Priority Polycyclic Aromatic Hydrocarbons Research Articles

Screening of organophosphate esters in different indoor environments: Distribution, diffusion, and risk assessment

Analysisof air conditioner (AC) filter dust can reveal the level of organophosphate ester (OPE) pollution in indoor environments, but comprehensive research on this topic remains lacking. This study combined non-targeted and targeted analysis to screen and analyze 101 samples of AC filter dust, settled dust, and air obtained in 6 indoor environments. Phosphorus-containing organic compounds account for a large proportion of the organic compounds found in indoor environments, and OPEs might be the main pollutants. Using toxicity data and traditional priority polycyclic aromatic hydrocarbons for toxicity prediction of OPEs, 11 OPEs were prioritized for further quantitative analysis. The concentration of OPEs in AC filter dust was highest, followed in descending order by that in settled dust and that in air. The concentration of OPEs in AC filter dust in the residence was two to seven times greater than that in the other indoor environments. More than 56% of the OPEs in AC filter dust showed significant correlation, while those in settled dust and air were weakly correlated, suggesting that large amounts of OPEs collected over long periods could have a common source. Fugacity results showed that OPEs were transferred easily from dust to air, and that dust was the main source of OPEs. The values of both the carcinogenic risk and the hazard index were lower than the corresponding theoretical risk thresholds, indicating low risk to residents through exposure to OPEs in indoor environments. However, it is necessary to remove AC filter dust in a timely manner to prevent it becoming a pollution sink of OPEs that could be rereleased and endanger human health. This study has important implications for comprehensive understanding of the distribution, toxicity, sources, and risks of OPEs in indoor environments.

A 10-Year Ecological Monitoring of Soils and Triticum aestivum in the Impact Zone of a Power Station

Based on 10 years of environmental monitoring located around the emission zone of an electricity supplier, the main regularities have been studied for the content of heavy metals (HMs), such as Pb, Cd, Zn, Cu, Ni, Mn, and Cr, and 16 priority polycyclic aromatic hydrocarbons (PAHs) in the soils of agricultural landscapes and their accumulation in Triticum aestivum. It has been shown that one of the most significant factors for the pollutants accumulation in soils and plants was the prevailing wind direction on the territory and atmospheric transfer of the dust particles of the enterprise with adsorbed pollutants. As the content of pollutants in the soil increased, their accumulation in Triticum aestivum increased with each season to a level exceeding maximum permissible concentrations (MPC), especially for Pb, Cd, and benzo[a]pyrene (BaP). The unambiguous influx of pollutants from the soil into the roots and further into the aboveground organs of the plant was typical only for Mn, Cr, and BaP, and the accumulation of other studied pollutants can be explained by their foliar influx. It has been established that Triticum aestivum was a more tolerant plant with respect to heavy metals pollution than PAHs.

Spatiotemporal variability and measurement uncertainty in atmospheric polycyclic aromatic hydrocarbons (PAHs): A quantitative variance component analysis

A comprehensive understanding of the spatial and temporal variability in air pollution facilitates air monitoring designs, exposure assessment, and environmental epidemiology research. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the air but are challenging to measure due to their low concentrations. To date, no study has been specifically designed to quantify the spatial and temporal aspects of variability in ambient PAH concentrations. This study aims to decompose the variability in PAH concentrations measured in the ambient air in a metropolitan area into different components. Air samples were collected using high-volume samplers at 19 stations in the Memphis Tri-state Area across Tennessee, Arkansas, and Mississippi, USA, every 12 days from March 2018 to May 2019. Samples were collected on polyurethane forms and quartz fiber filters and analyzed using gas chromatography/mass spectrometry (GC/MS) for 32 PAHs. Variance components of the total variance were computed using mixed models for individual PAHs and sum concentrations of the 16 priority PAHs (Σ16PAHs). For Σ16PAHs, spatial and temporal variability represented 16% and 84% of the total variance. The total variance could be further apportioned to between-urbanicity (0.5%), between-site (5.5%), between-season (41%), and within-season (53%) variances. Sampling and analytical uncertainties represented 39% and 0.01% of the total variance, when monitoring uncertainties were considered. Concentrations of individual PAHs followed similar variance structures. These findings confirmed the validity of centralized monitoring stations to represent a large area, suggested the need for repeated samples across seasons and at multiple time points within a season, and warranted improving quality control for field sample collections.

Characterization, risk assessment, and source estimation of PM10-bound polycyclic aromatic hydrocarbons during wintertime in the ambient air of Basrah City, Iraq

In this study, the concentration and structure of polycyclic aromatic hydrocarbons (PAHs) associated with the ambient PM10 in Basrah City, Iraq have been investigated for the first time. From December 2021 to February 2022, PM10 samples were collected on quartz fiber filters, extracted using an optimized extraction protocol, and analyzed for the sixteen US EPA priority PAHs. The results indicated that 4- and 5-ring PAHs represent 52% of the total detected PAHs. The most abundant PAHs over the study period were chrysene (1.2 ± 1.5 ng m−3), fluorene (0.9 ± 1.4 ng m−3), and benzo[b]fluoranthene (0.7 ± 0.9 ng m−3). Source identification suggested that PM10-bound PAHs primarily originated from pyrogenic and petrogenic activities in Basrah City. In addition, the cancer risk associated to PAH exposure was assessed based on benzo[a]pyrene equivalent concentration and was found ranging from 0.07 to 6.32 ng m-3; hence, it exceeded the threshold limit of 1.0 ng m−3 established by the European legislation (EU, 2014). Benzo[a]pyrene was determined to be main contributor to total carcinogenic power of the detected PAHs, accounting for 50.3%, followed by dibenz[a,h]anthracene (22.3%). Similarly, benzo[a]pyrene represented a major contributor to PAH associated mutagenicity, accounting for 43.5% of the total.

Carcinogenic Potentials of Toxic Metals and Polycyclic Aromatic Hydrocarbons in Telfairia occidentalis and Talinum triangulare Impacted by Wastewater, Southern Nigeria

Health risks of toxic metals and polycyclic aromatic hydrocarbons (PAHs) associated with the consumption of Telfairia occidentalis and Talinum triangulare impacted by wastewater from water treatment plants within Uyo Metropolis, Southern Nigeria, were investigated using standard methods. The level of toxic metals and PAHs was higher in vegetables impacted by wastewater from food processing industries than in the other investigated sources. The levels of cadmium (Cd), lead (Pb), arsenic (As), and chromium (Cr) in the vegetables exceeded their recommended limits by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Wastewater was confirmed as the major source of toxic metals in the vegetables. The estimated chronic daily intake of toxic metals through vegetables for both child and adult populations was lower than their tolerable daily intake. The hazard quotients of noncarcinogenic PAHs indicated higher values for children than adults. The vegetables contained all the priority PAHs except dibenz[a,h]anthracene. The estimated daily intake of PAHs was higher in children than in adults, except for phenanthrene. The threshold screening values for PAHs indicated lower non-carcinogenic health risks for consumers. The carcinogenic health risks of metals and PAHs via vegetables indicated a moderately high risk for both populations. The consumption of vegetables impacted by wastewater could result in serious health problems for both child and adult populations. This study has exposed the environmental and human health problems related to the use of wastewater for the irrigation of vegetable gardens, which hitherto were unavailable in the study area.

Chemical fingerprints and implicated cancer risks of Polycyclic aromatic hydrocarbons (PAHs) from fine particulate matter deposited in human lungs

Exposure to fine particles (PM2.5) and associated PAHs are frequently linked with lung cancer, which makes the understanding of their occurrence and health risk in human lungs urgently important. Using the ultrasonic treatment and sequencing centrifugation (USC) extraction method coupled with gas chromatography-tandem mass spectrometry (GC - MS/MS) analysis, we revealed the molecular fingerprints of PM-accumulated PAHs in human lungs from a cohort of 68 patients with lung cancer in a typical air-polluted region, China. Sixteen priority PAHs can be grouped by concentrations as ∼ 1 × 104 ng/g (ANT/BkF/ACE/DBA/BgP/PHN/PYR), 2–5 × 103 ng/g (BaP/FLE/NaP/BbF), and ∼ 1 × 103 ng/g (IND/Acy/CHR/FLT/BaA). The sum concentration of 16 PAHs was approximately equaled to 13% of those in atmospheric PM2.5, suggesting significant pulmonary leaching of PAHs deposited in lungs. Low- and high-molecular weight PAHs accounted for ∼ 41.8% and ∼ 45.1% of the total PAHs, respectively, which indicated that atmospheric PM2.5, tobacco and cooking smoke were likely to be important sources of pulmonary PAHs. The evident increasing concentrations of NaP and FLE in pulmonary PM were significantly correlated with smoking history among smokers. The implicated carcinogenic potency of PM-accumulated PAHs among the participants aged 70–80 was 17 times that among participants aged 40–50 on the basis of BaP equivalent concentration (BaPeq) evaluation. The particulate enrichment factor (EFP), the PAH content in pulmonary PM relative to the bulk lung tissue, was equaled to 54 ∼ 835 and averaged at 436. The high value of EFP suggested that PAHs were essentially accumulated in pulmonary PM and exhibited a pattern of “hotspot” distribution in the lungs, which would likely increase the risk of monoclonal tumorigenesis. The chemical characteristics of PM-accumulated PAHs in human lungs together with their implicated lung cancer risks could provide significant information for understanding health effects of particulate pollution in the human body.

In situ investigation of N deposit effects on polycyclic aromatic hydrocarbons (PAHs) photolysis in snow

As snow is an ideal scavenger of polycyclic aromatic hydrocarbons (PAHs) for both particulate- and gas-phase PAHs, a large amount of PAHs are accumulated in snowpacks. These PAHs could be released from seasonal snowpacks into environment over a short time during the snow melting period, causing a flush of contaminants. Understanding the fate of PAHs in snow therefore is important to evaluate the contaminant flush during snow melting. However, as an important natural process, PAH photolysis in snow is still unclear, especially in the context of global climate change. Therefore, photolysis of the 16 PAHs, which are listed as priority controlled pollutants by United States Environmental Protection Agency (US EPA), was investigated with N deposit in field in snow in this study. A mixture of the 16 US EPA priority PAHs and nitrate/ammonia were spiked into sealed quartzose bottles containing snow samples in field. The bottles were then exposed to solar radiation in field for 6 h. Experimental results showed that >50% of PAHs were lost during 6 h photolysis, mostly occurred in the first hour. Generally, HMW PAHs were photolyzed faster than LMW PAHs, though the photolysis rate did not strictly increase with molecular weight. Low concentrations of nitrate can enhance photolysis of Ant and Pyr, while photolysis of investigated PAHs was inhibited with nitrate concentration increasing. In contrast, both low and high concentration of ammonium can inhibit PAH photolysis. The inhibiting effect of both nitrate and ammonia on photolysis of HMW PAH is stronger than that of LMW PAHs, indicating direct photolysis of PAHs is the main pathway of PAH degradation in snow in situ. This study firstly showed the effect of N deposition on PAH photolysis in snow. Under current increasing N deposition in northeast China, this study implied that more PAHs in snow could be preserved during winter and released shortly during snowmelt, resulting in high ecological risk in spring.

Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in surface water in the coal mining area of northern Shaanxi, China.

This study investigated the spatial distribution, pollution source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Kuye River, which is a typical river in the mining area of China, 16 priority PAHs were quantitatively detected at 59 sampling sites by high-performance liquid chromatography-diode array detector-fluorescence detector. The results showed that the ∑PAHs concentrations in the Kuye River were in the range of 50.06-278.16 ng/L. The PAHs monomer concentrations were in the range 0-121.22 ng/L, of which chrysene had the highest average concentration (36.58 ng/L), followed by benzo[a]anthracene and phenanthrene. In addition, the 4-ring PAHs showed the highest relative abundance in the 59 samples, ranging from 38.59 to 70.85%. Moreover, the highest concentrations of PAHs were mainly observed in coal mining, industrial, and densely populated areas. On the other hand, according to the diagnostic ratios and positive matrix factorization (PMF) analysis, it can be concluded that coking/petroleum sources, coal combustion, vehicle emission, and fuel-wood combustion contributed to the PAHs concentrations in the Kuye River by 37.91%, 36.31%, 13.93%, and 11.85%, respectively. In addition, the results of the ecological risk assessment indicated that benzo[a]anthracene had a high ecological risk. Among the 59 sampling sites, only 12 belong to low ecological risk areas, and others were at medium to high ecological risks. The current study provides data support and a theoretical basis to effectively manage pollution sources and ecological environment treatment in mining areas.

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Leaf and Bark Samples of Sambucus nigra Using High-Performance Liquid Chromatography (HPLC)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds coming from natural or anthropogenic activities. Tree organs such as leaves and barks have been used to monitor urban air quality and have achieved remarkable ecological importance. However, the potential of many tree species as biomonitors is still unknown and efforts should be focused on conducting studies that analyze their capabilities with a viable analytical method. In this work, an analytical method for quantification of the 16 EPA priority PAHs from the leaves and bark of Sambucus nigra was validated. In general, the method showed good linearity, detection limits, precision, and recoveries, demonstrating that it is suitable for analyzing PAHs in both the leaves and bark of the Sambucus nigra species for which no analytical method for PAHs is yet available. The high prevalence of fluoranthene in the samples, which is a PAH related to coal combustion and biomass burning, and benzo[a]pyrene, which has a carcinogenic effect, was identified.

Polycyclic aromatic hydrocarbons (PAHs) levels in PM10 and bulk deposition using Mosspheres: A pilot study in an urban environment

Study air polycyclic aromatic hydrocarbons (PAHs) capturing the spatial variability of their concentrations is not economically feasible with conventional methods. In the present work we tested, for the first time and under real conditions, the suitability for intensive monitoring and mapping these contaminants of innovative, cost-effective passive air samplers known as “Mosspheres”. The Mosspheres, filled with a devitalised Sphagnum palustre L. moss clone, were placed in a 575 m. grid in a medium-sized European city for three months. Concentrations in the moss tissues of 15 priority PAHs, including benzo(a)pyrene, were determined and converted into PM10 and bulk deposition with the equations proposed in a recent study. Low concentrations of PAHs were detected, with only a few enriched points never exceeding the legal thresholds, near industrial areas and busy roads. Despite these low PAH concentrations, Mosspheres were able to detect spatial structure for several PAHs and high-resolution pollution maps were constructed for these compounds. The results prove the high sensitivity and suitability of Mosspheres for mapping PAH levels and for quantitative (i.e. PAHs with 4 or more rings) and qualitative (3-ring PAHs) monitoring. Thus, this study supports their widespread application and its potential inclusion in European Directives on air quality control.

Emission factors for polycyclic aromatic hydrocarbons from laboratory biomass-burning and their chemical transformations during aging in an oxidation flow reactor

Atmospheric polycyclic aromatic hydrocarbons (PAHs) can be emitted from different combustion sources including domestic biomass burning, internal combustion engines, and biomass burning (BB) in wild, prescribed, and agricultural fires. With climate warming and consequent global increases in frequency and severity of wildfires, BB is a dominant source of PAHs emitted into the atmosphere.In this study, six globally and regionally important and representative fuels (Alaskan peat, Moscow peat, Pskov peat, eucalyptus, Malaysian peat, and Malaysian agricultural peat) were burned under controlled conditions in the combustion chamber facility at the Desert Research Institute (DRI, Reno, NV, USA). Gas- and particle-phase BB emissions were aged in an oxidation flow reactor (OFR) to mimic five to sevendays of atmospheric aging. To sample gas- and particle-phase BB emissions, fresh and OFR-aged biomass-burning aerosols were collected on Teflon-impregnated glass fiber filters (TIGF) in tandem with XAD resin media for organic carbon speciation. The objectives of this study were to i) quantify the emission factors for 113 PAHs emitted from the combustion of the six selected fuels, ii) characterize the distribution of PAH compounds between gas and particle phases for these fuels, iii) identify the changes in PAHs during OFR-aging, and iv) evaluate toxicity potential with characterized compounds.We found that combustion emissions of gas-phase PAHs were more abundant (>80 % by mass) than particle-phase PAHs, for emissions from all combusted fuels. The mass fraction of substituted napthalenes in Moscow peat and Malaysian peat emissions were ∼70 % & 84 %, respectively, whereas in Eucalyptus the same fraction was <50 %, which indicates that these substituted compounds can be used as tracers for peat emissions. Mass concentrations of gas- and particle-phase PAHs were reduced by ∼70 % after OFR oxidation. However, the understanding of the fate of PAHs during OFR oxidation requires further investigations. Our results also indicate that the PAH toxicity of BB samples would be underestimated by 10–100 times if only the BaPeq for the 16 US EPA priority PAHs in the particle phase are included.

Priority Polycyclic Aromatic Hydrocarbons and Heavy Metals in Urban Roadside Soils of Heavy-Traffic Density Areas in Ibadan, Nigeria: Levels, Sources and Health Risk Assessment

Priority polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) were investigated in heavy-traffic roadside soils in Ibadan, Nigeria to assess the level of contamination and human health risk. PAHs and HMs were analyzed using gas chromatography-mass spectrometry (GC-MS) and atomic absorption spectroscopy. The concentrations of ∑11PAHs were 263.2 ± 20.9 to 380.0 ± 23.8 µg kg–1, with a dominance of the higher molecular PAHs, and the soils can be classified as weakly contaminated. The most abundant PAH was fluoranthene. Also, five carcinogenic PAH were identified in the study. PAH diagnostic ratios suggested mixed pyrogenic and petrogenic sources. Roadside soil concentrations (mg kg−1) of Cd, Ni and Pb were 1.3 ± 1.2–5.3 ± 7.4, 15.0 ± 7.3–24.5 ± 4.8 and 41.6 ± 13.7–56.8 ± 8.3, respectively. Pollution indices revealed roadside soils were highly contaminated with Cd and Pb according to contamination factor and geoaccumulation index. Cd presented a considerable to high ecological risk. Health risk assessment for children and adults revealed soil ingestion was the main exposure pathway to metals. The hazard quotient (HQ) and health index (HI) were within the safe level (<1.0), although, HI values were higher for children. The cancer risk of exposure to Pb in roadside soils (1.18 E–06 to 1.61 E–06) was within safe limit (1.0 E–04 to 1.0 E–06). This study provides the basis for the reduction of anthropogenic emissions of PAHs and HMs.

Accumulation of heavy metal(loid)s and polycyclic aromatic hydrocarbons in the sediment of the Prahovo Port (Danube) and associated risks.

The current study investigated the concentrations, possible sources, toxicity, and ecological risk of eight heavy metal(loid)s (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) and sixteen priority polycyclic aromatic hydrocarbons (PAHs) in surface sediments in the port of Prahovo (Danube, Serbia). Among the examined HMs, the most abundant was Cu (38.3mg/kg), followed by Zn. The Σ16PAHs concentrations ranged from 25 to 112.5µg/kg, with 4-ring PAHs (17.3µg/kg) being the most dominant in the study area. The mean and maximum values of HMs and PAHs obtained in this study were below the national regulatory limits and within environmental criteria. Particularly significant correlations between As, Cd, Cr, Ni, Pb, Zn, 5-, 6-ring PAHs, as well as between Pb and Hg, indicated their similar anthropogenic sources, pathways, and adsorption mechanisms. These findings were confirmed by cluster analysis and principal component analysis. Diagnostic ratios demonstrated that contamination in inner port stations was characterized by pyrogenic sources, while PAHs of petrogenic origin prevailed in samples near the port entrance. The mean ERM quotient (mERMq), toxic risk index (TRI), and toxic equivalent quotient (TEQ) were also calculated to assess the toxicity of the investigated HMs and PAHs in sediments. Positive matrix factorization suggested four potential sources as the main components of sediment contamination, whereas the risk assessment indicated a low or relatively insignificant risk of adverse biological effects from the combined toxicity of HMs and PAHs for the entire study area.

PM2.5-bound polycyclic aromatic hydrocarbons of a megacity in eastern China: Source apportionment and cancer risk assessment

Ninety-six fine particulate matter (PM2.5) samples covering four seasons from October 2020 to August 2021 were collected at a ‘super’ site in Hangzhou, a megacity in eastern China. These samples were analyzed to determine the sources and potential cancer risks to humans of 16 United States Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs). The average concentrations of the PAHs in PM2.5 in autumn, winter, spring, and summer were 8.35 ± 4.90, 27.9 ± 13.6, 8.3 ± 5.97, and 1.05 ± 0.50 ng/m3, respectively, and with an annual average of 11.9 ± 13.2 ng/m3. The source apportionment by positive matrix factorization analysis indicated that, based on the yearly average, the major sources of PAHs were traffic emissions (38.2 %), coal combustion (28.9 %), coke (21.7 %), and volatilization (11.1 %). Strong correlations between high concentrations of carbonaceous aerosols and high-molecular-weight PAHs in winter could be attributed to incomplete combustion. Long-range transport of air from the sea to the southeast resulted in low concentrations of carbonaceous aerosols and low-molecular-weight PAHs in summer. Trajectory clustering and the potential source contribution function both indicated that the Yangtze River Delta was the main source region of PAHs for PM2.5 in Hangzhou in spring and summer. In autumn and winter, it was dominated by long-range transport from northern China. Lifetime lung cancer risk assessment revealed that the PAHs in PM2.5 impose moderate human health risks in Hangzhou due to traffic emissions. The results of this study provide important information for policymakers to establish abatement strategies to reduce PAH emissions in Hangzhou, and perhaps other urban centers across China.

The recalcitrance and potential toxicity of polycyclic aromatic hydrocarbons within crude oil residues in beach sediments at the BIOS site, nearly forty years later

The Arctic is a unique environment characterized by extreme conditions, including daylight patterns, sea ice cover, and some of the lowest temperatures on Earth. Such characteristics in tandem present challenges when extrapolating information from oil spill research within warmer, more temperate regions. Consequently, oil spill studies must be conducted within the Arctic to yield accurate and reliable results. Sites of the Baffin Island Oil Spill (BIOS) project (Cape Hatt, Baffin Island, Canadian Arctic) were revisited nearly 40 years after the original oil application to provide long-term monitoring data for Arctic oil spill research. Surface and subsurface sediment samples were collected from the intertidal zone of the 1981 nearshore oil spill experiment (Bay 11), from 1980 supratidal control plots (Crude Oil Point) and 1982 supratidal treatment plots (Bay 106). Samples were analyzed for Polycyclic Aromatic Hydrocarbons (PAHs) and alkylated homologues via Gas Chromatography – Mass Spectrometry (GC-MS). Our results suggest that total mean concentrations of all measured PAHs range from 0.049 to 14 mg/kg, whereas total mean concentrations of the 16 US EPA priority PAHs range from 0.02 to 2.1 mg/kg. The relative proportions of individual PAHs were compared between sampling sites and with the original technical mixture. Where available, percent loss of individual PAHs was compared with data from samples collected at the BIOS site, in 2001. All three sites featured samples where concentrations of various priority PAHs exceeded the established Interim Marine Sediment Quality Guidelines. All supratidal samples contained potentially toxic levels of PAHs. Even after nearly four decades of weathering, the recalcitrant crude oil residues remain a potential hazard for the native organisms. Continued monitoring of this unique study site is crucial for establishing a timeline for oil degradation, and to observe a reduction in toxicity over time.

Distribution, source, risk and phytoremediation of polycyclic aromatic hydrocarbons (PAHs) in typical urban landscape waters recharged by reclaimed water

A park that had used reclaimed water as the sole water supply for fourteen years, was selected to analyze the distribution, sources and risks of 16 priority polycyclic aromatic hydrocarbons (PAHs) in waters and sediments. The effects of phytoremediation were investigated in waterbodies classified as phytoremediation, transitional and non-phytoremediation areas. Diagnostic ratio (DR) and principal component analysis (PCA) were used to analyze the sources of PAHs, while risk quotient (RQ) was used as risk assessment tool. Results showed that ∑PAH concentrations in sediments ranged from 29.4 to 1245.6 ng‧g−1, with average of 354.3 ng‧g−1, corresponding to a moderate pollution level. The concentration of PAHs in water ranged from 10.6 to 326.3 ng‧L−1, with average of 147.2 ng‧L−1, corresponding to a low pollution level. The ∑PAHs in sediments showed a downward trend from northwest to southeast along with the water flow direction, with average values of 459.5, 362.9 and 246.1 ng‧L−1 in the upstream, midstream and downstream, respectively. In contrast, PAH concentrations in water were consistent with recreational activities in the urban park area. There were 95% of water samples and 72% of sediment samples obtaining the Ant/(Ant + Phe) > 0.1 and Flu/(Flu + Pyr) > 0.5, indicating that coal combustion was the major source of PAHs in both the water and sediment. The RQ∑PAH(NCs) values in water and sediment were all between 1 and 800, while RQ∑PAH(MPCs) reached equal to 0, suggesting that ∑PAHs presented a low ecological risk. Acenaphthene accounted for 28.4% of RQ(NCs), and became the most risk PAH in water column. Aquatic plants effectively removed high-ring PAHs from water and middle-ring PAHs from sediments, reducing the overall risks posed by PAHs.

Contamination and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Seasoning Flour Products in Hunan, China.

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with carcinogenic, teratogenic, and mutagenic effects. Dietary intake is one of the significant exposure pathways of PAHs. In this study, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to detect 16 priority PAHs listed by the United States Environmental Protection Agency (USEPA) in seasoning flour products distributed in Hunan Province. The consumption of seasoning flour products by the Hunan population was investigated by questionnaire. The results showed that the detection rate of PAHs in seasoning flour products in Hunan Province was 92.41%. Among them, benzo[a]anthracene (BaA), phenanthrene (PHE), fluoranthene (FLA), and chrysene (CHR) were dominant. The total PAHs and benzo[a]pyrene (BaP) contents of soggy seasoning flour product samples were higher than those of crisp samples and chewy samples. The total amount of PAHs in rod-shaped and flaky samples were higher than that in filamentous and granular samples. The margin of exposure (MOE) values of various seasoning flour products and all age groups (children, adolescents, and adults) was much more significant than 10,000. Moreover, the incremental lifetime of cancer risk (ILCR) values of all age groups were below 1 × 10-5. The above results indicate that PAHs in seasoning flour products have a relatively low health risk for the Hunan population. Still, it is recommended that susceptible populations (children, adolescents, etc.) should control their intake of flour products.

Kapaciteti Hedera helix iz borskog regiona za akumulaciju PAU u korenu i implikacije za fitostabilizaciju

Polycyclic aromatic hydrocarbons (PAHs) are considered as the pollutants of highest priority, and their remediation is of a global concern. The purpose of this study was to investigate the phytoremediation potential of Hedera helix (Hh) determining the content of 16 priority PAHs in its soil and root samples collected from the rural and industrial zones of the Bor's municipality (Serbia). The content of Ʃ16 PAHs in the soils was: 326.49 mg/kg at the site Borsko jezero to maximal 1937.64 mg/kg at the site Slatinsko naselje. The level of soil pollution (depending on the concentration of S16 PAHs), was high at many tested sites and it was under the significant influence of anthropogenic activities. The concentration for S16 PAHs in the samples of roots ranged from 480.71 mg/kg at the site Krivelj to 1748.32 mg/kg at the site Naselje Sunce. Interestingly, the extremely toxic benzo(a)pyrene, was not detected in the roots of Hh. Bioconcentration factors (BCFs) were applied to determine the capacity of Hh for PAH accumulation in the root, and consequently, for determination of its phytostabilization potential. In most cases, BCF values were higher at the locations from UI zone. The calculated BCFs were higher for LMW PAHs than for HMW PAHs. At the majority of the investigated locations, the tested plant species was especially successful in the root accumulation of the compounds such as acenaphthene, fluorene, anthracene, dibenzo(a,h)anthracene, and the sum of benzo(k)fluoranthene and benzo(b)fluoranthene. These findings showed that Hh can be successfully used in phytostabilization of many PAHs.

Geochemistry of Soils from the Surrounding Area of a Coal Mine Waste Pile Affected by Self-Burning (Northern Portugal)

Coal mining can generate organic and inorganic contaminants that can be disseminated in the surrounding soils by leaching and/or aerial deposition. This study aims to identify and characterize the physicochemical and geochemical changes promoted in soils from the surrounding area of a self-burning waste pile in an abandoned coal mine. A soil sampling campaign was conducted bordering the waste pile, comprising the main drainage areas as well as the areas uphill. The soils were characterized geochemically for major and trace elements and multivariate statistics was used in combination with geostatistical methodologies to study the statistical and spatial relations of the different elements and infer their Potentially Toxic Elements (PTEs) sources. The 16 priority Polycyclic Aromatic Hydrocarbons (PAHs) were identified and quantified in soils according to their spatial distribution, and their pyrogenic/petrogenic sources were inferred. Different sources were identified as contributing to the soil geochemical signature, considering not only the mine but also anthropogenic urban contamination or naturally enhanced regional geochemical background in multiple PTEs. PAHs tend to concentrate downstream of the waste pile, along the runoff areas, presenting a greater variety of the 16 priority PAHs and an increase of High Molecular Weight (HMW) PAHs pointing to its pyrogenic origin, possibly related to the self-combustion phenomenon occurring in the waste pile.

A baseline study of polycyclic aromatic hydrocarbons distribution, source and ecological risk in Zhanjiang mangrove wetlands, South China

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants and pose a severe threat to human health. Here, 38 surface sediment samples collected from the Gaoqiao mangrove wetland in Zhanjiang, south China, were analyzed to determine 16 Environmental Protection Agency (EPA) priority PAHs. Total PAHs concentrations ranged from 33.5 µg/kg to 404.8 µg/kg with an average of 147.7 ± 77.7 µg/kg, inferring a moderate pollution level. Three and four-ring compounds dominated the PAHs composition patterns. Significant positive correlations were observed between the PAHs and the physicochemical properties of the sediments. According to the characteristic molecular ratio method, PAHs in sediments were mainly derived from combustion sources, including the incomplete combustion of liquid fossil fuels, grass, wood, and coal. The result based on the PMF model indicates that the primary combustion sources of PAHs are coal combustion, diesel-powered vehicles, biomass combustion and gasoline-powered vehicles, with a share of 39.01%, 25.21%, 12.72% and 10.48%, respectively. The petrogenic source contributes 12.58% PAHs to the sediments. The mean effects range median quotient (m-ERM-Q) and toxic equivalent method (TEQ) indicate a low comprehensive ecological risk of PAHs in the study area. Still, the evaluation results of effects range low (ERL) suggest that PAHs in the sediment would occasionally have adverse biological effects. Therefore, this situation demands attention and calls for protection strategies in the processes of urbanization and industrialization in south China.