warning was based on a major mathematical error.

In October, researchers from the environmental health advocacy group Toxic-Free Future and the Amsterdam Institute for Life and Environment published a report He studies In the magazine Atmosphere Which suggests the black plastic kitchen utensils released alarming amounts of a toxic fire-retardant chemical. This warning took the Internet by storm, convincing legions of people Toss their trusty black spoons. However, a chemist in Canada has now discovered a mathematical error in the ill-fated study that upends its results, or at least complicates them, as first reported by the journal Science. National Post.

the Atmosphere The study was based on the idea that some black e-waste — which contains a fire-retardant chemical, which is linked to serious health risks — is being recycled and turned into household products sold in the United States. As a result, researchers sought to estimate how much of these chemicals seep from black plastic kitchen utensils and contaminate people while cooking.

The team concluded that using this type of black kitchen utensil could result in people absorbing an average daily amount of 34,700 nanograms of decabromodiphenyl ether, also known as BDE-209. This is significantly higher than previous modeling estimates of human exposure through other means, and alarmingly close to the US Environmental Protection Agency (EPA) reference dose (recommended safety limit) of 42,000 nanograms per day for 60 kg (132.3 lbs). adult.

There’s just one problem: the EPA’s reference dose for BDE-209 is not 42,000 nanograms per day. The agency’s reference dose is 7,000 nanograms per kilogram (2.2 pounds) of body weight per day. When the researchers calculated this for a 60-kilogram (132.3 lb) individual, they multiplied 60 by 7,000 and got 42,000, but the correct result is 420,000.

The main point of the study — that recycling some e-waste puts a toxic chemical into kitchen utensils sold in the United States — remains true. However, the error changes its effects dramatically, warning readers that their black kitchen utensils are exposing them to more than 80% of the EPA reference dose. In fact, less than 10%.

“I think it changes the flavor of the whole thing somewhat when you’re wrong by a factor of ten in comparing something to a reference value,” said Joe Schwartz, director of McGill University’s Office of Science and Society and a plastics expert who discovered the error while reading the study. National Post. “All of this deserves attention,” he added. “But you have to do it right, and you have to make sure your numbers are right before you scare people away.”

Megan Liu of Toxic-Free Future, who co-led the study, said they provided a correction for the “typo” but the error “does not affect our results,” according to the British newspaper “Daily Mail”. National Post. “The levels of flame retardants we found in black plastic household items continue to be of significant concern, and our recommendations remain the same,” she added.

Tell that to all the people who threw away their favorite spoons because the warning was off by a factor of 10.