Scientists detect 55 never-before-reported chemicals in people – 42 ‘mysterious chemicals’ whose sources are unknown

Chemist working in laboratory

Scientists at the University of California at San Francisco detected 109 chemicals in a study of pregnant women, including 55 chemicals never before reported in humans and 42 “mystery chemicals,” whose sources and uses are unknown.

The chemicals most likely come from consumer products or other industrial sources. They have been found in both the blood of pregnant women and their newborns, suggesting that they travel through the mother’s placenta.

The study was published on March 16, 2021 in Environmental science and technology.

“These chemicals have probably been present in humans for some time, but our technology is now helping us identify more of them,” said Tracey J. Woodruff, PhD, professor of obstetrics, gynecology and reproductive sciences at UCSF.

A former US Environmental Protection Agency scientist, Woodruff heads the Program on Reproductive Health and the Environment (PRHE) and the Center for Environmental Research and Translation for Health (EaRTH), both at the UCSF.

“It is alarming that we continue to see certain chemicals travel from pregnant women to their children, which means these chemicals can be with us for generations,” she said.

The science team used high-resolution mass spectrometry (HRMS) to identify man-made chemicals in humans.

But, although these chemicals can be tentatively identified using chemical libraries, they need to be confirmed by comparing them to pure chemicals produced by manufacturers which are known as “analytical standards”. And manufacturers don’t always make them available.

Recently, for example, chemicals maker Solvay stopped providing access to a chemical standard for a perfluorooctanoic acid. acid (PFAS) which emerged to replace the eliminated PFAS compounds. The researchers used this chemical standard to assess the presence and toxicity of the replacement PFAS.

“These new technologies hold promise in allowing us to identify more chemicals in people, but the results of our study also show that chemical manufacturers must provide analytical standards so that we can confirm the presence of chemicals and assess their toxicity ”, said co-author of the author Dimitri Panagopoulos Abrahamsson, PhD, postdoctoral fellow at the PRHE of the UCSF.

The 109 chemical researchers found in blood samples from pregnant women and their newborns are found in many types of products. For example, 40 are used as plasticizers, 28 in cosmetics, 25 in consumer products, 29 as pharmaceuticals, 23 as pesticides, three as flame retardants and seven are PFAS compounds, which are used in carpets, upholstery fabrics and other applications. Researchers say it’s possible that there are other uses for all of these chemicals as well.

The researchers report that 55 of the 109 chemicals they tentatively identified do not appear to have been previously reported in people:

  • 1 is used as a pesticide (bis (2,2,6,6-tetramethylpiperidini-4-y) decanedioate)
  • 2 are PFAS (methyl perfluoroundecanoate, most likely used in the manufacture of non-stick cookware and waterproof fabrics; 2-perfluorodecyl ethanoic acid)
  • 10 are used as plasticizers (e.g. Sumilizer GA 80 – used in food packaging, paper plates, small appliances)
  • 2 are used in cosmetics
  • 4 are high volume production chemicals (HPV)
  • 37 have little or no information on their sources or uses (for example, 1- (1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl) -3-dodecylpyrrolidine-2,5-dione , used in the manufacture of perfumes and paints – this chemical is so little known that there is currently no acronym – and (2R0-7-hydroxy-8- (2-hydroxyethyl) -5-methoxy-2-, 3-dihydrochromene-4-one (Acronym: LL -D-253alpha), for which there is no information on its uses or sources

“It is of great concern that we cannot identify the uses or sources of so many of these chemicals,” said Woodruff. “The EPA needs to do a better job of requiring the chemical industry to standardize its reporting on chemical compounds and their uses. And they must use their authority to ensure that we have adequate information to assess potential health risks and remove chemicals from the market that pose a risk. ”

Reference: “Suspect Screening, Prioritization and Confirmation of Environmental Chemicals in Mother-Newborn Couples in San Francisco” by Aolin Wang, Dimitri Panagopoulos Abrahamsson, Ting Jiang, Miaomiao Wang, Rachel Morello-Frosch, June-Soo Park, Marina Sirota and Tracey J. Woodruff, March 16, 2021,, Environmental science and technology.
DOI: 10.1021 / acs.est.0c05984

Authors: Aolin Wang and Marina Sirota, from UCSF, joined Woodruff and Panagopoulos Abrahamsson in the study; Ting Jiang, Miamiao Wang, and June-Soo Park of the California Environmental Protection Agency; and Rachel Morello-Frosch of UC Berkeley.

Funding: This study was funded by NIH / NIEHS grant numbers P30-870 ES030284, UG3OD023272, UH3OD023272, P01ES022841, 871 R01ES027051 and by US EPA grant number 872 RD83543301.