Dominant Polycyclic Aromatic Hydrocarbons Research Articles

Distribution and bioconcentration of semivolatile organic compounds (SVOCs) in soils and vascular plant Colobanthus quitensis from Sub-Antarctic and Antarctic regions.

Semi-volatile organic compounds (SVOCs) are widely distributed across the globe, including polar regions. This study investigates the distribution and bioconcentration of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in soils and Colobanthus quitensis, while also estimating potential emission sources. Results indicated high concentrations of PAHs in soils and plants from the Sub-Antarctic region, while OCPs and PCBs were more prevalent in the Antarctic region, with higher contaminant concentrations found in soils than in plant tissues. Hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (p,p'-DDE) were significantly higher in the Antarctic region, suggesting historical dichlorodiphenyltrichloroethane (DDT) use, while PCB 153 and 180 were the most representative PCBs in the Antarctic region. Phenanthrene (Phe) was the dominant PAH in both regions. The bioconcentration factor analysis from soils (BCFSoils) revealed potential anthropogenic influences for certain contaminants, including γ-hexachlorocyclohexane (γ-HCH) and PCB 9 in the Sub-Antarctic region, and HCB, p,p'-DDE, PCB 9, and benzo-naphtho-thiophene in the Antarctic region. However, compounds with higher hydrophobicity showed lower Bioconcentration factor (BCFSoils) values, indicating a tendency to accumulate in soil rather than plant tissues. This was consistent with the inverse relationship found between BCFSoils and the octanol-water partition coefficient (Log KOW). Diagnostic ratios of PAHs revealed a predominantly pyrogenic source in the Sub-Antarctic region, while a mixture of sources was observed in the Antarctic region.

Experimental study on emissions and particulate characteristics of diesel engine fueled with plastic waste oil, acetone-butanol-ethanol and diesel blends

Plastic waste poses a significant environmental challenge due to its non-biodegradable nature and accumulation in landfills. Converting plastic waste into usable fuel could offer a promising solution for mitigating these issues while addressing the emission-related challenges of diesel engines. This study investigates the impact of plastic waste oil (WPO) obtained through pretreatment and catalytic pyrolysis, blended with acetone-butanol-ethanol (ABE) and diesel fuel, on diesel engine. The aim was to evaluate how these blends affect gaseous emissions, organic compounds, and particle-bound carbon, focusing on their potential to reduce harmful pollutants compared to pure diesel fuel. The results indicated that the ABE5W15D blend significantly reduced smoke and CO emissions by 35.7 % and 17.43 %, respectively, with a slight decrease in HC emissions. However, the ABE20W blend showed elevated NOx levels due to higher ignition delay and increased cylinder pressure. Compared to pure diesel (D100), ABE10W10D and ABE5W15D blends reduced total polycyclic aromatic hydrocarbons (PAHs) emissions by 26.8 % and 37.4 %, respectively. Naphthalene was the dominant PAH, remarkably increasing with W20D use, while longer-chain alkanes associated with lubricant oil had higher W20D emissions. The ABE5W15D blend notably reduced organic carbon (OC) emissions by approximately 38.26 % compared to D100. ABE20D exhibited lower elemental carbon (EC) emissions than D100, although it had higher EC than OC. The W20D blend resulted in larger particle diameters, whereas ABE10W10D showed lower particle counts in the 7–15 nm range. In conclusion, blending plastic waste oil with ABE and diesel fuel can effectively mitigate certain pollutants, depending on the blend composition.

Biomonitoring polycyclic aromatic hydrocarbon levels in domestic kitchens using commonly grown culinary herbs

Cooking is a significant source of polycyclic aromatic hydrocarbon (PAHs) emissions in indoor environments. A one-month biomonitoring study was carried out in previously selected rural Hungarian kitchens to evaluate cooking-related PAHs concentrations in 4 common kitchen vegetables such as basil, parsley, rocket and chives. The study had two mainobjectives: firstly, to follow PAHs accumulation pattern and to find out if this pattern can be associated with different cooking habits. Also, the usefulness of culinary herbs for indoor bioaccumulation studies was assessed. The 2-ring naphthalene was the dominant PAH in the majority of the samples, its concentrations were in the range of 25.4 µg/kg and 274 µg/kg, of 3-ring PAHs the prevalency of phenanthrene was observed, with highest concentration of 62 µg/kg. PAHs accumulation pattern in tested plants clearly indicated differences in cooking methods and cooking oils used in the selected households. Use of lard and animal fats in general resulted in the high concentrations of higher molecular weight (5- and 6-ring) PAHs, while olive oil usage could be associated with the emission of 2- and 3-ring PAHs. Culinary herbs, however, accumulated carcinogenic PAHs such as benzo[a]anthracene (highest concentration 11.9 µg/kg), benzo[b]fluoranthene (highest concentration 13.8 µg/kg) and chrysene (highest concentration 20.1 µg/kg) which might question their safe use.

Melanin-mediated accumulation of polycyclic aromatic hydrocarbons in human hair: Insights from biomonitoring and cell exposure studies

While human hair is widely used to monitor micro-organic contaminants (MOCs), their incorporation mechanisms are poorly understood. Melanin, known to facilitate the accumulation of drugs in hair, hasn’t been studied in the field of MOCs. Here, polycyclic aromatic hydrocarbons (PAHs), a class of priority MOCs, were investigated through hair biomonitoring as well as cell exposure experiments. PAH concentrations and melanin contents were measured in black and white hairs from the same individual. The results showed that five dominant PAHs (phenanthrene, fluoranthene, pyrene, benzo[a]anthracene and chrysene) in black hair (0.66 ng/g – 35.1 ng/g) were significantly higher than those in white hair (0.52 ng/g – 29.6 ng/g). Melanin contents in black hair (14.9 – 48.9 ng/g) were markedly higher than in white hair (0.35 – 2.15 ng/g) and were correlated to PAH concentrations, hinting melanin-mediated accumulation of PAHs in hair. The in vitro experiment using murine melanoma cells demonstrates that PAH levels in cells were affected by melanin, suggesting the affinity of melanin to PAHs. Both biomonitoring and cell exposure experiment implicate the pivotal role of melanin in PAH accumulation in hair. Therefore, to ensure the accuracy of hair biomonitoring for MOCs, attention must be paid to the melanin content uniformity.

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of the East China marginal seas: Significance of the terrestrial input and shelf mud deposition

To investigate the distribution, sources, influencing factors, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in East China Marginal Seas (ECMSs) sediments, we measured the concentrations of 16 PAHs in 104 surface sediment samples collected from the ECMSs in 2014 and 2016. Total PAH concentration (∑PAHs) ranged from 4.49 to 163.66 ng/g dry weight (dry w), with 65.98 ± 33.00 (mean ± SD) ng/g dry w. The highest PAH concentrations and total organic carbon were observed in areas with fine-grained sediments in the Bohai Sea (BS), Yellow Sea (YS), and coastal East China Sea (ECS), indicating the prominent influence of regional hydrodynamics and sediment properties. The dominant PAH congener in BS and YS was BbF, whereas coastal ECS was Phe. The heterogeneity of PAH sources implies that terrestrial PAH input and shelf mud deposition have crucial roles in the source–sink processes of PAHs in a strongly human-influenced marginal sea.

Characteristics and health risk assessment of indoor and outdoor PM2.5 in a rural village, in Northeast of China: impact of coal and biomass burning.

Fine particulate matter (PM2.5) has health effects that may depend on its sources and chemical composition. In this study, characteristics of PM2.5 chemical composition and health risk assessment from Songyuan, China, were investigated during day and night in indoor and outdoor from February 4 to 19, 2021. Relative high concentrations of PM2.5 were obtained in indoor environment than outdoor, with 503.95 ± 209.62μg/m3 during the day and 357.52 ± 232.81μg/m3 at night for the indoor environment. Relatively high total carbon, organic carbons, elemental carbons, polycyclic aromatic hydrocarbons (PAHs), and oxygenated polycyclic aromatic hydrocarbons (OPAHs) were obtained in indoor environment. However, the average concentrations of PAHs were higher during night (73.57 ± 43.09ng/m3) in indoor and OPAHs during day (6.027 ± 2.960ng/m3) in outdoor. They had different I/O distributions of these compounds during day and night. Indeno(1,2,3-cd) pyrene was the dominant PAHs, and benzanthrone was the dominant OPAHs; this is different with the previous studies. The high indoor/outdoor ratios showed the indoor coal and biomass burning greatly affect the indoor pollutants. Average ILCR health risk assessment for PAHs was all higher than 10-6 for different age gender, suggesting there has potential cancer risk existed for populations living in the rural coal and biomass burning area Songyuan, China.

Emission profiles, source identifications, and health risk of polycyclic aromatic hydrocarbons (PAHs) in a road tunnel located in Xi'an, China.

Understanding the sources and characteristics of PM2.5-bound PAHs from traffic-related pollution can provide valuable data for mitigating air contamination from traffic in local urban regions. However, little information on PAHs is available regarding the typical arterial highway-Qinling Mountains No.1 tunnel in Xi'an. We estimated the profiles, sources, and emission factors of PM2.5-bound PAHs in this tunnel. The total PAH concentrations were 22.78 ng·m-3 and 52.80 ng·m-3 at the tunnel middle and exit, which were 1.09 and 3.84 times higher than that at the tunnel entrance. Pyr, Flt, Phe, Chr, BaP, and BbF were the dominant PAH species (representing approximately 78.01% of total PAHs). The four rings PAHs were dominant (58%) among the total PAH concentrations in PM2.5. The results demonstrated that diesel and gasoline vehicles exhaust emissions contributed 56.81% and 22.60% to the PAHs, respectively, while the corresponding value for together brakes, tyre wear, and road dust was 20.59%. The emission factors of total PAHs were 29.35 μg·veh-1·km-1, and emission factors of 4 rings PAHs were significantly higher than those of the other PAHs. The sum of ILCR was estimated to be 1.41×10-4, which accorded with acceptable level of cancer risk (10-6-10-4), PAHs should not ignored as they still affect the public health of inhabitants. This study shed light on PAH profiles and traffic-related sources in the tunnel, thereby facilitating the assessment of control measures targeting PAHs in local areas.

Bioremediation of polycyclic aromatic hydrocarbons in crude oil by bacterial consortium in soil amended with Eisenia fetida and rhamnolipid.

The present study investigated the concerted effort of Eisenia fetida and rhamnolipid JBR-425 in combination with a five-member bacterial consortium exhibiting elevated degradation levels of low and high molecular weight polycyclic aromatic hydrocarbons (PAH) from soil contaminated with Digboi crude oil. Application of bacterial consortium (G2) degraded 30-89% of selected PAH from the artificial soil after a 45-day post-exposure, in which chrysene showed the highest level of degradation with 89% and benzo(a)pyrene is the lowest with 30%, respectively. Moreover, an acute exposure study observed that earthworm biomass decreased, and mortality rates increased with increasing crude oil concentrations (0.25 to 2%). Earthworms with a 100% survival rate at 1% crude oil exposure suggest the tolerance potential and its mutual involvement in the bioremediation of crude oil with selected bacterial consortia. Bacterial consortium assisted with E. fetida (G3) showed 98% chrysene degradation with a slight change in benzo(a)pyrene degradation (35%) in crude oil spiked soil. Besides, the most dominant PAH in crude oil found in the current work, fluoranthene, undergoes 93% and 70% degradation in G3 and G5 groups, respectively. However, rhamnolipid JBR-425 coupled with the bacterial consortium (G5) has resulted in 97% degradation of chrysene and 33% for benzo(a)pyrene. Overall, bacterial consortium assisted with earthworm group has shown better degradation of selected PAH than bacterial consortium with biosurfactant. Catalase (CAT), glutathione reductase (GST) activity and MDA content was found to be reduced in earthworms after sub-lethal exposure, suggesting oxidative stress prevalence via reactive oxygen species (ROS). Hence, the findings of the present work suggest that the application of a bacterial consortium, along with earthworm E. fetida, has huge potential for field restoration of contaminated soil with PAH and ecosystem sustainability.

Application of Positive Matrix Factorization for Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAH) in the Adriatic Sea, and the Evaluation of PAH-Related Carcinogenic Risks

Concentrations of polycyclic aromatic hydrocarbons (PAH) were studied in 36 sediment samples collected from 29 sites in the central Adriatic Sea. The total concentration of PAH showed high variability, ranging from 42.85 µg kg−1 in open sea sediments to 28,662 µg kg−1 in the sediments of Šibenik Bay. Unsubstituted, parent PAH were dominant PAH compounds in the entire area of Šibenik Bay and most of the stations in the coastal area. In Kaštela Bay, methyl PAH concentrations were higher than the concentrations of unsubstituted PAH, whereas in the sediments along the mid-Adriatic transect, similar concentrations of both PAH fractions were determined. PAH sources were investigated by applying the Positive Matrix Factorization software developed by the U.S. Environmental Protection Agency (USEPA). The results indicate the presence of four sources, two of which can be considered petrogenic and two pyrogenic. The contribution of the sources to the total concentration PAH at each station indicates the dominance of pyrogenic sources in Šibenik Bay and at most stations in the coastal area. In the sediments along the mid-Adriatic transversal, as well as in Kaštela Bay, PAHs originate mainly from petrogenic sources. The obtained results show that PMF can be a suitable tool for control of PAH pollution and thus, for the management of various activities in the Adriatic region. Seasonal differences between the contributions of sources in the Kaštela and Šibenik bays indicate that the contribution of traffic to the total concentration of PAH was higher during the tourist season. The carcinogenic risk of PAH determined by toxicity equivalent (TEQ) calculations showed an increased carcinogenic risk in the whole area of Šibenik Bay, regardless of the number of PAH compounds considered for the calculations. A low PAH-related carcinogenic risk was found for the rest of the study area.

Synergistic cancer risk assessment from PM1 bound metals and PAHs in the Indo-Gangetic Region

The atmospheric particulate matter (PM) contains a significant amount of human carcinogens such as metals and Polycyclic Aromatic Hydrocarbons (PAHs). Previous studies have clearly shown that these carcinogens pose serious health issues due to the inhalation of particulate matter. Since the synergistic roles of these carcinogens are rarely considered, these studies frequently underestimate the health risk to humans. The current research aims to bridge this information gap by estimating the synergistic carcinogenic risk assessment owing to PM1 bound metals and PAHs across the densely populated Indo-Gangetic Plain (IGP). The carcinogenic risk assessment was conducted in accordance with the USEPA guidelines on these various PM1 bound components. The Incremental Lifetime Cancer Risk (ILCR) due to heavy metals, such as Lead (Pb) and Chromium (Cr), was found beyond the acceptable limit (> 10−4). The risk due to PM1 bound USEPA PAHs was also significantly higher (> 10−5). This study further estimated the potential toxicity from broad domain of environmental PAHs present in ambient air by considering relevant estimation factors from existing literature. The projected risk from these diverse environmental PAHs was of the order 10−4. Further, source identification of PAHs based on diagnostic isomer ratios revealed that diesel exhaust, biomass burning, and coal combustion are the dominant PAHs sources. Moreover, the exposure to these pollutants is higher in winter and post-monsoon periods. Overall, the synergistic carcinogenic risk found from metals and PAHs was of the order 10−3. In a nutshell, inhalation of PM1 bound heavy metals and PAHs at IGP can result in the development of 1000 cancer cases per million population, which is the highest value compared to other parts of the world. The present study demands immediate policy interventions not only for the reduction of particulate pollution, but also for the reduction of carcinogenic species from the ambient air in order to improve human health.

Assessment of entrainment of key PAHs emanating from major combustion sources into the ambient air

Increasing health problems owing to air pollution is the major cause of concern in the present time, especially in regions with exceptionally high particulate matter (PM) namely Indo-Gangetic Plains (IGP). In the ambient PM, polycyclic aromatic hydrocarbons (PAHs) have been reported to be carcinogenic in nature and its dominant sources are diesel emissions, coal combustion, agricultural waste burning, wood, and cow-dung cake burning. The chemical characteristics of particulate-bound PAHs from all the mentioned sources, their intercomparison, and entrainment into the atmosphere have been assessed in this study. High-molecular weight (HMW) PAHs fraction is highest in emissions from coal combustion (∼95%), followed by agricultural waste burning (83%), wood burning (83%) and cow-dung cake (77%) combustion. Among all the PAH compounds, benzo (b,j) fluoranthene (B[bj]F) was found to be predominant (highest in wood combustion ∼20.3%) in all source samples except exhaust from diesel and bio-diesel engine installed with diesel oxidation catalyst (DOC). Dominant PAH compounds contributing to the carcinogenic potential (CP) are benzo (a) pyrene (B[a]P), dibenzo (a,h) anthracene (D[ah]A), benzo (b,j) fluoranthene (B[bj]F), benzo (a) anthracene (B[a]A) and indeno (1,2,3-c,d) pyrene (IP). Wood combustion (CP = 1.4 ± 0.8) emission is observed to be the most carcinogenic followed by coal combustion (0.8 ± 0.2), diesel exhaust emission (0.4 ± 0.3), cow-dung cake burning (0.2), and agricultural waste burning (0.2 ± 0.1). Further, the range of various diagnostic ratios for each of the source samples has been reported that can be utilized in future studies for more comprehensive source apportionment.

Health Risk Assessment of Polycyclic Aromatic Hydrocarbons from Cooking Fuels burning in Nigeria

Cooking activities are an important source of indoor air pollution which contributes significantly to Polycyclic Aromatic Hydrocarbons (PAHs) in the environment. This study investigated sixteen (16) priority PAHs emitted from smoke in eight (8) cooking fuels commonly used in Nigeria. Gas Chromatography Mass Spectrometry (GC-MS) was used for sample analysis and the potential health risk associated with exposure to PAHs were evaluated. The highest total quantified PAHs concentration was obtained from the burning of palm kernel fiber with an average ΣPAHs of 14.06 mg/kg. The result showed a variation in the average concentration of 10.82 − 14.06 mg/kg for all the cooking fuels. 3-ringed PAHs were found to be the dominant PAHs in the samples considered in terms of concentrations and frequency of occurrence at 7.03-9.42 mg/kg. Benzo[a]anthracene was the most abundant PAHs in biomass materials while Benzo[a]pyrene was the most abundant in liquified petroleum gas and Benzo[b]fluoranthene in kerosene. The cancer risk for both the children and adult obtained for all the cooking fuel samples were less than 10 − 6 which is satisfactory except in sawdust which has a value of 1.30 × 10 − 5 and 1.44 × 10 − 5 for child and adult, respectively. It is recommended that cleaner cooking fuels be used in well-ventilated environments to reduce exposure to these pollutants. Highlights Sixteen priority PAHs in emissions from the burning of eight cooking fuels in Nigeria were investigated Emission sources of the PAHs were identified using diagnostic ratios Health risks of PAHs in emissions from the burning of cooking fuels is higher in adult

An evaluation of the impact of traffic on the distribution of PAHs and oxygenated PAHs in the soils and moss of the southeast Tibetan Plateau

Contaminants in high-altitude mountains such as the Tibetan Plateau (TP) have attracted extensive attention due to their potential impact on fragile ecosystems. Rapid development of the economy and society has promoted pollution caused by local traffic emissions in the TP. Among the pollutants emitted by traffic, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) are of particular concern due to their high toxicity. The TP provides an environment to explore the degree and range of contribution for traffic-induced PAHs and OPAHs. In this study, soils and moss were collected at different altitudes and distances from the G318 highway in the southeast TP. The total concentrations of PAHs (∑16PAHs) and OPAHs (∑6OPAHs) in soils were in the range of 3.29–119 ng/g dry weight (dw) and 0.54–9.65 ng/g dw, respectively. ∑16PAH and ∑6OPAH concentrations decreased logarithmically with increasing distance from traffic. A significantly positive correlation between ∑16PAHs and altitude was found at sampling points closest to traffic. Dominant PAHs constituents in soil and moss included chrysene (CHR), benzo[g,h,i]perylene (BghiP), and benzo[b]fluoranthene (BbF); prevalent OPAH compounds were 9-fluorenone (9-FO) and 9,10-anthraquinone (ATQ). These compounds were related to characteristics of traffic emissions. The multiple diagnosis ratio and correlation analysis showed that exhaust emissions were the main source of the PAHs and OPAHs in the studied environment. PMF modeling quantification of the relative contribution of traffic emissions to PAHs in roadside soils was 45 % on average. The present study characterized the extent and range of traffic-induced PAH and OPAH emissions, providing valuable information for understanding the environmental behaviors and potential risks of traffic-related contaminants in high-altitude areas.

Polycyclic aromatic hydrocarbons and polybrominated diphenyl ethers in urban road dust from Tianjin, China: pollution characteristics, sources and health risk assessment

• Pollution characteristics of PAHs and PBDEs in urban road dust were revealed. • PAHs came from petroleum, petroleum combustion, and biomass/coal combustion. • BDE209 was major PBDE congener, and deca-BDE was primary PBDEs source. • Children showed higher health risk to PAHs and PBDEs in urban road dust. Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs) in urban road dust from Tianjin, the largest industrial and commercial city in Northern China, were monitored to assess health risks to local people. The ∑ 16 PAHs ranged 696–7229 ng/g dry weight (dw) with a mean level of 2673 ± 1313 ng/g dw. Ace showed the highest value, and the dominant PAH was 4-ring. The ∑ 16 PBDEs displayed 53.5–214 ng/g dw with a mean value of 95.3 ± 32.1 ng/g dw. BDE209 was the dominating PBDE congener. Petroleum, petroleum combustion, and biomass/coal combustion were major sources of PAHs. Deca-BDE (BDE209) was the main source of PBDEs, while lower brominated PBDEs mainly originated from the degradation of higher brominated PBDEs. Exposure pathways to PAHs in both children and adults were revealed to be dermal contact > ingestion > inhalation. The total carcinogenic risk (CR) of PAHs was a little higher than 10 −6 , indicating that PAHs have certain CR to humans. The non-cancer hazard index (HI) suggested PBDEs posed no adverse health effects to people. Overall, PAHs and PBDEs posed higher health risks to children than adults. This study can serve as a valuable reference point demonstrating Tianjin's need to control environmental pollution and protect human health.

Assessment of Pesticide, Dioxin-like Polychlorinated Biphenyl, and Polycyclic Aromatic Hydrocarbon Existence around Galindez Island, and Comparison with the Organic Pollution Bibliography of the Antarctic Peninsula

Sediment, notothenioid fish, and moss samples were collected from the vicinity of Galindez Island, Antarctic Peninsula during the austral autumn of 2016 and 2017. Pesticide, Polycyclic Aromatic Hydrocarbon (PAH), and dioxin-like Polychlorinated Biphenyl (dl-PCB) concentrations were measured using High-Resolution Gas and Liquid Chromatography. Pollutant concentrations were below detection limits in sediment and moss samples. However, pesticides, PAH, and dl-PCB congeners were detected in the muscle tissue of fishes. Pesticide concentrations varied between 0.46 and 12.2 ng/g-dw, and Mecarbam was the dominant compound. Kresoxim-methyl, Mecarbam, Procymidone, Pyridaben, and Quinoxyfen were reported in the muscle tissue of the fishes, for the first time from the Antarctic. PCB-118, PCB-105, and PCB-156 were dominant dl-PCBs. The ∑12-dl-PCB concentration was 160,929 pg/g-dw, and WHO-TEQ-total dl-PCB was 8.30 pg/g-dw in Trematomus bernachii, over the consumable limit in fishes according to the European Commission. The PCB-126 concentration was 36 pg/g-dw in the muscle tissue of fish, the first reported from the Antarctic. Phenanthrene was the dominant PAH congener. The ∑16-PAH concentration was 22.5 ng/g-dw. PAH sources were local and petrogenic in the fishes, likely after long-term bioaccumulation. The flow rate is rather low around Galindez Island; accordingly, contaminant removal takes time and may demonstrate long-lasting effects including bioaccumulation in the marine food web.

Sources, pollution, and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in Porto-Novo Lagoon, Benin Republic.

The Porto-Novo Lagoon is influenced by agricultural discharges and human activities. In order to evaluate the impact of wastes and human activities on Porto-Novo Lagoon, the sources and ecological risks of sixteen polycyclic aromatic hydrocarbons (PAHs) were assessed. The physicochemical and biological parameters of the water were also determined. The result showed that between the sampling sites, the mean concentration of dissolved oxygen ranged from 4.8 ± 0.5 to 5.1 ± 0.2mg/L; biochemical oxygen demand varied from 12.6 ± 2.0 to 77.9 ± 81.9mg/L; biological oxygen demand ranged from 2.8 ± 2.6 to 5.6 ± 0.9mg/L; total phosphorus varied between 4.7 ± 2.7 and 15.3 ± 9.5mg/L; total dissolved solids ranged from 183.0 ± 115.8 to 337.5 ± 413.3mg/L, and Escherichia coli varied from 495.0 ± 542.9 to 1920.0 ± 2676.5 UFC/100mL. Water parameter values obtained were not within World Health Organization (WHO)-recommended limits except pH and TDS. Total PAHs (∑PAHs) concentration varied from 38.8 to 123.9mg/L. The mean ∑PAH concentration was 83.2 ± 20.3mg/L. Benzo[b]fluoranthene, benzo[g,h,i]perylene, and benzo[k]fluoranthene were the most dominant PAHs and contributed to 55.9%, 15.3%, and 4.5% of the ∑PAHs concentration, respectively. Douane-Tokpa and Djassin recorded the lowest and highest concentrations. PAHs of four to six rings were the most abundant across the sampling sites. Naphthalene showed the lowest risk in the lagoon. Acenaphthene showed low risk at Djassin, while Indeno(1,2,3cd)pyrene showed low risk at Benin Industry Body Fat. Except for those that were not detected, all the PAHs at individual or complex mixture levels showed high risk at all the sites. The highest total concentration was recorded in Djassin followed by Beaurivage. The high level of PAHs pollution was attributed to both human and goods traffic, runoff, and the complex hotels close to the lagoon. Molecular diagnostic ratios and principal component analysis suggest that the target hydrocarbons were from both petrogenic and pyrogenic sources with predomination of vehicular emission and coal/woods combustion. ∑LWM/HWM confirmed also the predominance of pyrolytic sources of PAHs in Porto-Novo Lagoon. The predominance of the vehicular emission may be due to the position of the complex Porto-Novo Lagoon-Nokoué Lake which is between the two big cities of the country.

Effect of charcoal grilling on polycyclic aromatic hydrocarbons (PAHs): content, composition, and health risk in edible fish in Japan.

The content and composition of polycyclic aromatic hydrocarbons (PAHs) induced by charcoal grilling of fish were determined in this study. Using HPLC-DAD, the simultaneously quantitative method for 16 priority PAHs was developed and applied to three common Japanese fish: mackerel, pacific saury, and sardine. Charcoal grilling largely increased the content of both total and representative PAHs. Moreover, all of the three fish showed a similar PAH composition under the effect of charcoal grilling: in raw samples, naphthalene was observed as the dominant PAH, while in charcoal-grilled samples, phenanthrene, fluoranthene, and pyrene served as the major PAHs. Furthermore, a health risk assessment showed that charcoal grilling resulted in high levels of the toxic equivalence quotients, the daily dietary intake exposure to PAHs, and the incremental lifetime cancer risk in three fish, which outclassed the raw samples and exceeded the recommended limitations. The results suggested that charcoal grilling-induced accumulation of PAHs and their potential health risk on human health should be of great concern, which might contribute to the dietary guidance and risk management of food-contained PAHs.

North-south geographic heterogeneity and control strategies for polycyclic aromatic hydrocarbons (PAHs) in Chinese lake sediments illustrated by forward and backward source apportionments

As universal and supervirulent pollutants, understanding the potential sources of polycyclic aromatic hydrocarbons (PAHs) in lakes is critical for formulating pollutant control policies that will ensure the ecological safety of aquatic environments. Geographic heterogeneity of PAHs in lake sediments from China nationwide was investigated to indicate north-south dissimilarities in PAH levels and sources and propose specific PAH control strategies. Geographic PAH patterns showed that higher concentrations were found in the south compared to the north due to higher energy consumption and more intense industrial activities. Furthermore, the primary contributors in the south were high molecular weight (HMW) PAHs, whereas low molecular weight (LMW) PAHs were dominant in the north. The results of forward source apportionment based on the PAH emission method (EM) were consistent with the backward method using the positive matrix factorization (PMF) model, which verified the feasibility of the combined methods. Petroleum from transport was the dominant PAH source in the south, and purifying gasoline and diesel, promoting new energy vehicles and direct injection engines might effectively reduce PAH emission. Domestic coal was the main PAH source in the north, thereby adding active substance in coal and using cleaner energy could reduce PAH release.

Quantitative filter forensics for semivolatile organic compounds in social housing apartments.

Residents from low-income social housing are vulnerable to adverse health effects from indoor air pollution. Particle-bound concentrations of eight phthalates and 12 polycyclic aromatic hydrocarbons (PAHs) in indoor air were measured using quantitative filter forensics with portable air cleaners deployed for three one-week periods from 2015 to 2017. The sample included 143 apartments across seven multi-unit social housing buildings in Toronto, Canada, that went through energy retrofits in 2016. Eight phthalates and six PAHs were found in more than 50% of the apartments in either of the three sampling periods. Di(2-ethylhexyl) phthalate (DEHP) and phenanthrene were the dominant phthalate and PAH, with median concentrations of 146, 143, and 130ng/m3 and 1.51, 0.58, and 0.76ng/m3 in the late spring of 2015, and after retrofits in late spring 2017 and winter of 2017, respectively. SVOC concentrations were generally lower after energy retrofits, with significant differences for phenanthrene, fluoranthene, and pyrene. Lower concentrations post-retrofit may be related to less overheating and less need for opening windows. Concentrations of phthalates and PAHs in this study were similar to or higher than those reported in the literature. Results suggest that the use of portable air filters is a promising method to assess concentrations of indoor particle-bound SVOCs.

English

Effect of smoking technologies on nutritional quality and concentration levels of polycyclic aromatic hydrocarbons (PAHs) in Mormyrus caschive and Oreochromis niloticus were determined to enable adoption and utilization of suitable facility that maintains good quality for sustainable supply of nutritious fish products in South Sudan. A total of 72 fresh M. caschive and O. niloticus were purchased, of which 24 were iced for reference and the other 48 were divided into two groups for pit and chorkor smoking. Experimental smoking of fish samples was conducted twice in a randomized design. Fish samples were analyzed for nutritional values using standard methods of the association of official analytical chemists and levels of PAHs using gas chromatography-mass spectrometry. Results revealed; the two smoking methods concentrated crude protein, fat and ash contents. However, fish smoked using chorkor had significantly higher nutritional values than fish smoked using pit kiln. About seven types of PAHs comprising of low and medium molecular weight were recorded from the two smoked fish species. Naphthalene and fluorene were the two dominant PAHs with fish smoked using pit kiln having significantly higher concentration levels of naphthalene (5.86±4.16 µg/kg) and fluorene (3.83±0.10 µg/kg) than fish smoked using chorkor oven. The study concluded that chorkor oven has better quality smoked fish than pit. Hence, its utilization and adoption for artisanal fisheries in South Sudan is recommended.   Key words: Nutritional values, food quality and safety, smoking techniques, polycyclic aromatic hydrocarbons (PAHs).