Airborne microplastics in Europe's largest plastic-covered semi-arid agricultural region. A pilot study

This study investigates airborne microplastic (MP) pollution in Europe's largest greenhouse-based agricultural region. Despite the intensive use of plastics in this production system, evidence on airborne MP occurrence and spatial patterns remains scarce. Furthermore, this is particularly relevant in arid and semi-arid areas, where wind erosion and dust resuspension can enhance atmospheric transport. To achieve this, a portable active air-sampling device was developed and validated to accurately measure sampled air volume and provide comparable estimates of MP abundance (items/m³). The monitoring campaign covered environments strongly influenced by intensive agriculture (greenhouse interiors and surrounding areas), as well as urban zones and a protected natural area. MPs were detected in all air samples (n = 100 filter meshes) collected between February and October 2025. The concentration levels ranging from 8 to 59 items/m³. A clear land-use gradient was observed. The highest mean abundance was found inside greenhouses (31 items/m³), followed by urban air (28 items/m³) and greenhouse surroundings (23 items/m³), while the protected natural area showed the lowest levels (16 items/m³). Fibres were the dominant particle type in all environments (70-83%), and 31% of particles were < 100 µm, highlighting a potentially inhalable fraction. Polymer composition also varied by site: PET was predominant overall (46-69%), PE was relatively enriched inside greenhouses (27%), and PP was more common in urban samples (24%). Contamination factor analysis indicated mainly moderate to considerable pollution, with higher average contamination in greenhouse and urban areas than in the natural area. These findings provide baseline evidence for exposure assessment in plastic-intensive agricultural landscapes.