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.

Water-sanitation-health nexus in the Indus-Ganga-Brahmaputra River Basin: need for wastewater surveillance of SARS-CoV-2 for preparedness during the future waves of pandemic.

The Indus-Ganga-Brahmaputra River Basin (IGBRB) is a trans-boundary river basin flowing through four major countries in South Asia viz., India, Pakistan, Bangladesh, and Nepal. Contamination of surface water by untreated or inadequately treated wastewater has been a huge problem for pathogenic microorganisms in economies in transition. Recent studies have reported that sewage surveillance can provide prior information of the outbreak data, because faeces can contain the novel coronavirus (SARS-CoV-2) shed by infected humans. Hence, in this study we geo-spatially mapped the COVID-19 hotspots during the peak time in the first and second wave of pandemic to demonstrate the need and usefulness of wastewater surveillance strategy in IGBRB during ongoing pandemic. Further we discussed the status of sanitation, health and hand-hygiene in the IGBRB along with characterization of the challenges posed by the pandemic in achieving the United Nations Sustainable Development Goals (UN-SDGs). Monthly Geographical Information System (GIS) mapping of COVID-19 hotspots in the IGBRB showed an increase in the spread along the direct sewage discharge points. The social inequalities expose the vulnerabilities of the urban poor in terms of the burden, risks and access to Water, Sanitation, and Hygiene (WASH) needs. Such an evidence-based image of the actual SARS-CoV-2 viral load in the community along the IGBRB can provide valuable insights and recommendations to deal with the future waves of COVID-19 pandemic in this region that can go a long way in achieving the UN-SDGs.