Assessment of Physicochemical, Microbiological and Toxicological Hazards at an Illegal Landfill in Central Poland.

This study aimed to assess the physicochemical, microbiological and toxicological hazards at an illegal landfill in central Poland. The research included the analysis of airborne dust (laser photometer), the number of microorganisms in the air, soil and leachate (culture method) and the microbial diversity in the landfill environment (high-throughput sequencing on the Illumina Miseq); the cytotoxicity ( PrestoBlue ) and genotoxicity (alkaline comet assay) of soil and leachate were tested. Moreover, an analysis of UHPLC-Q-ToF-UHRMS (ultra-high-performance liquid chromatography-quadrupole-time-of-flight ultrahigh-resolution mass spectrometry) was performed to determine the toxic compounds and microbial metabolites. The PM ₁ dust fraction constituted 99.89% and 99.99% of total dust and exceeded the threshold of 0.025 mg m ^-3 at the tested locations. In the air, the total number of bacteria was 9.33 × 10 ¹ -1.11 × 10 ³ CFU m ^-3 , while fungi ranged from 1.17 × 10 ² to 4.73 × 10 ² CFU m ^-3 . Psychrophilic bacteria were detected in the largest number in leachates (3.3 × 10 ⁴ to 2.69 × 10 ⁶ CFU mL ^-1 ) and in soil samples (8.53 × 10 ⁵ to 1.28 × 10 ⁶ CFU g ^-1 ). Bacteria belonging to Proteobacteria (42-64.7%), Bacteroidetes (4.2-23.7%), Actinobacteria (3.4-19.8%) and Firmicutes (0.7-6.3%) dominated. In the case of fungi, Basidiomycota (23.3-27.7%), Ascomycota (5.6-46.3%) and Mortierellomycota (3.1%) have the highest abundance. Bacteria ( Bacillus , Clostridium , Cellulosimicrobium , Escherichia , Pseudomonas ) and fungi ( Microascus , Chrysosporium , Candida , Malassezia , Aspergillus , Alternaria , Fusarium , Stachybotrys , Cladosporium , Didymella ) that are potentially hazardous to human health were detected in samples collected from the landfill. Tested leachates and soils were characterised by varied cyto/genotoxins. Common pesticides (carbamazepine, prometryn, terbutryn, permethrin, carbanilide, pyrethrin, carbaryl and prallethrin), quaternary ammonium compounds (benzalkonium chlorides), chemicals and/or polymer degradation products (melamine, triphenylphosphate, diphenylphtalate, insect repellent diethyltoluamide, and drugs (ketoprofen)) were found in soil and leachate samples. It has been proven that the tested landfill is the source of the emission of particulate matter; microorganisms (including potential pathogens) and cyto/genotoxic compounds.