EPA Priority PAHs Research Articles

Variation in urban snow quality indicated by three seasonal sampling surveys conducted in Luleå (Sweden) within a span of 27 years

Concentrations of total suspended solids (TSS), trace metals (Cu, Cd, Cr, Zn, Cd, Pb), Na and 16 US EPA priority PAHs in urban snow were studied in the City of Luleå in Northern Sweden. Snow was sampled at six central urban and suburban sites with various traffic intensities, in three sampling surveys (1994–95, 2002–03, 2020–21), repeated for three ages of the urban snow cover of 40, 80, and 120 days, respectively. The older data, from the 1994–95 and 2002–03 surveys, were obtained from the existing literature. The concentrations and mass loads of TSS and most trace metals studied (Zn, Cu, Pb, and Cd) varied with time. TSS, Zn, and Cu showed slightly higher concentrations and mass loads in the 2003 (TSS avg = 2300 μg/L, Zn avg = 620 μg/L and Cu avg = 250 μg/L) and 2021 (TSS avg = 1500 μg/L, Zn avg = 530 μg/L and Cu avg = 220 μg/L) sampling surveys, compared to the 1995 survey (TSS avg = 620 μg/L, Zn avg = 240 μg/L and Cu avg = 97 μg/L). However, no evident trend was observed between the 2003 and 2021 sampling surveys. The highest concentrations of Pb and Cd were observed in snow samples from the 1994–95 sampling survey (Pb max = 570 μg/L, Cd max = 4.6 μg/L). Results indicated higher concentrations of the pollutants studied in the city centre, compared to the residential suburbs, and in areas with heavier traffic, where concentrations of metals correlated well with traffic intensity. Fractionation analysis of trace metals indicated that Zn, Cu and Pb occurred mostly in the particulate-bound phase (>0.45 μm) containing the most of Zn, Cu, and Pb mass, at 80, 84 and 94% of the total, respectively. Over 50% of the dissolved phase of Zn and Cu was in the truly dissolved fraction (<3000 MWCO). Concentrations of PAHs also increased with traffic intensity, with pyrene being the most frequently detected PAH, likely because of the strength of sources and various physical processes influencing the snowbanks development and causing spatial and temporal variations in pollutant concentrations.

Polycyclic Aromatic Hydrocarbons (PAHs) in paddy soil around Nam Son landfill area, Ha Noi, Viet Nam

The paddy soils were collected in the rice growing fields and the uncultivated lands around the Nam Son domestic waste landfill in Hanoi. The average concentration of 16 US EPA priority PAHs in dry soil was 61.61 ng/g, with a range of 22.15-115.1 ng/g. The higher levels of PAHs in soil samples were observed in cultivated paddy fields near the landfill in comparison with the fields far from the landfill. On the other hand, there was no difference in PAHs levels in cultivated paddy fields near the landfill and along the irrigation water canal. Concentrations of 16 PAHs in paddy soils decreased in the order: 5 rings &gt; 3 rings &gt; 4 rings &gt; 2 rings &gt; 6 rings in this area. The PAH isomeric diagnostic ratios including Fluth/(Fluth+Pyr) ratio (Ave 0.43, a range of 0.17-0.61), BaA/(BaA+Chr) ratio (Ave 0.51, a range of 0.26-0.63), IcdP/(IcdP+BghiP) ratio (Ave 0.71, a range of 0.51-0.90) indicated that the potential main sources emitted PAHs in paddy soils from pyrogenic biomass combustion and coal burning. Compared with the risk threshold causing adverse impacts on the ecological environment from different countries in the world, concentrations of PAHs in the soil surrounding the Nam Son landfill area were still below the affected limit. However, environmental quality around the landfill area still needs to be regularly monitored to take timely measures to protect the environment in this area.

Investigation of some Persistent Organic Pollutants in Soil around selected Auto-Mechanic Workshops in Osogbo

Public health is at risk due to pollution from activity in car workshops as the quality of the soil near auto businesses has received less attention. This study assessed soil quality in auto shops in Osogbo, Osun State, South-West Nigeria. Two car workshops were chosen and soil samples were collected from two different points each using a random survey method (i.e., picked two sites randomly). The soil samples were collected at irregular positions within the vicinity of the two auto repair shops at 0–20 cm and 20–40 cm depth. The samples were taken for examination of polychlorinated biphenyls (PCBs) and (Polycyclic aromatic hydrocarbons) PAHs. The samples were analysed in the lab according to regular technique, and 16 US EPA priority PAHs and PCBs were then examined using a gas chromatography-mass spectrometer (GC-MS). The potential toxicities were evaluated and values obtained were compared with United States permissible limits for soil quality. The total PAH values in the soil were between 0.17 μg/m3 to 4.97 μg/m3, with the soil samples near the truck maintenance shops having the greatest PAH concentrations between 0 – 20 cm below the surface. The most prevalent PAH species in soil samples was Fluoranthene, followed by Fluorene and Indeno [1,2,3-cd] pyrene. Also, PCBs were found in the location with 1,1′-Biphenyl, 2,2′,3,4,4′,5′-hexachloro- (PCB 138) having the highest concentration value followed by 1,1′-Biphenyl, 3,3′,4,4′-tetrachloro- (PCB 77). The findings of this study showed that both of these pollutants investigated are very prevalent in these areas. There is a grave environmental concern because the discovered levels of PCBs and PAHs exceed the permissible limits set by the USEPA standards.

Simulating diluted bitumen spills in boreal lake limnocorrals - Part 1: Experimental design and responses of hydrocarbons, metals, and water quality parameters

Large-scale, in-lake enclosures (limnocorrals) were used to simulate spills of diluted bitumen (dilbit) in a boreal lake. In this study we use these simulated spills, which covered a range of sizes (oil:water ratio) representative of the upper 25% of onshore crude oil spills in North America (2008–2019), to assess the fate of dilbit-derived hydrocarbons and metals as well as the impacts of the spills on standard water quality parameters. The systems were monitored over 70 days following the application of dilbit amounts ranging between 1.5 and 179.8 L into 10-m diameter, ~100 m3 limnocorrals. The concentration of total petroleum hydrocarbons (TPH) in the water column increased rapidly over the first two weeks reaching a plateau that ranged between 200 μg/L and 2200 μg/L for the lowest and highest treatment respectively. The concentration of total polycyclic aromatic compounds (PACs) also increased over the first two weeks, prior to a slow decrease until day 70. The maximum measured concentrations in the highest treatment were 2858 ng/L for the sum of all 46 quantified PACs, 2716 ng/L for alkylated PACs and 154 ng/L for the 16 EPA priority PAHs. The concentrations of PACs in the sediment increased continuously over the study in the three highest treatments with maximum observed concentrations of 189 ng/g for ΣPAC46, 169 ng/g for ΣPACalk. No significant treatment-related changes in the 16 EPA priority PAHs were observed in the sediment. Of the 25 metals quantified in the water column, only manganese, molybdenum, and vanadium displayed a significant treatment effect with increases of 280, 76 and 25% respectively in the total fraction. These results can help us understand and predict the fate of oil-derived contaminants following a spill and characterize the exposure of freshwater organisms living within them. These results should help inform the risk assessment of future dilbit transportation projects.

Seasonal Changes of PAHs in Water and Suspended Particulate Matter from Cross River Estuary, SE Nigeria in Response to Human-Induced Activity and Hydrological Cycle

Profile assessment of the behavior of total polycyclic aromatic hydrocarbons (TPAH – sum of 16 US EPA priority PAHs) in water and suspended particulate matter (SPM) from Cross River estuary, SE Nigeria in response to hydrological cycles and human-induced activities as well as their sources were undertaken using gas chromatography-flame ionization detector (GC-FID). TPAH concentrations in water were in the range 0.23–3.98 ng/L, with a minimum and maximum values found in April and December, respectively (mean = 0.97 ± 0.65 ng/L) having higher concentrations in the dry season. The low PAHs levels recorded in water for the wet season were linked to dilution effect. On the other hand, TPAH concentrations in SPM (suspended particulate matter) ranged between 5.16 ng/g in February and 40.52 ng/g in June (mean = 17.77 ± 8.48 ng/g). Higher PAHs levels found in the wet season were associated with greater wash-in of terrigenous materials occasioned by intense rainfall events via river discharges/wet precipitation coupled with the high adsorption capacity of PAHs toward solid matrix as well as proximity to fish settlement. Seasonal changes in salinity, temperature and suspended sediment concentration (SSC or SPMC) somewhat influenced the PAH phase association. Higher SSC in the wet season accounted for the higher PAHs levels in SPM (r = 0.9295), whereas lower salinity aided desorption from SPM in the wet season, temperature did not show regular trend with PAHs levels in both seasons. Application of principal component analysis (PCA) and multiple linear regression (MLR) to both water and SPM data indicated a scenario predominated by petroleum and wood combustion PAHs with a moderate vehicular exhaust emission and coal tar inputs (11%).

Efficiencies of selected biotreatments for the remediation of PAH in diluted bitumen contaminated soil microcosms.

Unconventional oils such as diluted bitumen from oil sands differs from most of conventional oils in terms of physiochemical properties and PAHs composition. This raises concerns regarding the effectiveness of current remediation strategies and protocols originally developed for conventional oil. Here we evaluated the efficiency of different biotreatment approaches, such as fungi inoculation (bioaugmentation), sludge addition (bioaugmentation/biostimulation), perennial grasses plantation (phytoremediation) and their combinations as well as natural attenuation (as control condition), for the remediation of soil contaminated by synthetic crude oil (a product of diluted bitumen) in laboratory microcosms. We specifically monitored the PAHs loss percentage (alkylated PAHs and unsubstituted 16 EPA Priority PAHs), the residue of PAHs and evaluated the ecotoxicity of soil after treatment. All treatments were highly efficient with more than ~ 80% of ∑PAHs loss after 60days. Distinctive loss efficiencies between light PAHs (≤ 3 rings, ~ 96% average loss) and heavy PAHs (4-6 rings, ~ 29% average loss) were observed. The lowest average PAHs residue (0.10 ± 0.02mg·kg-1, for an initial concentration of 0.29 ± 0.12mg·kg-1) was achieved with the "sludge-plants (grasses)" combination. Sludge addition was the only treatment that achieved significantly lower ecotoxicity (3% ± 4% of growth inhibition of L. sativa) than the control (natural attenuation, 13% ± 4% of inhibition). Sludge addition, grasses plantation and "sludge-fungi combination" treatments could result in lower PAH exposure (than other treatments) in post-treated soil when using the Canadian Soil Quality Guidelines for the protection of environmental and human health for potentially carcinogenic and other PAHs.

Seasonal and spatial variations in atmospheric PM2.5-bound PAHs in Karaj city, Iran: Sources, distributions, and health risks

Potential sources, temporal and spatial distribution, and health risks of 16 US EPA priority PAHs bound to PM2.5 in Karaj city have been monitored in order to assess the effect abatement and cleanup strategies. A total of 130 PM2.5 samples were collected in three different sites located in the southeast, northwest, and central parts of Karaj city in 2018 and 2019 and the average annual PAHs concentrations were 22.55 ± 13.74, 16.16 ± 10.62, and 16.67 ± 9.21 ng/m3, respectively. Atmospheric PM2.5-bound PAHs levels at all sites were lower in warm seasons than cold seasons, dominated by low molecular weight PAHs in the spring and high molecular weight PAHs in other seasons. The positive matrix factorization modeling (PMF) showed that diesel and gasoline engine emissions were dominant contributors to PAHs which accounted for 37.4 % and 31.1 %, respectively, followed by natural gas and biomass burning (14.8 %), industrial emissions (10.1 %), and petrogenic sources (6.6 %). The conditional bivariate probability function plots (CBPF) for PMF-resolved factor contributions were consistent with the predominant wind directions from northwest and southeast and known local emission sources. Benzo(a)pyrene (BaP) carcinogenic equivalent (BaPPEQ), BaP mutagenic equivalents (BaPMEQ) and the incremental lifetime lung cancer risk (LLCR) methodologies were calculated to evaluate human exposure to carcinogenic PAHs. The health risk related to PAHs was higher in cold seasons. Based on LLCR model, the total cancer risk related to PAHs exceeded the “safe limit” recommended by the USEPA (10−6) at all sites, indicating serious health risks for population of Karaj city mostly due to gasoline engine emissions.

A one-year monitoring of spatiotemporal variations of PM2.5-bound PAHs in Tehran, Iran: Source apportionment, local and regional sources origins and source-specific cancer risk assessment.

PM2.5-bound PAHs were analyzed in a total of 135 daily samples collected during four seasons from 2018 to 2019, at three urban sites in Tehran, Iran. This study aims to investigate spatio-temporal variations, source apportionment, potential local and regional sources contributions and lung cancer risks associated with the 16 US EPA priority PAHs. PM2.5 concentrations ranged from 43.8 to 80.3μgm-3 with the highest concentrations observed in summer. Total PAHs (TPAHs) concentrations ranged between 24.6 and 38.9ngm-3. Autumn period exhibited the highest average concentration (48.3ngm-3) followed by winter (29.5ngm-3), spring (25.9ngm-3) and summer (16.1ngm-3). Five PAHs sources were identified by positive matrix factorization (PMF) analysis: diesel exhaust, unburned petroleum-petrogenic, industrial, gasoline exhaust and coal/biomass combustion-natural gas emissions, accounting for 22.3%, 15.6%, 7.5%, 30.9%, and 23.6% of TPAHs, respectively. Site-specific bivariate polar (BP) and conditional bivariate probability function (CBPF) plots were computed to assess PM2.5 and TPAHs local source locations. CBPF pointed out that TPHAs sources are likely of local origin, showing the highest probability close to the sampling sites associated with low wind speed (<5ms-1). The potential source contribution function (PSCF) and the concentration weighted trajectory (CWT) models were applied to investigate the long-range transport of PM2.5 and TPAHs. In addition to local sources contributions, Eastern areas were highly related to long-distance transport of PM2.5 and the Western areas showed the highest contribution of the total, medium molecular weight (MMW) (4 rings) and high molecular weight (HMW) (5-6 rings) PAHs. The upper bound of incremental lifetime cancer risk (ILCR) via inhalation exposure to PM2.5-bound PAHs was at a moderate risk level (3.14×10-4 to 6.17×10-4).

Distribution of PAHs in coal ashes from the thermal power plant and fluidized bed combustion system; estimation of environmental risk of ash disposal

The comparison of fly ash generated from lignite combustion in a thermal power plant Kolubara A (Veliki Crljeni) and bottom and fly ash from coal waste combustion in a semi-industrial fluidized bed boiler (Vinča) was performed as the function of particle size. The average total concentrations of the 16 EPA priority PAHs in ash fractions are 0.49 mg kg−1 of ash (thermal power plant) and 17.48 mg kg−1 of ash (fluidized bed boiler). The sum of 3- and 4-ring PAHs accounts for more than 93% of overall PAHs concentration, and the most abundant among them is fluoranthene.The portions of PAHs groups defined based on their physico-chemical properties, as obtained from quantitative structure-activity relationship (QSAR) models included in the Vega platform, were determined. These portions, emission factors, and benzo[a]pyrene equivalence concentrations were further on used to estimate the potential environmental impact of ash disposal. The PAHs emission factors are higher compared to values in the air pollutant emission inventory guidebook of the cooperative program for monitoring and evaluation of the long-range transmission of air pollutants in Europe (EMEP/EEA). The overall emission factors of 16 PAHs for combustion of lignite and coal waste are determined to be 0.15 and 249.97 mg kg−1 of fuel, respectively. Based on the ratios of benzo[a]pyrene equivalence concentrations of each ash and correspondent fuel, the disposal of fly ash from the cyclone of fluidized bed boiler represents the highest risk to the environment among tested ashes.

A Method to Improve the Performance of Gold Nanoparticle Suspensions for Trace Detection of 16 EPA Priority PAHs

The growing demand for fast, simple and inexpensive analytical techniques to investigate environmental pollution has resulted in a large number of studies where surface enhanced Raman spectroscopy is used to detect environmental contaminants. However, extraction of weak Raman spectra from complex background signals remains challenging. In this current work, the author has presented a method to improve the performance of gold nanoparticles suspensions for trace detection of the 16 EPA priority PAHs. The gold nanoparticles in suspension are first mixed with the analyte in the liquid phase and then transferred to a solid state by drying (as opposed to liquid sample + dry substrate or liquid sample + liquid substrate). This method allows for a complete background signal removal (including fluorescence and signal from the substrate), strong Raman signal enhancement from the analyte and a reduction in substrate preparation time. Performance of a developed substrate (CNP-Au) was compared with a commercially available 3D substrate (Ram-SERS-Au) by measuring of all 16 EPA priority PAHs. The developed CNP-Au substrate exhibited experimentally obtained LODs three orders of magnitude lower than Ram-SERS-Au, down to the range of 1 ppb. The standard deviation of signal reproducibility for CNP-Au is 14%. Ram-SERS-Au and CNP-Au were characterized using SEM imaging.

Polycyclic aromatic hydrocarbons in soils and lichen from the western Tibetan Plateau: Concentration profiles, distribution and its influencing factors

The Tibetan Plateau (TP) is a huge area and rarely affected by human activity, and is regarded as one of the most remote regions on the earth. Many studies about the long-range atmospheric transport (LRAT) of semi-volatile organic compounds (SVOCs) were conducted in southern and central TP. However, there are very limited studies focused on PAHs in the western TP and the concentrations profiles, distribution and its controlling factors in this area remains unclear. Thus, to explore this knowledge gap, 37 surface soil samples and 23 lichen samples were collected and analyzed for PAHs. The total concentration of 16 US EPA's priority PAHs (∑16PAHs) in western TP ranges 14.4–59.5ng/g and 38.0–133ng/g dry weight (dw) with a mean value of 30.8 and 84.6ng/g dw in soil and lichen, respectively, which is lower than the concentrations in most remote areas worldwide. In the western TP, low molecular weight PAHs (2–3 rings) are dominant (occupied 77.4% and 87.9% on average in soil and lichen, respectively), implying a significant contribution of LRAT in this area. The significant linear correlations (R2 = 0.372–0.627, p < 0.05) between longitude and soil concentration suggest a strong impact of the westerly wind on the distribution of PAHs in soil. In addition, the concentration ratio of lichen/soil (L/S) was found to linearly increase with the increasing log KOA of individual PAH, suggesting lichen has a strong ability in filtering more lipophilic airborne pollutants in western TP.

Studies on Persistent Organic Pollutants in the Lagos Lagoon ii: Evaluation and Spatial Distribution of Polycyclic Aromatic Hydrocarbons in Sediments of the Lagoon

PAHs in the Lagos lagoon are high enough to raise concern over possible adverse effects on aquatic organisms and human health. Their spatial distribution in the sediment was largely dependent on the proximity of the sediment deposition site to known sources of pollution. Due to their tendency to accumulate in sediments at the bottom of the food chain, PAHs in the lagoon could pose a toxicological threat to benthic organisms and their predators. In this study, the PAH levels in the sediments of the lagoon at twelve locations were evaluated. This work is a follow-up on an earlier paper showing the levels of PAHs in the water samples of the lagoon. All sixteen EPA priority PAHs were found in eight of the locations. Significant amounts of most of the PAHs were found in all the sediments throughout the year. The higher PAHs were more abundant and distributed across the lagoon. Bioavailability assessment revealed that the PAHs were not bioavailable. Adjusted Equilibrium Sediment Benchmark Toxic Units ΣESBTU revealed that the lagoon sediments at all the locations were not toxic to aquatic life.

Distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air in cold zone

In this study we investigated the distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air done in Harbin city, northeastern China. Simultaneous indoor and outdoor sampling was done to collect 264 PM2.5 samples from four sites during winter, summer, and spring. Infiltration of PAHs into indoors was estimated using Retene, Benzo [ghi]perylene and Chrysene as reference compounds, where the latter compound was suggested to be a good estimator and subsequently used for further calculation of infiltration factors (IFs). Modeling with positive matrix factorization (PMF5) and estimation of diagnostic isomeric ratios were applied for identifying sources, where coal combustion, crop residues burning and traffic being the major contributors, particularly during winter. Linear discriminant analysis (LDA) has been utilized to show the distribution patterns of individual PAH congeners. LDA showed that, the greatest seasonal variability was attributed to high molecular weight compounds (HMW PAHs). Potential health risk of PAHs exposure was assessed through relative potency factor approach (RPF). The levels of the sum of 16 US EPA priority PAHs during colder months were very high, with average values of 377 ± 228 ng m−3 and 102 ± 75.8 ng m−3, for the outdoors and indoors, respectively. The outdoor levels reported to be 19 times higher than the outdoor concentrations during warmer months (summer + spring), while the indoor concentrations were suggested to be 9 times and 10 times higher than that for indoor summer (average 11.73 ± 4 ng m−3) and indoor spring (9.5 ± 3.3 ng m−3). During nighttime, outdoor PAHs revealed wider range of values compared to datytime which was likely due to outdoor temperature, a weather parameter with the strongest negative influence on ∑16PAHs compared to low impact of relative humidity and wind speed.

Polycyclic Aromatic Compounds in the Atmosphere – A Review Identifying Research Needs

Most of the 16 EPA priority PAHs (or a subset of these) are targeted in the current monitoring of air and air pollution studies. However, other parent PAHs may account for up to another ≈10%, nitro-PAHs up to ≈20%, and oxy-PAHs for even more. The reactivity in the atmospheric gas and particulate phases is incompletely quantified, in particular with regard to coverage of aerosol matrix diversity and photochemical age. Therefore, the model-based characterization of exposure is still limited. Nitro- and oxy-PAHs pose a higher health risk in ambient air than parent PAHs but have not been measured as extensively so far and are usually not included in monitoring programs. Nitro-PAHs are also interesting as tracers for air pollution source identification and pathways of photochemistry. Among heterocyclic aromatic compounds in ambient air dibenzofuran and dibenzothiophene should be targeted.

Source contributions of PAHs and toxicity in reed wetland soils of Liaohe estuary using a CMB–TEQ method

16 US EPA priority PAHs were analyzed in surface soils collected from reed wetland of Liaohe estuary. Total concentrations of the sixteen PAHs ranged from 235ngg−1 to 374ngg−1, while the total concentrations of seven carcinogenic PAHs (cPAHs) varied from 82.6ngg−1 to 109ngg−1. Toxicity of PAHs was assessed using toxic equivalent quantity (TEQ). The BaP and DBahA were the major contributors to TEQBaP, although IND showed the highest concentration level. Quantitative source apportionment of PAHs and toxicity (i.e. TEQBaP) were performed, using the CMB–TEQ (chemical mass balance model and TEQ) method. Results showed that, the vehicular sources (gasoline and diesel engine emissions) yielded a higher contribution to TEQBaP (95.7%) than that to PAHs (57.1%), while petrogenic source and biomass burning, two important contributors for total PAHs (21.6% and 21.3%, respectively), contributed a little to TEQBaP (3.6% and 0.7%, respectively).

The Effect of Starter Cultures on the Portuguese Traditional Sausage “Paio do Alentejo” in Terms of Its Sensory and Textural Characteristics and Polycyclic Aromatic Hydrocarbons Profile

&lt;p&gt;“Paio do Alentejo” is a Portuguese dry-cured sausage, made with meat from the Alentejano pig breed. The main aim of this study is to evaluate the benefits of the use of starter cultures on the quality of the sausage, mainly with regard to its sensory properties, rheological characteristics and PAH profile.&lt;/p&gt; &lt;p&gt;Three batches of the product were examined: S1-inoculated with a commercial starter comprising &lt;em&gt;Lactobacillus&lt;/em&gt; spp., &lt;em&gt;Micrococcaceae &lt;/em&gt;and yeasts; S2-inoculated with a starter comprising &lt;em&gt;Lactobacillus sakei &lt;/em&gt;and &lt;em&gt;Staphylococcus xylosus&lt;/em&gt;; C-the control batch, was not inoculated.&lt;/p&gt; &lt;p&gt;A sensory panel of 12 experts analysed samples in accordance with a descriptive analysis using a structured scale. A Texture Profile Analysis and 16 EPA priority PAHs for dry fermented sausages were performed.&lt;/p&gt; &lt;p&gt;Both inoculated batches were well received by the judges, no significant differences being noted between them. The use of S2 led to a slight improvement in terms of cohesiveness. However, the use of starter cultures was not found to influence PAH content.&lt;/p&gt;

Air quality in urban parking garages (PM10, major and trace elements, PAHs): Instrumental measurements vs. active moss biomonitoring

This study was performed in four parking garages in downtown of Belgrade with the aim to provide multi-pollutant assessment. Concentrations of 16 US EPA priority PAHs and Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were determined in PM10 samples. The carcinogenic health risk of employees' occupational exposure to heavy metals (Cd, Cr, Ni and Pb) and PAHs (B[a]A, Cry, B[b]F, B[k]F, B[a]P and DB[ah]A) was estimated. A possibility of using Sphagnum girgensohnii moss bags for monitoring of trace element air pollution in semi-enclosed spaces was evaluated as well. The results showed that concentrations of PM10, Cd, Ni and B[a]P exceeded the EU Directive target values. Concentration of Zn, Ba and Cu were two orders of magnitude higher than those measured at different urban sites in European cities. Cumulative cancer risk obtained for heavy metals and PAHs was 4.51 × 10−5 and 3.75 × 10−5 in M and PP, respectively; upper limit of the acceptable US EPA range is 10−4. In the moss, higher post-exposure than pre-exposure (background) element concentrations was observed. In comparison with instrumental monitoring data, similar order of abundances of the most elements in PM10 and moss samples was found. However, using of the S. girgensohnii moss bag technique in indoor environments needs further justification.

Tourmaline combined with Phanerochaete chrysosporium to remediate agricultural soil contaminated with PAHs and OCPs

The potential application on tourmaline was explored. The combination of tourmaline and Phanerochaete chrysosporium was conducted to remediate the field soil from the Dagu Drainage River bank of Tianjin in China. The total PAH and OCP concentrations in the soil were 6.4±0.05 and 145.9±1.9mg/kg, respectively. During the 60 day remediation program, the remediation degradation rates of all the 16 U.S. EPA priority PAHs and OCPs were 53.2±4.7% and 43.5±3.1%, respectively. The PAH and OCP removal rates were 31.9±2.9% and 26.4±1.8%, respectively, in soil with the addition of tourmaline, and the removal rates were 40.5±2.3% and 34.2±3.9%, respectively, in soil with the addition of P. chrysosporium. Thus, the combination of tourmaline and P. chrysosporium promoted the bioremediation rate of PAHs and OCPs in the soil, compared with the rates obtained using tourmaline or P. chrysosporium individually for the remediation of PAH and OCP degradation. In addition, tourmaline can promote the generation of soil hydrogen peroxidase and invertase enzyme, significantly increase the indigenous bacterial community and the number of PAH and OCP-degraders compared to those in the control, and reduce the soil humic acid content. Hence, the present study provides a potential alternative for the remediation of soils contaminated by PAHs and OCPs.

Reproductive toxicity assessment of surface water of the Tai section of the Yangtze River, China by in vitro bioassays coupled with chemical analysis

Reproductive toxicity of organic extracts of the surface water from the Tai section of the Yangtze River was assessed by in vitro cytotoxity assays and selected persistent organic pollutants including PCBs, OCPs and PAHs were quantified by instrumental analysis. Eleven of the US EPA priority PAHs were detected. Individual PAHs were found to range from 0.7 to 20 ng/L. Concentrations of BaP did not exceed the national drinking water source quality standard of China. However, a 286-fold concentrated organic extract induced significant reproductive toxicity in adult male rats. The morphology of cells, MTT assay and LDH release assay were all affected by exposure to the organic extracts of water. The results of the reproductive toxicity indicated that PAHs posed the greatest risk of the chemicals studied. The compounds present in the water could be bioconcentrated and result in adverse effects.

Distribution and Numerical Prediction of Polycyclic Aromatic Hydrocarbons (PAHs) on Atmospheric Particles in Jinan, China

16 EPA-priority PAHs on ambient airborne particles with different diameters were measured at 7 urban sites in Jinan during heating and non-heating periods to characterize their distribution and pollution levels. The concentrations of 16 particulate PAHs were between 7.56 and 800 ng•m−3 with an average of 308 ng•m−3. PAHs on atmospheric particles were dominated by 4- to 6-ring components and exhibited pronounced spatial distribution, temporal variation and size distribution. The emission strength and meteorological conditions were the most important factors affecting these trends. Furthermore, a numerical prediction model was proposed to forecast and prevent PAHs air pollution in Jinan. The coincidence between predicted and measured concentrations of PAHs demonstrated the good capability of this prediction model system.