Airborne Organic Pollutants Research Articles

Airborne organic pollutants impact microbial communities in temperate and Antarctic seawaters

Airborne Organic Pollutants (AOPs) reach remote oceanic regions after long range atmospheric transport and deposition, incorporating into natural microbial communities. This study investigated the effects of AOPs on natural microbial communities of the Mediterranean Sea, the Atlantic Ocean and the Bellingshausen Sea, by assessing the impact of both non-polar and polar AOPs on cell abundances, chlorophyll a concentrations and cell viabilities of different microbial groups. Our results indicate that almost all groups, except flagellates in the Bellingshausen Sea, were significantly affected by AOPs. While no significant differences in chlorophyll a concentrations were observed between non-polar and polar AOPs, significant variations in cell abundances were noted. Cell death occurred at AOP concentrations as low as five times the oceanic field levels, likely due to their high chemical activity. Cyanobacteria in temperate waters exhibited the highest sensitivity to AOPs, whereas medium and larger diatoms in the Bellingshausen Sea were more affected than smaller diatoms or flagellates, contrary to the expected size-related sensitivity trend. Additionally, microorganisms in temperate waters were more sensitive to the polar fraction of AOPs compared to the non-polar fraction, which showed an inverse sensitivity pattern. This differential sensitivity is attributed to variations in the ratio of polar to non-polar AOPs in the respective environments. Our findings underscore the varying impacts of AOPs on marine microbial communities across different oceanic regions.

Personal exposure to airborne organic pollutants and lung function changes among healthy older adults

Epidemiological evidence on the impact of airborne organic pollutants on lung function among the elderly is limited, and their underlying biological mechanisms remain largely unexplored. Herein, a longitudinal panel study was conducted in Jinan, Shandong Province, China, involving 76 healthy older adults monitored over a span of five months repetitively. We systematically evaluated personal exposure to a diverse range of airborne organic pollutants using a wearable passive sampler and their effects on lung function. Participants’ pulmonary function indicators were assessed, complemented by comprehensive multi-omics analyses of blood and urine samples. Leveraging the power of interaction analysis, causal inference test (CIT), and integrative pathway analysis (IPA), we explored intricate relationships between specific organic pollutants, biomolecules, and lung function deterioration, elucidating the biological mechanisms underpinning the adverse impacts of these pollutants. We observed that bis (2-chloro-1-methylethyl) ether (BCIE) was significantly associated with negative changes in the forced vital capacity (FVC), with glycerolipids mitigating this adverse effect. Additionally, 31 canonical pathways [e.g., high mobility group box 1 (HMGB1) signaling, phosphatidylinositol 3-kinase (PI3K)/AKT pathway, epithelial mesenchymal transition, and heme and nicotinamide adenine dinucleotide (NAD) biosynthesis] were identified as potential mechanisms. These findings may hold significant implications for developing effective strategies to prevent and mitigate respiratory health risks arising from exposure to such airborne pollutants. However, due to certain limitations of the study, our results should be interpreted with caution.

Pollution levels and deposition processes of airborne organic pollutants over the central Adriatic area: Temporal variabilities and source identification

First data on polycyclic aromatic hydrocarbons (PAHs) and nitro-aromatic compounds (NACs) in aerosols as well as of PAHs, polychlorinated biphenyls (PCBs) and NACs in bulk and wet atmospheric deposition samples were simultaneously obtained during 6-month-long field campaign at the costal central Adriatic area. Special attention was given to open-fire biomass burning episodes as extreme events common for the overall Mediterranean coastal area in order to gain a better understanding of the atmospheric variabilities and potential sources of trace organic pollutants in coastal environments. Diesel and gasoline combustion related to land and maritime traffic as well as occasional open-fire episodes (forest fires) were found to be the dominant pollution sources of PAHs in PM10 particles. NACs were determined almost exclusively in samples affected by biomass burning episodes. Open-fire episodes had a strong contribution to the overall NACs atmospheric deposition fluxes. Several chlorinated congeners of PCBs were predominantly contributed in deposition samples.

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban-rural gradient in Shanghai.

This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners in the soil in a rural-urban fringe and correlated them with multiple variables in the area. Variables, including road density, normalized difference vegetation index (NDVI), distance to the nearest highway and industrial area from the soil experimental sites, land-use impact index, population density, population change index (PCI), total population, and percentage of water area, were used to explain the concentration of different PCB congeners in soil during the experimental period. A proportion of 40.1%, 22.6%, 56.9%, and 34.3% accumulation rates of PCB8, PCB18, PCB28, and PCB118, respectively was explained by industrial developments, using stepwise linear regression analysis. NDVI was used to explain 33.6%, 61.5%, 49.1%, and 53.2% accumulation rates of PCB44, PCB101, PCB187, and PCB180, respectively. Filtering and transferring of airborne organic pollutants from atmosphere to soil by forests or tree stands and farmlands were all NDVI-related factors that affected the concentrations and accumulation rates of PCB congeners in soil. The traffic-related particle deposition might be the reason why the concentrations and accumulation rates of PCB congeners in soil were affected by road density. The findings can help quantitatively understand urbanization and the associated environmental effects. Graphic abstract.

Seasonally varied cytotoxicity of organic components in PM2.5 from urban and industrial areas of a Chinese megacity

The atmospheric fine particulate matters (PM2.5) induce significant negative effects on human health, such as in the form of oxidative stress and pro-inflammatory response. Organic pollutants are important harmful and toxic compositions in PM2.5, risks of which usually show temporal and spatial variations. To investigate the toxic effects of airborne organic pollutants on human lung epithelial cells A549, the PM2.5 samples were collected monthly from both urban and industrial areas during a whole year in Nanjing, eastern China. After exposure to organic components extracted from these PM2.5, the cell viability, lactate dehydrogenase content, oxidative stress index level and inflammatory factor expression level were measured. Supported by the concentrations of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, results showed that, organic components of PM2.5 from cold season (winter and spring) typically influenced cell membrane, cell oxidation and inflammatory damage, while the urban samples of warm season (summer and autumn) impacted cell viability more prominently. Spatially, the toxicity of samples from industrial sources was generally stronger than that from urban source, but urban samples induced much stronger damage to cell membranes than industrial one. The correlations between the PAHs, n-alkanes contents and toxicity parameters indicated that, the airborne organic components derived from motor vehicle exhaust and coal combustion were possibly the key toxic sources.

Evaluation of Airborne Organic Pollutants in a Pyrenean Glacial Lake (The Sabocos Tarn)

Mountain lakes are excellent indicators for airborne organic pollutant transport and accumulation studies. However, very few studies have been focused on lake water mass. Also, there is a lack of studies performed after 2004–2009 period when the enforcement of most international organic pollutant banning policies (e.g., The Stockholm convention) occurred. We report concentration of 66 different semi-volatile organic compounds (SOCs) in the Sabocos tarn water mass (a Spanish Pyrenees cirque glacial lake) from 2011 to 2014. Analyzed SOCs include compounds of current and past use with different sources (i.e., current and historic-use pesticides, industrial and urban-use compounds, and combustion by-products) and chemical properties (i.e., volatility, water solubility, and persistence in the environment). Most banned chemicals such as dichlorodiphenyl trichloroetanes (DDTs), aldrins, most polybromodiphenyl ether (PBDE) congeners, endosulfans, triazine, and simazine were detected in consistently low concentrations. In contrast, chemicals still in use such as BDE-209, terbutilazine, diuron, metolachlor, and chlorpyrifos were found in higher and more variable amounts. Polychlorobiphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were high as compared to previous studies in other Pyrenean and European lakes suggesting airborne pollution from nearby anthropogenic sources. Overall, levels of hexacyclohexanes (HCHs) during most of the sampling period were low according to other studies in similar environments. However, the Sabocos water mass recorded a concentration peak of some HCH isomers in summer 2014 related with the HCH residues transfer operation at the nearby (20 km) Bailin landfill site (Sabinanigo, Spain).

Control of Airborne Organic Pollutants Using Plug-Flow Reactor Coated With Carbon Material-Titania Mixtures Under Visible-Light Irradiation

Graphene oxide (GO)-titania composites have emerged as an attractive heterogeneous photocatalyst that can enhance the photocatalytic activity of TiO2 nanoparticles owing to their potential interaction of electronic and adsorption natures. Accordingly, TiO2-GO mixtures were synthesized in this study using a simple chemical mixing process, and their heterogeneous photocatalytic activities were investigated to determine the degradation of airborne organic pollutants (benzene, ethyl benzene, and o-xylene (BEX)) under different operational conditions. The Fourier transform infrared spectroscopy results demonstrated the presence of GO for the TiO2-GO composites. The average efficiencies of the TiO2-GO mixtures for the decomposition of each component of BEX determined during the 3-h photocatalytic processes were 26%, 92%, and 96%, respectively, whereas the average efficiencies of the unmodified TiO2 powder were 3%, 8%, and 10%, respectively. Furthermore, the degradation efficiency of the unmodified TiO2 powder for all target compounds decreased during the 3-h photocatalytic processes, suggesting a potential deactivation even during such a short time period. Two operational conditions (air flow entering into the air-cleaning devices and the indoor pollution levels) were found to be important factors for the photocatalytic decomposition of BEX molecules. Taken together, these results show that a TiO2-GO mixture can be applied effectively for the purification of airborne organic pollutants when the operating conditions are optimized.

Systematic Investigation of the Sorption Properties of Tenax TA, Chromosorb 106, Porapak N, and Carbopak F

A variety of sorbents is available for the sampling of airborne organic pollutants. However, choosing the right sorbent for a certain analytical target is still a challenge. Here we present a systematic sorption study for a diverse set of up to 200 compounds at temperatures between 40 and 250 degrees C for four frequently used sorbents: Tenax TA, Chromosorb 106, Porapak N, and Carbopack F. The experimental data are used to calibrate a polyparameter linear free energy relationship (pp-LFER) for each sorbent which allows one to predict the safe sample volume and the complete sample elution volume of chemicals not tested here at any desirable temperature.

Systematic Investigation of the Sorption Properties of Polyurethane Foams for Organic Vapors

Polyurethane foams (PUFs) have long been used for the sampling of airborne organic pollutants. However, a comprehensive investigation of their sorption properties for various organic compounds is still lacking. Here we present a systematic sorption study for a diverse set of up to 100 compounds at temperatures between 15 and 95 degrees C, at various humidities, and for various types of PUFs. The results can be summarized as follows: The performance of PU-ethers is not susceptible to the humidity of the sampled air. Variability between different types of PU-ethers is small, and the compound variability in the sorption constants as well as the enthalpies of sorption can accurately be described with linear free energy relationships (LFERs) presented in the text. PU-esters revealed an inferior sorbent behavior as compared to PU-ethers: sorption was kinetically hindered and was affected by humidity. Sorption varied between different types of esters and prediction with LFERs was less accurate than for the ethers.

Bacterial degradation of airborne phenol in the phyllosphere

Despite the vast surface area of terrestrial plant leaves and the large microbial communities they support, little is known of the ability of leaf-associated microorganisms to access and degrade airborne pollutants. Here, we examined bacterial acquisition and degradation of phenol on leaves by an introduced phenol degrader and by natural phyllosphere communities. Whole-cell gfp-based Pseudomonas fluorescens bioreporter cells detected phenol on leaves that had previously been transiently exposed to gaseous phenol, indicating that leaves accumulated phenol; moreover, they accumulated it in sites that were accessible to epiphytic bacteria and to concentrations that were at least 10-fold higher than those in the air. After inoculated leaves were exposed to gaseous 14C-phenol, leaves harbouring the phenol-degrading Pseudomonas sp. strain CF600 released eight times more 14CO2 than did leaves harbouring a non-degrading mutant, demonstrating that CF600 actively mineralized phenol on leaves. We evaluated phenol degradation by natural microbial communities on green ash leaves that were collected from a field site rich in airborne organic pollutants. We found that significantly more phenol was mineralized by these leaves when the communities were present than by these leaves following surface sterilization. Thus, phenol-degrading organisms were present in these natural communities and were metabolically capable of phenol degradation. Collectively, these results provide the first direct evidence that bacteria on leaves can degrade an organic pollutant from the air, and indicate that bacteria on leaves could potentially contribute to the natural attenuation of organic air pollutants.

Is there a ?Forest Filter Effect? for airborne organic pollutants?

Is there a ?Forest Filter Effect? for airborne organic pollutants?

Are airborne organic pollutants subject to a ?forest filter effect??

Are airborne organic pollutants subject to a ?forest filter effect??

Forests as Filters of Airborne Organic Pollutants: A Model

The role of forests in filtering airborne organic pollutants from the atmosphere and transferring them to soil was examined. A mathematical model was assembled to calculate the filter factor, defined as the quotient of the net deposition of a given compound to a forest and its net deposition to a bare soil. A simple equation was obtained that expressed the filter factor as a function of just two physical-chemical properties of the chemical: the octanol/air and air/water partition coefficients (KOA and KAW). The model was then applied to a spruce and to a beech/oak canopy close to Bayreuth for which measured deposition velocities were available. The model simulations indicated that there was little filter effect for volatile compounds with log KOA < 7 and for hydrophilic substances with log KAW < −6. Similarly, although forest canopies are thought to be effective filters of airborne particles, the filter factor for compounds that are primarily particle bound was also close to 1, since the dry particle bound deposition to the canopies was overshadowed by the wet deposition of particle bound chemical at these sites. However, for semivolatile compounds with 7 < log KOA < 11 and log KAW > −6, a pronounced filter effect was predicted with filter factors as high as 10 at the sites studied. The results are in good agreement with deposition measurements conducted at the same sites. Thus, forests influence the atmospheric deposition of only a small subset of organic chemicals. However, this subset includes many contaminants of particular concern such as chlorinated dioxins, furans, biphenyls, and pesticides. Forests can be expected to play a key role in the environmental fate of these compounds, decreasing their atmospheric half-lives (and hence long-range transport, input into agricultural ecosystems and human exposure) and transferring the chemical to forest soils.

Deposition of airborne organic pollutants on historic buildings

The black crusts coating the surfaces of building materials located in urban (polluted) environments contain all kinds of organic compounds present in aerosols and particulate matter. Wet and dry deposition processes combined with gypsum crystal growth result in dirty, grey-to-black crust formation, in which aerosols, spores, pollen, dust and every class of particulate matter are entrapped in the mineral matrix. Analysis of the organic compounds extracted from black crusts demonstrate them to be mainly composed of molecular markers that are characteristic of petroleum derivatives. The composition of each crust is governed by the composition of the particular airborne pollutants in the area.

Atmospheric transport of atrazine: A simple device for its detection

Thin-layer chromatography plates were exposed at three different locations in Bavaria for 3-week periods during the growing season of maize. The adsorption of traces of atrazine was detected by thin-layer chromatography, GC-MS, and by an enzyme immunoassay. It was restricted to the sowing season, which coincides with the application of atrazine. The herbicide could not be detected after this time. The simplicity of the adsorption device, combined with a serological assay, render this procedure suitable for detecting airborne organic pollutants.