Detection of the Herbizide Atrazine in PM2.5 at a Rural Background Station in Germany: Evidence of Long-Range Atmospheric Transport

Atrazine is a selective synthetic triazine herbicide that is primarily used for the management of weeds in corn. Despite being banned in the EU in 2004, it is still used in large quantities globally. Numerous studies have demonstrated adverse effects of atrazine on organisms, particularly its role as an endocrine disruptor causing reproductive dysfunction in vertebrates.¹ The occurrence, effects and fate of atrazine in soil and water has been well studied. However, a less investigated pathway for the spread of pesticides is through the atmosphere. Via long-range atmospheric transport (LRAT) pesticides can be transported to pristine environments.^2,3

To investigate atmospheric concentrations of atrazine, particulate matter (PM_2.5) samples were collected at the rural background station Taunus Observatory, Germany. The collected filters underwent liquid extraction, enrichment, and analysis using high-performance liquid chromatography - high resolution mass spectrometry. Samples from April 2021 to May 2022 were analyzed in two-week increments. For a more detailed examination one intensive two-week period was analyzed. Using the FLEXible PARTicle Lagrangian transport and dispersion model (FLEXPART)⁴ we identified source regions of atrazine.

The analysis successfully quantified atrazine in PM_2.5 samples. Concentrations showed seasonal variation, with high concentrations observed in May and June, corresponding to typical agricultural application periods in the Northern Hemisphere. These results suggest that atrazine detected in the atmosphere is linked to recent usage rather than legacy contamination and wind-driven resuspension from soil.  A simple partitioning calculation suggests that atrazine primarily partitions into the partice phase, especially at higher altitudes, which may extend its atmospheric half-life facilitating its potential for LRAT. Backward trajectory modeling indicated that low atrazine concentrations were associated with air masses originating from Europe, whereas higher concentrations corresponded to transatlantic transport from North America.

Our study confirms the presence of atrazine in PM and provides evidence of its LRAT from regions where it is still in use. These results highlight the need for revising pesticide risk assessments accounting for the potential extension of pesticides atmospheric half-life in the condensed phase.⁵

 

 (1) Rohr, J. R.; McCoy, K. A. A qualitative meta-analysis reveals consistent effects of atrazine on freshwater fish and amphibians. Environmental health perspectives 118, 20–32, 2010.

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(3) Thurman, E. M.; Cromwell, A. E. Atmospheric Transport, Deposition, and Fate of Triazine Herbicides and Their Metabolites in Pristine Areas at Isle Royale National Park. Environ. Sci. Technol. 34, 3079–3085, 2000.

(4) Bakels, L.; Tatsii, D.; Tipka, A.; Thompson, R.; Dütsch, M.; Blaschek, M.; Seibert, P.; Baier, K.; Bucci, S.; Cassiani, M.; et al. FLEXPART version 11: improved accuracy, efficiency, and flexibility. Geosci. Model Dev. 17, 7595–7627, 2024.

(5) Socorro, J.; Durand, A.; Temime-Roussel, B.; Gligorovski, S.; Wortham, H.; Quivet, E. The persistence of pesticides in atmospheric particulate phase: An emerging air quality issue. Scientific reports 6, 33456, 2016.