Microplastic contamination in water and sediments of Mahanadi River, India: An assessment of ecological risk along rural-urban area.

Worldwide, environmental concerns about MPs pollution have increased. Microplastic contamination that pollutes the ocean is mostly caused by terrestrial transfer from close proximity locations. A study of MPs pollution near coastal locations becomes necessary to address the MPs transit, fate, and mitigation. In the current study MPs pollution in the surface water and sediment of the Mahanadi River estuary was assessed during Pre-MS and MS. The size, shape, and colour of the MPs were determined using a stereomicroscope, and the MPs polymer composition was identified by Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The mean concentration of MPs that were potentially discovered in water was 16.6 ± 5.2 and sediments 197.3 ± 5.4 during Pre-MS. In the MS observed mean abundance of MPs was 15.1 ± 5.4 in water and 164.6 ± 76.9 in sediments. The highest abundant size was smaller than 1 mm; the most prevalent shape were fibers followed by film and fragments; black and white was a prominent colour in water and sediments respectively. Polyesters (PEs), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), Polystyrene (PS), and Polycarbonates (PC) were found in the analysis of the chemical composition of MPs in water and sediments samples. The calculated PLI value shows pollution load at category I, with polymer hazard levels at categories III, IV, and V, indicating very high risk. The current research results show that river inflows and fishing-related actions are probably the main causes of MPs pollution.

The Health Risk and Source Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Soil of Industrial Cities in India.

Industrial areas play an important role in the urban ecosystem. Industrial site environmental quality is linked to human health. Soil samples from two different cities in India, Jamshedpur and Amravati, were collected and analyzed to assess the sources of polycyclic aromatic hydrocarbons (PAHs) in industrial areas and their potential health risks. The total concentration of 16 PAHs in JSR (Jamshedpur) varied from 1662.90 to 10,879.20 ng/g, whereas the concentration ranged from 1456.22 to 5403.45 ng/g in the soil of AMT (Amravati). The PAHs in the samples were dominated by four-ring PAHs, followed by five-ring PAHs, and a small percentage of two-ring PAHs. The ILCR (incremental lifetime cancer risk) of the soil of Amravati was lower compared to that of Jamshedpur. The risk due to PAH exposure for children and adults was reported to be in the order of ingestion > dermal contact > inhalation while for adolescents it was dermal contact > ingestion > inhalation in Jamshedpur. In contrast, in the soil of Amravati, the PAH exposure path risk for children and adolescents were the same and showed the following order: dermal contact > ingestion > inhalation while for the adulthood age group, the order was ingestion > dermal contact > inhalation. The diagnostic ratio approach was used to assess the sources of PAHs in various environmental media. The PAH sources were mainly dominated by coal and petroleum/oil combustion. As both the study areas belong to industrial sites, the significant sources were industrial emissions, followed by traffic emissions, coal combustion for domestic livelihood, as well as due to the geographical location of the sampling sites. The results of this investigation provide novel information for contamination evaluation and human health risk assessment in PAH-contaminated sites in India.

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.

Deposition of trace metals associated with atmospheric particulate matter: Environmental fate and health risk assessment.

Anthropogenic and natural sources influence trace metals (TMs) bound to different sized particulate matter (PM) in dry and wet atmospheric deposition, which can create ecosystem and human health issues in the long run. Limited reviews are available summarizing worldwide concentrations in TMs in atmospheric PMs, their sources and pathways. Simultaneously, quantitative assessment of the potential human and ecosystem health risks imposed by the atmospheric particulate matter has not been adequately reviewed. Addressing this gap, here we review, the concentration of TMs in dry deposition mainly varies with the responsible sources, whereas, in wet deposition, it depends on the solubility of TMs. Other than deposition on impervious surfaces, the TMs incorporated PM can be deposited on biological agents. Health risk assessments show that ingestion and dermal contact pathways are more likely to cause health issues, however, the probability of occurring ingestion and dermal contact pathways is limited. Attention must be paid to the contribution from non-exhaust and exhaust vehicular emissions for TMs in atmospheric deposition, understanding their impact on stormwater management and urban agriculture. Behaviors of TMs in the atmosphere depends on many complex factors including origin, wind patterns, and weather conditions. Therefore, future research needs to be carried to model and predict the fate and transfer of TMs once they are generated through natural and anthropogenic sources. We believe that such research would allow establishing pollution control policies and measures in urban environments which will be critical to reduce the levels of TMs associated with atmospheric deposition in the environment.

Temporal variability of atmospheric particulate-bound polycyclic aromatic hydrocarbons (PAHs) over central east India: sources and carcinogenic risk assessment.

Atmospheric polycyclic aromatic hydrocarbons (PAHs) are of significant interest owing to their high potential health effects, including mutagenicity and carcinogenicity. We report 16 PAHs measured in ambient PM2.5 from June 2018 to May 2019 over three different sites located in central east India. The annual average PM2.5 mass concentrations of 97.3 ± 18.1 µg m-3, 101.9 ± 19.4 µg m-3, and 93.9 ± 20.3 µg m-3 were measured at RCI (Ranchi), GHY (Gamharia), and BKR (Bokaro), respectively. The mass concentrations at all sampling sites are relatively higher than the annual average concentration of the National Ambient Air Quality Standard. Total annual PAH concentrations (ng m-3) are found to be comparable at BKR (797.9 ± 39.1 ng m-3) and RCI (887.7 ± 38.8 ng m-3); however, a relatively higher average is observed over GHY (1015.1 ± 42.7 ng m-3). Using PAH diagnostic ratios and principal component analysis (PCA), their major sources were attributed to coal and wood combustion as well as vehicular emission of diesel and gasoline at all sampling sites. Significant seasonal variability is observed for PAH composition and mainly attributed to change in emission sources. Summer and winter compositions were found to be impacted by the transport from Indo-Gangetic Plains (IGP). However, ambient level PAHs during the post-monsoon season were impacted by mixed sources from Indo-Gangetic Plain and eastern India. These observations are supported by the analysis of back-trajectory and fire count data. The excess life time cancer risk (ELCR) values estimated for the study sites are within acceptable limits suggesting acceptable risk levels at BKR, GHY, and RCI. This study highlights the significance of ambient aerosol concentration for health risks in the pre-COVID-19 scenario.

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.

Characterization and health risk assessment of particulate bound polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor atmosphere of Central East India.

The selected 16 high-priority polycyclic aromatic hydrocarbons (PAHs) were characterized in PM2.5 in the indoor and outdoor air samples collected at the urban slum and rural sites in the Central East India. At the urban slum site, the indoor and outdoor concentrations of PAHs were 466.03± 11.94 ng/m3 and 321.71± 34.87 ng/m3, respectively. At the rural location, the indoor and outdoor concentrations were 294.85± 20.53 ng/m3 and 241.74± 29.04 ng/m3, respectively. Three-four and five-ring PAHs were found to be dominant in both urban slum and rural sites. Diagnostic ratio (DR) analysis and principal component analysis (PCA) conclude that diesel exhaust, gasoline, biomass, and coal combustion were the significant sources of 16 PAHs in indoor and outdoor environments, the urban slum and rural sites. Lifetime average daily dose (LADD) and incremental lifetime cancer risk (ILCR) values were calculated for health risk assessment for 6-year-old children and 24-year-old adults. The ELCR values in the urban slum site and the rural location were calculated 43.24 × 10-6 and 28.3 × 10-6. The ELCR values were observed between the acceptable limit 10-6-10-4 given by regulatory agency USEPA United States Environmental Protection Agency (1989).

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.