The authors of a paper that went viral with attention-grabbing headlines urging people to throw out their black plastic kitchen tools have corrected the work for a second time.
But a letter accompanying the correction suggests the latest update still fails “to completely correct the math and methodological errors present in the study,” according to Mark Jones, an industrial chemist and consultant who has been following the case. “The errors are sufficient to warrant a restating of the abstract, sections of the paper and conclusions, if not a retraction.”
The paper, “From e-waste to living space: Flame retardants contaminating household items add to concern about plastic recycling,” originally appeared in Chemosphere in September. The study authors, from the advocacy group Toxic-Free Future and the Amsterdam Institute for Life and Environment at Vrije Universiteit Amsterdam, looked for the presence of flame retardants in certain household plastic items, including toys, food service trays and kitchen utensils.
The researchers found toxic flame retardants in several items that wouldn’t ordinarily need fire protection, such as sushi trays, vegetable peelers, slotted spoons and pasta servers. Those items, the authors suggested, could have been made from recycled electronics — which do contain flame retardants.
Then, for kitchen utensils, the authors used findings from another study, which measured how toxic chemicals including BDE-209 transfer from black plastic utensils into hot cooking oil, to estimate potential intake based on findings in their own study. They estimated a daily intake of 34,700 ng/day of BDE-209 from using contaminated utensils, which “would approach the U.S. BDE-209 reference dose” set by the Environmental Protection Agency, they reported.
But the authors miscalculated that reference dose. They had put it at 42,000 ng/day instead of 420,000 ng/day. That hiccup led to the first correction to the paper, published in December. “This calculation error does not affect the overall conclusion of the paper,” the authors said in the corrigendum.
The latest corrigendum, published July 3, states the formula the authors used to estimate exposure to the flame retardant BDE-209 “was misinterpreted.” It continues:
This misinterpretation led to an overestimation of the BDE-209 exposure concentration. The corrected estimated BDE-209 exposure is 7900 ng/day instead of 34,700 ng/day.
“While we regret the error, this is a correction in one exposure example in the discussion section of the study,” lead author Megan Liu of Toxic-Free Future told us by email. “The example was not part of the core research objectives or methods of the study.”
Jones, who spent his career at Dow Chemical, told us the second corrigendum is “inadequate and still incorrect.”
“If the error is sufficiently large to only provide context, the statement in the Conclusions that brominated flame retardants ‘significantly contaminate products’ no longer can be supported and must be corrected or retracted following the reasoning presented in the second corrigendum,” Jones wrote in a letter to the editor published with the second correction.
Jones took to task some of the calculations and other estimates Liu and colleagues made, which the authors refute in a response to Jones’ letter, also published in Chemosphere this week.
The Elsevier journal was delisted from Clarivate’s Web of Science in December for failing to meet editorial quality criteria. Last December an Elsevier spokesperson told us the publisher’s ethics team was“conducting in-depth investigations” of “potential breaches of Chemosphere’s publishing policies.” The journal had published more than 60 expressions of concern in 2024 and has retracted 34 articles so far this year.
Part of delisting means Clarivate no longer indexes the journal’s papers or counts its citations. Google Scholar shows seven citations to Liu’s paper, and Dimensions lists four scholarly citations.
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Decades ago, Chemosphere published “Investigation of polychlorinated dibenzo-p-dioxins, dibenzo-p-furans and selected coplanar biphenyls in Scottish farmed Atlantic salmon (Salmo salar)” where what was deliberately said in the abstract was contradicted by their data.
Abstract: “Farmed and wild Scottish Atlantic salmon were obtained from retail suppliers, producers, and Stirling University in Scotland during January, 1999, for determination of 17 2,3,7,8-Cl-substituted PCDDs and PCDFs, and seven non-ortho- and mono-ortho-PCBs. The study confirms previous reports of relatively high concentrations of PCDDs, PCDFs and, especially, PCBs in farmed Scottish salmon. The results indicate that high consumption of salmon, particularly by children under 5 years, could lead to intakes above the tolerable daily intake (TDI) and tolerable weekly intake (TWI) for these chemicals, especially the PCBs, when combined with mean or high level intakes from the typical UK diet. These results suggest further investigation of farmed salmon and salmon feed, including feed fortified with fish oil and feed fortified with selected vegetable oils, is warranted.”
The impression is created by stating that we tested both farmed and wild salmon, and then saying that PCBs were found in farmed salmon. They did not mention that their data showed no significant difference between farmed and wild salmon, with all the “wild” data falling within the range of variation of the farmed salmon. The source is the ocean water itself for both wild and farmed fish in the same area, but this answer can’t be used to attack farmed salmon without harming commercial wild fisheries.
This was during a time (2002) when environmental activists were attempting to dismantle the small and growing net-pen salmon farming industry by any means necessary, utilizing million-dollar budgets. In the USA, regulations have successfully eliminated the ability to farm fish, and aquaculture has experienced zero production growth. Meanwhile, aquaculture worldwide has increased by 5,000% or more, as the growing world population demands greater efficiency in converting animal feed into meat on the table. Aquatic animals don’t have to stand up or keep warm which allows that farmed salmon to only eat 1.0 kg of salmon feed and produce a kg of live salmon (food conversion rate FCR) where a pig required 3 kg ot make a kg of live pig with a much lower dress-out to meat on the table (more bone and tendon).
A Science article then cited this article as stating that PCB was a significant contaminant of “farmed fish,” and the activist tactic of getting junk science into low-ranking Journals (Chemosphere), then upgrading the false or misleading statements into quality journals to achieve the desired political impact was underway. The Science article by Hites “Global Assessment of Organic Contaminants in Farmed Salmon” then compared low-fat wild dog salmon species from Alaska with high-fat farmed Atlantic Salmon, and reporting the results per gram of whole fish rather than per gram of fat, achieved the desired political results of harming salmon farming and aquaculture in the US and Canada.
A good friend was doing a similar tracing of eNGOs (environmental non-governmental organizations) attacking oyster culture on a different issue with three stages of a poorly supported implied or actual statement in a Junk Journal, then cited by a better Journal, and a “Government report,” then a Quality journal, and then into regulations will millions of dollars and peoples lives impacts. A fantasy became a junk scientific truth.
Feeding the additional 3 billion people expected to inhabit this finite planet, plus the 2 billion already here but unable to access meat, could be achieved through the efficiency advantage of farmed aquatic animals, which don’t have to expend energy maintaining their body temperature or standing upright.