Effect-based assessment of passive air samples from four countries in Eastern Europe

Developing an Approach for Integrating Chemical Analysis and Transcriptional Changes to Assess Contaminants in Water, Sediment, and Fish

Pharmaceuticals in aquatic environments pose threats to aquatic organisms because of their continuous release and potential accumulation. Monitoring methods for these contaminants are inadequate, with targeted analyses falling short in assessing water quality's impact on biota. The present study advocates for integrated strategies combining suspect and targeted chemical analyses with molecular biomarker approaches to better understand the risks posed by complex chemical mixtures to nontarget organisms. The research aimed to integrate chemical analysis and transcriptome changes in fathead minnows to prioritize contaminants, assess their effects, and apply this strategy in Wascana Creek, Canada. Analysis revealed higher pharmaceutical concentrations downstream of a wastewater-treatment plant, with clozapine being the most abundant in fathead minnows, showing notable bioavailability from water and sediment sources. Considering the importance of bioaccumulation factor and biota-sediment accumulation factor in risk assessment, these coefficients were calculated based on field data collected during spring, summer, and fall seasons in 2021. Bioaccumulation was classified as very bioaccumulative with values >5000 L kg-1, suggesting the ability of pharmaceuticals to accumulate in aquatic organisms. The study highlighted the intricate relationship between nutrient availability, water quality, and key pathways affected by pharmaceuticals, personal care products, and rubber components. Prioritization of these chemicals was done through suspect analysis, supported by identifying perturbed pathways (specifically signaling and cellular processes) using transcriptomic analysis in exposed fish. This strategy not only aids in environmental risk assessment but also serves as a practical model for other watersheds, streamlining risk-assessment processes to identify environmental hazards and work toward reducing risks from contaminants of emerging concern. Environ Toxicol Chem 2024;43:2252-2273. © 2024 SETAC.

Informing the public about chemical mixtures in the local environment: Currently applied indicators in the Netherlands and ways forward

The current use of chemicals puts pressure on human and ecological health. Based on the Aarhus Convention, citizens have the right to have access to information on substances in their local environment. Providing this information is a major challenge, especially considering complex mixtures, as the current substance-by-substance risk assessment may not adequately address the risk of co-exposure to multiple substances. Here, we provide an overview of the currently available indicators in the Netherlands to explore current scientific possibilities to indicate the impacts of complex chemical mixtures in the environment on human health and ecology at the local scale. This is limited to impact estimates on freshwater species for 701 substances, impact estimates of four metals on soil organisms, and impacts on human health for particulate matter (PM10) and nitrogen dioxide (NO2) in air. The main limiting factors in developing and expanding these indicators to cover more compartments and substances are the availability of emission and concentration data of substances and dose-response relationships at the population (human health) or community (ecology) level. As ways forward, we propose; 1) developing cumulative assessment groups (CAGs) for substances on the European Pollutant Transfer and Release Register and Water Framework Directive substance lists, to enable the development of mixture indicators based on mixture risk assessment and concentration addition principles; 2) to gain insight into local mixtures by also applying these CAGs to emission data, which is available for soil and air for more substances than concentrations data; 3) the application of analytical non-target screening methods as well as effect-based methods for whole-mixture assessment.

Assessment of genotoxicity of air pollution in urban areas using an integrated model of passive biomonitoring

Atmospheric pollution is a major public health issue and has become increasingly critical for human health. Urban atmospheric pollution is typically assessed through physicochemical indicators aligned with environmental legislation parameters, providing data on air quality levels. While the effects of pollution on sensitive organisms serve as a warning for public health decision-makers, there remains a need to explore the interpretation of environmental data on pollutants. The use of species adapted to urban environments as sentinels enables continuous and integrated monitoring of environmental pollution implications on biological systems. In this study, we investigated the use of the plant species Tradescantia pallida as a biomonitor to evaluate the genotoxic effects of atmospheric pollution under diverse vehicular traffic conditions. T. pallida was strategically planted at the leading urban intersections in Uberlândia, Brazil. During COVID-19 pandemic lockdowns, we compared indicators such as physical, biological, and traffic data at different intersections in residential and commercial zones. The reduction in vehicular traffic highlighted the sensitivity of plant species to changes in air and soil pollutants. T. pallida showed bioaccumulation of heavy metals Cd and Cr in monitored areas with higher traffic levels. Additionally, we established a multiple linear regression model to estimate genotoxicity using the micronucleus test, with chromium concentration in the soil (X1) and particulate matter (PM) in the atmosphere (X2) identified as the primary independent variables. Our findings provide a comprehensive portrait of the impact of vehicular traffic changes on PM and offer valuable insights for refining parameters and models of Environmental Health Surveillance.

Air monitoring of organochlorine pesticides (OCPs) in Bursa Türkiye: Levels, temporal trends and risk assessment

Monitoring concentration levels of persistent organic pollutants (POPs) is required to evaluate the effectiveness of international regulations to minimize the emissions of persistent organic pollutants (POPs) into the environment. In this manner, we evaluated the spatial and temporal variations of 22 organochlorine pesticides (OCPs) using polyurethane foam passive air samplers at ten stations in Bursa in 2017 and 2018. The highest concentration value for Σ22OCPs was detected in Ağaköy (775 pg/m3) and Demirtaş (678 pg/m3) sampling sites, while the lowest value was observed in Uludağ University Campus (UUC, 284 pg/m3) site. HCB, γ-HCH, Endo I, and Mirex were the most frequently detected OCPs, which shows their persistence. Diagnostic ratios of β-/(α + γ)-HCH have pointed to historical and possible illegal OCP usage in the study area. The seasonality of air concentrations (with spring and summer concentrations higher than winter and autumn concentrations) was well exhibited by α-HCH, β-HCH, ɣ-HCH, HCB, Endo I, and Mirex but not aldrin, dieldrin, and α-chlordane (CC). Levels of OCPs detected in ambient air in the current study were relatively similar to or lower than those reported in previous studies conducted in Türkiye. Back trajectory analysis was applied to identify the possible sources of OCPs detected in the sampling regions. The Clausius-Clapeyron approach was used to investigate the temperature dependence of OCP gas-phase atmospheric concentrations. The data showed that long-range atmospheric transport affects ambient air OCP concentrations in the study area.

Atmospheric endocrine disruptors: A systematic review on oestrogenic and androgenic activity of particulate matter

The alarming human health effects induced by endocrine disruptors (ED) have raised the attention of public opinion and policy makers leading worldwide to regulations that are continuously improved to reduce exposure to them. However, decreasing the exposure levels is challenging because EDs are ubiquitous and exposure occurs through multiple routes. The main exposure route is considered ingestion, but, recently, the inhalation has been hypothesized as an important additional route. To explore this scenario, some authors applied bioassays to assess the endocrine activity of air. This review summarizes for the first time the applied methods and the obtained evidences about the in vitro endocrine activity of airborne particulate matter (PM) collected outdoor. Among the bioassay endpoints, (anti)oestrogenic and (anti)androgenic activities were selected because are the most studied endocrine activities. A total of 24 articles were ultimately included in this review. Despite evidences are still scarce, the results showed that PM can induce oestrogenic, antioestrogenic, androgenic and antiandrogenic effects, suggesting that PM has an endocrine disrupting potential that should be considered because it could represent a further source of exposure to EDs. Although it is difficult to estimate how much inhalation can contribute to the total burden of EDs, endocrine activity of PM may increase the human health risk. Finally, the results pointed out that the overall endocrine activity is difficult to predict from the concentrations of individual pollutants, so the assessment using bioassays could be a valuable additional tool to quantify the health risk posed by EDs in air.

2,4,6-TCP migrates and transforms in different cultivated soil in China: Kinetic analysis and mechanistic modeling

Organochlorine pesticides are widely used in agriculture, wood preservation, pulp bleaching and other fields, which increased the pollution risk of cultivated land. In this study, a typical organochlorine pesticides-2,4,6-TCP was conducted as the target pollutants to investigated the migration and transformation characteristics in different cultivated soils in China. The results indicated that the adsorption of 2,4,6-TCP in soil samples was in order: black soil＞laterite＞fluvo-aquic soil, and the maximum adsorption was 71.0870, 27.0575 and 6.1292 mg/kg, respectively. The dispersion coefficient of black soil, laterite and fluvo-aquic soil was 0.0329, 0.0501 and 0.0149, and the hysteretic factor R was 5.381, 1.455 and 2.238, respectively, indicating that the migration ability of 2,4,6-TCP in different cultivated soils samples was in order: black soil＞laterite＞fluvo-aquic soil. The fitting results of one-dimensional migration model indicated that the model well reflected the migration and transformation of 2,4,6-TCP in different cultivated soil samples. Meanwhile, the Two-dimensional migration model fitting results indicated that the maximum concentration of 2,4,6-TCP of different cultivated soil samples were found along the longitudinal flow direction, reaching 40% of the initial pollution concentration at 15 m, corresponding to the center of the pollutant plume.

Can oestrogenic activity in air contribute to the overall body burden of endocrine disruptors?

Endocrine disruptors (EDCs) are emerging contaminants that are harmful to health. Human exposure occurs mainly through ingestion or dermal contact, but inhalation could be an additional exposure route; therefore, this study was conducted to evaluate the oestrogenic activity of airborne particulate matter (PM). Outdoor PM was collected for a year in five Italian sites and extracted with organic solvents (four seasonal extracts/site). The oestrogenic activity was assessed using a gene reporter assay (MELN), and the risk to human health through inhalation was quantified using the results. Moreover, extracts were analysed to assess cytotoxicity (WST-1 and LDH assays) on human bronchial cells (BEAS-2B). The extracts induced a significant cytotoxicity and oestrogenic activity. Oestrogenic activity showed a seasonal trend and was correlated with concentrations of benzo(a)pyrene and toxic equivalency factor. Although a low inhalation cancer risk was found, this study confirmed that oestrogenic activity in air could contribute to overall health risks due to EDC exposure.

Past, present and future trends of selected pesticidal and industrial POPs in Kuwait

Given the background of current global initiatives for controlling persistent organic pollutants (POPs), an overview of the scientific knowledge about the POPs issues in Kuwait is presented in this study. Both acute and chronic exposure to POPs can be associated with a wide range of deleterious health effects, including illness and death. POPs have drawn significant political and scientific interest in their fate and actions, particularly where local releases have resulted in dispersed contamination far from the source regions. These concerns inevitably led to the establishment of the Stockholm Convention (SC) on POPs. In recent years, Kuwait has carried out a wide variety of environmental research, in particular, on the monitoring of POPs in different matrices. The technological development facilitated to achieve the opposite monitoring of pesticidal and industrial POPs. The majority of these POPs are from a point source. Kuwait does not have pesticide manufacturing facilities and has not produced pesticides for POPs in the past. In the agriculture sector, Kuwait primarily imports pesticides for pest and disease control. This review encompasses the historical presence and current status of (pesticidal) organochlorine pesticides (OCPs) and (industrial POPs) PCBs and PBDEs in Kuwait based on the export, import, consumption and usage. This research also contrasts pesticide and industrial POP data from various Kuwaiti environmental matrices with data from other parts of Asia, the EU, the USA and Africa.

Toxicity screening of air extracts representing different source sectors in the Greater Toronto and Hamilton areas: In vitro oxidative stress, pro-inflammatory response, and toxicogenomic analysis

In the present study, the suitability and sensitivity of different in vitro toxicity endpoints were determined to evaluate and distinguish the specific contributions of polycyclic aromatic carbon (PAC) mixtures from various sites in Toronto (Canada), to pulmonary toxicity. Air samples were collected for two-month periods from April 2014 to March 2015 from one location, and from August 2016 to August 2017 from multiple locations reflecting different geographical areas in Toronto, and the Greater Toronto Area, with varying source emissions including background, traffic, urban, industrial and residential sites. Relative concentrations of PACs and their derivatives in these air samples were characterised. In vitro cytotoxicity, pro-inflammatory, and oxidative stress assays were employed to assess the acute pulmonary effects of urban-air-derived air pollutants. In addition, global transcriptional profiling was utilized to understand how these chemical mixtures exert their harmful effects. Lastly, the transcriptomic data and the chemical profiles for each site and season were used to relate the biological response back to individual constituents. Site-specific responses could not be derived; however, the Spring season was identified as the most responsive through benchmark concentration analysis. A combination of correlational analysis and principal component analysis revealed that nitrated and oxygenated polycyclic aromatic hydrocarbons (PAHs) drive the response at lower concentrations while specific PAHs drive the response at the highest concentration tested. Unsubstituted PAHs are the current targets for analysis as priority pollutants. The present study highlights the importance of by-products of PAH degradation in the assessment of risk. The study also demonstrates the usefulness of in vitro toxicity assays to derive meaningful data in support of risk assessment.

Cytotoxic and Transcriptomic Effects in Avian Hepatocytes Exposed to a Complex Mixture from Air Samples, and Their Relation to the Organic Flame Retardant Signature

Assessing complex environmental mixtures and their effects is challenging. In this study, we evaluate the utility of an avian in vitro screening approach to determine the effects of passive air sampler extracts collected from different global megacities on cytotoxicity and gene expression. Concentrations of a suite of organic flame retardants (OFRs) were quantified in extracts from a total of 19 megacities/major cities in an earlier study, and levels were highly variable across sites. Chicken embryonic hepatocytes were exposed to serial dilutions of extracts from the 19 cities for 24 h. Cell viability results indicate a high level of variability in cytotoxicity, with extracts from Toronto, Canada, having the lowest LC50 value. Partial least squares (PLS) regression analysis was used to estimate LC50 values from OFR concentrations. PLS modeling of OFRs was moderately predictive of LC50 (p-value = 0.0003, r² = 0.66, slope = 0.76, when comparing predicted LC50 to actual values), although only after one outlier city was removed from the analysis. A chicken ToxChip PCR array, comprising 43 target genes, was used to determine effects on gene expression, and similar to results for cell viability, gene expression profiles were highly variable among the megacities. PLS modeling was used to determine if gene expression was related to the OFR profiles of the extracts. Weak relationships to the ToxChip expression profiles could be detected for only three of the 35 OFRs (indicated by regression slopes between 0.6 and 0.5 when comparing predicted to actual OFR concentrations). While this in vitro approach shows promise in terms of evaluating effects of complex mixtures, we also identified several limitations that, if addressed in future studies, might improve its performance.

Extremophiles, a Nifty Tool to Face Environmental Pollution: From Exploitation of Metabolism to Genome Engineering

Extremophiles are microorganisms that populate habitats considered inhospitable from an anthropocentric point of view and are able to tolerate harsh conditions such as high temperatures, extreme pHs, high concentrations of salts, toxic organic substances, and/or heavy metals. These microorganisms have been broadly studied in the last 30 years and represent precious sources of biomolecules and bioprocesses for many biotechnological applications; in this context, scientific efforts have been focused on the employment of extremophilic microbes and their metabolic pathways to develop biomonitoring and bioremediation strategies to face environmental pollution, as well as to improve biorefineries for the conversion of biomasses into various chemical compounds. This review gives an overview on the peculiar metabolic features of certain extremophilic microorganisms, with a main focus on thermophiles, which make them attractive for biotechnological applications in the field of environmental remediation; moreover, it sheds light on updated genetic systems (also those based on the CRISPR-Cas tool), which expand the potentialities of these microorganisms to be genetically manipulated for various biotechnological purposes.

Passive air sampling for semi-volatile organic chemicals

During passive air sampling, the amount of a chemical taken up in a sorbent from the air without the help of a pump is quantified and converted into an air concentration. In an equilibrium sampler, this conversion requires a thermodynamic parameter, the equilibrium sorption coefficient between gas-phase and sorbent. In a kinetic sampler, a time-averaged air concentration is obtained using a sampling rate, which is a kinetic parameter. Design requirements for kinetic and equilibrium sampling conflict with each other. The volatility of semi-volatile organic compounds (SVOCs) varies over five orders of magnitude, which implies that passive air samplers are inevitably kinetic samplers for less volatile SVOCs and equilibrium samplers for more volatile SVOCs. Therefore, most currently used passive sampler designs for SVOCs are a compromise that requires the consideration of both a thermodynamic and a kinetic parameter. Their quantitative interpretation depends on assumptions that are rarely fulfilled, and on input parameters, that are often only known with high uncertainty. Kinetic passive air sampling for SVOCs is also challenging because their typically very low atmospheric concentrations necessitate relatively high sampling rates that can only be achieved without the use of diffusive barriers. This in turn renders sampling rates dependent on wind conditions and therefore highly variable. Despite the overall high uncertainty arising from these challenges, passive air samplers for SVOCs have valuable roles to play in recording (i) spatial concentration variability at scales ranging from a few centimeters to tens of thousands of kilometers, (ii) long-term trends, (iii) air contamination in remote and inaccessible locations and (iv) indoor inhalation exposure. Going forward, thermal desorption of sorbents may lower the detection limits for some SVOCs to an extent that the use of diffusive barriers in the kinetic sampling of SVOCs becomes feasible, which is a prerequisite to decreasing the uncertainty of sampling rates. If the thermally stable sorbent additionally has a high sorptive capacity, it may be possible to design true kinetic samplers for most SVOCs. In the meantime, the passive air sampling community would benefit from being more transparent by rigorously quantifying and explicitly reporting uncertainty.

Seasonal variation of endocrine disrupting potentials of pollutant mixtures associated with various size-fractions of inhalable air particulate matter

Ambient air pollution, namely exposure to air particulate matter (PM), has been shown to be connected with a number of adverse health effects. At least part of the effects can be caused by organic pollutant mixtures associated with PM, which can elicit a wide range of specific toxic potentials. These potentials could be affected by seasonal variation of pollutant mixtures and PM size fraction. To examine this, six size subfractions of PM₁₀ were collected at rural and urban site in the Czech Republic in a year-long sampling campaign. The samples were assessed for aryl hydrocarbon (AhR)-mediated activity, estrogenicity and anti-androgenicity using mammalian cell models. The concentrations of detected toxic potentials differed among seasons. The greatest levels were observed in samples collected during winter when AhR-mediated effects and estrogenicity were at least 10-times greater than in summer. While the observed potentials were mostly less pronounced in samples from rural area, during winter, their AhR-mediated activity was twice as great as at the urban site. This was probably caused by the low-quality of fuel used for heating at the rural site. Assessed toxic potentials were associated mainly with PM size fractions with lesser aerodynamic diameters (<1 μm). Toxic potentials were compared with data from chemical analyses covering 102 chemicals from different pollutant groups to model their contribution to the observed effects. For AhR-mediated activity, chemical analyses explained on average 44% of the effect and the main identified effect-drivers were polycyclic aromatic hydrocarbons. For estrogenicity and anti-androgenicity, detected chemicals were able to explain on average less than 1.6% and 11% of the potentials, with their highest explicability reaching 13% and 57%, respectively. This was affected by the lack of data on specific toxic potency of some detected air pollutants, but also indicates a possible role of further not analyzed chemicals in these effects.

Aryl hydrocarbon receptor-mediated activity of gas-phase ambient air derived from passive sampling and an in vitro bioassay

The gaseous fraction of hydrophobic organic contaminants (HOCs) in ambient air appears to be responsible for a significant portion of aryl hydrocarbon receptor (AhR)-mediated activity, but the majority of compounds contributing to this activity remain unidentified. The present study investigated the use of polyethylene passive samplers to isolate gaseous HOCs from ambient air for use in in vitro bioassays and to improve our understanding of the toxicological relevance of the gaseous fraction of ambient air in urban and residential environments. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and organic flame retardants were measured in polyethylene passive sampler extracts. Extracts were also analyzed using an in vitro bioassay to measure AhR-mediated activity. Bioassay-derived benzo[a]pyrene (BaP) equivalents (BaP-Eq_bio ), a measure of potency of HOC mixtures, were greatest in the downtown Cleveland area and lowest at rural/residential sites further from the city center. The BaP-Eq_bio was weakly correlated with concentrations of 2-ring alkyl/substituted PAHs and one organophosphate flame retardant, ethylhexyl diphenyl phosphate. Potency predicted based on literature-derived induction equivalency factors (IEFs) explained only 2 to 23% of the AhR-mediated potency observed in bioassay experiments. Our results suggests that health risks of gaseous ambient air pollution predicted using data from targeted chemical analysis may underestimate risks of exposure, most likely due to augmentation of potency by unmonitored chemicals in the mixture, and the lack of relevant IEFs for many targeted analytes. Environ Toxicol Chem 2019;38:748-759. © 2019 SETAC.

Spatial gradients of polycyclic aromatic hydrocarbons (PAHs) in air, atmospheric deposition, and surface water of the Ganges River basin

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous semi-volatile organic pollutants. Their environmental occurrence is of global concern as some of them are carcinogens, mutagens, and teratogens. In this study, concentrations and distributions of 16 priority PAHs (∑PAHs) were measured in air, atmospheric deposition, and surface water at various locations in Himalayan, Middle, and Lower Reaches of the Ganges River, covering a spatial transect of 2500km, during two seasons (pre-monsoon and monsoon). The concentration of ∑PAHs ranged between 2.2 and 182.2ngm^-3 in air, between 186 and 8810ngm^-2day^-1 in atmospheric deposition, and between 0.05 and 65.9ngL^-1 in surface water. Air concentrations were strongly correlated with human population density. In the Middle and Lower Reaches of the Ganges River, atmospheric PAHs were mainly attributed to fossil fuel combustion sources. In the Himalayan Reach the influence of forest fire or biomass combustion was evident during the dry pre-monsoon season. Seasonality in concentrations of PAHs in river water was evident in the Himalayan Reach of the river, as a probable consequence of climate-modulated secondary source intensity (i.e. releases from glacier melting). Seasonality faded in the Middle and Lower Reaches of the Ganges where water contamination is expected to mainly reflect anthropogenic primary sources. Ambient air concentrations were used to calculate the probabilistic incremental lifetime cancer risk (ILCR). It was expectedly found to be higher in the Middle and Lower Reaches compared to the Himalayan Reach. The strong correlation between population density and air concentrations suggests population density may be used as a surrogate variable to assess human health risk in data-sparse regions such as the Ganges River basin.

Mapping Indicators of Toxicity for Polycyclic Aromatic Compounds in the Atmosphere of the Athabasca Oil Sands Region

Extracts of passive air samples collected from 15 passive sampling network sites across the Athabasca Oil Sands region were used to explore the application of in vitro assays for mutagenicity (Salmonella mutation assays) and cytotoxicity (lactate dehydrogenase assay) to assess the toxicity of the air mixture. The air monitoring of polycyclic aromatic compounds (PACs) and PAC transformation products, including nitrated polycyclic aromatic hydrocarbons (NPAHs) and oxygenated polycyclic aromatic hydrocarbons (OPAHs) was then linked to the potential toxicity of air. The PACs in air during April to May 2014 were elevated near mining activities and declined with distance from the source region, whereas NPAHs and OPAHs exhibited a more variable spatial distribution with the highest levels in Fort McMurray. Overall, the air samples exhibited a weak mutagenicity. The highest indirect-acting mutagenicity was observed for sites closest to mining activities; however, the indirect-acting mutagenicity did not decline sharply with distance from mining areas. Indirect-acting mutagenicity was strongly correlated with levels of total PACs, benzo(a)pyrene equivalent mass, and OPAHs. Most of the samples exhibited cytotoxic potential, but the magnitude of the response was variable across the sample region and did not correlate with levels of target analytes. This indicates that PACs and PAC derivatives were not a major contributor to the cytotoxicity observed in the air samples.