Microplastic became ubiquitous in popular science writing in the Covid years. As The Climate Wars noted in 2022, https://vvattsupwiththat.blogspot.com/2022/10/science-is-settled.html
some magazines, Wired included, even speculated on them changing climate.
In 2024 I read with puzzlement the first of many press reports, in the Guardian and elsewhere, claiming that scientists at the University of New Mexico had found massive amounts of "microplastic" particles in all sorts of human tissues, amounting to body burdens reckoned in grams- " the equivalent of a plastic credit card. The Guardian article was accompanied by a color photo of a small tray full of plastc shards, some of millimeter dimensions, much in keeping with its vociferous campaign against marine pollution with macroplastic "nurdles" and sixpack rings.
No explanation was offered as to how these shards got into blood vessels. or crossed the blood-brain barrier famed for keeping out even the smallest bacteria.
Finding few details in the NM group's paper in Nature, a journal whose review processes I know at first hand from having published in its pages, I sent the following note to one of the authors:
Microplastics methodology
| May 22, 2024, 1:46 PM | |||
| ||||
‘A bombshell’: doubt cast on discovery of microplastics throughout human body
Exclusive:
Some scientists say many detections are most likely error, with one high-profile study called a ‘joke’
High-profile studies reporting the presence of microplastics throughout the human body have been thrown into doubt by scientists who say the discoveries are probably the result of contamination and false positives. One chemist called the concerns “a bombshell”.
Studies claiming to have revealed micro and nanoplastics in the brain, testes, placentas, arteries and elsewhere were reported by media across the world, including the Guardian. There is no doubt that plastic pollution of the natural world is ubiquitous, and present in the food and drink we consume and the air we breathe. But the health damage potentially caused by microplastics and the chemicals they contain is unclear, and an explosion of research has taken off in this area in recent years…
micro- and nanoplastic particles are tiny and at the limit of today’s analytical techniques, especially in human tissue. There is no suggestion of malpractice, but researchers told the Guardian of their concern that the race to publish results, in some cases by groups with limited analytical expertise, has led to rushed results and routine scientific checks sometimes being overlooked.
The Guardian has identified seven studies that have been challenged by researchers publishing criticism in the respective journals, while a recent analysis listed 18 studies that it said had not considered that some human tissue can produce measurements easily confused with the signal given by common plastics.
There is an increasing international focus on the need to control plastic pollution but faulty evidence on the level of microplastics in humans could lead to misguided regulations and policies, which is dangerous, researchers say. It could also help lobbyists for the plastics industry to dismiss real concerns by claiming they are unfounded. While researchers say analytical techniques are improving rapidly, the doubts over recent high-profile studies also raise the questions of what is really known today and how concerned people should be about microplastics in their bodies.
