Pharmaceuticals and Personal Care Products in Soil and Water: Mass Spectrometry Insights into Emerging Contaminants

Freshwater systems around the world are under increasing pressure from emerging contaminants, including pharmaceuticals and personal care products (PPCPs). These contaminants persist in the environment due to long half-lives and inefficient removal by wastewater treatment. In Illinois, nine antibiotics were measured in Shoal Creek using LC–MS/MS and found that levels of penicillin G, ampicillin, and cephalexin declined in 2020, likely due to reduced prescribing during the early COVID-19 pandemic, only to rebound the following year. In Mexico’s Yucatán Peninsula, aquifer contamination in a karst system central to local communities and tourism was measured with respect to antibiotics and sunscreens. Hourly sampling at tourist teeming sinkholes revealed sunscreen levels rising and falling with the presence of swimmers, demonstrating how quickly human activity can alter water quality. Complementing these field studies, earthworm, Eisenia hortensis, was exposed to statins in modeled agricultural soil followed by analysis using a benchtop MALDI-MSI to visualize how statins are uptaken. Distinct localization patterns for atorvastatin, lovastatin, and simvastatin revealed both dermal and gastrointestinal uptake, establishing E. hortensis as sensitive sentinels of pharmaceutical contamination in soils, a novel use for this species. Mass spectrometry was utilized to capture their temporal, geographical, and spatial variability of pharmaceuticals in different settings. By linking analytical chemistry with ecotoxicology and field monitoring, our work highlights the essential role of mass spectrometry in measurement science to protect freshwater resources from today’s emerging contaminants.