Estimate public exposure to PAHs and environmental risks through wastewater-based epidemiology

 Waterwater-based epidemiology (WBE) may be able to monitor public health emergencies by analyzing human urinary biomarkers in wastewater. This work proposes a novel approach utilizing WBE for the spatial and temporal evaluation of PAHs exposure using hydroxyl derivatives of PAHs. These are 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyfluorene, 9-hydroxyphenanthrene, 1-hydroxypyrene and 3-hydroxybenzo(a)pyrene. Most target markers were found at quantifiable concentrations in raw and treated wastewater. The total loads identified in raw sewage ranged from 88.33 g/day  to 154.77 g/day during the summer period and from 137.66 g/day to 283.78 2 g/day during the winter period. The obtained results for the removal efficiencies of OH-PAHs indicate a seasonal dependency in their degradation. Removal efficiencies were higher in January compared to August.

The results of the back calculations allowed to estimate that during the summer, on average, a resident of Krakow could absorb approximately 2.1 µg of the assessed OH-PAHs per day, while in winter, this value increased to 4.1 µg. This is close to the reported in the literature value that the total daily exposure to OH-PAHs is estimated at 3 µg/day.

Moreover, the risk quotation (RQ) values on the base of acute and chronic data base for compounds present in effluents were calculated. The RQ values in January were relatively low, but in August the RQ values were higher, indicating a high concentration of effluent and nitrogen in summer as these compounds were removed in winter and summer.

To the authors’ knowledge, this is the first time wastewater profiling of OH-PAHs in wastewater for the evaluation of exposure to PAHs have been used, also their removal as well emission with effluent were determined.