Ubiquitous microplastics detection in mosquitoes from urban and rural regions signals a widespread pollution threat – the unseen carriers of hazard

Abstract This study is the first to quantify the prevalence of microplastics in field-collected mosquito larvae across distinct species in Shiraz, Iran, and to assess potential bioaccumulation risks, providing insights into the ecological impacts of MPs. Using a stratified sampling approach, 721 mosquito larvae were collected from six locations in Shiraz. The MPs were characterized by optical microscopy and Raman spectroscopy, focusing on their quantity, size, morphology, and polymer type. Of the five representative mosquito species collected (Culex pipiens, Culiseta alaskaensis, Culex pusillus, Culex vagans, and Culex bitaeniorhynchus), all specimens selected at random tested positive for MPs, which were predominantly white (81%) and black (84%). Polyethylene was the most encountered polymer, especially in Culex pipiens and Culex pusillus, comprising 52.81% and 25.84% of the total MPs, respectively. These findings not only highlight the ubiquity of MPs in freshwater ecosystems but also suggest potential bioaccumulation risks within food webs. Given the environmental and health implications of MP contamination, further research is necessary to explore the ecological effects of MPs on mosquito vectors, and their capacity for pathogen transmission.