California researchers have found new evidence that several chemicals used in plastic production and a wide array of other industrial applications are commonly present in the blood of pregnant women, creating increased health risks for mothers and their babies. The researchers said their findings add to a growing body of evidence showing that many chemicals people are routinely exposed to are leading to subtle but harmful changes in health. The work should be a “wake-up call” to policymakers, they said. “This is such an important issue,” said Tracey Woodruff, professor and director of the University of California San Francisco (UCSF) program on reproductive health and the environment. “It’s urgent we do more to understand the role that chemicals have in maternal conditions and health inequities. We are being exposed to hundreds of chemicals and this research contributes to better understanding the impact they are having on our health.” The US has the highest maternal mortality in the developed world. Maternal death rates in the US doubled between 1999 and 2019, with mortality highest for Black mothers. In the government-funded study, which was published on Wednesday in the Environmental Health Perspectives journal, a team led by Woodruff and other UCSF researchers said it found multiple harmful chemicals, including types of per- and polyfluoroalkyl substances (PFAS), in the blood of 302 pregnant study participants as well as in the umbilical cord blood of their babies. At least 97% of the blood samples contained a type of PFAS known as PFOS, which has long been associated with multiple serious health problems, including birth defects. The fresh findings of PFOS in maternal blood samples comes despite the fact that the US Environmental Protection Agency (EPA) announced an agreement with PFOS maker 3M more than 23 years ago to phase out the use of PFOS. Other chemicals found in the majority of the pregnant women included abnormal fatty acids and other chemicals used to make pesticides, certain medications and plastics. The researchers said many of the chemicals found in the maternal blood are associated with an increased risk of gestational diabetes, the rates of which are climbing in the US; pre-eclampsia, a serious and sometimes deadly pregnancy complication; and pregnancy-related hypertension. The long-chain fatty acids found have previously only been documented in people suffering from Reye’s syndrome – a serious condition that causes swelling in the liver and brain – but not in healthy individuals, the researchers noted. Those specific types of fatty acids found in the blood of study participants is an area of particular concern because little is known about their health impacts and they are used in the production of plastics, said Jessica Trowbridge, another UCSF-affiliated author of the study. The work, which was funded by the National Institutes of Health, the National Institute of Environmental Health Sciences and the EPA, should be seen as a “wake-up call” for policymakers regarding the effects of the proliferation of plastic chemicals and PFAS, Woodruff said. The research paper comes at the same time that new testing commissioned by the Environmental Working Group (EWG) found the “widespread presence” of PFAS in the drinking water of dozens of US cities. Elevated levels of PFAS were discovered in Austin, Denver and Los Angeles, as well as in smaller communities including Glencoe, Illinois; Monroe, New Jersey; and elsewhere. Earlier this month, the US Geological Survey (USGS), a unit of the US Department of Interior, reported that 45% of US drinking water is contaminated with PFAS. There are more than 12,000 types of PFAS chemicals, which are sometimes called “forever chemicals” because they do not naturally break down and persist not only in the environment, but also in the bodies of animals and people. PFAS have been linked to health problems including cancer, decreased fertility and kidney disease. The chemicals, which have been used to make many popular consumer goods, can leach into drinking water from industrial sites, sewage treatment plants, landfills or certain firefighting foams. US officials have proposed national drinking water standards for six types of PFAS, and the Environmental Protection Agency (EPA) has announced a new framework aimed at preventing some new PFAS chemicals from entering the market. Chemical giants 3M and Dupont, and other manufacturers, recently agreed to settlements that may provide affected communities with billions of dollars to test for the toxic chemicals and remove them from their drinking water. This story is co-published with the New Lede, a journalism project of the Environmental Working Group