Elevated Concentrations Of Polycyclic Aromatic Hydrocarbons Research Articles

Spatial interaction and risk zoning of compound pollutants in farmland soils: Insights from heavy metals and polycyclic aromatic hydrocarbons in Hezhang County, China

The accurate identification and assessment of comprehensive risks associated with compound pollution in agricultural ecosystems remain significant challenges due to the complexity of pollution sources, soil heterogeneity, and spatial variability. In this study, bivariate local indicators of spatial association (LISA) were applied to analyze the spatial interaction between heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in farmland soils in Hezhang County. The results revealed distinct clusters with elevated concentrations of both HMs and PAHs, predominantly in areas affected by long-standing lead-zinc mining and smelting activities. Positive matrix factorization (PMF) was utilized to identify mining and smelting activities, and associated coal consumption as common sources of both pollutants, contributing 53 % and 28 %, respectively. Ecological health risk assessment results indicated that the combined pollution in this area has led to particularly severe ecological and cancer risks, with the pollution coefficient (Pc) exceeding 3.0, and risk values for both adults and children surpassing the threshold of 10−4. Through the integration of advanced bivariate LISA mapping and thorough risk assessment, this study precisely delineated ecological risk zones (33.1 %) and more refined health risk zones (40.1 %) associated with combined pollution. The southwest of Hezhang was identified as a critical hotspot for combined pollution risks, primarily due to intensive mining and smelting activities in the region. Overall, this study underscores the utility of bivariate LISA as a robust approach for delineating spatial clustering patterns caused by combined pollutants. It provides crucial insights for identifying regions with heightened human health and ecological risks in rural settings.

Characterization of persistent organic contaminants in the atmosphere of Gadani's ship breaking yards and its surrounding: Implications for sustainable ship recycling practices

Gadani is internationally renowned for its extensive ship-breaking operations, positioning it as one of the globe's primary ship-breaking hubs. A comprehensive study was conducted to evaluate the presence of organic contaminants in the air within Gadani, encompassing the areas surrounding ship-breaking facilities, proximate residential settlements, and adjacent roadways. Passive air samplers were employed to collect a total of 30 air samples. The analytical results unveiled a notably elevated concentration of specific organic compounds, with a pronounced prevalence of polycyclic aromatic hydrocarbons (PAHs), short-chain chlorinated paraffins (SCCPs), and polychlorinated biphenyls (PCBs) at the ship-breaking yard. Notably, dichlorodiphenyltrichloroethanes (DDTs) and DDE were detected at substantially lower levels. In particular, sites in close proximity to ship-breaking activities exhibited elevated concentrations of PCBs (Σ7PCB 0.065429 to 7.345714 ng/sample), PAHs (Σ8PAH 2.44 to 134.23 ng/sample), and SCCPs (0.18 to 25.6 ng/sample). Conversely, DDTs and DDE demonstrated higher concentrations near residential settlements. The evaluation of Molecular Diagnostic Ratios for PAHs revealed anthracene/anthracene + phenanthrene ratios of 0.88, 0.69, and 0.5 for ship-breaking areas, roadside locations, and community surroundings, respectively. Furthermore, the benz[a]anthracene/benz-[a]anthracene + chrysene molecular ratios were measured at 0.77 (ship-breaking sites), 0.82 (roadside), and 0.83 (community), respectively. The molecular ratio of fluoranthene/fluoranthene + pyrene at ship-breaking sites was 0.23, while roadside and community ratios were 0.36 and 0.89, respectively. These findings underscore the significant contribution of ship-recycling activities to the atmospheric release of SCCPs, PCBs, and PAHs, emphasizing the global imperative for responsible ship recycling practices.

Wet deposition of polycyclic aromatic hydrocarbons in a remote area of Central South China from 2014 to 2017

AbstractIn recent years, there has been a notable increase in the consumption of fossil energy, leading to a significant rise in environmental pollution, particularly in China due to its rapid development. This has resulted in the frequent occurrence of large‐scale fog and haze weather, highlighting the urgent need for environmental protection measures. To gain insights into the atmospheric conditions in China, an analysis was conducted on the wet deposition of polycyclic aromatic hydrocarbons (PAHs) in a remote region of Central South China from 2014 to 2017. The study revealed that the average concentrations and peak values of Ʃ16PAHs in 2014 and 2015 were considerably higher than those observed in 2016 and 2017. Furthermore, it was found that five‐ring PAH species were the predominant components during 2014 and 2015, indicating a shift in the main sources of PAHs. The peaks of Ʃ16PAHs were predominantly detected in samples collected during light rain in the winter, specifically on days without heavy rainfall. This can be attributed to the absence of heavy rain, which would otherwise reduce the concentration of air pollutants. Consequently, contaminants accumulated in the air are easily enriched in rainwater. The concentrations of Ʃ15Alkyl‐PAHs also exhibited a significant correlation with the number of rainfall days. Notably, a much higher annual average concentration of Ʃ15Alkyl‐PAHs was observed in 2017, which experienced fewer rainfall days. Coal combustion, petroleum sources, and vehicular emissions accounted for 58%, 12%, and 30% of the PAHs in the air, respectively. Despite improvements in air quality in China since 2016, it is crucial to address the elevated concentrations of PAHs in the atmosphere, particularly under adverse meteorological conditions characterized by reduced rainfall.

Particle characterization and quantification of organic and inorganic compounds from Chinese and Iranian aerosol filter samples using scanning laser desorption/ionization mass spectrometry

Besides their influence on climate and cloud formation, many organic and inorganic substances in aerosol particles pose a risk to human health. Namely, polycyclic aromatic hydrocarbons (PAH) and heavy metals are suspected to be carcinogenic or acutely toxic. The detection and quantification of such compounds is difficult if only small amounts of particulate matter (PM) are available. In addition, filter samples are often complex and time-consuming to prepare for chromatographic measurements and elemental analysis. Here, we present a method based on high-resolution atmospheric pressure laser desorption ionization mass spectrometry imaging (AP-LDI-MSI) and statistical analysis which allows the analysis and characterization of very small sample quantities (< 30 µg) without any sample preparation. The power and simplicity of the method is demonstrated by two filter samples from heavily polluted mega cities. The samples were collected in Tehran (Iran) and Hangzhou (China) in February 2018. In the course of the measurement, more than 3200 sum formulae were assigned, which allowed a statistical evaluation of colocalized substances within the particles on the filter samples. This resulted in a classification of the different particle types on the filters. Finally, both megacities could be distinguished based on characteristic compounds. In the samples from Tehran, the number of sulphur-containing organic compounds was up to 6 times as high as the samples from Hangzhou, possibly due to the increasing efforts of the Chinese government to reduce sulphur emissions in recent years. Additionally, quantification of 13 PAH species was carried out via standard addition. Especially, the samples from Tehran showed elevated concentrations of PAHs, which in the case of higher-molecular-weight species (> m/z 228) were mostly more than twice as high as in Hangzhou. Both cities showed high levels of heavy metals and potentially harmful organic compounds, although their share of total particulate matter was significantly higher in the samples from Tehran. The pre-treatment of the samples was reduced to a minimum with this method, and only small amounts of particles were required to obtain a comprehensive picture for a specific filter sample. The described method provides faster and better control of air pollution in heavily polluted megacities.Graphical abstract

Air pollution levels near crossroads with different traffic density and the estimation of health risk.

The aim of this study was to determine the influence of traffic density on air pollutant levels as well as to analyse the spatial and temporal distribution of particulate pollutants and their health risk. The following species related to traffic pollution were measured: PM10, elemental and organic carbon and polycyclic aromatic hydrocarbons (PAHs) in PM10 and gas pollutants (SO2, NO2 and CO). The measurements were carried out at four crossroad sites in the city. Samples of PM10 were collected over three periods (6 am to 2pm, 2pm to 10pm and 10pm to 6 am) on working days and weekends. Statistically significant differences were found between sampling sites for all pollutant concentrations, except for NO2. The highest mass concentrations of PM10, carbon and PAHs were observed in the south of the city with the highest traffic density. Concentrations of gasses (CO and NO2) showed high values in morning and in the late afternoon and evening (west and east). At all measuring sites, the highest concentration of particle-bound pollutants was mostly recorded during morning and afternoon, except at the south, where elevated PAHs concentrations were recorded during night period, which indicated that residential heating takes up a portion of pollution sources in this area. Although for most of the pollutants the concentrations varied during the day, statistically significant differences between sampling periods were not found. The highest health risk was obtained at the south, where it was scored as significant.

Hepatobiliary PAHs and prevalence of pathological changes in Red Snapper

Red Snapper (Lutjanus campechanus) were collected throughout the Gulf of Mexico (GoM) from 2011 to 2017 and analyzed for biliary (n = 496) fluorescent aromatic compounds (FACs), hepatic (n = 297) polycyclic aromatic hydrocarbons (PAHs) and microscopic hepatobiliary changes (MHC, n = 152). Gross and histological evaluations were conducted with liver tissues to identify and characterize pathological changes. This is the first report to interrelate hepatobiliary PAH concentrations and MHCs in Red Snapper. Hepatic PAHs measured in GoM Red Snapper ranged from 192 to 8530 ng g−1 w.w. and biliary FACs ranged from 480 to 1,100,000 ng FAC g−1 bile. Biliary FACs in Red Snapper collected along the west Florida Shelf and north central region declined after 2011 and were relatively stable until a sharp increase was noted in 2017. Increases in the PAH exposures are likely due to a number of sources including leaking infrastructure, annual spills, riverine input and the resuspension of contaminated sediments. In contrast, hepatic PAH concentrations were relatively stable indicating Red Snapper are able to maintain metabolic clearance however this energetic cost may be manifesting as microscopic hepatic changes (MHCs). Virtually all (99 %) of the evaluated Red Snapper had one to nine MHCs with an average of five coinciding changes in an individual fish. The observed changes were broadly classified as inflammatory responses, metabolic responses, degenerative lesions, nonneoplastic proliferation and neoplastic lesions. Biliary FACs were associated with parasitic infection and intracellular breakdown product accumulation such as intra-macrophage hemosiderin, lipofuscin and ceroid laden prevalence. Whereas, hepatic PAHs were associated with increased myxozoan plasmodia prevalence. This study evaluates relationships between hepatobiliary PAH concentrations and biometrics, somatic indices, condition factors and microscopic hepatic changes in Red Snapper located in the north central GoM. Together, these results may be signaling increased disease progression in Gulf of Mexico Red Snapper more than likely resulting from chronic environmental stressors including elevated PAH exposures and concentrations.

A comparison of PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt;-bound polycyclic aromatic hydrocarbons in summer Beijing (China) and Delhi (India)

Abstract. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in air, soil, and water and are known to have harmful effects on human health and the environment. The diurnal and nocturnal variations of 17 PAHs in ambient particle-bound PAHs were measured in urban Beijing (China) and Delhi (India) during the summer season using gas-chromatography–quadrupole time-of-flight mass spectrometry (GC-Q-TOF-MS). The mean concentration of particles less than 2.5 µm (PM2.5) observed in Delhi was 3.6 times higher than in Beijing during the measurement period in both the daytime and night-time. In Beijing, the mean concentration of the sum of the 17 PAHs (∑17 PAHs) was 8.2 ± 5.1 ng m−3 in daytime, with the highest contribution from indeno[1,2,3-cd]pyrene (12 %), while at night-time the total PAHs was 7.2 ± 2.0 ng m−3, with the largest contribution from benzo[b]fluoranthene (14 %). In Delhi, the mean ∑17 PAHs was 13.6 ± 5.9 ng m−3 in daytime and 22.7 ± 9.4 ng m−3 at night-time, with the largest contribution from indeno[1,2,3-cd]pyrene in both the day (17 %) and night (20 %). Elevated mean concentrations of total PAHs in Delhi observed at night were attributed to emissions from vehicles and biomass burning and to meteorological conditions leading to their accumulation from a stable and low atmospheric boundary layer. Local emission sources were typically identified as the major contributors to total measured PAHs in both cities. Major emission sources were characterized based on the contribution from each class of PAHs, with the four-, five- and six-ring PAHs accounting ∼ 95 % of the total PM2.5-bound PAHs mass in both locations. The high contribution of five-ring PAHs to total PAH concentration in summer Beijing and Delhi suggests a high contribution from petroleum combustion. In Delhi, a high contribution from six-ring PAHs was observed at night, suggesting a potential emission source from the combustion of fuel and oil in power generators, widely used in Delhi. The lifetime excess lung cancer risk (LECR) was calculated for Beijing and Delhi, with the highest estimated risk attributed to Delhi (LECR = 155 per million people), which is 2.2 times higher than the Beijing risk assessment value (LECR = 70 per million people). Finally, we have assessed the emission control policies in each city and identified those major sectors that could be subject to mitigation measures.

Evaluation of silicone-based wristbands as passive sampling systems using PAHs as an exposure proxy for carcinogen monitoring in firefighters: Evidence from the firefighter cancer initiative

Compared to the general population, firefighters are known to sustain greater levels of exposure to hazardous compounds, despite their personal protective equipment, also known as turnout gear. Among the most significant toxins that firefighters are chronically exposed to are polycyclic aromatic hydrocarbons (PAHs). Additionally, firefighters have also been noted to exhibit an increased incidence of certain types of cancer. Considering a probable link between exposure to PAHs and increased rates of cancer in the fire service, we aim to document ambient chemical concentrations in the firefighter work environment. Our strategy involves the use of silicone-based wristbands that have the capacity to passively sorb PAHs. To determine if wristbands can serve as an effective chemical monitoring device for the fire service, silicone wristbands were pilot-tested as personal sampling devices for work environment risk monitoring in active-duty firefighters. Recovered wristbands underwent multiple extraction steps, followed by GC-MS analysis to demonstrate their efficacy in monitoring PAHs in the firefighter environment. Initial findings from all wristband samples taken from firefighters showed multiple exposures to various PAHs of concern for the health of the firefighters when in a fire environment. In addition to PAH monitoring, we examined known and potential sources of PAH contamination in their work environment. To that end, profiles of elevated PAH concentrations were documented at various fire stations throughout South Florida, for individual firefighters both during station duties and active fire response.

Impacts of Independence Day fireworks on pollution levels of atmospheric polycyclic aromatic hydrocarbons (PAHs) in the U.S.

Fireworks on Independence Day have been identified as a nationwide but short-term source of particulate matter in the U.S. No study has specifically examined their impacts on ambient polycyclic aromatic hydrocarbons (PAHs). Based on data between 1990 and 2019 in the Air Quality System, we identified 76 unique events that had PAH measurements on both July 4th days and control days (within 15 days before and after July 4th). We compared concentrations and diagnostic ratios of 16 priority PAHs between event and control days using Wilcoxon signed-rank tests and multivariable regressions. A local PAH monitoring campaign was conducted at eight sites in Memphis, Tennessee, to obtain a close observation of PAH changes. The national geometric mean (GM) concentrations of summed 16 PAHs (ΣPAHs) were similar between event and control days (48.1 ng/m3 vs. 52.8 ng/m3, p = 0.98). About a quarter of events had elevated PAH concentrations compared with control days. Higher diagnostic ratios were found on event days, suggesting more contributions from fireworks sources. PAHs on July 4th were unlikely to cause acute or chronic health effects. While the local monitoring showed a 15% increase of ΣPAHs on July 4th, the difference was not significant (p = 0.62). Elevated PAH concentrations occurred at sites near fireworks sources and without major traffics, but did not occur at those in remote areas or near major interstate highways. In conclusion, this study finds that Independence Day fireworks have negligible impacts on atmospheric PAHs at the national level, and are unlikely to pose significant health risks. The firework effect is localized within a limited geographic scale, suggesting potential needs for local monitoring and control programs.

Novel and specific source identification of PAH in urban soils: Alk-PAH-BPCA index and “V”-shape distribution pattern

Soils in urban and industrial areas, especially in larger metropolitan areas such as the Ruhr area, Germany, are commonly characterized by severe anthropogenic overprinting due to urbanization processes including land development measures. Such urban soils often contain various anthropogenic substrate admixtures, like ash, coal, tailings, building rubble, industrial waste materials, as well as urban dust, soot, fly ash, and others. These admixtures often carry higher contents of pollutants such as polycyclic aromatic hydrocarbons (PAH). Whereas elevated PAH concentrations are commonly attributed to non-point pyrogenic carbon sources like soot and particulate matter, petrogenic PAH sources are still largely neglected in this context.In this study, an extended sample set of 62 samples of PAH source materials and urban soils containing anthropogenic substrate components was investigated by combining extended PAH analysis of 59 PAH, alkylated PAH distributions and benzene polycarboxylic acid (BPCA) analysis with regard to petrogenic and pyrogenic PAH source identification. For more reliability of source apportionment by a more integrative signal, the alkylated PAH distributions of different PAH groups were combined according to their degrees of alkylation. Based on this combination, a new PAH alkylation index (ΣC0/(ΣC0+ΣC2)) was derived, which considers, in contrast to commonly used single PAH ratios, a series of non-alkylated and alkylated PAH.By comparison of this PAH alkylation index with the degree of aromatic condensation a new robust and economic method for identifying petrogenic, pyrogenic and mixed PAH sources within soil samples and sediments was developed. It is shown that coal and coal ash particles are a not negligible PAH source in urban soils of mining-dominated regions and can make up a large proportion of the anthropogenic substrate components encountered.Further analyses of samples with defined levels of petrogenic and pyrogenic PAH are necessary to finally evaluate the usefulness of this proposed new PAH-BPCA approach.

Appraisal of coal- and coke-derived wastes in soils near a former manufactured gas plant, Jacksonville, Florida

Preliminary site assessments revealed visibly-impacted soils in downtown Jacksonville, Florida (USA) suspected to be associated with a historic (1875–1912) manufactured gas plant (MGP) nearby. In this study, 19 soils from 11 borings within the impacted area were collected and analyzed using GC/FID for quantification of total petroleum hydrocarbons (TPH) and GC/MS for quantification of 87 volatiles and 50 parent and alkylated polycyclic aromatic hydrocarbons (PAHs). The results showed soils (up to 11 m deep and spanning ~90 m) containing elevated concentrations of TPH and PAHs, wherein the total PAHs, which were exclusively pyrogenic in character, comprised (on average) 40 ± 10% of the TPH in most (14 of 19) soils. In accord with visual observations of black-to-maroon, viscous non-aqueous phase liquid (NAPL) in some soils, the chemical results confirm the widespread occurrence of variably-weathered MGP tars throughout the area's subsurface. Multiple PAH isomer ratios indicate all but one of the tars likely were produced from the carbureted water gas (CWG) process; the exceptional tar likely was produced via the coal carbonization process. Both processes were historically used by the nearby former MGP. Three soils contained distinct hydrocarbons and pyrogenic PAHs consistent with particulate coke or coal ash (clinker) or heavy (C10 to C22) gas oil, a feedstock for CWG, the latter of which appeared as a yellowish-green NAPL. When interpreted in light of the typical MGP waste management and decommissioning practices, the results demonstrate the area's soils contain MGP wastes consistent with the discharge and/or disposal of wastes and demolition debris from the former MGP.

Remediation of soil contaminated with organic and inorganic wood impregnation chemicals by soil washing

The aim of this study was to evaluate the efficiency of a large scale washing/wet sieving technique for a soil contaminated with wood impregnation chemicals by 1) defining the final distribution of trace elements (As, Cu, Cr, Zn) and polycyclic aromatic hydrocarbons (PAH) in separated soil particle size fractions; and 2) defining the leaching behavior of the contaminants in these soil fractions. A soil washing experiment was implemented at waste management facility in Sweden using a full scale soil sorting and washing equipment. Five tons of soil was loaded to the equipment and wet-sieved into the following fractions: >16 mm, 8–16 mm, 2–8 mm, 0.2–2 mm, <0.2 mm and a fraction that floated on top of the slurry before the final separation phase, composed of organic matter (OM). Analysis of total concentrations of contaminants in all soil fractions indicated that wet sieving/soil washing was not efficient to reduce the total volume of soil that needs further treatment. Even the coarsest soil fractions (>8 mm) contained elevated concentrations of total As and PAH. Leaching of As from all washed soil fractions was so high, that none of the particle size fractions could be disposed of without additional treatment.

High Urinary Polycyclic Aromatic Hydrocarbon Concentrations in Bomet County, Kenya, a Region With a High Incidence of Esophageal Squamous Cell Carcinoma

Abstract 43 Background: Polycyclic aromatic hydrocarbons (PAHs) are a group of more than 100 compounds that are formed during incomplete combustion of organic materials, many of which have been classified as known carcinogens. Exposure to PAHs has been suggested as an important risk factor for developing esophageal squamous cell carcinoma (ESCC) in several high-incidence areas, such as China and Iran, but corresponding PAH assessments have not been conducted in East Africa, another ESCC hot spot. To assess the internal uptake of PAH as a result of external exposures, body fluids and tissues can be monitored for PAHs or their metabolites. The primary aim of this study was to quantify the concentration of seven PAH urine metabolites in a cross-section of participants from Bomet, Kenya, an endemic area for ESCC. An additional aim was to assess demographic and lifestyle factors that may be associated with PAH metabolites. Methods: A community-based sample of 294 asymptomatic adults were recruited. Participants collected spot urine specimens and completed a questionnaire. Urine specimens were analyzed at the National Center for Environmental Health at the Centers for Disease Control—the same lab has performed similar analyses on urine samples from the US National Health and Nutrition Examination Survey (NHANES). The seven PAH analytes were hydroxylated metabolites of naphthalene, fluorene, phenanthrene, and pyrene. Median creatinine-adjusted PAH metabolite concentrations (nanogram per gram of creatinine) were compared by all relevant questionnaire items. Results: All seven measured PAH metabolites in the study population were markedly elevated compared with the US population. For example, the median value for 1-hydroxypyrene in Bomet was 1,190 ng/g in males versus 106 ng/g in NHANES, and 2,840 ng/g in females versus 133 ng/g in NHANES. Age (&lt; 50 years), sex (female), and performing indoor cooking were significantly ( P &lt; .01) associated with higher PAH concentrations for all measured metabolites. Regular tobacco use was not reported by many participants (19%) and was not associated with PAH concentrations. Conclusion: PAH metabolite concentrations in Bomet were high compared with the US population. Elevated PAH concentrations were associated with age, sex, and indoor cooking. Additional studies are needed to define the association between high PAH exposure and the risk of developing ESCC as well as to determine the sources of PAH exposure in this high-risk population. Funding: The African Organization for Research and Training in Cancer’s Beginning Investigator Grant for Catalytic Research (BIG Cat) Program, in collaboration with the US National Institutes of Health’s National Cancer Institute, Office of International Affairs. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST No COIs from the authors.

Linking sources to early effects by profiling urine metabolome of residents living near oil refineries and coal-fired power plants

BackgroundThis study aims at identifying metabolic changes linking external exposure to industrial air toxics with oxidative stress biomarkers. MethodsWe classified 252 study subjects as 111 high vs. 141 low exposure subjects by the distance from their homes to the two main emission sources, oil refineries and coal-fired power plants. We estimated individual's external exposure to heavy metals and polycyclic aromatic hydrocarbons (PAHs) by dispersion and kriging models, respectively. We measured urinary levels of heavy metals and 1-hydroxypyrene (1-OHP) as biomarkers of internal exposure, and 8-OHdG, HNE-MA, 8-isoPGF2α, and 8-NO2Gua as biomarkers of early health effects. We used two-dimensional gas chromatography time-of-flight mass spectrometry to identify urine metabolomics. We applied “meet-in-the-middle” approach to identify potential metabolites as putative intermediate biomarkers linking multiple air toxics exposures to oxidative stress with plausible exposures-related pathways. ResultsHigh exposure subjects showed elevated ambient concentrations of vanadium and PAHs, increased urine concentrations of 1-OHP, vanadium, nickel, copper, arsenic, strontium, cadmium, mercury, and thallium, and higher urine concentrations of all four urine oxidative stress biomarkers compared to low exposure subjects. We identified a profile of putative intermediate biomarkers that were associated with both exposures and oxidative stress biomarkers in participants. Urine metabolomics identified age-dependent biological pathways, including tryptophan metabolism and phenylalanine metabolism in children subjects (aged 9–11), and glycine, serine, and threonine metabolism in elderly subjects (aged>55), that could associate multiple exposures with oxidative stress. ConclusionBy profiling urine biomarkers and metabolomics in children and elderly residents living near a petrochemical complex, we can link their internal exposure to oxidative stress biomarkers through biological pathways associated with common complex chronic diseases and allergic respiratory diseases. The internal exposure may possibly be traced to multiple air toxics emitted from specific sources of oil refineries and coal-fired power plants.

Initial environmental impacts of the Obed Mountain coal mine process water spill into the Athabasca River (Alberta, Canada)

On October 31, 2013, a catastrophic release of approximately 670,000m3 of coal process water occurred as the result of the failure of the wall of a post-processing settling pond at the Obed Mountain Mine near Hinton, Alberta. A highly turbid plume entered the Athabasca River approximately 20km from the mine, markedly altering the chemical composition of the Athabasca River as it flowed downstream. The released plume traveled approximately 1100km downstream to the Peace-Athabasca Delta in approximately four weeks, and was tracked both visually and using real-time measures of river water turbidity within the Athabasca River. The plume initially contained high concentrations of nutrients (nitrogen and phosphorus), metals, and polycyclic aromatic hydrocarbons (PAHs); some Canadian Council of Ministers of the Environmental (CCME) Guidelines were exceeded in the initial days after the spill. Subsequent characterization of the source material revealed elevated concentrations of both metals (arsenic, lead, mercury, selenium, and zinc) and PAHs (acenaphthene, fluorene, naphthalene, phenanthrene, and pyrene). While toxicity testing using the released material indicated a relatively low or short-lived acute risk to the aquatic environment, some of the water quality and sediment quality variables are known carcinogens and have the potential to exert negative long-term impacts.

Distribution and Attenuation of Polycyclic Aromatic Hydrocarbons in Gulf of Mexico Seawater from the Deepwater Horizon Oil Accident.

The extended duration of the oil release from the Deepwater Horizon accident (April 20-July 15, 2010) triggered a need to characterize environmental exposures in four dimensions through sampling and tracking the changes in distributions, concentrations, and compositions of oil and total polycyclic aromatic hydrocarbons (TPAH) in the Gulf of Mexico over time and space. More than 11,000 water samples were collected offshore during more than 100 cruises and were measured for 50 parent and alkylated polycyclic aromatic hydrocarbons (PAHs). Elevated concentrations (greater than 1 ppb) of TPAH were largely limited to an area within about 20 km of the wellhead in the subsurface deepwaters at 1000-1200 m depth to the southwest of the wellhead and in the top 3 m underlying the surface oil. Concentrations decreased with distance and time, and changes in the PAH composition indicate that these changes were due to differential solubilization, photodegradation, evaporation, and/or biodegradation of individual PAH compounds. These limited areas of elevated PAH concentrations disappeared within weeks after the release was stopped.

Embryo aberrations in the amphipod Monoporeia affinis as indicators of toxic pollutants in sediments: A field evaluation

Reproduction in the amphipod Monoporeia affinis is sensitive to contaminant exposure, and embryo aberrations are used in the Swedish National Monitoring Program to indicate biological effects of contaminants. However, empirical support for a causal relationship between contaminant load and frequency of aberrations is largely based on experimental studies. A field evaluation of aberration frequency in relation to contaminant exposure is required, if we are to use reproductive disorders as indicators of contaminant effects in risk assessment. In this study, we evaluated occurrence of females carrying malformed embryos and frequency of specific embryo aberrations in broods of M. affinis in relation to concentrations of various pollutants in sediments. Gravid M. affinis and surface sediment were sampled at ten sites in the Gulf of Bothnia located at varying proximity to historical and current polluting point sources. At each site, concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and trace and heavy metals in surface sediments were determined. Amphipod fecundity and embryo development status were assayed with regard to morphologically recognizable aberrations (malformed embryos, membrane-damaged embryos, embryos with arrested development and females with dead brood). Our key finding is that different types of embryo aberrations were significantly associated with specific contaminant groups in the sediment. In particular, occurrence of females with embryo malformations was strongly related to elevated concentrations of Cd and PCBs, while females with membrane-damaged embryos occurred at high PAH concentrations. Also, frequency of embryos with arrested development was linked to elevated concentrations of PAHs and metals. Finally, frequency of females carrying dead broods, which was earlier considered to be a hypoxia-induced pathology, was significantly positively related to PAH concentrations. Thus, these reproductive aberrations in M. affinis can serve as contaminant-specific indicators of PCB, PAH and heavy metal exposure in biological effect monitoring.

Potential bioavailability of lead, arsenic, and polycyclic aromatic hydrocarbons in compost-amended urban soils.

Urban soils may contain harmful concentrations of contaminants, such as lead (Pb), arsenic (As), and polycyclic aromatic hydrocarbons (PAHs), that can transfer from soil to humans via soil ingestion and consumption of food crops grown in such soils. The objective of this research was to assess the effectiveness of adding different compost types to reduce both direct (soil-human) and indirect (soil-plant-human) exposure of Pb, As, and PAHs to humans. A field experiment was conducted in 2011 and 2012 at an urban garden site with elevated concentrations of Pb (475 mg kg), As (95 mg kg), and PAHs (23-50 mg kg). Soil amendments were composted biosolids, noncomposted biosolids, mushroom compost, leaf compost, and a nonamended control. Collard greens, tomatoes, and carrots were then grown in the amended and nonamended soils and nonamended soils that received urea in 2011. At the beginning of the second season, N-P-K fertilizer was added to all plots. The potential for direct and indirect exposure was evaluated. Soil Pb bioaccessibility was 1 to 4.3%, and As bioaccessibility was 7.3 to 12.3%. Composted biosolids reduced the bioaccessibility of soil Pb by ∼17% compared with the control but temporarily increased the bioaccessibility of As by ∼ 69% compared with the control when soluble inorganic P concentration in soil was elevated by P fertilizer application in 2012. The bioaccessibility of soil Pb decreased by ∼38% in all treatments when soluble inorganic P concentration in soil was elevated by P fertilizer. Compost amendments reduced the concentrations of low molecular weight PAHs in soil. Regardless of the treatments, the concentrations of Pb, As, and PAHs measured in the vegetables were low or nondetectable, except for Pb in carrots. Consumption of vegetables grown at this site will cause insignificant transfer of Pb, As, and PAHs to humans.

Polycyclic aromatic hydrocarbons in sediments at dredged material disposal sites around England: Concentrations in 2013 and time trend information at selected sites 2008–2013

The maintenance of navigation channels to ports and the development of their facilities present a need to conduct dredging operations, and the subsequent disposal of dredged material at sea. Contaminant concentrations in candidate dredged material are determined and their possible impacts considered during the licensing process, which can result in the exclusion of some material from sea disposal. Monitoring of disposal sites is conducted in order to ensure that no undesirable impacts are occurring. In this study we consider the levels of polycyclic aromatic hydrocarbons (PAHs) in sediments at a number of disposal sites monitored in 2013 and variations in concentrations over time at three sites during the period 2008–2013. These were assessed using established sediment quality guidelines. Elevated PAH concentrations were generally observed only within the boundaries of the disposal sites studied.

PAHs in sediment cores at main river estuaries of Chaohu Lake: implication for the change of local anthropogenic activities.

In the present study, 28 polycyclic aromatic hydrocarbons (PAHs) were investigated in four sediment cores collected from the main river estuaries of Chaohu Lake, one of the severely polluted lakes in China. The results indicate that elevated concentrations of total PAHs (Σ28PAH) were found in the samples from the estuary of Nanfei River (ENF), considering BaP-based total toxicity equivalent (TEQ-BaP) and toxic unit (TU) results; there are potential adverse environmental implications. The total organic carbon (TOC) played an important role on the accumulation of PAHs at ENF and the estuary of Tongyang River (ETY). The predominant PAHs are high molecular weight (HMW) homologous for all samples; as a result, industrial wastewater from a steel company is expectedly the key source of PAHs in ENF, while coke consumption would be the important source of PAHs at other three sampling sites. Vertical distribution of PAHs in the sediment cores could be explained by the local social and economic activities. Furthermore, a minor variation of PAH composition in the sediment core could be justified by the stable structure of energy consumption in the Anhui Province. These results justify the need for further enhancement of industrial wastewater treatment and development of renewable energies which are the key factors on the control of PAH pollution in China.