An updated status of currently used pesticides in India: Human dietary exposure from an Indian food basket.

Currently used pesticides (CUPs) were introduced to have lower persistence and bioaccumulation, and lesser bioavailability towards non-target species. Nevertheless, CUPs still represent a concern for both human health and the environment. India is an important agricultural country experiencing a conversion from the use of obsolete organochlorine pesticides to a newer generation of phytosanitary products. As for other developing countries, very little is known about the transfer of CUPs to the human diet in India, where systematic monitoring is not in place. In this study, we analyzed ninety four CUPs and detected thirty CUPs in several food products belonging to five types: cereals and pulses, vegetables, fruits, animal-based foods, and water. Samples were taken from markets in Delhi (aggregating food produced all over India) and in the periurban area of Dehradun (northern India) (representing food produced locally and through more traditional practices). Overall, chlorpyrifos and chlorpropham were the most detected CUPs with a detection frequency of 33% and 25%, respectively. Except for vegetables and fruits, the levels of CUPs in all other food types were significantly higher in samples from Delhi (p < 0.05). Exposure dosage of CUPs through different food matrices was calculated, and chlorpropham detected in potatoes had the maximum exposure dosage to humans (2.46 × 10-6 mg/kg/day). Risk analysis based on the hazard quotient technique indicated that chlorpyrifos in rice (2.76 × 10-2) can be a concern.

Microplastics in packaged water, community stored water, groundwater, and surface water in rivers of Tamil Nadu after the COVID-19 pandemic outbreak.

The increased load of plastic in waste streams after the COVID-19 pandemic outbreak has increased the possibility of microplastics (MPs) contamination channelling through the rivers and infiltrating the aquatic ecosystems. MPs in packaged water, community-stored water, groundwater, and surface water of Kaveri River (KR), Thamirabarani River (TR), Adyar River (AR), and Cooum River (CR) in Tamil Nadu were therefore investigated about 2 years after the COVID-19 pandemic outbreak. Using µFTIR and µRaman spectroscopy, polyamide, polypropylene, polyethylene, ethylene vinyl alcohol copolymer resin, and polyvinyl chloride were identified as the primary polymer types. The average number of MPs was 2.15 ± 1.9 MP/L, 1.1 ± 0.99 MP/L, 5.25 ± 1.15 MP/L, and 4 ± 2.65 MP/L in KR, TR, AR, and CR, respectively, and 1.75 ± 1.26 MP/L in groundwater, and 2.33 ± 1.52 MP/L in community stored water. Only LDPE was detected in recycled plastic-made drinking water bottles. More than 50% of MPs were found to be of size less than 1 mm, with fibrous MPs being the prevalent type, and a notable prevalence of blue-coloured microplastics in all the sample types. The Pollution Load Index (PLI) was >1 in all the rivers. Toxicity rating based on the polymer risk index (PORI) categorized AR and TR at medium risk (category II), compared to KR and CR at considerable risk (category III). Overall pollution risk index (PRI) followed a decreasing trend with CR > AR > KR > TR of considerable to low-risk category. Ecological risk assessment indicates a negligible risk to freshwater biota, except for four sites in the middle and lower stretches of Adyar River (AR - 2, AR - 4) and upper and lower stretches of Cooum River (CR - 1, CR - 3), located adjacent to direct sewer outlets, and one location in the lower stretch of Kaveri River (KR - 9), known for fishing and tourist activities.

Sediment-water exchange and risk assessment of pesticidal persistent organic pollutants in Bharathappuzha and Periyar Riverine region along the Arabian Sea.

Considering the extensive agricultural practices along the perennial rivers, viz. Periyar and Bharathappuzha of Kerala in the southwest coast of India, the first comprehensive surveillance of new and legacy organochlorine pesticides (OCPs) in surface sediment was conducted. Further, the sediment-water exchange fluxes have been elucidated. Mean concentrations of total HCH, DDT and endosulfan were 0.84 ng/g, 0.42 ng/g and 0.30 ng/g for Bharathappuzha Riverine sediment (BRS) and 1.08 ng/g, 0.39 ng/g and 0.35 ng/g for Periyar Riverine sediment (PRS). The dominance α-HCH and ß-HCH isomers in PRS and BRS reflect the ongoing use of technical HCH in Kerala. The calculated KSW in both rivers was very low in comparison with other Indian rivers. The average log K'OC for all the detected OCPs in both the rivers was lower than the predicted log KOC in equilibrium indicating the higher adherence of OCPs to sediment. Furthermore, fugacity fraction (fs/fw) was < 1.0 for all OCPs confirming the net deposition of OCPs into the sediment. Sediment concentrations for each of the OCPs in PRS and BRS did not surpass the threshold effect level and probable effect level as stipulated by the Canadian Council of Ministry of the Environment Guidelines. In addition, all the sites of both rivers had sediment quality guideline quotient (SQGQ) values below 0.1 indicating the absence of significant biological and ecological risks.

Pharmaceuticals and personal care products contamination in the rivers of Chennai city during the COVID-19 pandemic.

Pharmaceuticals and personal care products (PPCPs) monitoring in surface water is crucial to address the escalating threat of antimicrobial resistance and safeguard public health. This study aimed to investigate the occurrence of 21 different PPCPs, including wastewater chemical markers, antibiotics, and parabens in the surface water of Chennai city using Ultra Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry (UPLC-MS/MS) analysis. It is noteworthy that chemical markers viz., carbamazepine (CBZ) and caffeine (CAF) were detected in all the sites and contributed to more than 95% of the total PPCPs load indicating a significant intrusion of wastewater. Among the antibiotics, fluoroquinolones were dominant in this study. Interestingly, a significant and strong correlation was seen between fluoroquinolones, CBZ and CAF (R2 = 0.880-0.928, p < 0.05), suggesting similarities in their sources. More than 50% of the sites exhibited a risk for antimicrobial resistance (RQAMR) with RQAMR > 1 for ciprofloxacin, indicating a significant public health concern. The ecotoxicological risk assessment of PPCPs showed no risk to any organisms, except for triclosan, which posed a risk to fish and daphnids at one site near an open drain in Buckingham canal.

Occurrence, Source and Dietary Exposure of Toxic and Essential Elements in the Indian Food Basket.

In this study, representative urban and peri-urban Indian food baskets have been studied for the presence of toxic and essential elements. The concentration of target toxic and essential elements was used to estimate dietary intakes (EDIs) and health risks. Across all food matrices, toxic elements like Cd and Pb were dominant. The highest concentrations of the target elements were found in vegetables, with Cd, Pb, and Ni being beyond permissible limits of the Food and Agriculture Organization of the United Nations and the World Health organization (0.05 mg/kg, 0.1 mg/kg, and 1.5 mg/kg, respectively) in okra, spinach, and cauliflower. The sum of concentrations of the toxic elements (As, Ni, Hg, Cr, Cd, Pb) in vegetables had a range of 0.54-12.08 mg/kg, the highest sum was found in spinach (median 12.08 mg/kg), followed by okra (median 1.68 mg/kg). The EDI was observed for vegetables with a contribution as high as 92% for Cd. Dairy products were found with the highest loading for Ni with a dietary intake of 3.1 mg/kg/day for adults and twice as much for children. Carcinogenic risk for Ni was the highest and found above the threshold for all food categories, as was the case with As. Cumulative carcinogenic and non-carcinogenic risks were mostly contributed by milk and vegetables, in particular, spinach.

Identifying Primate ACE2 Variants That Confer Resistance to SARS-CoV-2.

SARS-CoV-2 infects humans through the binding of viral S-protein (spike protein) to human angiotensin I converting enzyme 2 (ACE2). The structure of the ACE2-S-protein complex has been deciphered and we focused on the 27 ACE2 residues that bind to S-protein. From human sequence databases, we identified nine ACE2 variants at ACE2-S-protein binding sites. We used both experimental assays and protein structure analysis to evaluate the effect of each variant on the binding affinity of ACE2 to S-protein. We found one variant causing complete binding disruption, two and three variants, respectively, strongly and mildly reducing the binding affinity, and two variants strongly enhancing the binding affinity. We then collected the ACE2 gene sequences from 57 nonhuman primates. Among the 6 apes and 20 Old World monkeys (OWMs) studied, we found no new variants. In contrast, all 11 New World monkeys (NWMs) studied share four variants each causing a strong reduction in binding affinity, the Philippine tarsier also possesses three such variants, and 18 of the 19 prosimian species studied share one variant causing a strong reduction in binding affinity. Moreover, one OWM and three prosimian variants increased binding affinity by >50%. Based on these findings, we proposed that the common ancestor of primates was strongly resistant to and that of NWMs was completely resistant to SARS-CoV-2 and so is the Philippine tarsier, whereas apes and OWMs, like most humans, are susceptible. This study increases our understanding of the differences in susceptibility to SARS-CoV-2 infection among primates.

Placental levels of polycyclic aromatic hydrocarbons (PAHs) and their association with birth weight of infants.

As an alarming group of pollutants, polycyclic aromatic hydrocarbons (PAHs) gather much public health concern not only because of their carcinogenic or co-carcinogenic risk but also by interfering with hormone systems or by causing oxidative damage, henceforth liable to toxic actions on reproduction. Accordingly, the present study was aimed to explore the association between in-utero exposure to PAHs by evaluating their placental levels and infant birth weight among 110 healthy and nonsmoking pregnant women. Placental tissue samples were collected instantly after delivery and were analyzed for the presence of sixteen Environmental Protection Agency (EPA) listed PAHs with the help of Gas chromatography equipped with flame ionization detector (GC-FID). Chrysene and benzo(k)fluoranthene were the predominant PAHs detected in tissue samples. To assess the source of origin of PAHs in placenta tissue samples, the ratio of low molecular weight PAHs to high molecular weight (∑LMW/∑HMW PAHs) was calculated, showing the predominance of pyrogenic sources of PAHs possibly responsible for the exposure of the studied population. Results of regression analysis demonstrated the inverse although not significant association of naphthalene (Nap), acenaphthylene (Acy), anthracene (Anth), pyrene (Pyr), benzo(b)fluoranthene (BbF), benzo(k)Fluoranthene (BkF), benzo(a)pyrene (BaP), indeno (123 cd pyrene (IcdP), dibenzo(ah)anthracene (DahA) and benzo(ghi)Perylene (BghiP) with birth weight of neonates. Additionally, the regression model lay light upon the significant association of fluoranthene (Fla) (coefficient= -1.41 gram, p < 0.05) to the depletion trend of birth weight after adjusting for potential covariates. These findings suggest the possible role of an environmental contaminants like PAHs on impairment of fetal growth.

Seasonality, atmospheric transport and inhalation risk assessment of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from industrial belts of Odisha, India.

This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM2.5 and PM10 from industrial areas of Odisha State, India. During 2017-2018, bimonthly sampling of PM10 and PM2.5 was carried out for 24 h in the industrial and mining areas of Jharsuguda and Angul in Odisha during the pre-monsoon, monsoon, and post monsoon seasons. Highest mean concentration of ∑16PAHs in PM2.5 was observed during the post monsoon (170 ng/m3) period followed by pre-monsoon (48 ng/m3) and monsoon (16 ng/m 3) periods, respectively. A similar trend of ∑16PAHs was also observed in PM10 with higher levels observed during post monsoon (286 ng/m3) followed by pre-monsoon (81 ng/m3) and monsoon (27 ng/m3) seasons. Diagnostic ratios and principal component analysis suggested diesel, gasoline and coal combustion as the major contributors of atmospheric PAH pollution in Odisha. Back trajectory analysis revealed that PAH concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents ranged between 0.24 and 94.13 ng TEQ/m3. In our study, the incremental lifetime cancer risk ranged between 10-5 and 10-3, representing potential cancer risk.

Migration of Plasticizers from Polyethylene Terephthalate and Low-Density Polyethylene Casing into Bottled Water: A Case Study From India.

Mineral bottled water packed in three polymers viz., virgin polyethylene terephthalate (PET), recycled PET, and low-density polyethylene (LDPE) were investigated for the occurrence, migration, and health risk of phthalic acid esters (PAEs) at 25 °C, 35 °C, and 45 °C. The average concentration of six USEPA priority PAEs in refrigerated water samples was highest in recycled PET> LDPE > virgin PET. The highest leaching was seen at 45 °C after 2 days for LDPE water packets with ∑6PAEs amounting to 64,300 ng/L. Similarly, for recycled PET, the highest migration was seen at 45 °C after seven days (3,800 µg/L). Bis 2-ethyl hexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the predominant plasticizers from PET bottles and LDPE water packets, respectively. Predicted concentration after three weeks based on best fit obtained through the polynomial model for PET bottles was seen higher than the recommended limit suggested by USEPA (6 µg/L) and WHO (8 µg/L).

Interlinkage Between Persistent Organic Pollutants and Plastic in the Waste Management System of India: An Overview.

Improper handling of plastic waste and related chemical pollution has garnered much attention in recent years owing to the associated detrimental impacts on human health and the environment. This article reports an overview of the main interlinkages between persistent organic pollutants (POPs) and plastic in the waste management system of India. Both plastics and POPs share certain common traits such as persistence, resistance to biological degradation, and the ability to get transported over long distances. Throughout the processes of production, consumption, and disposal, plastics interact with and accumulate POPs through several mechanisms and end up co-existing in the environment. Plastic waste can undergo long-range transport through rivers and the oceans, break down into microplastics and get transported through the air, or remain locked in waste dump yards and landfills. Over time, environmental processes lead to the leaching and release of accumulated POPs from these plastic wastes. Plastic recycling in the Indian informal sector including smelting, scrubbing, and shredding of plastic waste, is also a potential major POPs source that demands further investigation. The presence of POPs in plastic waste and their fate in the plastic recycling process have not yet been elucidated. By enhancing our understanding of these processes, this paper may aid policy decisions to combat the release of POPs from different waste types and processes in India.

Passive Air Sampling of PCDD/Fs, PCBs, PAEs, DEHA, and PAHs from Informal Electronic Waste Recycling and Allied Sectors in Indian Megacities.

Xenobiotic chemical emissions from the informal electronic waste recycling (EW) sector are emerging problem for developing countries, with scale and impacts that are yet to be evaluated. We report an intensive polyurethane foam disk passive air sampling study in four megacities in India to investigate atmospheric organic pollutants along five transects viz., EW, information technology (IT), industrial, residential, and dumpsites. Intraurban emission sources were estimated and attributed by trajectory modeling and positive matrix factorization (PMF). ∑17PCDD/Fs, ∑25PCBs, ∑7plasticizers, and ∑15PAHs concentrations ranged from 3.1 to 26 pg/m3 (14 ± 7; Avg ± SD), 0.5-52 ng/m3 (9 ± 12); 7.5-520 ng/m3, (63 ± 107) and 6-33 ng/m3 (17 ± 6), respectively. EW contributed 45% of total PCB concentrations in this study and was evidenced as a major factor by PMF. The dominance of dioxin-like PCBs (dl-PCBs), particularly PCB-126, reflects combustion as the possible primary emission source. PCDD/Fs, PCBs and plasticizers were consistently highest at EW transect, while PAHs were maximum in industrial transect followed by EW. Concentrations of marker plasticizers (DnBP and DEHP) released during EW activities were significantly higher (p < 0.05) in Bangalore than in other cities. Toxic equivalents (TEQs) due to dl-PCBs was maximum in the EW transect and PCB-126 was the major contributor. For both youth and adult, the highest estimated inhalation risks for dl-PCBs and plasticizers were seen at the EW transect in Bangalore, followed by Chennai and New Delhi.

Legacy persistent organochlorine pollutants and polycyclic aromatic hydrocarbons in the surface soil from the industrial corridor of South India: occurrence, sources and risk assessment.

Conversion of agricultural fields into the industrial corridor under the State Industries Promotion Corporation of Tamil Nadu Limited (SIPCOT) necessitated the investigation of soil-borne organic contaminants. This study is the first attempt to evaluate the occurrence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in soils from Mambakkam and Cheyyar SIPCOT belt, along the residential, industrial and agricultural transects. Concentrations of Σ28PCBs, Σ16PAHs and OCPs were in the range 0.3-9 ng/g, 33-2934 ng/g and nd-81.4 ng/g, respectively. Residential areas showed higher OCP concentrations than other site types, probably due to their frequent use in vector control programmes. DDT isomers and α-isomer of endosulfan showed low concentrations indicating past usage of these OCPs. Principal component analysis indicated that high-temperature combustion and industrial processes might be the major sources of high molecular weight PAHs, while low-temperature combustion processes might be responsible for low molecular weight PAHs. PCBs in soil were probably attributed to unaccounted combustion processes of e-waste in the region. Carcinogenic PAHs and Σ28PCBs were higher in the industrial sites. Mean Σ28PCBs at Mambakkam (4.8 ng/g) was significantly higher (p < 0.05) than that at the incipient industrial corridor Cheyyar (2.7 ng/g). Lower chlorinated PCBs (3-Cl and 4-Cl) amounted to more than half of Σ28PCBs in 75% of the sites. Total toxic equivalents (TEQs) of PAHs (total BaPeq) were found to be maximum in industrial areas. Maximum contribution to TEQs due to dioxin-like-PCBs was from PCB-157, followed by PCB-189.

Plasticizers and bisphenol A in Adyar and Cooum riverine sediments, India: occurrences, sources and risk assessment.

Adyar and Cooum, the two rivers intersecting Chennai city, are exposed to serious pollution due to the release of large quantities of dumped waste, untreated wastewater and sewage. Sediments can act as repository for emerging organic contaminants. Hence, we have monitored the occurrence and risk associated with plasticizers [six phthalic acid esters (PAEs), bis(2-ethyl hexyl adipate) (DEHA)] and bisphenol A (BPA) in surface riverine sediments of Adyar and Cooum rivers from residential/commercial, industrial and electronic waste recycling sites. Σ7plasticizers (PAEs + DEHA) in the Adyar riverine sediment (ARS) and Cooum riverine sediment (CRS) varied between 51.82-1796 and 28.13-856 ng/g, respectively. More than three-fourth of Σ7plasticizers came from bis(2-ethylhexyl) phthalate (DEHP), in accordance with the high production and usage of this compound. BPA varied between 10.70-2026 and 7.58-1398 ng/g in ARS and CRS, respectively. Average concentrations of plasticizers and BPA were four times higher in electronic waste (e-waste) recycling sites when compared with industrial and residential/commercial sites. BPA and DEHP showed a strong and significant correlation (R2 = 0.7; p < 0.01) in the e-waste sites thereby indicating common source types. Sites present at close proximity to raw sewage pumping stations contributed to 70% of the total BPA observed in this study. For the derived pore water concentration of plasticizers and BPA, the ecotoxicological risk has been found to be higher in ARS over CRS. However, sediment concentrations in all the sites of ARS and CRS were much below the recommended serious risk concentration for human (SRChuman) and serious risk concentration for ecotoxicological (SRCeco).

Polychlorinated Biphenyls in Surface Soil from North-East India: Implication for Sources Apportionment and Health-Risk Assessment.

Although India never manufactured polychlorinated biphenyls (PCBs), evidence suggests the prevalence of PCBs in multi-environmental matrices. Despite the high level of PCBs that has been detailed in the major urban areas of India, little is known about the fate and sources of PCBs in Northeast India (NEI). This motivated us to investigate the contamination level and sources of PCBs in the surface soil. In this study, the environmental concentration and sources of 25 PCBs were investigated in surface soil (n = 60) from three states of NEI (lower Assam, Manipur, and Tripura). Additionally, the relationship between soil organic carbon (SOC) and PCBs was studied to investigate the role of SOC in the distribution of PCBs. Overall, the concentration of ∑25PCBs ranged from 2950 to 16,700 pg/g dw (median 7080 pg/g dw), 3580-21,100 pg/g dw (median 11,500 pg/g dw), and 2040-11,000 pg/g dw (median 4270 pg/g dw) in Assam, Manipur, and Tripura, respectively. Low-chlorinated PCBs were more prevalent than highly chlorinated PCBs. PCB-49 was identified as the most abundant in soil, followed by PCB-52, and accounted for 13% and 12.9% of ∑25PCBs, respectively. With respect to land use categories, high ∑25PCBs were related to grassland areas and proximity to the roadside soil. The principal component analysis indicated emissions from technical PCB mixtures, combustion of municipal wastes/residential wood, incineration of hospital wastes, and e-waste recycling/disposal sites are the real sources of PCBs. Marginally, a moderate-to-weak correlation of SOC with ∑25PCBs (R2 = 0.144, p < 0.05) and their homologs (R2 = 0.280-0.365, p < 0.05) indicated the little role of SOC in the dispersion of PCBs. The estimated toxic equivalency of dioxin-like PCBs suggested that PCB-126 is the most toxic contaminant to endanger the human population.

Screening of atmospheric short- and medium-chain chlorinated paraffins in India and Pakistan using polyurethane foam based passive air sampler.

Production and use of chlorinated paraffins (CPs) have been increasing in India. Distribution of CPs in the area and vicinity have become a great concern due to their persistency and toxicity. Polyurethane foam based passive air samplers (PUF-PAS) was deployed in order to screen the presence of short- and medium- chain chlorinated paraffins (SCCPs and MCCPs) in the outdoor atmosphere at many sites in India (in winter 2006) and Pakistan (in winter 2011). Concentrations of SCCPs and MCCPs ranged from not detected (ND) to 47.4 and 0 to 38.2 ng m(-3) with means of 8.11 and 4.83 ng m(-3), respectively. Indian concentrations showed higher average levels of both SCCPs and MCCPs India (10.2 ng m(-3) and 3.62 ng m(-3)than the samples from Pakistan (5.13 ng m(-3) and 4.21 ng m(-3)). Relative abundance patterns of carbon number are C10 > C11 > C12 ∼ C13 for SCCPs and C14 > C15 > C16 C17 for MCCP with similarity to the profiles of samples from China, the biggest CPs producer in the world. Principal Component Analysis suggested that detected SCCPs and MCCPs in this study originated from the same emission source.

Modeling the emission sources for polychlorinated biphenyls in India: implications for human health risk assessment.

In addition to the electronic waste generated in India, toxic wastes containing polychlorinated biphenyls (PCBs) are dumped in India for recycling purpose. In addition tropical climate facilitates the rapid entry of PCBs to the atmosphere from the contaminated surfaces. Therefore it is important to identify the pathway for atmospheric PCB loading so as to regulate the ongoing release of PCBs. Hence active and passive air sampling of PCBs were conducted along the urban and suburban transects of seven major Indian cities and from the hotspots and rural/background locations in India during 2006-2012. A sinusoidal model could very well describe the diurnal pattern observed in New Delhi, Kolkata, Mumbai and Chennai, which suggests that concentrations in air are influenced by temperature-dependent air-soil surface exchange processes.

Spatial distribution of persistent organic pollutants in the surface water of River Brahmaputra and River Ganga in India.

Persistent organic pollutants (POPs) like organochlorine pesticides (OCPs), polychlorinated biphenyles (PCBs) and polyaromatic hydrocarbons (PAHs) are discharged in surface water by various point and nonpoint sources thereby degrading the functioning of the ecosystem and threatening human health. Chlorinated pesticides such as Hexachlorocyclohexane (HCHs) and Dichlorodiphenyltrichloroethane (DDTs) are effective pest control chemicals, used in agriculture and public health activities (malaria eradication, etc.) in India for the past several decades and are still in use. POPs can cause endocrine disruption and food chain biomagnification because of their lipophilicity and environmental persistence. This study aims to assess the environmental occurrence and spatial distribution of OCPs, PAHs and PCBs in the surface water of River Brahmaputra and Ganga ending at the of the Bay of Bengal.The order of organochlorine pesticides is as: heptachlor>HCHs>DDTs>dieldrin>aldrin>endosulfan. Diamond Harbour and Bakkhali were the two places with elevated level of all individual HCH isomers compared to all other sites. ß-Endosulfan and α-Endosulfan were high at Dibrugarh than other sampling sites. This is due to the ongoing use of Endosulfan in the tea estates in Assam especially the estates close to the town of Dibrugarh. p,p'-DDT and o,p'-DDT levels indicate the fresh input of DDT in all the sampling sites. Heptachlor has been observed in 57% of the total samples reported in the present study.These reasons may attribute to high deposition of pesticides in the surface water of Ganga and Brahmaputra.In addition the catchments area of the Ganga River is surrounded by agricultural lands so a relatively higher residue of pesticides was prevalent. Σ27 PCBs varied from BDL to 142 (Avg±SD, 3.96±6.71) ng L-1. PCB-18, PCB-52 & PCB-44 showed the highest concentration levels for all the sampling sites. PCB-126 was observed in samples taken from sites close to the city limit of Kolkata and Assam which is an indication of higher toxic effect from this highly toxic congener. PCB-169 was prevalent in most of the sites. The total concentrations of PAHs varied from BDL to 31 (Avg±SD, 0.2±1.5) µg L-1. PAHs concentrations were very low as PAHs are particle bound compounds.

Dissolved and particulate phase phthalic acid esters in urban, suburban, and rural riverine catchments along the southeast coast of India after the COVID-19 pandemic.

Dumped waste plastics have been evidenced as a potential source for harmful chemicals along the riverine regions of India. Furthermore, Corona Virus Disease - 19 (COVID-19) pandemic resulted in a subsequent surge in the use of personal protective equipment (PPE) related single-use plastics and Tamil Nadu was India's second major waste generator. Given the newer challenges from dumped waste plastics along the four major rivers of Tamil Nadu emptying into the Bay of Bengal, we investigated thirteen phthalic acid esters (PAEs), in both dissolved and particulate phases of river water and drinking water samples. Æ©13PAEs in both phases followed the urban > suburban > rural catchment trend. Di (2-ethyl hexyl) phthalate (DEHP) was ubiquitous in both phases and the sites having a prevalence of open burning activities in the urban catchment showed elevated levels. The suburban and rural catchments of the Kaveri River (KR) and Thamirabharani River (TR) were predominated by DEP and DEHP. It is noteworthy that in the urban catchment, Ln (DiBP) and dissolved organic carbon (Ln DOC), were strongly correlated (R2 = 0.894, p < 0.05). Furthermore, a significant increase of DiBP (p < 0.05) in the urban catchment after the second phase of the pandemic most likely resulted from the wide use of DiBP in PPE plastics. Community-stored water from urban catchment was found to have a maximum of ∑13PAEs up to 3769.38 ng/L in the dissolved phase with elevated DMP concentrations leading to higher estrogenic equivalent. The average daily intake for dissolved phase PAEs was below the USEPA-recommended limit for drinking water. However, prolonged exposure to heavier PAEs in particulate matter cannot be ignored. Estimated ecotoxicological risk assessment showed the highest risk for fish species due to DEHP.

Polychlorinated biphenyls in bovine milk from a typical informal electronic waste recycling and related source regions in southern India before and after the COVID-19 pandemic outbreak.

For more than a decade, Chennai city in southern India has been evidenced with informal electronic waste (e-waste) recycling and open burning practices as the potential sources for polychlorinated biphenyls (PCBs). PCBs can bioaccumulate in livestock particularly cows grazing on the contaminated soil. The outbreak of the COVID-19 pandemic led to additional challenges associated with waste management practices. Hence this study aims to elucidate twenty-five PCB congeners in bovine milk from the previously reported PCB source regions in Chennai and the suburbs before and after about three years of the pandemic outbreak along electronic waste recycling (EWR), open burning dumps (OBD), and residential (RES) transects. The geomean concentration of Æ©25PCBs in ng/g lipid weight (lw) followed a decreasing trend of EWR (13 ng/g lw) > OBD (8 ng/g lw) > RES (4 ng/g lw). Over 80 % of PCBs stemmed from EWR and OBD transects before and after the pandemic. However, a significant surge in the level of PCB-52 was observed in the OBD transect after the pandemic outbreak. Most toxic PCB congeners, PCB-126 and -169 were significant contributors to TEQs in EWR and OBD transects and can be reasoned with the burning of waste materials and mixed plastics in these transects. The highest average daily dose (ADD) exposure risk was for children from EWR and was significantly higher (p < 0.05) than other transects. Mean ADD-induced TEQ (6.6 pg TEQ/kg-bw/day) from the cows grazing around Kodungaiyur dumpsite slightly exceeded the EU guideline of 5.5 pg TEQ/kg-bw/day after the outbreak of the pandemic due to PCB-126. However, none of the samples exceeded the US FDA (1.5µg/g milk fat) recommendation limits for PCBs in milk fat. Prolonged exposure to such persistent organic pollutants interlinked with the burning of mixed waste in the open dumps can be a public health concern.

Polychlorinated biphenyls in the surface and deep waters of the Southern Indian Ocean and Coastal Antarctica.

Polychlorinated biphenyl compounds (PCBs) are industrial chemicals whose production was discontinued in the early nineties in most countries. Sill, PCBs are detectable in pristine and remote locations. Occurrence in regions such as Southern Oceans and Antarctica are influenced by the global, and regional, cycling. Here, we studied the surface and deep ocean distribution of indicator- and dioxin-like PCB congeners in the Southern Indian Ocean (SIO), and the coast of Antarctica (COA) during the tenth Indian Southern Ocean Expedition (SOE-10), December 2017-February 2018. ∑21PCBs in SIO surface waters ranged from 3.8 to 167.1 pg L-1 (average ± standard deviation: 35.7 ± 48.4 pg L-1), and in COA from 1.0 to 41.8 pg L-1 (13.8 ± 12.7 pg L-1), respectively. A noticeable gradient was observed, with higher PCBs levels in northern latitudes than southern latitudes in the SIO, and higher levels in the eastern longitudes compared to western longitudes in the COA. Results suggest the influence of secondary sources, or re-emission, of PCBs in the Southern Oceans and Antarctica. Both regions showed notable PCB levels in surface and deep waters (up to 1000 m) due to ongoing surface sources and remineralization processes in deeper waters. Multimedia modeling with the global model (BETR-Global) suggests the SIO act as a net sink for PCBs in the ocean.