Measuring pesticides in the atmosphere: current status, emerging trends and future perspectives

There is a long history in environmental sciences to investigate and understand the fate of chemicals in the environment. For pesticides, this has led to systematic assessments of compounds by both academic and regulatory bodies, particularly for soil and water. As we show here, in recent years, there is an increasing interest in the potential presence of pesticide residues in air and related exposure risks. Based on a literature review for the years 2002-2022, we find a growing number of air monitoring studies with an average of 6.7 studies/year since 2020, with passive sampling methods contributing significantly to this rise. Most studies are concentrated in Europe and North America, with France leading in the number of monitoring studies. However, due to a lack of harmonization, and thus, the use of diverse methods and approaches, it remains challenging to derive potential exposure risks, to assess data quality of studies, and to compare datasets. In this perspective, we focus on current and emerging trends of different air monitoring approaches and highlight how they influence the interpretation of data. To improve the comparability and utility of data, and to ensure that air monitorings meet certain quality requirements, we propose a path forward, including: (1) Standardization and harmonization of methods: Adopting well-characterized and widely applied methods from air quality research as a basis for standardizing pesticide monitoring, with a clear distinction between relevant exposure and total air concentrations. (2) Tiered approach for monitoring programs: A dynamic concept where initial passive sampling identifies potential exposure risks, followed by active sampling for quantitative data, and, if necessary, extensive monitoring programs. This approach balances the need for detailed data with resource constraints. (3) Data interpretation and transparency: Public availability of data and clear reporting of methods, analysis, and uncertainties are crucial for the credibility and utility of monitoring studies. Overall, we see that harmonization of standards is critical for assessing exposure risks from pesticides in air and for informing regulatory decisions and mitigation strategies. Collaboration with the air quality and atmospheric research community is strongly recommended to leverage existing expertise in sampling, analysis, and data interpretation.