Longitudinal mass loads of phthalate esters in sewage sludge and their association with public health and social measures for COVID-19 control in Beijing

This study examines the concentrations and population-normalized mass loads (PNML) of five phthalate esters (PAEs) and four metabolites (mPAEs) in 390 sewage sludge samples collected from two municipal wastewater treatment plants in Beijing between July 2020 and June 2023, amidst the COVID-19 pandemic. Through GC/MS analysis, the compounds were simultaneously quantified, with peak concentrations in 2020. Bis(2-ethylhexyl) phthalate (DEHP) and mono(2-ethyl-5-oxohexyl) phthalate emerged as predominant PAE and mPAE congeners with concentrations of 78.7 µg/g dw and 259 µg/g dw, respectively. DEHP and monobenzyl phthalate had the highest median PNML among PAEs and mPAEs, respectively, at 128 µg/inhabitant/day and 798 µg/inhabitant/day. Linear regression models revealed a positive association between PNML of PAEs and five public health and social measures aimed at mitigating the COVID-19 pandemic. This research contributes to the expanding body of literature by emphasizing the role of wastewater-based epidemiology as a vital tool for monitoring community-level exposure to environmental contaminants. [Display omitted] •Novel use of sewage sludge analysis to assess phthalate exposure during the COVID-19 pandemic.•Positive association found between COVID-19 policy stringency and phthalate mass loads.•DEHP and DBP identified as the most prevalent phthalate esters in Beijing's sewage sludge.•Advances wastewater-based epidemiology as a tool for monitoring community-level environmental exposures.