Impact of fertilisers on drinking water quality in Europe: implications for sustainable agriculture

Purpose. The purpose of the study is to reveal and evaluate the influence of different types of mineral fertilisers on drinking water quality, providing recommendations for mitigating environmental risks in European countries. Methodology / approach. The approach includes a panel analysis using fixed and random effects models, which allowed the identification of dependencies between fertiliser consumption levels and water quality indicators. The input data for the study covered indicators from 39 European countries, including EU member states, countries with harmonised legislation, and nations in the process of joining the EU. The analysis period covers 2006–2021, ensuring a balanced data panel with the same number of observations for each country over time. Key variables included the amounts of fertilisers (nitrogen, phosphorus, and potassium) used per hectare and capita, as well as food export and import indicators, enabling an estimation of the overall effect of agricultural activity on water quality. Results. The study results of random effects models demonstrate that pesticide use per unit of cropland area and per capita area positively impacts the Unsafe Drinking Water Index (UDWI). Pooling models indicated fertiliser consumption reduced water safety overall (β = -0.0143, p = 0.0026). Increased nitrogen fertiliser use per hectare demonstrated a slight positive relationship with the UDWI (β = 0.0491, p = 0.048), indicating marginal improvement in water quality. Conversely, phosphate fertilisers (per hectare and capita) had a significant negative impact, with a 1 kg/ha increase associated with a reduction of UDWI by 0.2261 units (p < 0.001) and a per capita increase by 1.2815 units accordingly, underscoring risks to water safety. The intensity of agricultural exports also had a negative impact on drinking water safety, particularly when combined with broader economic export activities (interaction effect β = -0.0147, p < 0.001). In contrast, imports showed a positive relationship with drinking water safety. Originality / scientific novelty. The novelty of the study lies in identifying a quantitative relationship between mineral fertiliser use in agriculture and drinking water quality in European countries, using panel analysis to develop recommendations for mitigating environmental risks. Practical value / implications. The study’s findings underscore the need for differentiated policies in managing fertiliser application, particularly recommending stricter regulation of phosphate use due to its pronounced negative impact on drinking water quality. Policymakers should encourage sustainable agricultural practices, such as precision farming and regulated nutrient application, especially in regions with intensive export-driven agriculture. Additionally, fostering the development and adoption of environmentally friendly alternatives, including biopesticides and controlled-release fertilisers, could significantly mitigate the adverse environmental impacts identified in this research.