ANNOUNCEMENTS
This research investigates the concentration and spatial distribution of heavy metals—i.e., arsenic, chromium, mercury, lead, and iron—in the aquatic system of River Yamuna with special reference to seasonal variation in pre-monsoon and post-monsoon seasons. Five major sampling points—Wazirabad Barrage, Hathi Ghat, Chhat Ghat, Upstream Okhla Barrage, and Downstream Okhla Barrage—were selected to investigate the spatial variation of metal pollution.
A comprehensive literature review revealed the major anthropogenic sources of heavy metal contamination as urban stormwater runoff, industrial effluents, and agricultural discharges, and urban areas of Delhi as the major hotspots of contamination. Field observation revealed that chronic adverse human activities further increase the pollution load of the river. Through graphical representation, we understood that although most of the concentrations of heavy metals were below the permissible limits of Water Quality Standards (as per IS: 2296) Class B – Water for outdoor bathing.
Application of spatial interpolation by Inverse Distance Weighting (IDW) using ArcGIS enabled the detection of intense hotspots of pollution, which may be utilized to guide the design of focused remedial interventions. Correlation matrix indicated intense correlations of various metals, reflecting common sources and similar environmental behavior. The research also contrasted the IS: 2296 standards for surface water quality with those developed by international regulatory bodies, e.g., USEPA and the European Union, and detected differences in allowed limits and highlighted the necessity of a systematic and scientific domestic regulatory policy. The findings present an overall view of seasonal and spatial patterns of heavy metal pollution in the Delhi environment's River Yamuna.
Keywords: Yamuna River, heavy metals, water quality, seasonal variation, toxicity, public health, environmental impact
