Despite levels of older “forever chemicals” declining in many foods over the past 20 years, a new study shows that drinking water, seafood, eggs, and brown rice remain significant sources of PFAS exposure for adults.
Food has been identified as a primary means of PFAS exposure for many years, with these chemicals lingering in the environment and being linked to serious health risks.
A new study from researchers at Boston University School of Public Health (BUSPH) finds that exposure to PFAS through food has actually declined among adults over the past 20 years.
However, the study also highlights that drinking water is still a significant source of PFAS exposure.
Seafood, eggs and rice among top contributors to PFAS exposure
The research examined the relationship between diet and drinking water and blood levels of “legacy” PFAS – older chemicals that were phased out in the US in the early 2000s.
The team analysed blood samples from California residents and found that PFAS exposure was linked to eating seafood, eggs, and brown rice. Surprisingly, they found fewer food-related connections than earlier studies suggested.
They also discovered that people living in areas with detectable PFAS in their tap water had higher levels of the chemicals in their blood.
However, these levels were lower than those found in severely contaminated regions.
Harmful chemicals in drinking water must be regulated
The study provides the first analysis of the effects of simultaneously consuming a diet and drinking water on PFAS concentrations in blood, filling a critical gap in research on this topic.
Most US information on PFAS in food relies on earlier European studies, which cannot be fully applied to the US population or lifestyle due to differences in sampling times, diets, food production, and industrial practices.
To understand and mitigate the harmful effects of PFAS on individuals and the environment, the US needs current data on the possible contributing sources of PFAS exposure.
“While we observed fewer dietary associations compared to previous studies, diet and water may still be an important source of exposure in the general population,” said study lead and corresponding author Dr Emily Pennoyer.
“These findings emphasise the need to continue ongoing efforts to regulate PFAS in drinking water.”
Shifts in dietary PFAS exposure
For the study, Dr Pennoyer and colleagues at BUSPH, the California Department of Public Health (CDPH), and the California Department of Toxic Substances Control estimated associations among legacy serum PFAS concentrations, self-reported food consumption, and PFAS concentrations in public drinking water supplies.
The 700 adult participants were selected from the California Regional Exposure Study, conducted from 2018-2020, which measures and compares environmental chemicals in people across the state to better understand how to reduce chemical exposure and improve public health.
The participants provided survey responses detailing demographic information and the frequency with which they consume red meat, poultry, seafood, dairy, eggs, potatoes, brown rice, takeaways, and packaged foods that are heated at home. The researchers observed associations between legacy serum PFAS and the consumption of seafood, eggs, and brown rice.
However, overall, PFAS exposure through food appeared to be lower than in earlier studies in other populations – a surprising result to the team.
“It is encouraging that we see fewer associations with food in this study, but concern about PFAS in some food groups remain,” commented study co-author Dr Nerissa Wu, biomonitoring California program lead at CDPH.
“We will continue to work to understand how to lower PFAS levels in the California food supply.”
