Concentrations Of Carcinogenic Polycyclic Aromatic Hydrocarbons Research Articles

Personal exposure monitoring to polycyclic aromatic hydrocarbons bound to size-segregated aerosol

Air pollution is a global problem, where impaired air quality significantly damages human health and the environment. Twenty-four hours of personal exposure to size-segregated airborne particulate matter (PM) and associated polycyclic aromatic hydrocarbons (PAHs) were measured in 129 non-smoking residents living in two Czech cities, Ostrava (an industrial area with high levels of air pollution) and Ceske Budejovice (an agricultural area with lower air pollution level) in various seasons between years 2018–2020. Particulate matter (PM) was sampled by cascade impactors based on their aerodynamic diameter (dae, μm) and divided into size fractions: coarse (2.5 < dae), fine (0.25 < dae < 2.5) and ultrafine (<0.25). Size distributions of 20 priority PAHs adsorbed on these PM fractions were analyzed by gas chromatography coupled to tandem mass spectrometry in electron ionization (GC-EI-MS/MS). The total concentration of ∑20PAHs to which residents were exposed ranged from 0.09 ng/m3 to 47.18 ng/m3. A higher level of PAHs was detected in Ostrava (mean: 5.59 ng/m3) than in Ceske Budejovice (mean: 1.96 ng/m3). Statistically significant concentration differences between PAHs in individual seasons were observed in both sampled localities, with higher concentrations measured in winter than in summer. Fine and ultrafine particles predominated in the mass composition of the particulate matter. The ultrafine particle size contained 67–80% of total PAHs. Respiratory health risk was estimated based on inhalation cancer risk (ICR). Cancer risk attributable to personal inhalation exposure ranged from 2.8 × 10−8 to 4.3 × 10−4. In winter, higher cancer risk were found in Ostrava, mainly caused by a high concentration of carcinogenic PAHs bound to ultrafine particles. Overall, the personal monitoring data confirmed a higher air pollution burden in the industrial area and the winter season and highlighted the importance of focusing on ultrafine particles as the main carriers of potentially mutagenic and carcinogenic substances, such as PAHs. In addition, personal monitoring data provided more detailed and accurate information on individual-level exposures, revealing significant differences in exposure concentrations in people living in the same area.

Characterisation of polycyclic aromatic hydrocarbons associated with indoor PM0.1 and PM2.5 in Hanoi and implications for health risks

Polycyclic aromatic hydrocarbons (PAHs) associated with indoor PM pose a high risk to human health because of their toxicity. A total of 160 daily samples of indoor PM2.5 and PM0.1 were collected in Hanoi and analysed for 15 PAHs. In general, the concentrations of carcinogenic PAHs (car-PAHs) accounted for 21% ± 2%, 19.1% ± 2%, and 26% ± 3% of the concentrations of 15 PAHs in PM2.5, PM0.1-2.5, and PM0.1, respectively. Higher percentages of car-PAHs were found in smaller fractions (PM0.1), which can be easily deposited deep in the pulmonary regions of the human respiratory tract. The concentrations of 15 PAHs were higher in winter than in summer. The most abundant PAH species were naphthalene and phenanthrene, accounting for 11%–21% and 19%–23%, respectively. The PAH content in PM0.1 was almost twice as high as those in PM2.5 and PM0.1-2.5. Principal component analysis found that vehicle emissions and the combustion of biomass and coal were the main outdoor sources of PAHs, whereas indoor sources included cooking activities, the combustion of incense, scented candles, and domestic uses in houses. According to the results, 60%–90% of the PM0.1-bound BaP(eq) was deposited in the alveoli region, whereas 63%–75% of the PM2.5-bound BaP(eq) was deposited in head airways (HA), implying that most of the particles deposited in the HA region were PM0.1-2.5. The contributions of dibenz[a,h]anthracene and benzo[a]pyrene were dominant and contributed from 36% to 51% and 31%–50%, respectively, to the carcinogenic potential, whereas benzo[a]pyrene contributed from 30% to 49% to the mutagenic potential for both size fractions. The incremental lifetime cancer risk, simulated by Monte Carlo simulation, was within the limits set by the US EPA, indicating an acceptable risk for the occupants. These results provide an additional scientific basis for protecting human health from exposure to indoor PAHs.

Quantification and risk assessment of polycyclic aromatic hydrocarbons in street dust from functional areas of Khamis-Mushait, Saudi Arabia

The aim of present work is focused on determination of the residual concentrations of 16 PAHs and their health risk assessment in selected sectors of the street dust along Khamis-Mushait, Asir area. Objectives/backgrounds: With the recent rapid development of urbanization, polycyclic aromatic hydrocarbons (PAHs) in street dust pose serious problems to human health and ecological environment. Method: HPLC system (HPLC Nexera-i LC 2040 C 3D Plus Shimadzu Integrated) was used to perform the measurements following well-established USEPA 3550B method . Results: The average value of PAHs in Khamis-Mushait street dust was 2809.46 ng/g, ranging from 1250.41 to 4249.29 ng/g. Incinerator and industrial locations had the highest concentration of fossil PAHs, accounting for 69.62% of PAHs. The King Fahd Garden and Al-Hayat National Hospital regions had the highest concentrations of carcinogenic PAHs and combustion PAHs, which accounted for 41.70 and 27.46% of all PAHs, respectively. Naphthalene (NAP), acenaphthylene (ACY), and acenaphthene (ACE) were more effective range low. However, ACE was more effective range medium, and ACY, ACE, and DBA (dibenzo-anthracene) were more probable effect level. Furthermore, the effects of NAP, fluoranthene (FLT), pyrene (PYR), and benzo(a)pyren (BaP) were greater than the threshold effect level (TEL). For both kids and adults, the hazardous index (HI) was in the following order: ACE>ACY>NAP>PYR>fluorene (FLR)>FLT> benzo(ghi)perylene (BghiP)>phenanthrene (PHN)>ANT. However, total HI for noncancer risks for PAHs varied between 9.91´10-5 and 2.69´10-2 and from 9.22´10-4 to 2.50´10-1 for adults and children, respectively. Conclusion: Various approaches (geochemical indices, statistical analysis, and health risk assessment) were exploited to evaluate the levels of 16 PAHs in street dust from Abha and Khamis-Mushait City, Saudi Arabia. These values are considered safe level and insignificant to adults and children. In addition, ACE may pose risk based on acute and intermediate oral exposure. The following order from several sources was reported by the cluster analysis of dust samples: commercial>industrial>traffic.

Quantification and Risk Assessment of PAHs in Street Dust from Functional Areas of Khamis-Mushait, Saudi Arabia

The average value of polycyclic aromatic hydrocarbons (PAHs) in Khamis-Mushait street dust was 2809.46 ng/g, ranging from 1250.41-4249.29 ng/g. Incinerator and industrial locations had the highest concentration of fossil PAHs (∑FPAHs), accounting for 69.62% of PAHs. The highest concentrations of carcinogenic PAHs (∑CARC) and combustion PAHs (∑COMB) were found in the King Fahd Garden and Al-Hayat National Hospital regions, accounting for 41.70 % and 27.46 % of PAHs, respectively. Naphthalene (NAP), Acenaphthylene (ACY) and Acenaphthene (ACE) were &gt; effective range low (ERL). However, ACE was &gt; effective range medium (ERM), and ACY, ACE, and DBA (dibenzo anthracene) were &gt; Probable Effect Level (PEL). Furthermore, the effects of NAP, fluoranthene (FLT), pyrene (PYR), and benzo (a)pyren (BaP) were greater than the threshold effect level (TEL). The order of Hazardous indices (HI) for both children and adults were ACE &gt; ACY &gt; NAP &gt; PYR &gt; fluorene (FLR) &gt; FLT &gt; benzo (ghi) perylene (BghiP) &gt; phenanthrene (PHN) &gt; ANT. However, total HI for non-cancer risks for PAHs were 2.69×10-2 -9.91×10-5 and 2.50x10-2 - 9.22×10-4 to adults and children, respectively. These values considered safe level and insignificant to adults and children. In addition, ACE may pose risk based on acute and intermediate oral exposure. The cluster analysis of dust samples declared the following order from different sources: traffic &gt; industrial &gt; commercial.

Methanetriyl-pi hydrogen bonding in nonpolar domains of supramolecular nanostructures: An efficient mechanism for extraction of carcinogenic polycyclic aromatic hydrocarbons from soils

Methanetriyl-pi hydrogen bonding (CH-π HB) in nonpolar domains of supramolecular nanostructures is proposed here as a new mechanism to increase the extraction efficiency of aromatic compounds. The approach is illustrated by the extraction of priority carcinogenic polycyclic aromatic hydrocarbons (CPAHs) in soils using supramolecular nanostructures of carboxylic acids with nonpolar domains consisting of hydrocarbon chains (C6-C10) dispersed in tetrahydrofuran (THF). The high concentration of CH-groups available in the supramolecular nanostructures (38.7–47.3 M) enabled the efficient extraction of CPAHs (recoveries between 89 and 106%), using a supramolecular solvent (SUPRAS) volume/soil amount ratio of 1.5 µL mg−1 and a simple and quick procedure (stirring for 15 min and centrifugation for 10 min). SUPRAS extracts were directly analysed by liquid chromatography-fluorimetry (LC-FL). No sample clean-up or solvent evaporation was required. Optimization of the composition of the nonpolar domains of the SUPRASs was carried out varying the length and concentration of the hydrocarbon chain of the carboxylic acid and the concentration of THF. Method detection limits were in the interval 0.07–0.4 µg kg−1. The relative standard deviations (n = 18, CPAH concentration = 300 µg kg−1), obtained under repeatability and reproducibility conditions, varied within the ranges 2.8–5.4% and 4.3–8.8%, respectively. The accuracy of the method was proved by analysing a certified reference material (CRM) from an industrial soil, contaminated with priority CPAHs at concentrations at the mg kg−1 level (BAM-U013c). The concentration of CPAHs found in soils taken in Southern Spain varied in the range 0.51–49 µg kg−1. The results here obtained demonstrate that CH-π HB is a valuable mechanism for increasing the extraction of aromatic compounds from soils.

Pollution investigation and risk assessment of polycyclic aromatic hydrocarbons in soil and water from selected dumpsite locations in rivers and Bayelsa State, Nigeria.

The transfer ratio of polycyclic aromatic hydrocarbons (PAHs) from soil dumpsite to borehole water is dependent of polluting source and exposure matrices that causes immerse health risk to man and environment over a period of time. PAHs were assessed in selected soil dumpsite and borehole water located at Rivers state (Eleme, Eliozu, Eneka, Oyigbo, and Woji) and Bayelsa state (Yenagoa), Nigeria. Soil samples were collected at four different points 30 m (North, South, East and West) locations at a depth of 15 cm for each dumpsite using soil auger while control samples were collected 200 m away (farmland), where there were little anthropogenic activities and no presence of active dumpsites. Borehole water samples were collected from 300 m distance, which were packaged in an amber container, labeled, and transported to the laboratory for analysis. Standard analytical methods were employed. PAHs concentrations were analyzed using gas chromatography-mass spectrometry (GC-MS) after extraction of water and soil using liquid-liquid and soxhlet extraction methods respectively and clean-up of the extracts, thereafter the laboratory data generated were subjected to statistical analysis. Total PAHs (∑PAHS) concentrations in soil samples from the study sites ranged from 2.4294 mg/kg in Yenagoa to 5.1662 mg/kg in Eleme while in water samples the total PAHs ranged from 1.3935 mg/L in Woji to 3.009 mg/L in Eleme. The total PAH concentrations in the soil were above the Agency for Toxic Substances and Disease Registry levels of 1.0 mg/kg for a considerably contaminated site except for the control sites. The total concentration of carcinogenic PAHs ranged from 0.0038 to 1.1301mg/kg in soil samples and 0.0014 to 0.9429 mg/L in borehole water samples, therefore raising concern of human exposure via food chain. The results indicate that low molecular weight PAHs were more dominant than high molecular weight PAHs in both soil and water samples, however molecular diagnostic ratio shows that pyrogenic activities are major sources of PAHs as compared to petrogenic origin. Multivariate analysis (principal component analysis and Pearson correlation) showed strong negative correlation implying that they were from dissimilar sources and different migratory route. Cancer and non-cancer risk showed that children were more at risk compared to adults, where inhalation exposure were major contribution as compared to ingestion and dermal exposure, as such there is a need to implement regulatory laws on indiscriminate release of PAHs contaminants to maintain sustainability.

Carcinogenic Content of PM10-Bound PAHs in University Classrooms and Outdoors at an Urban Location in Rome, Italy, during Winter Working and Not-Working Days

To assess the contribution of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) in ambient air, EU Directive 2004/107/EC indicates to monitor relevant carcinogenic PAHs in PM10 fraction other than benzo(a)pyrene at a limited number of measurement sites. This indication refers to outdoor environments, and the environmental air quality being taken as a reference also for indoors, it can be extended to indoor environments. In this work, the contribution of carcinogenic PAHs bound to PM10 has been evaluated in winter in two classrooms of a University campus in Rome with the aim of studying the relationship with the outdoors and with working activity. PM10-boundPAHs were monitored over five different periods selected to distinguish Weekend from daytime and nighttime Weekdays, separated into two parts of the week. Data aggregated over Weekend and Weekdays allowed calculating of the concentration of carcinogenic PAHs, the mass contribution to PM10, the Infiltration Factor, the indoor to outdoor Ratio, and the Total Carcinogenic Potency by Toxicity Equivalent Factors, for “not-working” and “working” days. In addition, some indications on contributions to the source have been obtained from the chemical profile normalized to the maximum value of concentration, which also provides the source fingerprint compound. Indoor PAH concentrations were lower than outdoor, and both accumulated as the week progressed. Although the two indoor environments were on the same floor and had a similar volume, they presented different contribution to PM10 and infiltration capacity, both higher during Weekend than on Weekdays. The analysis of indoor and outdoor chemical profiles normalized to the maximum concentration indicated an external source infiltrating the indoors environment. During Weekdays, the indoor fingerprint compound changed compared to that observed during Weekend, probably due to an additional contribution of local “fresh-traffic” source. The calculation of Total Carcinogenic Potency gave indoor values always lower than outdoor, confirming in the two classrooms different dynamics for carcinogenic PAHs. Moreover, the Total Carcinogenic Potency on Weekdays was twice that of Weekend, meaning a higher toxicological impact when urban “fresh-traffic” source is added. The present study shows that the dynamics of PM10-related carcinogenic PAHs can be different within adjacent classrooms of a building and during working and not-working days. This evidence suggests the possibility of a potential different impact on occupant exposure to be taken into account in planning monitoring programs of indoor pollution.

Occurrence and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dust of an emerging industrial city in Iran: implications for human health.

Polycyclic aromatic hydrocarbons (PAHs) bounded to street dust are a severe environmental and human health danger. This study provides preliminary information on the abundance of PAHs in street dust from Rafsanjan city, Iran, where industrial emissions are high and data are lacking. Seventy street dust samples were collected from streets with different traffic loads. The United States Environmental Protection Agency (USEPA) Standard Methods 8270D and 3550C were used for the measurement of PAHs using GC mass spectroscopy. The total concentration of PAHs was 1443 ng g-1, with a range of 1380-1550 ng g-1. Additionally, the concentration of carcinogenic PAHs (∑carcPAHs) ranged from 729.5 to 889.4 ng g-1, with a mean value of 798.1 ng g-1. Pyrene was the most abundant PAH, with an average concentration of 257 ng g-1. Source identification analyses showed that vehicle emissions along with incomplete combustion and petroleum were the main sources of PAHs. The ecological risk status of the studied area was moderate. Spatial distribution mapping revealed that the streets around the city center and oil company had higher PAH levels than the other sectors of Rafsanjan. The results indicated that dermal contact and ingestion of contaminated particles were the most important pathways compared to inhalation. The mean incremental lifetime cancer risk (ILCR) was 1.4 × 10-3 and 1.3 × 10-3 for children and adults, respectively. This implies potentially adverse health effects in exposed individuals. The mutagenic risk for both subpopulations was approximately 18 times greater than the one recommended by USEPA. Our findings suggest that children are subjected to a higher carcinogenic and mutagenic risk of PAHs, especially dibenzo[a,h]anthracene (DahA), bounded to street dust of Rafsanjan. Our study highlights the need for the development of emission monitoring and control scenarios.

Biomonitoring of concentrations of polycyclic aromatic hydrocarbons in blood and urine of children at playgrounds within Owerri, Imo State, Nigeria.

Polycyclic aromatic hydrocarbons (PAHs) exposure is among the leading air pollutants associated with diverse adverse health effects due to their persistent, bio-accumulative and toxic characteristics. Children are most affected by these pollutants, yet studies directly related children to these pollutants are scarce in Nigeria. In this study, blood and urine from 36 children between the ages 4-14 years were collected as per sterile procedures by a licensed phlebotomist from the antecubital fossa into BD vacutainer tubes® while a mid-stream urine sample into acid-washed 120 mL BD vacutainer urine cups and stored in refrigerator at –4˚C for 6 hours, then each 5 mL was extracted with 10 mL of pentane and analyzed for 15 PAHs using GC-MS. Results revealed that PAHs concentrations (53.48 to 70.8 μg/dL) in blood was lower than in urine (94.98 to 115.04 μg/dL). Mean values had no significant (p>0.5) differences between schools, possibly due to the fact that all schools were experiencing similar anthropogenic disturbances. At 5% level of significance, positive and strong correlationships (r=0.83, r=0.73) were observed for fluorene-fluoranthene (FLa) and benzo (a) anthracene-FLa respectively in blood samples. Two and three rings PAHs had generally low concentrations in both blood and urine. Despite being the most distributed compound, the concentration of dibenzo (a,h) anthracene was highest for urine than in blood. Urine PAHs showed higher concentration of carcinogenic PAHs than blood. Elimination ratios (ER) such as for acenaphthene (0.06) and anthracene (Ant; 0.11) were considered low while values such as for FLa (1.36) and indeno [1, 2, 3-cd] pyrene (1.55) were considered high ER. Trends in elimination ratios showed close similarity. In conclusion there was elevated PAHs in blood and urine of children with consequent high carcinogenic and then non-carcinogenic risks. This research is significant in setting the stage for more detailed work at same time alerting policy makers on the need for urgent mitigation steps that will reduce children exposure to this class of dangerous pollutants.

The Levels and Potential Carcinogenic Risks of PAHs in Liaohe Estuarine Reed Wetland Soils.

Sixteen polycyclic aromatic hydrocarbons (PAHs) were quantified by GC/MS in 30 soil samples of Liaohe estuarine reed wetland. The total concentrations of 16 PAHs ranged from 235 to 374ngg-1, and seven carcinogenic PAHs concentrations were in the range of 83-109ngg-1. A probabilistic carcinogenic potential for three age groups (including children, teenagers, and adults) exposed to soil PAHs via three pathways was quantitatively calculated based on Monte Carlo simulations. The 95th percentiles carcinogenic risks of PAHs for children, teenagers, and adults were 7.80×10-8, 4.03×10-8, and 1.14×10-7, respectively. The carcinogenic risk levels were all below 10-6, indicating no potential for cancer development. Dermal contact and accident ingestion of soil were the dominant exposure pathways to soil PAHs. BaP and DBahA were the major contributors to carcinogenic risk in this study.Sensitivity analysis demonstrated that exposure duration and PAH concentrations in soil were the key exposure parameters in calculating carcinogenic risk. Results from this study will provide valuable information for potential scientific evaluation and prevention for carcinogenic risk exposed to soil PAHs.

Distribution, sources, and toxicity assessment of polycyclic aromatic hydrocarbons in surface soils of the Gwangju City, Korea

Twenty-three individual polycyclic aromatic hydrocarbons (PAHs) including sixteen US Environmental Protection Agency (EPA) priority pollutants were analyzed in soil samples collected from twenty sites in the metropolitan city of Gwangju, Korea to investigate the levels of concentration, profiles, possible sources of PAHs, and a probabilistic human health risk. Soil samples (0–15cm top layer) were collected, and the sampling sites were classified into two groups, including a school area and a residential area. Regardless of the sampling site, the concentrations of ∑23 PAHs ranged from 120 to 273ng/g with an average value of 164ng/g. The molecular distribution of PAHs reflected the similarity between school and residential areas in soil PAHs profile, and the PAHs could be from the same emission sources. High molecular weight PAHs (5- and 6-ring) were predominant in the soil samples, followed by 4-ring PAHs, while the fraction of 2-ring PAHs was the lowest. The total concentration of carcinogenic PAHs accounted for 54% of ∑16-EPA PAHs. Considering the different diagnostic ratios of PAHs, such as Flt/(Flt+Pyr), BaA/(BaA+Chr), Ant/(Ant+Phe), and IcdP/(IcdP+BghiP) and the principal component analysis results, the soil samples were likely attributed to mixed pyrogenic sources (coal and fossil fuel combustion, regardless of fuel types). The cancer risks for two age groups were <10−4, indicating no potential cancer risk.

Polycyclic aromatic hydrocarbons (PAHs) at the Gulf of Kutch, Gujarat, India: Occurrence, source apportionment, and toxicity of PAHs as an emerging issue

The present study extrapolates the assessment and characterization of a barely studied region, the Gulf of Kutch, (near Jamnagar), Gujarat, India, in terms of PAH exposure, adverse effects caused by them, and various toxicological indices showing the catastrophic effects of their elevated concentrations. ΣPAH concentration in the site ranged from 118,280 to 1,099,410ngg−1 dw, with a predominance of 2–3-ring PAHs (79.09%) as compared to 4–5- and 6-ring PAHs (20.91%). The concentrations of carcinogenic PAHs were found to be between 8120 and 160,000ngg−1 dw, with a mean of 63,810ngg−1 dw, which is much higher than normal acceptable values. The toxic equivalent quotient for 6CPAHs ranged from 150.47 to 26,330ngg−1 BaPeq, encompassing 50.63% of ΣPAH toxicity. This toxicological profile of the present study site would be of paramount importance as it offers fresh information regarding the load of legacy pollutants such as PAHs and the inputs and methods to cope with their extremely high concentrations in less explored marine habitats.

Distribution, sources and ecological risk assessment of polycyclic aromatic hydrocarbons in water and sediments from Tiber River and estuary, Italy

The concentration, source and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. The 16 priority PAHs were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments collected from 21 sites in four different seasons. Total concentrations of PAHs ranged from 10.3 to 951.6ngL−1 and from 36.2 to 545.6ngg−1 in water (sum of DP and SPM) and in sediment samples, respectively. The compositions of PAHs showed that 2- to 4-ring PAHs were abundant in DP, 4- to 6-ring PAHs were predominant in SPM samples, and 4- to 5-ring PAHs were abundant in sediments. The diagnostic ratio analysis indicated that the PAHs mainly had a pyrolytic source. The toxic equivalent concentration of carcinogenic PAHs was 45.3ngTEQg−1, suggesting low carcinogenic risk for Tiber River. Total PAHs loads into the sea were calculated in about 3161.7kgyear−1 showing that this river is one of the main contribution sources of these contaminants to the Tyrrhenian Sea.

Investigation of PAHs, PCBs and PCNs in soils around a Heavily Industrialized Area in Kocaeli, Turkey: Concentrations, distributions, sources and toxicological effects

Soil is an important environmental medium reflecting the level and the spatial distribution of air pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs). Soil concentrations of PCNs measured in the present study were generally higher and PCBs concentrations were considerably higher than those reported in the literature, while PAHs concentrations were comparable. Combustion related PCNs congener ratios to their total concentrations and PAHs diagnostic ratios suggested the substantial contribution of combustion sources and the statistically significant correlation between PCBs and PCNs (r=0.88) indicated that these POPs were emitted from the common sources. Principal Component Analysis was also performed to further assess the possible sources of individual POPs. The results showed the contribution of traffic, petroleum and coal/biomass combustion and iron-steel production. Toxicological effects of POPs in soil were investigated. BaP was used as the marker of carcinogenic PAHs. Seven carcinogenic PAHs concentrations (Σ7cPAH) including BaA, CHR, BbF, BkF, BaP, IcdP and DahA were also used as a parameter to evaluate carcinogenic potency of PAHs. As PCBs and PCNs show dioxin-like toxicities, their toxicological implication were estimated using TCDD equivalence. The results show that the study area faced with severe environmental problems even though the data sets without the complete set of dioxin like PCBs and PCNs would show only a part of the whole toxicological picture.

Polycyclic aromatic hydrocarbons in the dagang oilfield (china): distribution, sources, and risk assessment.

The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 27 upper layer (0–25 cm) soil samples collected from the Dagang Oilfield (China) in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs) varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1), to oil well areas (mean of 627.3 µg·kg−1), to urban and residential zones (mean of 1856 µg·kg−1). Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B) or not classified/non-carcinogenic (NB). The total concentrations of carcinogenic PAHs (∑BPAHs) varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

국내 토지이용도별 토양 중 다환방향족탄화수소류(PAHs)의 농도 수준 및 분포 특성

We investigated soil contamination depending on the land use by examining the contamination levels and distribution characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in the national soil. Total PAHs (the sum of 16 PAH concentrations) and carcinogenic PAHs (the sum of seven carcinogenic PAH concentrations) were 8.50~3,437.16 µg/kg and 2.94~2,136.96 µg/kg, respectively. The concentration of benzo(a)pyrene, one of the contaminants regulated by the soil quality standard in the nation, was ND~924.73 µg/kg. Its maximum value of 924.73 µg/kg was detected in railroad (Region 3) and is approximately 13% of the standard value for Region 3 (i.e., 7 mg/kg). We also investigated the characteristics of contamination sources of PAHs in soil of the upland, forests, roads, and railroads, examining the fraction distribution of PAHs concentration by the number of benzene rings against the total PAHs concentration. The results demonstrate that the mean fraction of 4~6-ring PAHs against total PAHs concentration in soil was in the range of 51.8~80.7% with relative abundance of high-molecular PAHs, showing that the origin of contamination is under the category of combustion sources. When the molecular indices (Flu/(Flu/Pyr), Ant/(Ant+Phe), InP/(InP+BP), and BaA/ (BaA+Chr)) were applied, they were also categorized as petroleum-based combustion sources. The individual PAH concentrations in soil by the land use were grouped into Regions 1, 2, and 3, which are statistically treated and are the parts of the national category system of soil quality standard. As a result, the concentration level of 16 PAHs was 0.02~2.63 µg/kg in Region 1, 0.05~4.26 µg/kg in Region 2, and 2.36~178.27 µg/kg in Region 3. The concentration level of 6 carcinogenic PAHs was 14.2~320.4% against that of benzo(a)pyrene in Region 3 and sites of recycling waste sleepers. Considering that there were similarities among PAHs in terms of structures and toxicities, it would be recommended to review other types of carcinogenic PAHs together with benzo(a)pyrene when developing the soil quality standards in the nation.

A review of PAH exposure from the combustion of biomass fuel and their less surveyed effect on the blood parameters.

Many epidemiological studies from all over the world have reported that populations of rural and urban environments differ in their health issues due to the differences in the countrywide pollution pattern. In developing countries, various occupational cohorts and subsections of the population in urban and rural areas are routinely exposed to several environmentally widespread contaminants. Polycyclic aromatic hydrocarbons (PAHs) are a group of over hundred different compounds and have ubiquitous presence in rural and urban environments. Smoke from the combustion of biomass fuel contains a high concentration of carcinogenic PAHs, which are related with several human morbidities. The sources and types of biomass fuel are diverse and wide in distribution. Limited numbers of literature reports have focused the significant impact of PAHs on several components of blood, both in human and wildlife. The toxicity of PAHs to rapidly dividing cells (e.g., bone marrow cells) and other tissues is largely attributed to their reactive oxygenated metabolites, potential of causing oxidative stress, and the adducts of their metabolites with DNA. This review aims to encompass the blood-related effects of PAHs and associated human health risks-an aspect that needs further research-on the population of developing countries of the world in particular.

Polycyclic aromatic hydrocarbons collected from indoor built environments on heating, ventilation and air conditioning dust filters

People living in hot climates are likely to spend considerable time indoors and use of heating, ventilation and air conditioning (HVAC) systems. The effects of these systems upon environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) have not been well understood. In this study, ‘priority’ PAHs in 20 HVAC filter dust samples were measured using gas chromatography–mass spectrometry. The samples were taken in homes, schools and mosques in five provinces in Kuwait over a 2-month period in winter. The results showed that traffic and petrochemical refineries were the main outdoor sources of PAHs measured indoors in all of the locations. Benzo[b]fluoranthene and benzo[k]fluoranthene, which are classified as carcinogenic compounds, were present at the highest mean concentrations in most of the locations. The maximum total PAH concentration (∑PAHs is the sum of all target PAHs in each building) was 3645 ng/g and was found in a school that is located south of three refineries and a power station. The highest concentrations of carcinogenic PAHs were found in a home and the lowest in a mosque. Chrysene was found at the highest concentrations and fluoranthene was found at the lowest concentrations of all the PAHs analysed.

Cancer risk of polycyclic aromatic hydrocarbons (PAHs) in the soils from Jiaozhou Bay wetland

To estimate the cancer risk exposed to the PAHs in Jiaozhou Bay wetland soils, a probabilistic health risk assessment was conducted based on Monte Carlo simulations. A sensitivity analysis was performed to determine the input variables that contribute most to the cancer risk assessment. Three age groups were selected to estimate the cancer risk via four exposure pathways (soil ingestion, food ingestion, dermal contact and inhalation). The results revealed that the 95th percentiles cancer risks for children, teens and adults were 9.11×10−6, 1.04×10−5 and 7.08×10−5, respectively. The cancer risks for three age groups were at acceptable range (10−6–10−4), indicating no potential cancer risk. For different exposure pathways, food ingestion was the major exposure pathway. For 7 carcinogenic PAHs, the cancer risk caused by BaP was the highest. Sensitivity analysis demonstrated that the parameters of exposure duration (ED) and sum of converted 7 carcinogenic PAHs concentrations in soil based on BaPeq (CSsoil) contribute most to the total uncertainty. This study provides a comprehensive risk assessment on carcinogenic PAHs in Jiaozhou Bay wetland soils, and might be useful in providing potential strategies of cancer risk prevention and controlling.

Emission and profile characteristic of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from stationary sources based on dilution sampling

The mass concentrations and profile characteristic for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 from stack gases for six types of stationary sources in Shandong Province, China were studied by a dilution sampling system and GC–MS analysis method from February to March in 2010. The mass concentrations of PM2.5 and PM10 from the six types of stationary sources varied in 8.2–79.4 mg m−3 and 23.3–156.7 mg m−3, respectively. The total mass concentrations of analyzed PAHs in PM2.5 and PM10 were in the ranges of 0.40–94.35 μg m−3 and 9.16–122.91 μg m−3. The most toxic ashes were from sinter and coke oven for both PM2.5 and PM10 with high carcinogenic PAHs concentrations. BbF, Phe, NaP, BghiP, Pyr, BaP and BeP were abundant which was different from formers and one of the key reasons may be the differences of sampling methods. Diversities in PAHs compositions existed between fly ashes within PM2.5 and PM10 fractions for coke oven according to coefficient of divergence (CD) values. PAHs profiles for PM10 emitted from coke oven were different from those of other stationary sources (with CD values higher than 0.35) and for PM2.5, it was the same for sinter (with most CD values close to 0.30). There existed similar PAHs markers for fine particles emitted from stationary sources excepted for the sinter. For PM10, PAHs markers were primary 3-ring PAHs except for the coke oven with BbF, IND and BghiP as its signatures. Diagnostic ratios of BaA/(BaA + Chr), Flu/(Flu + Pyr), BaP/(BaP + BeP), BeP/BghiP and IND/(IND + BghiP) could be not well distinguished for the six types of stationary sources with the maximum/minimum ratios lower than 2 for both PM2.5 and PM10 of fly ashes which should be not used for source identification studies. The mass concentrations and source profiles of PAHs should be updated timely for size-differentiated fly ashes from various stationary sources by dilution sampling method.