Occurrence of PPCPs and evaluation of their consumption using wastewater-based epidemiology

Pharmaceuticals and personal care products (PPCPs) in wastewater are key indicators of chemical pollution and community health, yet most wastewater-based epidemiology (WBE) studies analyze only the dissolved phase and overlook veterinary contributions. Influent samples in 9 wastewater treatment plants (WWTPs) from Wuhan, China were collected to analyze 73 PPCPs in both dissolved phase (DP) and particulate phase (PP). The occurrence, and spatial-seasonal distribution of PPCPs, and their partitioning were investigated. PPCPs were ubiquitous in both phases, reaching up to 1.65 × 10⁴ ng/L (DP) and 2.00 × 10⁶ ng/g (PP). Inclusion of the PP substantially affected basic measurement of total wastewater concentrations. Partitioning was temperature-dependent, and showed correlation with physicochemical properties in winter and spring. The consumption of human, veterinary and shared pharmaceuticals were separately estimated using WBE. The population-normalized daily consumption of individual human pharmaceuticals ranged from 0 to 1.17 × 10⁵ mg/d/1000 inhabitants. Neglecting the PP of pharmaceuticals leads to consumption estimation errors, reaching up to 96.6 %. Statistical analyses indicated that pharmaceutical consumption varied with disease prevalence, substitution and contraindication practices, and socioeconomic indicators. Linear mixed-effects models further suggested that aging, social-service maturity, population density, per-capita output were associated with consumption variability. The daily Loads of individual veterinary pharmaceuticals ranged from 0 to 1.53 × 10³ g/d. Strong correlations with shared-use pharmaceuticals indicated clear animal-derived inputs. Under the two specific source allocation scenarios, human- and veterinary-use Loads of pharmaceuticals across 9 WWTPs ranged from 3.52 × 10⁵ to 3.83 × 10⁵ g/d and 9.77 × 10² to 4.26 × 10³ g/d, respectively. These findings demonstrate the need to include particulate-phase PPCPs and mixed human-animal sources to improve the accuracy of WBE-based research.