Baseline investigation, GIS-based sediment transport index and risk assessment for microplastics and pesticides profiling in the inter-fjord Arctic systems

Hazardous micropollutants contaminating the Arctic, are vital climate regulators. Therefore, in the Arctic's Kongsfjord and Krossfjord, we investigated the distribution, sedimentary dynamics, transport mechanisms, and ecological issues of microplastics and multi-pesticide contamination. 40 pesticides categorized as organochlorines, organophosphates, urea derivatives, pyrethroids, chloronitriles, and triazoles were analysed by using Gas Chromatography Tandem Mass Spectrometry (GC-MS/MS). Surface sediment was loaded with microplastics with average standard deviation of 112.3±61.25 particles/kg, with transparent fibres ranging from 0.3 to 1mm being the most prevalent polymer forms. Polyvinyl chloride (PVC) and polyethylene terephthalate (PET) were the most common polymers. Diuron and o,p'-DDD were the most abundant pesticides detected. Legacy pesticidal persistent organic pollutants (POPs) were absorbed by the fine-grained, organic-rich sediments in regions with low Sediment Transport Index (STI). However, because of glacier meltwater and hydrodynamic pressures, micropollutant migration was most likely more pronounced in high STI zones. Krossfjord had higher levels of pesticide concentration, while Kongsfjord had higher levels of microplastic, and therefore can pose environmental risk. This study insists that micropollutants in the Arctic's fragile ecosystem need targeted mitigation measures and policy actions.