Abstract
This study delved into the impact of open biomass burning on the distribution of pesticide and polycyclic aromatic hydrocarbon (PAH) residues across soil, rice straw, total suspended particulates (TSP), particulate matter with aerodynamic diameter ≤ 10 µm (PM(10)), and aerosols. A combination of herbicides atrazine (ATZ) and diuron (DIU), fungicide carbendazim (CBD), and insecticide chlorpyriphos (CPF) was applied to biomass before burning. Post-burning, the primary soil pesticide shifted from propyzamide (67.6%) to chlorpyriphos (94.8%). Raw straw biomass retained residues from all pesticide groups, with chlorpyriphos notably dominating (79.7%). Ash residue analysis unveiled significant alterations, with elevated concentrations of chlorpyriphos and terbuthylazine, alongside the emergence of atrazine-desethyl and triadimenol. Pre-burning TSP analysis identified 15 pesticides, with linuron as the primary compound (51.8%). Post-burning, all 21 pesticides were detected, showing significant increases in metobromuron, atrazine-desethyl, and cyanazine concentrations. PM(10) composition mirrored TSP but exhibited additional compounds and heightened concentrations, particularly for atrazine, linuron, and cyanazine. Aerosol analysis post-burning indicated a substantial 39.2-fold increase in atrazine concentration, accompanied by the presence of sebuthylazine, formothion, and propyzamide. Carcinogenic PAHs exhibited noteworthy post-burning increases, contributing around 90.1 and 86.9% of all detected PAHs in TSP and PM(10), respectively. These insights advance understanding of pesticide dynamics in burning processes, crucial for implementing sustainable agricultural practices and safeguarding environmental and human health.