Ecotoxicity testing of airborne particulate matter-comparison of sample preparation techniques for the Vibrio fischeri assay

Assessing the chemical composition, potential toxicity and cancer risk of airborne fine particulate matter (PM2.5) near a petrochemical industrial area

In the vicinity of a petrochemical industrial region in São Paulo, Brazil, PM_2.5-bound organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs, oxy-PAHs, hopanes, and inorganic species were evaluated. Oxidative potential (OP), burden (OB), and Alivibrio fischeri bioluminescence inhibition (AFBIA) assays were conducted to determine the potential health effects of exposure to these compounds. The PM_2.5 mean concentration was 32.0±18.2µgm^-3, and benzo (a)pyrene was found to exceed recommended levels by at least four times. Secondary sources and vehicular emissions were indicated by nitro-PAHs, oxy-PAHs, and inorganic species. The OP and OB results revealed that secondary compounds favored antioxidant depletion. The AFBIA results showed that 64% of the samples were toxic. These findings emphasize the need to reduce the exposure risk and take measures to protect human health.

Evaluation of flue gas emission factor and toxicity of the PM-bounded PAH from lab-scale waste combustion

Atmospheric particulate matter (PM) has a significant threat not only to human health but also to our environment. In Hungary, 54% of PM10 comes from residential combustion, which also includes the practice of household waste burning. Therefore, this work aims to investigate the quality of combustion through the flue gas concentrations (CO, CO₂, O₂) and to identify and evaluate the negative impacts of PM and PAHs generated during controlled lab-scale combustion of different mixed wastes (cardboard and glossy paper, polypropylene and polyethylene terephthalate, polyester and cotton). Mixed wastes were burnt in a lab-scale tubular furnace at different temperatures with 180 dm³/h air flow rate. Chemical analyses were coupled with ecotoxicological tests using the bioluminescent bacterium Vibrio fischeri. Ecotoxicity was expressed as toxic unit (TU) values, toxic equivalent factors (TEF) were also presented. During the combustion same amount of O₂ enters the reaction, but a different amount CO₂ is generated due to the C content of the sample. The waste with highest C-content related to the highest CO₂ emission. Increasing the combustion temperature produces more PM-bound PAHs, which remains the same composition in the case of plastic and textile groups. The TU of solid contaminants decreases with increasing combustion temperature and increases with the minerals which are left behind in the water from the solid contaminants.

PM10 Alters Trophoblast Cell Function and Modulates miR-125b-5p Expression

Air pollution is one of the largest global environmental health hazards that threaten premature mortality or morbidity. Particulate matter 10 (PM10) has been demonstrated to contribute to several human diseases via dysregulated miRNA expression. Trophoblast cells play a key role in implantation and placentation for a successful pregnancy. Nonetheless, the PM10 associated trophoblast cell functions during pregnancy and miRNA expression are still unknown. Our study showed that PM10 affected HTR-8/SVneo cell viability and also decreased cell proliferation, migration, and invasion. A high concentration of PM10 caused an increase in HTR-8/SVneo cell apoptosis. Treatment with PM10 induced inflammation through the upregulated IL-1β, IL-6, and TNF-α expression in trophoblast cells. In PM10-treated HTR-8/SVneo cells, miR-125b-5p expression was considerably increased and TXNRD1 was found to be negatively related to miR-125b-5p. Collectively, our findings revealed that PM10 could alter miR-125b-5p expression by targeting TXNRD1 and suppressing trophoblast cell functions. Additional investigations relating to the function of miR-125b-5p and its target on particulate pollution exposure in trophoblast are warranted for future biomarker or effective therapeutic approaches.