Variation in particulate PAHs levels and their relation with the transboundary movement of the air masses

History of organic pollution in montane lake Issyk-Kul, Kyrgyzstan, Central Asia, inferred from a sediment core

In arid regions, montane lakes are valuable water sources and play important ecological roles. However, recent human-induced inputs of organic pollutants are threatening lake ecology in such regions and becoming a matter of great concern. To investigate pollutant histories and sources, we measured polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in a dated sediment core that spans the last ∼350 years, from montane Lake Issyk-Kul (Kyrgyzstan, Central Asia). Results showed that organic pollutants were delivered to Lake Issyk-Kul in four stages and that their concentrations increased from Stage I (∼1670-1800 CE) to Stage IV (∼2000-2010 CE). Furthermore, we tracked the sources of sedimented PAHs using their ratios combined with n-alkanes data. Ratios of PAHs Ant/(Ant + Phe), Flt/(Flt + Pyr) and Bap/BghiP indicated that inputs during Stage II (∼1800-1970 CE) and Stage III (∼1970-2000 CE) came mainly from high-temperature combustion of coal and vehicle emissions. PAHs in Stage I and Stage IV, however, were mainly derived from low-temperature combustion and petrogenic sources. Diagnostic PAH ratios, combined with the natural n-alkane ratio (NAR＜0) and unresolved complex mixtures (UCM), showed that the sources of PAHs in Stage I were mainly from erosion of bedrock and partly influenced by forest wildfires, different from the source during Stage IV, which was mainly from refined petroleum caused by accidental spills. Our assessment of the contamination history of the lake indicates that toxicity risk to the waterbody from sediment PAHs is low, but recent discharges arising from traffic deserve attention.

Polycyclic aromatic hydrocarbons in surface water of rivers in Sergipe State, Brazil: A comprehensive analysis of sources, spatial and temporal variation, and ecotoxicological risk

This study conducted in Sergipe State, Brazil, aimed to investigate the presence of polycyclic aromatic hydrocarbons (PAHs) in the surface water of five rivers, determining their sources, spatial and temporal variations, and ecotoxicological risks. Correlation and principal component analyses were utilized to identify the relationship between PAH concentrations and water sample properties. Results indicated higher PAH concentrations during the rainy season, attributed to increased run-off and sediment resuspension. The composition of PAHs suggested a main petroleum source with organic material combustion in minor scale. Ecological risk assessment revealed potential risks to the ecosystem, emphasizing the need for continuous monitoring of PAHs pollution. This study highlights the importance of understanding and mitigating PAHs contamination in rivers to protect aquatic ecosystems.

Occurrence of high production volume chemicals and polycyclic aromatic hydrocarbons in urban sites close to industrial areas. Human exposure and risk assessment

Evaluating the occurrence of high production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) in the air is important because they carry a carcinogenic risk and can lead to respiratory or endocrine problems. Examples of HPVCs are organophosphate esters, benzosulfonamides, benzothiazoles, phthalate esters (PAEs), phenolic antioxidants and ultraviolet stabilizers. In this paper we develop a multi-residue method for determining HPVCs and PAHs in air samples via pressurized liquid extraction followed by gas chromatography-mass spectrometry. Air samples were collected by active sampling with high volume samplers using quartz fiber filter for the particulate matter (PM10) and polyurethane foams for gas phase. The compounds found at the highest concentrations were PAEs, with a concentration of up to 24 ng m-3 of DEHP in gas phase and up to 109 ng m-3 of DEHA in PM10. Non-carcinogenic risk assessment results ranged from 9.7E-05 to 9.5E-03 for most of the compounds studied. On the other hand, the results for carcinogenic risk showed that PAHs made the highest contribution.

The main strategies for soil pollution apportionment: A review of the numerical methods

Nowadays, a large number of compounds with different physical and chemical properties have been determined in soil. Environmental behaviors and source identification of pollutants in soil are the foundation of soil pollution control. Identification and quantitative analysis of potential pollution sources are the prerequisites for its prevention and control. Many efforts have made to develop methods for identifying the sources of soil pollutants. These efforts have involved the measurement of source and receptor parameters and the analysis of their relationships via numerical statistics methods. We have comprehensively reviewed the progress made in the development of source apportionment methodologies to date and present our synthesis. The numerical methods, such as spatial geostatistics analysis, receptor models, and machine learning methods are addressed in depth. In most cases, however, the effectiveness of any single approach for source apportionment remains limited. Combining multiple methods to address soil quality problems can reduce uncertainty about the sources of soil pollution. This review also constructively highlights the key strategies of combining mathematical models with the assessment of chemical profiles to provide more accurate source attribution. This review intends to provide a comprehensive summary of source apportionment methodologies to help promote further development.

Biomonitoring of PAHs and PCBs in industrial, suburban, and rural areas using snails as sentinel organisms

There is a worldwide concern about the presence of persistent organic pollutants (POPs) in the environment because of their toxicity, bioaccumulation, and resistance to degradation. Various conventional monitoring techniques have been used to assess their presence in diverse environmental compartments. Most currently available methods, however, have limitations with regards to long-term monitoring. In the present work, juvenile Cornu aspersum (O. F. Müller, 1774) snails were tested in field microcosms as biomonitors for two major classes of organic pollutants, namely, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The study assessed their deployment in one suburban, one rural, and two industrial sites over an 18-week period and monitored for temporal variations of 16 PAHs and 22 PCBs. Sampling was conducted once every 3 weeks. Targeted pollutants were extracted from the caged snails using the QuEChERS extraction procedure and subsequently analyzed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The results showed that the bioaccumulation of specific pollutants was site dependent; significantly higher levels of PCBs were observed at the industrial sites as compared to the suburban and rural ones. PAHs were bioaccumulated by the snails via ingestion of air and soil whereas PCBs were mainly bioaccumulated via soil contact and ingestion. The findings of this study indicate that C. aspersum is a reliable model organism for the biomonitoring of organic pollutants in air and soil compartments and can be used as part of an integrated environmental assessment.

Impact of Atmospheric Conditions and Source Identification of Gaseous Polycyclic Aromatic Hydrocarbons (PAHs) during a Smoke Haze Period in Upper Southeast Asia

Gaseous polycyclic aromatic hydrocarbons were measured in northern Thailand. No previous studies have provided data on gaseous PAHs until now, so this study determined the gaseous PAHs during two sampling periods for comparison, and then they were used to assess the correlation with meteorological conditions, other pollutants, and their sources. The total concentrations of 8-PAHs (i.e., NAP, ACY, ACE, FLU, PHE, ANT, FLA, and PYR) were 125 ± 22 ng m-3 and 111 ± 21 ng m-3, with NAP being the most pronounced at 67 ± 18 ng m-3 and 56 ± 17 ng m-3, for morning and afternoon, respectively. High temperatures increase the concentrations of four-ring PAHs, whereas humidity and pressure increase the concentrations of two- and three-ring PAHs. Moreover, gaseous PAHs were estimated to contain more toxic derivatives such as nitro-PAH, which ranged from 0.02 ng m-3 (8-Nitrofluoranthene) to 10.46 ng m-3 (1-Nitronaphthalene). Therefore, they could be one of the causes of local people's health problems that have not been reported previously. Strong correlations of gaseous PAHs with ozone indicated that photochemical oxidation influenced four-ring PAHs. According to the Pearson correlation, diagnostic ratios, and principal component analysis, mixed sources including coal combustion, biomass burning, and vehicle emissions were the main sources of these pollutants.

Polycyclic aromatic hydrocarbons in the sediments of highly polluted coastal area in the Red Sea: levels, spatial distribution, and risk assessment

The southern part of the Jeddah coast faces a range of pollution challenges that can impact the water quality and ecosystem in the area. Pollution sources are represented mainly by treated wastewater (TWW), harbor activities, and atmospheric deposition from vehicle exhaust emissions. Polycyclic aromatic hydrocarbons (PAHs) are among the persistent organic pollutants that interfere with all environmental matrices and could cause humane mutagenic and carcinogenic effects. In the present study, 16 priority parent and 21 methylated PAHs (∑37PAHs) were assessed in the sediments of three hot spot coastal sites (Islamic Jeddah port, Al-Arbaeen, and Al-Shabab lagoons) to evaluate the factors affecting their spatial distribution, examine their probable sources and potential adverse effects. The total detected concentrations of ∑37PAHs ranged from 785.9 to 8359.8 ng/g dw (average: 2296.3 ± 2017.3 ng/g dw). The highest levels of ∑37PAHs were detected near TWW stations. The highest individual PAH congeners observed were phenanthrene, anthracene, and pyrene. PAH molecular diagnostic ratios pointed out different pyrogenic sources. In some specific stations, there was an overlap of petrogenic origin. The sediment samples contained high concentrations of methylated PAHs, with concentrations ranging from 558.42 to 6321.21 ng/g dw and an average concentration of 1679.1 ± 1430.7 ng/g dw. The sediment quality guidelines indicated that adverse biological effects are likely to occur at least at the two TWW disposal stations and the sediments in these stations are at risk. The values of the mutagenic equivalence quotient (MEQ) and toxic equivalence quotient (TEQ) of carcinogenic PAHs were recorded at 39.88 and 33.17 ng/g, respectively.

Exposure and health risk assessment of PM2.5-bound polycyclic aromatic hydrocarbons during winter at residential homes: A case study in four Chinese cities

Residential indoor PM2.5 were concurrently collected in Hong Kong, Guangzhou, Shanghai, and Xi'an during the winter and early spring seasons of 2016-2017, for updating the current knowledge of the spatial variation of indoor air pollution and the potential health risks in China. PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were characterized, and the associated inhalation cancer risks were assessed by a probabilistic approach. Higher levels of indoor PAHs were identified in Xi'an residences (averaged at 176.27 ng m-3) with those of other cities ranging from 3.07 to 15.85 ng m-3. Traffic-related fuel combustion was identified as a common contributor to indoor PAHs through outdoor infiltration for all investigated cities. Indoor PAHs profiles showed city-specific differences, while distinctions between profiles based on indoor activities or ambient air quality were limited. Similar with the total PAHs concentrations, the estimated toxic equivalencies (TEQ) with reference to benzo[a]pyrene in Xi'an residences (median at 18.05 ng m-3) were above the recommended value of 1 ng m-3 and were magnitudes higher than the other investigated cities with estimated median TEQ ranging from 0.27 to 1.55 ng m-3. Incremental lifetime cancer risk (ILCR) due to PAHs inhalation exposure was identified with a descending order of adult (median at 8.42 × 10-8) > adolescent (2.77 × 10-8) > children (2.20 × 10-8) > senior (1.72 × 10-8) for different age groups. Considering the lifetime exposure-associated cancer risk (LCR), potential risks were identified for residents in Xi'an as an LCR level over 1 × 10-6 was identified for half of the adolescent group (median at 8.96 × 10-7), and exceedances were identified for about 90 % of the groups of adults (10th percentile at 8.29 × 10-7) and seniors (10th percentile at 1.02 × 10-6). The associated LCR estimated for other cities were relatively insignificant.

Biomonitoring of polycyclic aromatic hydrocarbons (PAHs) by Murraya paniculata (L.) Jack in South Kolkata, West Bengal, India: spatial and temporal variations

Attempts have been made in the present study for ascertaining the concentrations of atmospheric polycyclic aromatic hydrocarbons (PAHs) using passive biosamplers in preference to conventional air sampling methods. Mechanical stirring, sonication, Soxhlet technique and microwave-assisted Soxhlet extraction (MASE) were employed to extract PAHs from an evergreen plant (Murraya paniculata) leaves (having long life-span) sampled from polluted places of South Kolkata, India, with dense population and heavy traffic. Effects of extraction methods and operational parameters (solvent and time) on the recovery levels of PAHs were also investigated. Purified extracts, acquired through adsorption chromatography, were subjected to GC-MS and HPLC-UV analyses for qualitative and quantitative assessment of PAHs. Spatio-temporal distribution of accumulated PAHs across the sampling sites was monitored over premonsoon, postmonsoon and winter supported by pollutant source characterization. The results displayed that the extraction yields of Soxhlet (272.07 ± 26.15 μg g-1) and MASE (280.17 ± 15.46 μg g-1) were the highest among the four techniques. Conditions of extraction with toluene for 6 h were found to be most favorable for PAHs. In spatio-temporal analysis, total concentrations of PAHs in the foliar samples varied from 200.98 ± 2.72 to 550.79 ± 10.11 μg g-1 dry weight, and the highest values being recorded in the samples of Exide More because of daylong inexorable traffic flow/crowding increasing the burden of ambient PAHs. Widespread changes in meteorology exerted influence on seasonal concentrations of PAHs in plant leaves, and extent of leaf contamination by PAHs was observed extreme in winter followed by postmonsoon and then, premonsoon. Foliar accretion of PAHs differed in the study sites with diverse sources of emission from motor vehicles, fossil fuel and biomass burning along with other human interferences.

Polyaromatic hydrocarbons (PAHs) in the water environment: A review on toxicity, microbial biodegradation, systematic biological advancements, and environmental fate

Polycyclic aromatic hydrocarbons (PAHs) are considered a major class of organic contaminants or pollutants, which are poisonous, mutagenic, genotoxic, and/or carcinogenic. Due to their ubiquitous occurrence and recalcitrance, PAHs-related pollution possesses significant public health and environmental concerns. Increasing the understanding of PAHs' negative impacts on ecosystems and human health has encouraged more researchers to focus on eliminating these pollutants from the environment. Nutrients available in the aqueous phase, the amount and type of microbes in the culture, and the PAHs' nature and molecular characteristics are the common factors influencing the microbial breakdown of PAHs. In recent decades, microbial community analyses, biochemical pathways, enzyme systems, gene organization, and genetic regulation related to PAH degradation have been intensively researched. Although xenobiotic-degrading microbes have a lot of potential for restoring the damaged ecosystems in a cost-effective and efficient manner, their role and strength to eliminate the refractory PAH compounds using innovative technologies are still to be explored. Recent analytical biochemistry and genetically engineered technologies have aided in improving the effectiveness of PAHs' breakdown by microorganisms, creating and developing advanced bioremediation techniques. Optimizing the key characteristics like the adsorption, bioavailability, and mass transfer of PAH boosts the microorganisms' bioremediation performance, especially in the natural aquatic water bodies. This review's primary goal is to provide an understanding of recent information about how PAHs are degraded and/or transformed in the aquatic environment by halophilic archaea, bacteria, algae, and fungi. Furthermore, the removal mechanisms of PAH in the marine/aquatic environment are discussed in terms of the recent systemic advancements in microbial degradation methodologies. The review outputs would assist in facilitating the development of new insights into PAH bioremediation.

Impact of air pollution on human health in different geographical locations of Nepal

According to a recent survey, Nepal's urban air quality has been classified as one of the worst in the globe. A large portion of the country's population is subjected to health risks caused by air pollution. As Nepal has a wide variation in altitude coupled with socio-cultural and biological diversities, it is important to understand the different health hazards in the different geographical regions - Terai, Hills and Mountains. Constantly increasing physical infrastructures (such as transport vehicles, open burning of plastics and other fuels) are the main reasons for the escalating air pollution in the country. This study aims to critically review the current air pollution status in different geographical locations along with its impacts on public health in the country. It has been revealed that irrespective of geographic location, the air pollutants interfere with different human physiological systems related to respiration as well as cardiovascular, ophthalmic, and gastrointestinal functioning. Further, the research findings highlighting the influence of prolonged exposure of the population to the air pollution leading to the significant number of deaths have been presented. A notable rise in the number of hospitalized patients suffering from illnesses related to above mentioned pollution borne cases has been reported.

Spatio-temporal distribution and sources of polycyclic aromatic hydrocarbons in Tunis Lagoon: Concentrations in sediments and Marphysa sanguinea body and excrement

Despite international recognition as an important coastal wetland, Tunis Lagoon is still subjected to anthropogenic pressures. This article provides valuable data on the spatio-temporal distribution, toxicity, and origins of polycyclic aromatic hydrocarbons (PAHs) in the Tunis Lagoon complex. PAHs' concentrations were measured in Marphysa sanguinea body and excrements, as well as in surface sediments. Total mean PAHs' concentrations reached a maximum of 2398 ng/g dry weight (DW) in sediments, 1007.19 ng/g DW in M. sanguinea, and 2602.05 ng/g DW in excrements. Diagnostic PAHs' ratios were used to determine whether PAHs' origins were pyrogenic or petrogenic. Our data showed a predominance of PAHs with a pyrogenic source. Principal component analysis showed PAHs isolated from polychaetes clearly separated from those measured in sediment and excrement. We believe that sediments are not the main source of bioaccumulation by M. sanguinea. Moreover, the toxicity of PAHs in sediments is moderate to high for benthic organisms.

Spatial distribution, sources and risk assessment of polycyclic aromatic hydrocarbons in the surficial sediments of the Egyptian Mediterranean coast

The Egyptian Mediterranean coast (EMC) receives a considerable quantity of polycyclic aromatic hydrocarbons (PAHs). PAHs from EMC sediments were assessed to understand the effects of marine and riverine currents on their distribution. The concentrations of total PAHs ranged between 13,156-34,852 ng/g dw. PAH levels have increased even in areas far from the shoreline under the influence of riverine inputs from the Nile River; this is attributed to the tidally induced riverine freshwater re-suspension of surface sediments in the shallow near-shore section and re-precipitation in the fare stations. PAH levels generally increase as one moves from the western to the eastern part of the studied area, owing to the effect of the marine current. Diagnostic ratios pointed toward different pyrogenic sources. SQGs were used to assess the probability of observing adverse biological effects in benthic organisms in sediment samples. The toxic and mutagenic equivalent quotient for carcinogenic PAHs was extremely high.

Integrated Insights into Source Apportionment and Source-Specific Health Risks of Potential Pollutants in Urban Park Soils on the Karst Plateau, SW China

Polycyclic aromatic hydrocarbons (PAHs) and heavy metal(loid)s (HMs) pose risks to environmental and human health. Identification of priority control contaminants is important in guiding the management and control of these synchronous pollutants. A total of 247 soil samples were collected from 64 urban parks in the karst plateau city of Guiyang in SW China to determine the concentrations, spatial distributions, and health risks of PAHs and HMs. The results indicate that dibenz(ah)anthracene and benzo(a)pyrene are the main PAHs species of high ecological risk, and Cr, Mn, and Ni pose elevated ecological risk among the HMs. Four sources were identified for PAHs (biomass burning, coke oven, traffic sources, and coal burning) and HMs (traffic sources, coal burning, industrial sources, and natural sources). The non-carcinogenic risk (NCR) and total carcinogenic risk (TCR) of PAHs were all determined to be negligible and at acceptable levels, several orders of magnitude below those of HMs. The NCR and TCR values of HMs were relatively high, especially for children (11.9% of NCR > 1; 79.1% of TCR > 10-4). Coal burning and natural sources make the greatest contributions to the NCR and TCR values from karst park soils in Guiyang. Considering HMs bioavailability, NCR and TCR values were rather low, due to the high residual HM fractions. Integrated insights into source specific ecological and human health risk indicate future directions for management and control of synchronous PAH and HM pollution, particularly for karst plateau areas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-023-00534-3.

An extensive assessment on the distribution pattern of organic contaminants in the aerosols samples in the Middle East

Nowadays, in spite of a significant progress in indoor air quality (IAQ), an assessable and predictive understanding of atmospheric aerosol sources, chemical composition, transformation processes, and environmental effects are still rather incomplete and therefore signifies a key research challenge in the atmospheric science. Thus, the current comprehensive review is concerned with the dominant sources, organic compositions, and potential health impacts of the organic contaminants in the atmospheric particle matters (PMs) in the Middle East (ME). The ME contributes a major impact of organic contaminants on the atmosphere along with other Asian and African countries. In the Gulf Cooperation Council (GCC) countries, the communities are noted for being the center of the great majority of the world’s oil reserves and infrastructure for producing crude oil. The review starts with a historical outlook on the scientific queries regarding major source of organic contaminants to the atmospheric aerosols over the past centuries, followed by an explanation of the distribution, sources, transformation processes, and chemical and physical properties as they are formerly assumed. Natural product chemicals from biota, manufactured organic compounds including pesticides, chlorinated hydrocarbons, and lubricants, as well as organic compounds from the use and combustion of fossil fuels make up the aerosol contamination. Thus, in the recent years, IAQ may be seen as a significant health issue because of the increase in industrial activity. Fugitive emissions from industrial processes, as well as natural and anthropogenic emissions from other sources such as forest fires, volcanic eruptions, incomplete combustion of fossil fuels, wood, agricultural waste, or leaves, are typical sources of organic pollutants to the aerosol. In the spring and early summer in the GCC countries, aerosol concentration increases because of dust storms; however, in winter, there are fewer dust storms and higher precipitation rates, and aerosol concentrations are lower. Significances of future research and major suggestions are also outlined to narrow the gap between the present understanding of the contribution of both anthropogenic and biogenic aerosols to radiative forcing, resulting from the spatial nonuniformity, intermittency of sources, unresolved composition, and reactivity.

Horizontal and vertical segregation of polycyclic aromatic hydrocarbons in the Egyptian Mediterranean coast

Egyptian Mediterranean coast receives significant amounts of polycyclic aromatic hydrocarbons (PAHs) from industrial exhausts, riverine inputs, maritime shipping and fishers, and oil and natural gas production and exploration. The present study considers the first exhaustive assessment for the dissolved PAHs along the Egyptian Mediterranean coast (Alexandria to Manzallah) to monitor their spatial distribution and investigate the effect of the marine currents and the role of microorganisms in their distribution. Surface water levels ranged between 124.97 and 301.02 ng L^-1 with an average 223.68 ± 41.11 ng L^-1. The distribution increases from west to east based on the water circulation in the Mediterranean Sea. The levels in near shore stations were lower than those of middle and onshore stations. The intensive existence of micro-organisms near shore stations consumes great part of PAHs, while this bio-remediation process decreases gradually away from the shoreline leaving relative high concentrations of dissolved PAHs in the middle and onshore stations. Middle and deep-water levels ranged between 312.75 and 1042.95 ng L^-1 with an average 633.47 ± 225.53 ng L^-1. Deeper waters showed higher PAHs concentrations where the average concentrations of 50 m stations (868.12 ± 138.35 ng L^-1) ˃ 30 m stations (629.49 ± 143.85 ng L^-1) ˃ 10 m stations (402.79 ± 59.46 ng L^-1). The wind-induced waves re-suspend rich PAHs sediment particles to increase its concentration in the water column. Carcinogenic toxic equivalent quotient (TEQ) for total detected PAHs in the middle and deep water represented more than double (75.46 ng TEQ L^-1) the value in the surface water (34.76 ng TEQ L^-1). The diagnostic ratios and principal component analysis indicated mainly pyrogenic origin in surface, middle, and deep waters.

Kidney damage induced by repeated fine particulate matter exposure: Effects of different components

BACKGROUND

Exposure to fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) is associated with adverse health effects. This study aimed to evaluate the toxic effects of the constituents of PM_2.5 on mouse kidneys.

METHODS

We collected PM_2.5 near an industrial complex located in southern Kaohsiung, Taiwan, that was divided into water extract and insoluble particles. Male C57BL/6 mice were divided into five groups: control, low- and high-dose insoluble particle exposure, and low- and high-dose water extract exposure. Biochemical analysis, Western blot analysis, histological examination, and immunohistochemistry were performed to evaluate the impact of PM_2.5 constituents on mice kidneys.

RESULTS

PM_2.5 was collected from January 1, 2021, to February 8, 2021, from an industrial complex in Kaohsiung, Taiwan. Metallic element analysis showed that Pb, Ni, V, and Ti were non-essential metals with enrichment factors >10. Polycyclic aromatic hydrocarbon and nitrate polycyclic aromatic hydrocarbon analyses revealed that the toxic equivalents are, in the order, benzo(a)pyrene (BaP), indeno(1,2,3-cd) pyrene (IP), dibenzo(a,h)anthracene (DBA), and benzo(b)fluoranthene (BbF), which are potential carcinogens. Both water extract and insoluble particle exposure induced inflammatory cytokine upregulation, inflammatory cell infiltration, antioxidant activity downregulation, and elevation of kidney injury molecule 1 (KIM-1) level in mouse kidneys. A dose-dependent effect of PM_2.5 water extract and insoluble particle exposure on angiotensin converter enzyme 2 downregulation in mouse kidneys was observed.

CONCLUSION

We found that water-soluble extract and insoluble particles of PM_2.5 could induce oxidative stress and inflammatory reactions, influence the regulation of renin-angiotensin system (RAS), and lead to kidney injury marker level elevation in mouse kidneys. The lowest-observed-adverse-effect level for renal toxicity in mice was 40 μg water-soluble extract/insoluble particle inhalation per week, which was approximately equal to the ambient PM_2.5 concentration of 44 μg/m³ for mice.

Seasonality, atmospheric transport and inhalation risk assessment of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from industrial belts of Odisha, India

This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM_2.5 and PM₁₀ from industrial areas of Odisha State, India. During 2017-2018, bimonthly sampling of PM₁₀ and PM_2.5 was carried out for 24 h in the industrial and mining areas of Jharsuguda and Angul in Odisha during the pre-monsoon, monsoon, and post monsoon seasons. Highest mean concentration of ∑₁₆PAHs in PM_2.5 was observed during the post monsoon (170 ng/m³) period followed by pre-monsoon (48 ng/m³) and monsoon (16 ng/m ³) periods, respectively. A similar trend of ∑₁₆PAHs was also observed in PM₁₀ with higher levels observed during post monsoon (286 ng/m³) followed by pre-monsoon (81 ng/m³) and monsoon (27 ng/m³) seasons. Diagnostic ratios and principal component analysis suggested diesel, gasoline and coal combustion as the major contributors of atmospheric PAH pollution in Odisha. Back trajectory analysis revealed that PAH concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents ranged between 0.24 and 94.13 ng TEQ/m³. In our study, the incremental lifetime cancer risk ranged between 10^-5 and 10^-3, representing potential cancer risk.

Airborne Prokaryotic, Fungal and Eukaryotic Communities of an Urban Environment in the UK

Bioaerosols often contain human pathogens and allergens affecting public health. However, relatively little attention has been given to bioaerosols compared with non-biological aerosols. In this study, we aimed to identify bioaerosol compositions in Manchester, UK by applying high throughput sequencing methods and to find potential sources. Samples were collected at Manchester Air Quality Super Site at the Firs Environmental Research Station in November 2019 and in February 2020. Total DNA has been extracted and sequenced targeting the 16S rRNA gene of prokaryotes, ITS region of fungal DNA and 18S rRNA gene of eukaryotes. We found marine environment-associated bacteria and archaea were relatively more abundant in the February 2020 samples compared with the November 2019 samples, consistent with the North West marine origin based on wind back-trajectory analysis. In contrast, an OTU belonging to Methylobacterium, which includes many species resistant to heavy metals, was relatively more abundant in November 2019 when there were higher metal concentrations. Fungal taxa that fruit all year were relatively more abundant in the February 2020 samples while autumn fruiting species generally had higher relative abundance in the November 2019 samples. There were higher relative abundances of land plants and algae in the February 2020 samples based on 18S rRNA gene sequencing. One of the OTUs belonging to the coniferous yew genus Taxus was more abundant in the February 2020 samples agreeing with the usual pollen season of yews in the UK which is from mid-January until late April. The result from this study suggests a potential application of bioaerosol profiling for tracing the source of atmospheric particles.

A comprehensive evaluation of PM2.5-bound PAHs and their derivative in winter from six megacities in China: Insight the source-dependent health risk and secondary reactions

Atmospheric PAHs (polycyclic aromatic hydrocarbons) and their derivatives are a global concern that influences environments and threatens human health. Concentrations of 52 PAHs and the main derivatives in six Chinese megacities were measured in the winter of 2019. The concentrations of ∑PAHs (sum of 52 PAHs) ranged from 19.42 ± 7.68 to 65.40 ± 29.84 ng m^-3, with significantly higher levels in northern cities (Harbin [HB], Beijing [BJ], and Xi'an [XA]) than southern ones (Wuhan [WH], Chengdu [CD] and Guangzhou [GZ]). Source apportionment of ∑PAHs was conducted by the PMF model and results showed coal combustion and traffic emissions were the two dominant sources, which dominated ∑PAHs in northern and southern cities, respectively. Biomass burning was also characterized as a crucial source of ∑PAHs and showed extremely high contributions in XA (42.5%). Assisted by the individual PAH source apportionment results, the source-depend TEQ (total BaP equivalent) and incremental lifetime cancer risk (ILCR) were firstly reported in these cities. The results highlighted the contributions of coal combustion and biomass burning to both TEQ and ILCR, which were underestimated by ∑PAHs source apportionment. Secondary organic aerosol-derived PAHs were demonstrated to increase the TEQ compared with the fresh PAHs and three parameters, namely temperature, relative humidity, and O₃ concentrations were characterized by multiple linear regression as the principal factors influencing secondary reactions of PAHs in winter. This study provides accurate human health-orientated results and potential control measures to mitigate the toxicity of secondary formed PAHs, and significantly decrease the uncertainty level of traditional methods. The results also revealed great progress in air pollution control by the Chinese government in the past 20 years, but still a long way to go to formulate strict emission control strategies from both environmental and human health-protective perspectives.

Particulate matter-bound organic compounds: levels, mutagenicity, and health risks

Increased industrialization and consumption of fossil fuels in the Metropolitan Region of São Paulo (MRSP), Brazil, have caused a growth of the particulate matter emissions to the atmosphere and an increase in population health problems. Particulate and gaseous phase samples were collected in different short campaigns (2015, 2016, and 2017) near an urban-industrial area. Organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAH), and its derivatives (nitro and oxy-PAH), n-alkanes, hopanes, and pesticides were determined. The Salmonella/microsome test confirmed the mutagenic activity of these samples. Among PAH, benzo(a)pyrene was detected as one of the most abundant compounds. Benzo(a)pyrene equivalent concentrations for PAH and nitro-PAH, and the associated risk of lung cancer, showed values above those recommended in the literature. The profile of n-alkanes confirmed the predominance of anthropogenic sources. Pesticide concentrations and estimated risks, such as the daily inhalation exposure and hazard quotient, suggest that exposure to these compounds in this area may be dangerous to human health.

Assessment of Alkylated and Unsubstituted Polycyclic Aromatic Hydrocarbons in Air in Urban and Semi-Urban Areas in Toronto, Canada

22 alkylated polycyclic aromatic hydrocarbons (alk-PAHs) were characterized in ambient air individually for the first time in urban and semi-urban locations in Toronto, Canada. Five unsubstituted PAHs were included for comparison. Results from the measurements were used to estimate benzo[a]pyrene equivalent toxicity (BaPeq) of individual compounds in order to investigate the significance of a single compound in contributing to the overall toxic equivalency (TEQ) of air mixtures. To determine which compounds merit further investigation, BaPeq values of individual compounds were compared to the measured BaP toxicity. Our results showed that both unsubstituted and alkylated PAHs were more abundant in the urban area (38 and 30%, respectively). Benzo[a]pyrene levels at the urban location exceeded Ontario's 24 h guideline (40% of the events), and on average, it was 5 times higher than that at the semi-urban area. Gas-phase two- and three-ring compounds contributed up to 39% (urban) and 76% (semi-urban) of the TEQ of all compounds analyzed. Some alk-PAHs such as 7,12-dimethylbenzo[a]anthracene had a huge impact on the toxicity of urban air, and its BaPeq was on average 8 times higher than that of BaP. We emphasize that the toxic impact of alkylated and gaseous PAHs, which is not routinely included in many air monitoring programs, is significant and should not be neglected.

Potential Risks of PM2.5-Bound Polycyclic Aromatic Hydrocarbons and Heavy Metals from Inland and Marine Directions for a Marine Background Site in North China

Ambient PM_2.5-bound ions, OC, EC, heavy metals (HMs), 18 polycyclic aromatic hydrocarbons (PAHs), 7 hopanes, and 29 n-alkanes were detected at Tuoji Island (TI), the only marine background atmospheric monitoring station in North China. The annual PM_2.5 average concentration was 47 ± 31 μg m^-3, and the average concentrations of the compositions in PM_2.5 were higher in cold seasons than in warm seasons. The cancer and non-cancer risks of HMs and PAHs in cold seasons were also higher than in warm seasons. BaP, Ni, and As dominated the ∑HQ (hazard quotient) in cold seasons, while the non-carcinogenic risk in warm seasons was mainly dominated by Ni, Mn, and As. The ILCR (incremental lifetime cancer risk) values associated with Cr and As were higher in the cold season, while ILCR-Ni values were higher in the warm season. The backward trajectory was calculated to identify the potential directions of air mass at TI. Through the diagnostic ratios of organic and inorganic tracers, the sources of particulate matter in different directions were judged. It was found that ship emissions and sea salt were the main sources from marine directions, while coal combustion, vehicles emissions, industrial process, and secondary aerosols were the main source categories for inland directions. In addition, potential HM and PAH risks from inland and marine directions were explored. The non-cancerous effects of TI were mainly affected by inland transport, especially from the southeast, northwest, and west-northwest. The cancerous effects of TI were mainly simultaneously affected by the inland direction and marine direction of transport.

Cryoconites as biogeochemical markers of anthropogenic impact in high mountain regions: analysis of polyaromatic pollutants in soil-like bodies

The globalisation and omnidirectional character of anthropogenic processes has challenged scientists around the world to estimate the harmful effects of these processes on ecosystems and human health. Polycyclic aromatic hydrocarbons (PAHs) is one the most infamous group of contaminants, originated both from natural and anthropogenic processes. They could transport to high latitudes and altitudes through atmospheric long-distance transfer and further enter ecosystems of these vulnerable regions by deposition on terrestrial surfaces. An interesting object for tracking transboundary contamination processes in high mountain ecosystems is called cryoconite. Cryoconite, a dark-coloured supraglacial sediment which is abundant in polar and mountain environments, is considered as a storage of various pollutants, including PAHs. Thus, it may pose a risk for local human health and ecosystem through short-distance transfer. Studied cryoconite sediments were collected at the surface of Skhelda and Garabashi glaciers, Central Caucasus high-mountain region, as well as mudflow, moraine material and local soils at the Baksan Gorge in order to examine levels of their contamination. We analysed the content of 15 priority polyaromatic compounds from the US EPA list and used the method of calculation of PAHs isomer ratios with the purpose of identifying their source. To estimate their potential toxicity, Benzo[a]pyrene (BaP) equivalents were calculated. Maximum concentration was defined for NAP (84 ng×g-1), PHE (40 ng×g-1) and PYR (47 ng×g-1), with the minimum concentration for ANT (about 1 ng×g-1). The most polluted material is a cryoconite from Garabashi glacier because of local anthropogenic activities and long-distance transfer. High-molecular weight PAHs are dominated in PAHs composition of almost all samples. The most common sources of PAHs in studied materials are combustion processes and mixed pyrolytic/petrogenic origin. Toxicity levels of separate PAHs did not exceed the maximum permissible threshold concentrations values in most cases. However, the sum of PAHs in BaP equivalents exceed the threshold values in all samples, in some of them more than twice.

Effect-directed identification of novel aryl hydrocarbon receptor-active aromatic compounds in coastal sediments collected from a highly industrialized area

In this study, we identified major aryl hydrocarbon receptor (AhR) agonists in the sediments from Yeongil Bay (n = 6) using effect-directed analysis. Using the H4IIE-luc bioassays, great AhR-mediated potencies were found in aromatic fractions (F2) of sediment organic extracts from silica gel column chromatography and sub-fractions (F2.6-F2.8) from reverse phase-HPLC. Full-scan mass spectrometric analysis using GC-QTOFMS was conducted to identify novel AhR agonists in highly potent fractions, such as F2.6-F2.8 of S1 (Gumu Creek). Selection criteria for AhR-active compounds consisted of three steps, including matching factor of NIST library (≥70), aromatic structures, and the number of aromatic rings (≥4). Fifty-nine compounds were selected as tentative AhR agonist candidates, with the AhR-mediated activity being assessed for six compounds for which standard materials were available commercially. Of these compounds, 20-methylcholanthrene, 7-methylbenz[a]anthracene, 10-methylbenz[a]pyrene, and 7,12-dimethylbenz[a]anthracene exhibited significant AhR-mediated potency. Relative potency values of these compounds were determined relative to benzo[a]pyrene to be 3.2, 1.4, 1.2, and 0.2, respectively. EPA positive matrix factorization modeling indicated that the sedimentary AhR-active aromatic compounds primarily originated from coal combustion and vehicle emissions. Potency balance analysis indicated that four novel AhR agonists explained 0.007% to 1.7% of bioassay-derived AhR-mediated potencies in samples.

Emission factors and chemical characterization of particulate emissions from garden green waste burning

This work provides an evaluation of the emission factors (EFs) of typical garden waste burning (fallen leaves and hedge trimming) in terms of particulate matter (PM), elemental and organic carbon (EC-OC) together with a detailed chemical characterization of 88 particle-bound organic species including polycyclic aromatic hydrocarbons (PAHs), levoglucosan and its isomers, lignin breakdown products (methoxyphenols), cholesterol, alkanes, polyols and sugars. Furthermore, wood-log based burning experiments have been performed to highlight key indicators or chemical patterns of both, green waste and wood burning (residential heating) sources, that may be used for PM source apportionment purposes. Two residential log wood combustion appliances, wood stove (RWS) and fireplace, under different output conditions (nominal and reduced) and wood log moisture content (mix of beech, oak and hornbeam), have been tested. Open wood burning experiments using wood logs were also performed. Green waste burning EFs obtained were comparable to the available literature data for open-air biomass burning. For PM and for most of the organic species studied, they were about 2 to 30 times higher than those observed for wood log combustion experiments. Though, poor performance wood combustions (open-air wood log burning, fireplace and RWS in reduced output) showed comparable EFs for levoglucosan and its isomers, methoxyphenols, polyols, PAHs and sugars. Toxic PAH equivalent benzo[a]pyrene EFs were even 3-10 times higher for the fireplace and open-air wood log burning. These results highlighted the impact of the nature of the fuel burnt and the combustion performances on the emissions. Different chemical fingerprints between both biomass burning sources were highlighted with notably a predominance of odd high-molecular weight n-alkanes (higher carbon preference index, CPI), lower levoglucosan/mannosan ratio and lower sinapylaldehyde abundance for green waste burning. However, the use of such indicators seems limited, especially if applied alone, for a clear discrimination of both sources in ambient air.

Large-scale sediment toxicity assessment over the 15,000 km of coastline in the Yellow and Bohai seas, East Asia

The Yellow and Bohai seas have long been contaminated by persistent toxic substances (PTSs) from numerous (un)known anthropogenic sources. In this study, we used Vibrio fischeri bioassay to evaluate ecotoxicological profiles associated with sedimentary PTSs contamination at a large marine ecosystem (LME) scale. A total of 125 surface sediments collected from the coastal areas of the Yellow and Bohai seas were analyzed both for aqueous and organic extracts. Not surprisingly, the results indicated site-dependent toxicities, but most sites were identified as non-toxic to V. fischeri. For aqueous extracts and organic extracts, 13% and 8% of samples, respectively exhibited marginal toxicity, while 0% and 2% of samples exhibited moderate toxicity. However, it should be noted that organic extracts (mean TU = 56) induced stronger toxicities than aqueous samples (mean TU = 0.4). This result generally back-supported the high toxicity potentials associated with sedimentary sink of organic pollutants. Several PTSs measured in the samples indicated a significant contribution to the observed V. fischeri toxicities. Of note, polycyclic aromatic hydrocarbons (PAHs; r = 0.28, p < 0.05), styrene oligomers (r = 0.41, p < 0.01), and alkylphenols (r = 0.38, p < 0.05) showed significant associations to the observed bacterial inhibition. Among PAHs, benzo[a]anthracene and phenanthrene exhibited a significant contribution to the observed V. fischeri toxicities. Meantime, salinity which reflects the distance from the point sources of land-driven pollutants along the rivers and estuaries in the Yellow and Bohai seas was a key environmental variable representing the sample toxicities. Overall, the present study provides baseline information for evaluating the potential sediment toxicity to implement responsible coastal management at an LME scale, and elsewhere.

Using a hybrid approach to apportion potential source locations contributing to excess cancer risk of PM2.5-bound PAHs during heating and non-heating periods in a megacity in the Middle East

Polycyclic aromatic hydrocarbons (PAHs) represent one of the major toxic pollutants associated with PM_2.5 with significant human health and climate effects. Because of local and long-range transport of atmospheric PAHs to receptor sites, higher global attentions have been focused to improve PAHs pollution emission management. In this study, PM_2.5 samples were collected at three urban sites located in the capital of Iran, Tehran, during the heating and non-heating periods (H-period and NH-period). The US EPA 16 priority PAHs were analyzed and the data were processed to the following detailed aims: (i) investigate the H-period and NH-period variations of PM_2.5 and PM_2.5-bound PAHs concentrations; (ii) identify the PAHs sources and the source locations during the two periods; (iii) carry out a source-specific excess cancer risk (ECR) assessment highlighting the potential source locations contributing to the ECR using a hybrid approach. Total PAHs (TPAHs) showed significantly higher concentrations (1.56-1.89 times) during the H-period. Among the identified PAHs compounds, statistically significant periodical differences (p-value < 0.05) were observed only between eight PAHs species (Nap, BaA, Chr, BbF, BkF, BaP, IcdP, and DahA) at all three sampling sites which can be due to the significant differences of PAHs emission sources during H and NH-periods. High molecular weight (HMW) PAHs accounted for 52.7% and 46.8% on average of TPAHs during the H-period and NH-period, respectively. Positive matrix factorization (PMF) led to identifying four main PAHs sources including industrial emissions, petrogenic emissions, biomass burning and natural gas emissions, and vehicle exhaust emissions. Industrial and petrogenic emissions exhibited the highest contribution (19.8%, 27.2%, respectively) during the NH-period, while vehicle exhaust and biomass burning-natural gas emissions showed the largest contribution (40.7%, 29.6%, respectively) during the H-period. Concentration weighted trajectory (CWT) on factor contributions was used for tracking the potential locations of the identified sources. In addition to local sources, long-range transport contributed to a significant fraction of TPHAs in Tehran both during the H- and NH-periods. Source-specific carcinogenic risks assessment apportioned vehicle exhaust (44.2%, 2.52 × 10^-4) and biomass burning-natural gas emissions (33.9%, 8.31 × 10^-5) as the main cancer risk contributors during the H-period and NH-period, respectively. CWT maps pointed out the different distribution patterns associated with the cancer risk from the identified sources. This will allow better risk management through the identification of priority PAHs sources.

Pulmonary toxicity of actual alveolar deposition concentrations of ultrafine particulate matters in human normal bronchial epithelial cell

Air pollution is a major worldwide concern, and exposure to particulate matter (PM) can increase the risks of pulmonary diseases. Normal human bronchial epithelial cells were applied to clarify the role of ultrafine PM (UFPM) in the pathogenesis of pulmonary toxic effects with realistic alveolar deposition doses. The UFPM used in this research originated from vehicular emissions and coal combustion. UFPM exposure of up to 72 h was found to induce significant time- and concentration-dependent decreases in cell viability. Exposure to UFPM increased reactive oxygen species (ROS) accumulation through heme oxygenase-1 (HO-1) inhibition and induced massive oxidative stress that increased the interleukin-8 (IL-8) expression. UFPM also reduced the pulmonary trans-epithelial electrical resistance through the depletion of zonula occludens (ZO) proteins. Finally, UFPM decreased the α1-antitrypsin (A1AT) expression, which implies high risk of chronic obstructive pulmonary disease (COPD). The evidence demonstrates that exposure to UFPM, even at very low concentrations, may affect the functions of the respiratory system.

Spatial distribution, sources and quantitative human health risk assessments of polycyclic aromatic hydrocarbons in urban and suburban soils of Chile

This work investigated the concentrations and health risks of polycyclic aromatic hydrocarbons (PAHs) found in Chilean soils for the first time. The urban and suburban soils were collected from 28 sampling sites in three regions of Chile: Magallanes (in Punta Arenas commune), Valparaíso and the Santiago metropolitan area. The PAH concentrations, fractions and their potential sources were studied. Statistical analyses using t tests (p < 0.01) showed that (a) PAH concentrations in the urban sites were higher than those in the suburban sites; (b) the presence of anthracene and chrysene was significantly greater in the urban sites than the suburban sites; and (c) the fraction of four-ring PAHs to total PAHs was larger in the urban sites than the suburban sites. The primary PAH source in urban soils was determined to be the combustion of gasoline, grass, wood and coal. In contrast, PAHs in suburban soils were possibly derived from pyrogenic sources (e.g. incomplete combustions). The total cancer risks (TCRs) and the total hazard index (HI) were quantified from 12 PAHs in both urban and suburban soils in terms of cancer and non-cancer risks, respectively. The average TCR of all sites was within an acceptable level (TCR < 10^-6), and none of the HIs from any locations were deemed harmful (HI < 1).

Sources and pollution path identification of PAHs in karst aquifers: an example from Liulin karst water system, northern China

Karst water, with constituting major sources for water supply worldwide, is vulnerable and prone to be polluted. In this study, it is reported that karst water polycylic aromatic hydrocarbons (PAHs) pollution is caused by the infiltration of surface runoff in the bared carbonate areas, which is of universal significance for the protection of groundwater resources in karst region. Hydro-geochemistry, stable isotopes (δD, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr) and characteristic ratio method were conducted together to illustrate the concentration, distribution, sources and pollution path of polycyclic aromatic hydrocarbons in groundwater in the Liulin karst water system of northern China. The results showed that total concentration of polycyclic aromatic hydrocarbons ranged from 39.25 to 16,830 ng/L in groundwater, with Naphthalene being the dominant component, and the median value increased gradually along the flow path. The highest polycyclic aromatic hydrocarbons concentrations in karst water were mainly observed in the coal mining and the discharge areas. Based on the characteristic ratios, the polycyclic aromatic hydrocarbons in the study area mainly come from local incomplete combustion of woods, fossil fuels, coal and liquid fuels. The slight shift of δD and δ¹⁸O and moderate ⁸⁷Sr/⁸⁶Sr ratios suggest that the polycyclic aromatic hydrocarbons in karst water is mainly polluted by surface runoff during rain events in the bared karst region. The leakage of river water may partly contribute to the polycyclic aromatic hydrocarbons in some karst water, which normally located close to the karst water - river water mixing line. This study provides a new technical method for tracing the sources and identifying the pollution paths of organic pollution in a karst water system.

Indoor/outdoor relationships, signatures, sources, and carcinogenic risk assessment of polycyclic aromatic hydrocarbons-enriched PM2.5 in an emerging port of northern China

Humans spend most of their time in indoor environments, thus a thorough understanding of indoor and outdoor PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) origins for accurate assessment of health risks is required. In the present study, 84 pairs of PM_2.5 samples from indoor (laboratory) and outdoor (campus) locations were collected from April to December 2018 in Caofeidian, China. The annual median concentration of PM_2.5 outdoors was 90.80 µg/m³, 9.08 times higher than the annual standard of WHO guideline (10 µg/m³). Indoor PM_2.5 annual median concentration (41.80 µg/m³) was also higher than the annual standard of ASHRAE guideline (15 µg/m³). The annual median concentrations of ∑₁₈PAHs indoors (44.23 ng/m³) and outdoors (189.6 ng/m³) were highest in winter and descended in the order of autumn > spring > summer. Contrary to summer and autumn, indoor/outdoor concentration ratios were less than 1 in spring and winter, indicating that the contribution of outdoor particle infiltration was more significant than that of indoor sources. The positive matrix factorization model suggested that indoor PAHs came from three sources: vehicle emissions (43%), biomass burning (37%), industry emissions, and coal combustion (20%). Outdoor PAHs came from four sources: petroleum volatilization (39%), vehicle emissions (30%), coal combustion (18%), and biomass burning (13%). The incremental lifetime cancer risk values of indoor and outdoor PAHs in winter exceeded the acceptable level (10^-6), and the carcinogenic risk of adults was higher than that of children and teenagers. These results indicated that simultaneous monitoring of indoor and outdoor PAHs is recommended for accurate assessment of health risk, and the analysis in the current work should be helpful to formulate policies to reduce PAHs emissions.

Transition to clean household energy through an application of integrated model: Ensuring sustainability for better health, climate and environment

Sustained use and adoption of clean cooking fuels have become an important concern for developing countries due to the enormous burden of diseases attributable to household air pollution (HAP). The transition and adoption of clean household energy involve various socio-economic, behavioral, and technological barriers at different community levels. Hence, the present paper aims to scrutinize the factors, key determinants, and other interventions among rural households that limit clean cookstoves' sustained uses. The study proposes an integrated model to enhance clean cooking fuel uptake and uses based on the available evidence. The health, climate and environmental factors were identified as the key to trigger the adoption of clean cooking fuel alternatives. The model comprises the integration of components for targeted clean fuel policy interventions and promotes green recovery. The elements include Knowledge, Housing characteristics, Awareness, Interventions, Willingness to pay, Adoption, Lower emissions and Gender Equality (THE KHAIWAL model) to ascertain the intervention focus regions. Integration of model components in policy implementation will promote clean household energy to reduce emissions, leading to improve quality of life, good health, women empowerment, better air quality and climate.

Distribution, fate and sources of polycyclic aromatic hydrocarbons (PAHs) in atmosphere and surface water of multiple coral reef regions from the South China Sea: A case study in spring-summer

Our previous study revealed PAHs' wide occurrence in corals from multiple coral reef regions (CRRs) in the South China Sea. However, little is known about their occurrence, distribution, fate, and sources in the ambient environment of these CRRs. This study aimed to resolve these research gaps. The results showed ∑₁₅PAHs (total concentrations of 15 US EPA priority controlled PAHs exclude naphthalene) in the atmosphere (gas-phase: 0.31-49.6 ng m^-3; particle-phase: 2.6-649 pg m^-3) were mainly influenced by air mass origins. Southwesterly wind caused higher ∑₁₅PAHs than the southeasterly wind. The ∑₁₅PAHs in seawater from the nearshore (462 ± 244 ng L^-1) was higher than that from offshore Zhongsha Islands (80.5 ± 72.1 ng L^-1) because of the effect of terrigenous pollution and ocean current. Source apportionment indicated that the mixed sources of spilled oil and combustion from neighboring countries were the main contributors to PAHs in these CRRs. The total deposition fluxes showed that PAHs tended to migrate from the atmosphere to seawater. Global warming may inhibit this process, but PAHs still have a migration pattern of atmosphere-ocean-corals, which will further increase the environmental pressure on coral reef ecology.

Can the environmental health of urban centers be assessed through pollutants trapped in lakes? A study case in the biggest city of the southern hemisphere

Air and water quality in urban centers are summited to pollution from different sources, such as industrial activities, traffic, and wastewater effluents. A great number of chemicals can be spread by wind throughout the city, exposing the inhabitants to the health risks associated to them. Atmospheric analysis provides punctual data and represents the timing of the air sampling. A long-term evaluation of the atmospheric air quality can be assessed through the evaluation of pollutants that reach the soil by atmospheric deposition; however, they also can be redistributed and desorbed. The evaluation of pollutants in lakes could be a practical solution, given that lakes may act as traps to these compounds. In this context, organic pollutants were assessed in sediment and water from a lake located in the urban area of São Paulo, Brazil, the biggest city of the southern hemisphere. There were no evidences of sewage input to the lake and pyrogenic compounds reached the lake through atmospheric deposition. The content of pyrogenic PAH exposed the large amount of PAH emitted to the atmosphere by the multiple sources of PAH, mainly vehicular emission and diesel combustion. The PAH trapped in the lake highlighted the impact of all burning process in the air quality in which 12.3 million people are exposed.

Assessment of incremental lifetime cancer risks of ambient air PM10-bound PAHs in oil-rich cities of Iran

This study investigates the concentrations of PM₁₀-bound PAHs and their seasonal variations in three cities of Ahvaz, Abadan, and Asaluyeh in Iran. The mean concentrations of PM₁₀ in two warm and cold seasons in Ahvaz were higher and in Abadan and Assaluyeh were lower than the national standard of Iran and the guidelines of the World Health Organization. The Σ16 PAHs concentration in ambient air PM₁₀ during the cold season in Ahvaz, Abadan and Asaluyeh was 244.6, 633, and 909 ng m^- 3, respectively, and during the warm season in Ahvaz, Abadan, and Asaluyeh was 242.1, 1570 and 251 ng m^- 3, respectively. The high molecular weight PAHs were the most predominant components. The most abundant PAHs species were Pyr, Chr, B [ghi] P, and Flt. The results showed that the total PAHs concentration in the cold and warm seasons was dependent on industrial activities, particularly the neighboring petrochemical units of the city, vehicular exhausts, traffic and use of oil, gas, and coal in energy production. The total cancer risk values as a result of exposure to PAHs in ambient air PM₁₀ in all three cities for children and adults and in both cold and warm seasons were between 1 × 10^- 6 and 1 × 10^- 4, and this indicates a potential carcinogenic risk. Therefore, considering the various sources of air pollutants and its role on people's health, decision makers should adopt appropriate policies on air quality to reduce the ambient air PAHs and to mitigate human exposure.

Polycyclic aromatic hydrocarbons in PM1, PM2.5 and PM10 atmospheric particles: identification, sources, temporal and spatial variations

This study reports temporal and spatial variations of 16 different species of particulate polycyclic aromatic hydrocarbons (particle-bonded PAHs) in the indoor and outdoor environments of three sampling sites in Bandar Mahshahr city, Iran. A low-volume air sampler was employed to collect size-segregated particulate matter during winter (October to December 2015), and summer (July to September 2016). The results showed that the annual concentrations of indoor and outdoor PM10 and PM2.5 were much higher than the related World Health Organization guidelines. The concentration of total particle-bonded PAHs (TPAHs) was higher in winter than in summer and a significant difference between the two sampling seasons was observed. The indoor and outdoor carcinogenic PAHs to TPAHs concentrations ratios in the sampling sites in summer and winter were as follow: for PM10 40.15-42.51%, PM2.5 41.30-42.97%, and PM1 43.07-44.36%, respectively; furthermore, the smaller the particle size, the higher the percentage of carcinogenic PAHs. 2 ring PAHs had a very small contribution to the total PAHs (about 1%), whereas PAHs with 3-to-4 rings had much larger contributions, ranging from 71.65% to 75.17%. The results demonstrated that as PM size decreased, the proportion of 5-to-6-ring PAHs to the total PAHs increased. Since 5-to-6- ring PAHs are considered to be more toxic, hence more attention should be paid to fine particles. The diagnostic ratios of indoor and outdoor of three sampling sites in both seasons suggested that petrogenic sources, as well as combustion of petroleum and other fossil fuels were the main PAHs sources.

The Health Risks of Airborne Polycyclic Aromatic Hydrocarbons (PAHs): Upper North Thailand

Every year, Northern Thailand faces haze pollution during the haze episode. The particulate matter (PM), including fine fraction (PM2.5), a coarse fraction (PM2.5-10), and 16 polycyclic aromatic hydrocarbons (PAHs), was measured in six provinces in upper north Thailand during the haze and non-haze episodes in 2018. Eighty-three percent of the PM2.5 measurements (21.8-194.0 µg/m3) during the haze episode exceeded the national ambient air quality standard in Thailand. All 16 PAHs were detected in the study area in both periods. The average concentration of total PAHs (particle-bound and gas-phase) during the haze episode was 134.7 ± 80.4 ng/m3, which was about 26 times higher than those in the non-haze (5.1 ± 9.7 µg/m3). Naphthalene and acenaphthene were the dominant PAHs in the gas phase; whereas, indeno[123-cd] pyrene, benzo[a]pyrene, and Benzo[ghi]Perylene were dominant in the particle-bound phase. The estimated inhalation excess cancer risk from PAHs exposure was 9.3 × 10-4 and 2.5 × 10-5 in the haze episode and non-haze, respectively. Diagnostic ratios and principal component analysis revealed that PAHs were derived from mixed sources of vehicle emission and solid combustion in the haze episode and vehicle emission in the non-haze period. High pollution levels of PM and large cancer risk attributable to the exposure of PAHs in the haze episode suggest urgent countermeasures to reduce the source emission, especially from the solid combustion in the area.

Polycyclic aromatic hydrocarbons, antibiotic resistance genes, toxicity in the exposed to anthropogenic pressure soils of the Southern Russia

The influence of anthropogenic pollution, particularly with polycyclic aromatic hydrocarbons (PAHs) on soil toxicity and spread of antibiotic resistance genes (ARGs) is extremely important nowadays. We studied 20 soil samples from a technogenically polluted site, municipal solid wastes (MSW) landfills, and rural settlements in the southwestern part of the Rostov Region of Russia. A close correlation was established between the results of biosensor testing for integral toxicity, the content of genes for the biodegradation of hydrocarbons, and the concentration of PAHs in soils. The relation between the quantitative content of ARGs and the qualitative and quantitative composition of PAHs has not been registered. Soils subjected to different types of the anthropogenic pressure differed in PAHs composition. The technogenic soils are the most polluted ones. These soils are enriched with 5 ring PAHs and carry the maximum variety of assayed ARGs, despite the fact that they do not receive household or medical waste.

Integrated analysis of petroleum biomarkers and polycyclic aromatic compounds in lake sediment cores from an oil sands region

We examined polycyclic aromatic compounds (PACs) and petroleum biomarkers (steranes, hopanes, and terpanes) in radiometrically-dated lake sediment cores from the Athabasca oil sands region (AOSR) and the Peace-Athabasca Delta (PAD) region in Alberta (Canada) to determine whether contributions from petroleum hydrocarbons have changed over time. Two floodplain lakes in the PAD (PAD 30, PAD 31) recorded increased flux of alkylated PACs and increased petrogenic (petroleum-derived) hydrocarbons after ∼1980, coincident with a decline of sediment organic carbon content and a rise of bulk sedimentation rate, likely due to increased Athabasca River flow. A large expansion of upstream oilsands mining, upgrading, and refining may also have contributed to the observed shift to more petrogenic hydrocarbons to sediments since the 1980s. Alkylated PAC flux increased in the floodplain lake analyzed within the AOSR (Saline Lake) since the 1970s-1980s, coincident with a sharp rise in sediment organic carbon content and increased contributions of petrogenic hydrocarbons. These changes identify increased supply of petrogenic PACs occurred as Athabasca River floodwaters waned, and may implicate aerial contributions of petrogenic hydrocarbons from oilsands activity. PACs and petroleum biomarkers (steranes, hopanes, and terpanes) in sediment cores from Saline Lake, PAD 30 and PAD 31 revealed a predominance of petrogenic hydrocarbons in these lakes. In contrast, we recorded minimal petrogenic hydrocarbons in the reference lakes outside the surface minable area of the AOSR and PAD (Mariana Lake and BM11), though we noted slight increases in petrogenic contributions to modern (2010-2016) sediments. We show how a combined analysis of PACs and petroleum biomarkers in sediments is useful to quantify petrogenic contributions to lakes with added confidence and highlight the potential for petroleum biomarkers in lake sediment cores as a novel and effective method to track petroleum hydrocarbons in lake sediment.

Fugitive emissions of polycyclic aromatic compounds from an oil sands tailings pond based on fugacity and inverse dispersion flux calculations

Alberta's oil sands tailings ponds are suspected to be a source of fugitive emissions of polycyclic aromatic compounds (PACs) to the atmosphere. Here we report, for the first time, fluxes of 6 parent and 21 alkylated PACs based on the measured co-located air and water concentrations using a two-film fugacity-based model (FUG), an inverse dispersion model (DISP) and a simple box model (BOX). Air samples were collected at the Suncor Tailings Pond 2/3 using a high volume air sampler from the "pond" and towards the pond ("non-pond") directions separately. Mean ∑₂₇PACs in air from the "pond" direction was greater than the "non-pond" direction by a factor of 17. Water-air fugacity ratio of 20 PACs quantifiable in water indicated net volatilization from water. Dispersion and box model results also indicated upward fluxes of 22 PACs. Correlation between the estimated flux results of BOX and DISP model was statistically significant (r = 0.99 and p < 0.05), and correlation between FUG and DISP results ranged from 0.54 to 0.85. In this first-ever assessment of PAC fluxes from tailings pond, the three models confirmed volatilization fluxes of PACs indicating Suncor Tailings Pond 2/3 is a source of PAC emissions to the atmosphere. This study addressed a key data gap identified in the Joint Oil Sands Monitoring Emissions Inventory Compilation Report (Government of Alberta and Canada, 2016) which is the lack of consistent real-world tailings pond fugitive emission monitoring of organic chemicals. Our findings highlight the need for measurements from other tailings ponds to determine their overall contribution in releasing PACs to the atmosphere. This paper presents a practical method for estimating PAC emissions from other tailings ponds, which can provide a better understanding of these fugitive emissions, and thereby help to improve the overall characterization of emissions in the oil sands region.

Elucidating the distribution and sources of street dust bound PAHs in Durgapur, India: A probabilistic health risk assessment study by Monte-Carlo simulation

Spatial and seasonal distribution of PAHs, source identification, and their associated carcinogenic health risk was investigated in street dust of Durgapur, India. Street dust is an important indicator to detect the quality of the environment as well as the sources of pollutants. The obtained results showed fluctuation in PAHs concentrations from 2317 ± 402 ng/g to 5491 ± 2379 ng/g along with the sampling sites. Seasonal variation revealed higher PAHs concentrations in the winter season (5401 ± 993 ng/g) with the maximum presence of 4-ring PAHs. Two-way analysis of variance (ANOVA) exposed that the sites, seasons and site-season interactions were vividly affected by dissimilar PAHs. The PAHs source identification was investigated by principal component analysis (PCA), positive matrix factorization (PMF), diagnostic ratios, and they revealed pyrogenic, diesel, gasoline, wood and coal combustion to be the key sources of the PAHs in street dust. Obtained results from incremental lifetime cancer risk (ILCR) model exhibited the carcinogenic risk for children ranged from 2.4E-06 to 3.8E-06 while 2.1E-06 to 3.4E-06 for adults which were above the baseline value 1.0E-06. The Monte Carlo simulation model identified cumulative cancer risk of sixteen PAHs in 50th percentile were 2.8 and 1.7 times more while in 95th percentile, the values were 8.8 and 7.8 times higher than the acceptable value of 1E-06 for child and adult respectively.

Sources and diffusive air-water exchange of polycyclic aromatic hydrocarbons in an oligotrophic North-Patagonian lake

Polycyclic aromatic hydrocarbons (PAHs) are semivolatile organic compounds of environmental concern. This study aims to investigate the influence of local sources of anthropogenic PAHs and their air-water exchange fluxes in an oligotrophic North-Patagonian lake in Chile. The monitoring was carried out in Panguipulli Lake during a six-month period during the autumn and winter seasons (March to August 2017) using a high-volume air sampler and a pump system for water samples. We detected and quantified fifteen PAHs in the gas phase (mean ∑₁₅PAHs = 11.6 ng m^-3) and dissolved water phase (mean ∑₁₅PAHs = 961.8 pg L^-1). Methylphenanthrenes and pyrene dominated the concentrations of PAHs in the studied phases. To determine sources of PAHs we used the PAH ratios of Light Molecular Weight/Heavy Molecular Weight (∑LMW/∑HMW) and Phenanthrene/Anthracene (Phe/Ant). The PAH ratio results revealed a pyrogenic source. We estimated the air-water diffusive exchange fluxes and fugacity ratios for the studied compounds. In general, air-water diffusive exchanges of PAHs showed a net volatilization for the less hydrophobic (log K_OW < 4) and lighter PAHs (MW ≤ 170 g mol^-1), and a net deposition trend for the more hydrophobic (log K_OW 4-7) and higher molecular weight PAHs (MW ≥ 178 g mol^-1). We found a significant correlation between log water/air fugacity ratios and log K_OW of PAHs. Therefore, it is suggested that this oligotrophic lake acts as a sink by accumulating hydrophobic and mid-high molecular weight PAHs derived mainly from pyrogenic sources. This study is the first attempt to understand the sources and behavior of PAHs in oligotrophic lakes in the Southern Chile where information is scarce regarding the occurrence of PAHs.

Simultaneous determination of carcinogenic PAHs and levoglucosan bound to PM2.5 for assessment of health risk and pollution sources during a smoke haze period

Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in ambient PM_2.5 and a specific molecular marker of biomass burning, levoglucosan, are used to investigate the influence on public health of biomass burning. In this work, we present an effective method for one-time analysis of cPAHs and levoglucosan by GC-MS without derivatization. The method was applied for the analysis of PM_2.5 samples (64.3 ± 17.6 μg m^-3, n = 57) collected during a smoke haze period in Chiang Mai, Thailand. Levoglucosan was analyzed by using both the developed method (GC-MS) and a reference method (HPAEC-PAD) for comparison. Its average concentration obtained from GC-MS (0.31 ± 0.21 μg m^-3) was about 4 times less than the concentration obtained from the reference method (1.22 ± 0.76 μg m^-3). Therefore, a correcting factor (CF = 4) was used as a multiplying factor, to obtain a comparative value (1.23 ± 0.86 μg m^-3). The average concentration of cPAHs found in PM_2.5 samples was 5.88 ± 1.97 ng m^-3 with the highest value of 10.86 ng m^-3 indicating medium to high cancer risk due to PAHs exposure when referring to values of toxicity equivalence and inhalation cancer risk. Diagnostic ratios of BaA/(BaA + CHR) (0.48 ± 0.04) and IND/(IND + BPER) (0.58 ± 0.04) and strong correlations between PM_2.5, levoglucosan and cPAHs concentrations implied that the major source of air pollution in the study period was biomass burning. PM_2.5 concentration as a pollution indicator was labelled as BB-low, BB-medium, BB-high or BB-extreme; <50, 50-75, 75-100 and > 100 μg m^-3, respectively. The levoglucosan and cPAHs concentration during BB-extreme pollution was 4.3 times and 2.34 times, respectively, that during BB-low pollution, and the correlation coefficient (r) between the concentrations of levoglucosan and cPAHs was as high as 0.987, indicating that the more intense the burning of biomass, the higher the carcinogenic risk in the urban air.

Concentrations, distributions, sources, and risk assessment of polycyclic aromatic hydrocarbons in topsoils around a petrochemical industrial area in Algiers (Algeria)

Fifty-five samples were collected from topsoils around a petrochemical industrial area at the east of Algiers (Algeria) and analyzed for 16EPA priority PAHs in the aim to determine the concentrations, the distributions, and the possible sources of polycyclic aromatic hydrocarbons (PAHs). The results of the quantification are then devoted to the assessment of the potential risks as the toxicity, the risk for the ecosystem, and the risk for the human health. The sampling sites were classified into four categories: rural, suburban, urban, and industrial-urban. A new extraction method based on the insertion of a preliminary step, using hot water, was proposed to improve the extraction efficiency. Principal component analysis (PCA) and selected diagnostic ratio of PAHs were used to investigate the source apportionment of these PAHs. The potential toxicity, the ecological, and human health risk of PAHs in soil were estimated using the toxic equivalent quotient, the risk quotient, and the total lifetime cancer risk (TLCR) methods, respectively. The proposed new protocol gave improved recovery rates for the sixteen EPA PAHs particularly for low molecular weight PAHs, with satisfactory repeatability (RSD < 10%). The Σ16PAHs concentrations were varied from 143.73 to 4575.65 μg kg^-1 with a mean value of 1209.56 μg kg^-1. Σ16PAH concentrations found for the industrial areas would be 2 times higher than for urban soils and 3 times higher than for the rural soils. The biplots of PCA and the five diagnostic ratios suggested that the most sources of PAHs in the rural, the suburban, and the urban areas are traffic emissions, biomass burning, and coal combustion sources. Some points of the urban-industrial area are from the petroleum source. The found Σ16PAH concentrations and theirs calculated TEQs showed the following trend: industrial-urban > urban > suburban >rural. The potential cancer of human health risks calculated through TLCR results indicated that the exposure to the 7EPA PAH-contaminated soils produces negligible cancer risk to human health.

Source apportionment and seasonal variation in particulate PAHs levels at a coastal site in Belgium

In the present study, estimation of the atmospheric polycyclic aromatic hydrocarbons (PAHs) was done in particulate samples collected from De Haan, Belgium, during different seasons. The sampling site was situated very close to the north sea and far from the influence of local or industrial activities. The levels of PAHs depicted a distinct seasonal trend, being highest during the spring season. The observations of the study indicated a mean value of 2.6 ng m^-3 for concentration of all the 16 US EPA PAHs, thus being significantly lower when compared to results of previous studies focused on other sites. The dominating PAHs species reported were naphthalene, fluoranthene, benzo[a]anthracene, chrysene, and indeno[1,2,3c,d] pyrene. Assessment of the seasonal variation of the PAH levels was also done with respect to diagnostic ratio-based source identification, analysis of back trajectories, and principle component analysis. Burning of fossil fuels was observed to be the prominent source of atmospheric PAHs in the study area. Further, lifetime cancer risk assessment was performed to assess the detrimental health impacts on humans on being exposed to atmospheric PAHs. Particulate PAHs present in the ambient air of Belgium shows no carcinogenic health impacts. However, considering the industrial expansion in the region, efforts are required to prevent the environmental contamination of PAHs. Graphical abstract.

Contamination of Arctic Lakes with Persistent Toxic PAH Substances in the NW Part of Wedel Jarlsberg Land (Bellsund, Svalbard)

The expansion of glacier-free areas in polar regions favours the appearance of lakes in the non-glaciated parts of glacier basins. This paper presents the differentiation of organic compound concentrations in fifty-four Arctic lakes collected in four locations (Logne Valley, in the vicinity of the Scott, Renard and Antonia glaciers). We cover meteorological measurements, chemical analysis of sixteen dioxin-like compounds (Polycyclic Aromatic Hydrocarbons (PAHs)), formaldehyde (HCHO), sum parameters of phenolic compounds (∑phenols) and dissolved organic carbon (DOC). The most contaminated with PAH compounds were lakes exposed to the influence of the Greenland Sea (Logne Valley lakes) and to the prevailing winds (Scott and Renard lakes). Interpretation of the PAH compounds results allowed for identification of pyrogenic sources as the main sources of PAH compounds in the year 2012. The highest levels of HCHO and ∑phenols were observed for the Scott lakes, while the highest DOC levels were noted in Antonia lakes.

Chemical characterization, sources and potential health risk of PM2.5 and PM1 pollution across the Greater Athens Area

With the principal aim to assess the typical Mediterranean profile of the PM_2.5 and PM₁ pollution, three intensive monitoring campaigns took place simultaneously within different types of environment across an urban location of the basin. Focusing on the PM components with numerous anthropogenic sources and increased potential health risk, the samples were chemically analyzed for 20 p.m.-bound Polycyclic Aromatic Hydrocarbons (PAHs). Carbonaceous and ionic constituents were quantified as well. In order to uncover the spatiotemporal variation of the PM profile the key sources were identified, the seasonal effects and the role of the prevailing mesoscale atmospheric circulation were evaluated and most importantly the potential health risk was estimated. In general, the pollution status of the basin was the result of a complex interaction between the local and external input with Particulate Organic Matter (POM) and Secondary Inorganic Aerosols (SIA) being the main aerosols' components. PM₁ was a better indicator of the anthropogenic emissions while according to the results of factor analysis the co-existence of various combustion sources was determinant. Chemically, the maxima of the ΣPAHs, the differentiation of their structure in accordance with their molecular weight and the distribution of the individual compounds confirmed the significance of the emission sources. Similarly, the estimated carcinogenicity/mutagenicity was emission-dependent with the maximum contribution coming from B[a]P, IndP, B[ghi]Per, B[e]P and B[b]F. Seasonally, the highest potential health risk of the PAHs' mixture was recorded during the cold season while meteorologically, it was mostly associated with the south flow.

PAH levels in a furniture-manufacturing city atmosphere

In this study, in order to determine atmospheric PAH concentrations in Inegol/Turkey, ambient air samples were collected from two different sites representing industrial and uncontrolled furniture manufacturers regions. Sampling campaign took place between December 2017 and November 2018. Air samples were collected using high volume air samplers (HVAS) and PAH concentrations were determined in both gas and particulate phases. The mean of the atmospheric PAH concentrations obtained in the gas phase in the furniture workshops (FW) and industrial district (ID) regions were 697.82 ± 637 ng/m³ and 772.92 ± 864.23 ng/m³, respectively. The concentrations in the particulate phase in the regions were 413.52 ± 430.23 ng/m³ and 342.40 ± 527.48 ng/m³, respectively. The average total (gas + particlulate phases) concentration of ∑₁₆PAH determined in the site of FW was 1111.34 ± 1045.24 ng/m³ while that was 772.92 ± 864.23 ng/m³ in ID. These values are over the ambient levels reported for urban sites wherein big industries exist around the world. Additionally, the average of particle phase percentage was 30% because of nearby combustion sources. The determination of possible sources of PAHs in the regions was performed using principal component analysis (PCA). PCA results showed that the main sources of pollutants of the regions are intertwined (combustion, traffic, industries). However, the most effective source is thought to be uncontrolled combustion of furniture wastes as fuel for residential heating. Health risks for the citizens were calculated for both regions and were found not to be at high-class risk.