“Where do these chemicals come from?” Tracing-back chemical exposures to consumer products

Abstract

BACKGROUND AND AIM: Non-targeted analysis has enabled us to screen biological samples for a broad spectrum of chemical compounds that would otherwise remain undetected with traditional targeted analytical techniques. While our previous studies have presented a number of man-made chemicals in human serum, the sources of many of these chemicals remain unknown. The aim of our study was to understand the sources of a group of chemicals, some of which are not actively biomonitored, (n=18; phenols, surfactants and per- and polyfluoroalkyl substances) identified and quantified in 300 maternal and 300 cord matched blood samples collected at delivery and analyzed with a non-targeted analysis workflow. METHODS: We matched measured concentrations in serum to questionnaire responses about participants’ use of consumer products in homes (n total = 148 questions) and evaluated their relationship using linear models. We also used an indoor environment multimedia fate model to test observed relationships by simulating concentrations of the chemicals in the carpets, furniture, dust and indoor air to evaluate the potential of exposure based on chemical mobility. RESULTS:We found strong positive correlations (r 0.5 and p-value 0.05) between concentrations in serum and carpets (installation and treatment), furniture (renovation and treatment), and floor (installation and treatment). One example where we measured widespread exposure in pregnant women is 4-nitrophenol. Our modeling calculations estimated that when 4-nitrophenol is emitted from carpets, it is expected to be resuspended and redeposited on vinyl floors and other surfaces leaving only a small fraction in the air available for inhalation (0.01 % of the total mass). Our modeling calculations also estimated that, due to its low volatility, the main route of exposure to 4-nitrophenol in the indoor environment is through dermal contact. CONCLUSIONS:Integrating non-targeted analysis with questionnaire data and multimedia modeling provided unique insights into the sources of environmental chemicals and pathways of exposure. KEYWORDS: exposome, non-targeted analysis, chemicals, exposure, modeling