Estimation of community-wide exposure to bisphenol A via water fingerprinting

Molecular epidemiology in human biomonitoring allows for verification of public exposure to chemical substances. Unfortunately, due to logistical difficulties and high cost, it evaluates only small study groups and as a result does not provide comprehensive large scale community-wide exposure data. Wastewater fingerprinting utilizing metabolic biomarkers of exposure that are excreted collectively by studied populations into urine and ultimately into the community's wastewater, provides a timely alternative to traditional approaches. This study aimed to provide comprehensive spatiotemporal community-wide exposure to bisphenol A (BPA, including BPA intake) using wastewater fingerprinting. Wastewater fingerprinting was undertaken using high resolution mass spectrometry retrospective data mining of characteristic BPA human metabolism marker (bisphenol A sulphate), applied to a large geographical area of 2000 km² and a population of ~1.5 million served by 5 WWTPs (wastewater treatment plants) accounting for >75% of the overall population in the studied catchment. Community-wide BPA intake was found to be below temporary tolerable daily intake (t-TDI) level of 4 μg kg^-1 day^-1 set by the European Food Safety Agency (EFSA) suggesting overall low exposure at 3 WWTPs serving residential areas with low industrial/commercial presence. However, at two WWTPs serving communities with higher industrial/commercial presence, higher BPA sulphate loads corresponding to higher (up to 14 times) BPA intakes (exceeding 10 μg kg^-1 day^-1 at one WWTP and reaching 50 μg kg^-1 day^-1 at the second WWTP) were observed and they are likely linked with occupational exposure. Characteristic temporal variations of BPA intake were noted in most studied WWTPs with the lowest intake occurring during weekends and the highest during weekdays.