Pharmaceutical Pollution in Agricultural Environments: Fate, Behaviour, Uptake by Crops, and Implications for Human Health

Pharmaceutical pollution is ubiquitous in the environment, and there is widespread concern over the potential effects on human and ecological health. Agricultural systems are of particular concern due to their proximity to multiple sources of pharmaceutical contaminants and their position at the interface between human activities and natural ecosystems. Whilst numerous studies have examined pharmaceutical uptake by crops, inconsistent methodologies and limited understanding of influencing factors have hindered the ability to draw cohesive conclusions and effectively utilise current data.
This thesis investigates the key factors influencing pharmaceutical uptake by crops and the associated risks to human health. A novel database, the Uptake of Pharmaceuticals Into Crops (UTOPIC) database, was developed to systematically compile global evidence on pharmaceutical uptake by crops. The UTOPIC database was applied to a systematic review and meta-analysis to evaluate the current state of the science and elucidate the factors affecting pharmaceutical uptake by crops. The UTOPIC database also informed a human health risk assessment, evaluating potential exposure through consumption of contaminated crops.
Findings indicate that soil physicochemical properties are a key factor influencing pharmaceutical behaviour in the environment. Despite this, few studies accounted for soil variability in their experimental designs. Targeted experimental investigations demonstrated that pharmaceutical fate and crop uptake varied significantly with soil type, with soil porewater concentrations emerging as a key determinant of bioavailability and subsequent uptake.
These insights have critical implications for environmental risk assessments, which often do not account for the potential variability across diverse soil systems. Overall, this thesis advances understanding of pharmaceutical behaviour in agricultural environments and provides essential tools and recommendations for more accurate assessment and management of pharmaceutical pollution in the environment.