Plasticizer Exposure in Southern California Is Through the Roof

We live in a world where plastics and the chemicals associated with them are almost impossible to avoid.

Plasticizer exposure in southern California

New evidence indicates that the average person living in an urban area of southern California is exposed to plasticizers – substances used to soften plastics and make them more flexible – at levels that are "through the roof".

"No matter who you are, or where you are, your daily level of exposure to these plasticizer chemicals is high and persistent," concludes toxicologist David Volz from the University of California, Riverside (UCR).

"They are ubiquitous."

Although not every plasticizer is known to be toxic, several have been associated with serious health problems.

The California State Legislature recently acted to prohibit one such compound, DEHP, in IV bags and medical tubing. According to the state, DEHP (di (2-ethylhexyl) phthalate) may raise cancer risk, damage the reproductive system, and influence children's development.

California has already banned DEHP in children's products above specified concentrations since 2009. Yet the new study indicates that people in the state's southern region remain exposed to high concentrations of this chemical and similar compounds.

Wristbands reveal high levels of plasticizers

The results are based on experiments carried out in 2019 and 2020. Researchers gave silicone wristbands to 137 UCR students, who wore them continuously for five days while following their normal routines.

After collecting the wristbands, scientists from UCR and Duke University tested them for 10 known plasticizers that the silicone could have taken up from the surrounding environment. They were surprised to find remarkably high levels of pollutants that could be hazardous.

"The levels of these compounds are through the roof," says Volz. "We weren't expecting that."

Comparable levels of exposure have also been identified on the US east coast.

Of the total plasticizer mass absorbed by the wristbands in southern California, 94 to 97 percent was linked to DiNP, DEHP and a newer substance known as DEHT.

California has concluded that, like DEHP, DiNP (di-isononyl phthalate) may increase the likelihood of cancer.

DiNP and DEHP are part of the phthalate family, as are most plasticizers in use today. Phthalates occur in food packaging, vinyl, cosmetics and a wide range of household goods.

People can swallow phthalates, absorb them through their skin or breathe them in. They do not remain in the body for long, yet they are now detected in the urine of most Americans, with health effects that remain largely unclear.

Concerns over DiNP, DEHP and DEHT

DEHT is not a phthalate. It was introduced as a supposedly safer replacement, although researchers note that "little is known about the potential toxicity of DEHT in human-relevant model systems."

"Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California," warns the team.

These concerns are shared elsewhere. In response to emerging evidence indicating that the chemicals are likely carcinogenic, the US Environmental Protection Agency (EPA) is evaluating the toxicity of DEHP, DiNP and other phthalates.

An initial draft of the EPA's assessment finds that DiNP damages the liver and may cause cancer at greater exposure levels.

"EPA is concerned about phthalates because of their toxicity and the evidence of pervasive human and environmental exposure to these chemicals," reads the agency site on phthalates.

"Phthalates are used in many industrial and consumer products, many of which pose potentially high exposure. Phthalates have been detected in food and also measured in humans."

The study was published in Environmental Research.