Chrome Plating Facility Siting Is Associated with Neighborhood Demographic and Socioeconomic Factors and Elevated Per- and Polyfluoroalkyl Substances in Blood in California

Chrome plating facilities release toxic chemicals, including perfluoroalkyl and polyfluoroalkyl substances (PFAS), disproportionately affecting nearby neighborhoods. We analyzed census-tract-level demographic and socioeconomic data using the American Community Survey (2018-2022) alongside 2019 data on chrome plating facilities from the California State Water Board. Two cohorts were included: adolescents from the Study of Latino Adolescents at Risk of Type 2 Diabetes (SOLAR; <i>n</i> = 238; recruited between 2001 and 2012) and young adults from the Metabolic and Asthma Incidence Research study (Meta-AIR; <i>n</i> = 118; 2014-2018). Plasma PFAS were measured via liquid chromatography-high-resolution mass spectrometry. Multiple linear regression assessed associations between neighborhood characteristics, numbers of chrome plating facilities, and PFAS concentrations in participants' plasma. Compared to areas without chrome plating facilities, neighborhoods with one (or more than one) facility had 11% (22%) more Hispanic residents, 6% (9%) more residents without a high school education, and 3% (3%) more individuals below the poverty line. In Meta-AIR, residents within 3 km of these facilities were correlated with elevated plasma PFOS, PFHxS, and PFOA concentrations, and in SOLAR, with PFDA and PFHpS. Chrome plating facilities are concentrated in socioeconomically disadvantaged neighborhoods in California. Proximity to these facilities is linked to elevated blood PFAS levels.