Huge Math Error Corrected In Black Plastic Study (arstechnica.com) 16
Ars Technica's Beth Mole reports: Editors of the environmental chemistry journal Chemosphere have posted an eye-catching correction to a study reporting toxic flame retardants from electronics wind up in some household products made of black plastic, including kitchen utensils. The study sparked a flurry of media reports a few weeks ago that urgently implored people to ditch their kitchen spatulas and spoons. Wirecutter even offered a buying guide for what to replace them with. The correction, posted Sunday, will likely take some heat off the beleaguered utensils. The authors made a math error that put the estimated risk from kitchen utensils off by an order of magnitude.
Specifically, the authors estimated that if a kitchen utensil contained middling levels of a key toxic flame retardant (BDE-209), the utensil would transfer 34,700 nanograms of the contaminant a day based on regular use while cooking and serving hot food. The authors then compared that estimate to a reference level of BDE-209 considered safe by the Environmental Protection Agency. The EPA's safe level is 7,000 ng -- per kilogram of body weight -- per day, and the authors used 60 kg as the adult weight (about 132 pounds) for their estimate. So, the safe EPA limit would be 7,000 multiplied by 60, yielding 420,000 ng per day. That's 12 times more than the estimated exposure of 34,700 ng per day. However, the authors missed a zero and reported the EPA's safe limit as 42,000 ng per day for a 60 kg adult. The error made it seem like the estimated exposure was nearly at the safe limit, even though it was actually less than a tenth of the limit. "We regret this error and have updated it in our manuscript," the authors said in a correction.
"This calculation error does not affect the overall conclusion of the paper," the correction reads. The study maintains that flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."
Specifically, the authors estimated that if a kitchen utensil contained middling levels of a key toxic flame retardant (BDE-209), the utensil would transfer 34,700 nanograms of the contaminant a day based on regular use while cooking and serving hot food. The authors then compared that estimate to a reference level of BDE-209 considered safe by the Environmental Protection Agency. The EPA's safe level is 7,000 ng -- per kilogram of body weight -- per day, and the authors used 60 kg as the adult weight (about 132 pounds) for their estimate. So, the safe EPA limit would be 7,000 multiplied by 60, yielding 420,000 ng per day. That's 12 times more than the estimated exposure of 34,700 ng per day. However, the authors missed a zero and reported the EPA's safe limit as 42,000 ng per day for a 60 kg adult. The error made it seem like the estimated exposure was nearly at the safe limit, even though it was actually less than a tenth of the limit. "We regret this error and have updated it in our manuscript," the authors said in a correction.
"This calculation error does not affect the overall conclusion of the paper," the correction reads. The study maintains that flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."
Good. Science works. (Score:4, Informative)
(Slashdot editors take note.)
It would be a sign of their doing actual science if a few psychology papers were corrected sometimes.
Good Questions. (Score:2)
Speaking of actual science, I’d love to see how the FDA determined “safe” limits for ingesting flame retardant on a daily basis, and how often that is re-evaluated. Preferably before the expected class-action against flame retardants happens because of a math “error” that carved out billions in profit for decades while killing millions prematurely.
Sorry for my obvious skepticism, but class-actions like this have practically become an American tradition. I’d prefer to ma
Re: (Score:2)
*EPA not FDA. (Or perhaps it should be both.)
I think this youtuber (Adam Ragusea) told them. (Score:2)
Re: (Score:2)
You really have it out for the slashdot editors huh? Show us where they touched you.
Error of an order of magnitude (Score:2, Flamebait)
When such a big error is made, and the results indicate something that your employers (environmental health advocacy group Toxic-Free Future) may disagree with, and you claim that it does not change the conclusions, I think something smells.
Re: Error of an order of magnitude (Score:2)
Re: (Score:2)
Summary: The conclusions are unaffected because they did not use this number to draw conclusions.
1) The mistake, while big, was also exceptionally easy to spot and correct, due to their very explicit presentation of the multiplication. Anyone could find the mistake my just knowing 6x7=42 and finding out the missing zero (and indeed a youtuber foud it). The affected paragraph (my emphasis):
This compares to a BDE intake in the U.S. of about 250 ng/day from home dust ingestion and about 50 ng/day from food (Besis and Samara, 2012) and would approach the U.S. BDE-209 reference dose of 7000 ng/kg bw/day (42,000 ng/day for a 60 kg adult) (United States Environmental Protection Agency, 2008).
2) Their affected sentence "would approach the dose" is still correct to 1/10 of the exposure limit. 1/10 of limit is al
Re: (Score:2)
I correct myself, as they suggest to replace something with safer materials, they do advocate to somehow prohibit something as a result of their measurements.
But still 1/10 of exposure limit is a significant value that indeed "approaches" the problematic level. For example I don't want leaded paint leakage in drinking water, even if the lead amount is 1/10 of lead exposure limit. I'd want it to be thousands or millions of times smaller than the exposure limit. If you told me lead in my drinking water is 1/1
Re: (Score:1)
pretty much.
60 kg adult? (Score:5, Funny)
Obviously these weren't American scientists...
"The error doesn't affect our conclusion" (Score:3)
Except it absolutely does. The original conclusion was that using black plastic cooking utensils could potentially expose you to a nearly unsafe amount of BDE-209 and that this was a cause for concern. With the math error corrected though, it turns out black plastic cooking utensils don't even remotely expose you to unsafe amounts of BDE-209, and are thus in all likelihood as safe for use as any other utensil. Kudos to the authors for noticing and correcting the error, but they should have gone the distance and admitted that their error made the fundamental thesis of the paper incorrect.
Or there's the other option. (Score:2)
You know what exposes me to zero flame retarding chemicals? Metal and wooden utensils.
I feel like ingesting any of those chemicals isn't worth it. Maybe we shouldn't?
Math isn't a strong point in academia (Score:2)
I'm going to put the blame on highschool and university math teachers. I