Exotic airborne bacteria identified in urban resuspended dust by next generation sequencing

The airborne transport of bacteria is a well-known phenomenon, making it possible to exchange species between ecosystems, but it also provides a tool for spreading of pathogenic microorganisms. As part of a large-scale study, microbial community of inhalable and respirable fractions (PM1-10) of resuspended dust collected in Budapest (Hungary) has been characterised by culture-independent next generation sequencing (NGS) of variable 16S rRNA gene regions. Apart from common, mostly ubiqituos soil and organic material-dwelling bacteria, exotic airborne species have been identified, such as Variovorax ginsengisoli, previously isolated from Korean ginseng fields or Exiguobacterium sibiricum, isolated from the Siberian permafrost

Assessing Ecotoxicity of Size-fractionated Airborne Particulate Matter

Particulate matter (PM) is grouped as coarse, fine, and ultrafine particles (UFPs) with aerodynamic diameters of 2.5 to 10 μm (PM10), <2.5 μm (PM2.5), and <0.1 μm (PM0.1), respectively. The course and fine fractions have been well characterised from numerous aspects, including potential environmental hazard. However, more and more studies are targeted to the UFP fraction, as they bind relatively higher concentrations of potentially toxic materials and they might penetrate through cell biological barriers, posing higher risk to the biota. In our study, ecotoxic potential of size-fractionated urban aerosol was evaluated, using the kinetic version of the Vibrio fischeri bioluminescence inhibition bioassay. The kinetic protocol makes it possible to avoid false ecotoxicity readings which might appear in case of coloured and/or turbid samples. Our results showed that all PM fractions elucidated significant toxic response, highest toxicity was experienced in the range of 0.25/0.5μm and 0.5/1 μm (with the EC50s of 7.07 and 7.8%). Ecotoxicity in general followed the typical pattern of number size distributions of submicron particles experienced in Europe

Preliminary assessment of road dust from Portuguese motorways: chemical profile, health risks, and ecotoxicological screening

Among non-exhaust emissions, road dust resuspension represents a rather important contribution to particulate matter in urban areas. This study aimed to achieve a chemical characterisation of road dust particulate matter (PM10) on two motorway sections, one rural and one urban, and to explore the related health and ecotoxicological risks. Measured PM10 dust loadings reached very low levels (0.66–1.49 mg m-2) compared to equivalent studies in other road environments in Portugal and other countries. Emission factors ranged from 33 to 62 mg veh−1 km−1. The carbonaceous content represented 14% of the total PM10 mass, whereas the highest contribution to the mass was given by mineral matter. Elements such as Si, Al, Ca, Fe and K accounted for almost three quarters of the total element mass for all samples, whilst Cu and Zn, mostly associated with brake and tyre wear, were the most enriched elements in relation to the soil composition. Nonetheless, Ti and Zr presented the highest non-carcinogenic risks for human health. Despite the low amounts of particulate matter in the aqueous solution, the ecotoxicological screening with the Aliivibrio fisheri bioluminescence inhibition bioassay allowed to classify the samples as toxic.Open access funding provided by FCT|FCCN (b-on). This research was funded by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), and by national funds (OE), through FCT/MCTES, through the implementation of the project “Big data to improve atmospheric emission inventories (BigAir)”, PTDC/EAM-AMB/2606/2020. Furthermore, authors also acknowledge the financial support to CESAM (UIDB/50017/2020+UIDP/50017/2020+LA/P/0094/2020), to FCT/MCTES through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and COMPETE2020. Ismael Casotti Rienda is grateful to the Portuguese Foundation of Science and Technology (FCT) for funding the scholarship SFRH/BD/144550/2019. The research work was also supported by the LIFE-REMY (LIFE20 PRE/IT/000004) and the Spanish National research project NEXT (PID2019-110623RB-I00) funded by MCIN/AEI/10.13039/501100011033/.Peer reviewe

Cooking activities in a domestic kitchen: chemical and toxicological profiling of emissions

To obtain emission factors and cooking-related chemical signatures, a monitoring campaign was carried out in a modern kitchen where different dishes of the Latin cuisine were prepared. Particulate matter (PM10, PM2.5 and PM1) and total volatile organic compounds (TVOCs) were continuously measured. Passive tubes for carbonyls and a high volume PM10 sampler were simultaneously used. PM10 filters were analysed for organic and elemental carbon and for multiple organic compounds, including polyaromatic hydrocarbons (PAHs). The toxic potential of PM10 was evaluated using a bioluminescence inhibition bioassay. Acrolein was never detected, while formaldehyde and acetaldehyde levels were comparable to those in the background air. The protection limit for TVOCs was always exceeded. Fine particles comprised more than 86% of the PM10 mass concentrations. PM10 emission rates ranged from 124 to 369 μg min-1. Relatively low PAH concentrations were obtained. PM10 encompassed alcohols, acids, plasticisers, alkyl esters, sterols, sugars, polyols, glyceridic compounds, phenolics, among others. Total concentrations were 1.9-5.3 times higher during cooking than in the background air but, for some compounds, differences of tens or hundreds of times were registered. PM10 from grilled pork was found to contribute to non-negligible cancer risks and to be very toxic, while samples from other dishes were categorised as toxic.publishe

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, PM2.5-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 PM2.5 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.publishe

Outdoor charcoal grilling: particulate and gas-phase emissions, organic speciation and ecotoxicological assessment

Charbroiling is a major source of air pollution worldwide. In this study, the particulate and gas-phase emissions from the charcoal lighting phase and during the grilling of meat (pork and rump cap) and fish (sardine and salmon) on an outdoor barbecue grill were characterized. Some gaseous compounds (ethane, hexane, NO2, N2O, SO2, NH3, HCl) did not display significant variations between samples and the background level, indicating that they are not emitted during barbecuing. During the charcoal heating phase, levels of total volatile organic compounds (TVOCs) increased 6 times above the background value. Four-to 5-fold increases in TVOC concentrations were observed when grilling sardines and salmon, while rises of 1.3–1.5 were recorded for meat. Emission factors of 32.4 g PM10 kg−1 and 22.7 g TVOCs kg−1 were obtained for the biofuel ignition phase. PM10 emission rates of 472, 531, 1104 and 918 mg kg−1 were estimated for pork, rump cap, sardine and salmon charbroiling, respectively. TVOC emissions ranged from 23.9 mg kg−1 (pork) to 82.6 mg kg−1 (salmon). Organic carbon accounted for 35.0% of the PM10 emitted during the ignition and flaming phases of the biofuel but represented mass fractions of 56–64% of the particulate emissions during food charbroiling. About 235 organic compounds were quantified in the PM10 samples. The ecotoxicity was assessed using the kinetic version of the Vibrio fischeri bioluminescence inhibition bioassay. All samples were classified as very toxic or toxic. Ecotoxicity was statistically correlated with several n-alkanes, PAHs and alkyl-PAHs, anhydrosugars, acids, and phenolic compounds.publishe