Diamide insecticides in PM_2.5: The unreported rural and urban air pollutants

The broad application of various pesticides guarantees the development of agriculture all over the word but has ultimately led to their ubiquitous release into the environment as hazardous chemical residues. Diamide insecticides (DAIs) are regarded as new choice for prevention and protection of agricultural crops and city landscaping plants from the pests in more and more countries. However, their presence in fine particulate matter (PM_2.5) and associated health risks have not been studied. We reported for the first time the extensive distributions of PM_2.5-bound DAIs in rural and urban areas of China, one of the world's largest agricultural countries. Eight DAIs were analyzed, and five were consistently detected in PM_2.5 samples at concentrations primarily of pg m^-3 level. Evident spatial/temporal variations were observed, with generally more serious DAIs' contamination and long-term health risks in rural areas during spring, summer and autumn. The first exploration of DAIs' toxicities on human bronchial epithelial cells discovered their capability of inhibiting cell viabilities, further demonstrating the potential detrimental effects of these emerging pollutants in PM_2.5. This study confirms the widespread appearance of DAIs in PM_2.5, emphasizing the need and urgency for concern about their pollution in both rural and urban air.