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The unplanned Bhalswa landfill is located in one of the most urbanized area of Delhi, and its influence on the huge population are inevitable in the capital city of India lying in flood plain of the Yamuna River, and its alluvial lithology makes it more susceptible to contamination by leaching of pollutants. The present study highlights to assess the impact of non-engineered Bhalswa landfill site on the groundwater quality and associated potential health risk by its consumption to local residents of New Delhi, by collecting four leachate and sixty groundwater samples for pre- and post-monsoon seasons in the year 2013. The contamination potential of the leachate samples and the groundwater quality were evaluated with the help of leachate pollution index (LPI) and water quality index (WQI), respectively. The value of LPI is high in both the seasons but more in pre-monsoon (31.51) as compared to post-monsoon (29.36). The Obtained results of groundwater samples showed elevated level of Electrical conductivity (EC), major cations and anions. The EC of groundwater samples display concentration as follows: (pre-monsoon, 456–10870, average 3772; post-monsoon, 465–10450, average 3747). The groundwater samples close to the Bhalswa landfill shows very high value of EC and other chemical parameters. WQI calculated (using 17 physico-chemical parameters and WHO standards) to distinguish the areas of excellent and unsuitable for drinking purposes which will be helpful for the management of water resources. Our results showed that the concentration of majority of heavy metals exceed the WHO permissible limit except Cr and Cu which may be due to redox conditions that control the mobility of these ions in aqueous solutions. The average target hazard quotient (THQ) value of heavy metals were found in the order of Cd > Mn > Pb > Cu > Ni > Fe > Zn > Cr in both the seasons. The tube wells with more than one THQ value for Cd (100%), Mn (63%) and Pb (37%) will have potential human health risks. Hazard index (HI) shows greater than one value for all the samples and the average HI values are 10.241 for pre- and 10.402 for post-monsoon season. THQ and HI values suggest that the residents are highly susceptible to ingestion pathway. A conceptual model is used to describe the dispersal of leachate pollutants with reference to various kinds of geo-environmental features which degrades the groundwater quality. The health risk associated with metals in near future can be a serious threat for this region if this groundwater is being used for long run without proper remedial measures. [ABSTRACT FROM AUTHOR]

The present study aims at the assessment of environmental quality of the most polluted stretch of river Yamuna along the megacity of Delhi. The study was conducted in order to examine toxicity and health hazards associated with persistent pollutants present in the fluvial ecosystem. Eighty four sediment and 56 vegetable samples from same locations were collected from the Delhi segment of river Yamuna flood plain in order to examine 20 organochlorine pesticides (OCPs) and 9 heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Both the organic and inorganic groups of persistent toxic substances were monitored and analysed for the extent of eco-toxicological as well as dietary health risks posed to the local population. Eco-toxicological assessment was done based on sediment quality guidelines, enrichment factor, geo-accumulation index, degree of contamination and Pollution Load Index. The dietary-risk was assessed with the help of translocation factors (TF) of these pollutants in vegetables. Carcinogenic and non-carcinogenic health risks from consumption of vegetables were also investigated. The level of concern for heavy metals was greater than that of OCPs as per the sediment quality guidelines. DDT, Cd, Pb and Zn had maximum concentrations corresponding to level 3 of concern, while Cr and Ni reached up to the highest i.e., 4th level of concern. Sediment samples were found to be enriched and contaminated significantly with Cd and moderately with Pb, as represented respectively by enrichment factors and contamination factors (CF). CF for metals lied in order Zn > Cd > Cr Ni > Pb Cu. Pollution load index was highest at the location lying on the exit point of Yamuna in Delhi. TF values greater than 1 were observed in majority of samples analysed for Ni, Cr, Cu and Zn. Spinach topped among vegetables in terms of metal contamination. Cd, Ni and Pb accumulated more in the roots, as against Mn, Zn, Cu and Cr which had higher accumulation in the shoots. Translocation factors were substantially high in vegetables for most of the OCPs, clearly indicating bioaccumulation and potential health risk to the consumers. Health risk to humans was assessed for non-carcinogenic and carcinogenic potentials from ingestion of vegetables. Hazard Quotient (HQ) > 1 due to radish (roots and leaves) and cauliflower consumption in children indicated non-carcinogenic risk. Hazard Index (HI) beyond 1 for all the vegetables (except onion leaves) confirmed substantial cumulative risk. Lifetime cancer risk (LCR) revealed moderate (spinach, radish, beet root and cauliflower) to low (all the others) levels of carcinogenic risk to humans. Cancer risks from γ-HCH, β- HCH, Hept, Hept Ep, Ald, p,p'-DDT, and Cr exposure through the food chain could be well established. [Display omitted] • 20 OCPs and 9 heavy metals were studied in fluvial ecosystem of river Yamuna. • OCPs and heavy metals in sediment and vegetables exceeded freshwater sediment quality guidelines. • Metals showed high enrichment and contamination factors, geo-accumulation and pollution load indices. • High translocation factors in vegetables indicated bioaccumulation in the food chain. • Vegetable consumption carried potential non-carcinogenic and carcinogenic risks, especially in children. [ABSTRACT FROM AUTHOR]