Distribution, risk assessment, and source apportionment of polycyclic aromatic hydrocarbons (PAHs) using positive matrix factorization (PMF) in urban soils of East India.

This study investigated 16 United States environmental protection agency priority PAHs profiles and their sources in 40 urban soils collected from two industrialised cities, Jamshedpur and Bokaro, in east India and assessed their health risk to humans. The results showed the predominance of high molecular weight (HMW) PAHs (4-5 rings). The total PAHs concentration in surface soils ranged from 2223 to 11,266 ng/g and 729 to 5359 ng/g (dw), respectively, for Jamshedpur and Bokaro. Higher concentrations of PAHs were recorded at the selected industrial areas and heavy traffic zones of both cities. In JSR city 4-ring PAHs contributed 43% of total PAHs trailed by 5-ring PAHs 27.2%. Similarly, in BKR city 4-ring PAHs contributed 34% of the total PAHs, followed by 3-ring PAHs 28.9% and 5-ring PAHs 22.9%. Total organic carbon in surface soils exhibited moderate correlation with the low molecular weight (ΣLMW) PAHs (R2 = 0.69) and a comparatively strong correlation with the ΣHMW PAHs (R2 = 0.89), suggesting strong adsorption of HMW PAHs to urban soils. The Diagnostic and PMF modelling analysis indicated that the major sources of PAHs contamination in soils were petroleum combustion, vehicular emissions, biomass, and coal combustion. The health risk assessment shows that the cumulative probability of carcinogenic risks was under the acceptable limits of 10-4 to 10-6. At some sampling areas in both cities, the maximum value of total exposure cancer risk slightly exceeded the acceptable limits indicating some carcinogenic risk for adults.

Accumulation of polycyclic aromatic hydrocarbons (PAHs) in surface sediment residues of Mahanadi River Estuary: Abundance, source, and risk assessment.

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Mahanadi River Estuary (MRE), identified sources, and evaluated the ecological toxicity. The PAHs distributions in MRE ranged from 13.1 to 685.4 ng g-1 (dry weight), with a mean value of 192.91 ± 177.56 ng g-1 (dry weight). Sediments at sites S11, S8, and S13 have the highest 3-rings, 4-rings, and 5-rings PAHs, respectively. In MRE, pyrene has a significantly higher concentration with a mean value of 30.51 ng g-1, followed by Fluoranthene (86.2 ng g-1), Chrysene (67.4 ng g-1), and Benzo(k)fluoranthene (54.2 ng g-1). Site S8 had a higher total PAH concentration than sites S11, S13, and S1. The diagnostic and principal component analysis suggests that PAHs originated from petroleum, oil, biomass, and coal combustion. Higher toxic and mutagenic equivalent quotients indicate potential aquatic toxicity and a need for continuous monitoring of MRE for PAHs pollution.

Unregulated discharge of wastewater in the Mahanadi River Basin: Risk evaluation due to occurrence of polycyclic aromatic hydrocarbon in surface water and sediments.

Exposure to polycyclic aromatic hydrocarbons (PAHs) through contaminated water may adversely affect human health and ecology. Water and sediment samples collected from the Mahanadi River Basin (MRB) were analyzed for the presence of sixteen priority PAHs. Results showed that the concentrations of Σ16 PAHs in water and sediments ranged from 13.1 to 685.4 µg/L and 302.6 to 728.2 ng/g. In river water samples, the highest mean concentrations were recorded for Acenaphthylene (18.73 ± 11.61 µg/L) and Benzo(a)Anthracene (10.11 ± 8 µg/L). On the contrary, the maximum concentration was recorded for Phenanthrene (96.18 ± 50.66 ng/g) and Pyrene (76.69 ± 22.73 ng/g) in sediment samples. Human health risk assessment suggests low risk, with incremental lifetime cancer risk (ILCR) being 37.44 × 10-5 for children and 21.82 × 10-5 for adults. In contrast, ecological risk assessment showed a high toxic equivalent quotient of 40.68 ng/g and mutagenic equivalent quotient of 39.74 ng/g suggesting elevated adverse risk to aquatic species.

Characterization, Behavior, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Estuary Sediments.

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances that have ubiquitous presence in water, air, soil, and sediment environments. The growth of PAH toxicities and related ecotoxicology risk in estuary sediment has a serious concern. Present study examined the PAHs concentration, sources, and ecological risk from selected sites in Subarnarekha River estuary (SRE) sediment deposits. The sum of toxic 16 PAHs was ranged from 36.8 to 670.8 ng/g (mean = 223.46 ± 196.35 ng/g). The total PAH concentration varied significantly among the sampling sites (range 511.3 ng/g to 233.8 ng/g) based on allochthonous contaminant loads. Among the 16 compounds, Phen had the highest concentration (40.18 ng/g), followed by Pye (31.86 ng/g), Flur (29.36 ng/g), and NA (19.33 ng/g). Most of the sampling sites contained abundant 3-ring and 4-5-ring PAHs. Based on diagnostic ratios and PCA analysis petroleum combustion, biomass, and coal-burning have been identified as the major sources. The PAHs had high mutagenic equivalent factor and toxic equivalent factor values posing great ecological threats and health risks.

Health Risk Assessment, Composition, and Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Drinking Water of Southern Jharkhand, East India.

The studies on polycyclic aromatic hydrocarbons (PAHs) occurrence, distribution, health risk, and composition in drinking water are limited in India and worldwide. The main objective of this study was to find the contaminant sources, composition, health risk, and distribution of USEPA's 16 priority pollutant PAHs in the drinking water samples collected between July 2019 to September 2019 from six districts of Southern Jharkhand. The Σ16PAHs mean ± standard deviation [SD] concentration values were ordered as East Singhbhum (ES) (21.5 ± 14.8 ng L-1) > West Singhbhum (WS) (16.57 ± 13.21 ng L-1) > Saraikela Kharsawan (SK) (11.48 ± 9.92 ng L-1) > Khunti (KH) (10.32 ± 9.09 ng L-1) > Simdega (SM) (9.96 ± 7.85 ng L-1) > Gumla (GU) (9.41 ± 8.63 ng L-1). The results show that ES and WS districts' groundwater samples were more contaminated by the PAHs, which may be attributed to the presence of many small-, medium-, and large-scale industries and high vehicular density in these districts. The concentrations of lower molecular weight ring (3-rings) and middle molecular weight ring (4-rings) PAHs were dominant throughout all drinking samples. The concentration of the 3-ring PAH Anthracene and 4-ring PAH Fluoranthene were dominant in all districts. The molecular ratios suggested that the potential sources of PAHs are fuel combustion and coal, grass, and wood burning. Risk assessment shows that the incremental lifetime cancer risk and risk index (RI) were ranged from 0.02 × 10-10 to 4.93 × 10-10 for children and 0.01 × 10-10 to 2.98 × 10-10 for adults. The RI values for seven carcinogenic PAHs were 8.83 × 10-10 for children and 7.38 × 10-10 for adults. Although the carcinogenic risks were within the permissible values, chronic exposure to PAHs through the ingestion of drinking water could still be a human health concern.