Integrated Resource Recovery at East Calcutta Wetland: How Safe is These?

Abstract

East Calcutta Wetland (ECW) is an example of wise use of cities solid and liquid waste through integrated resource recovery, mainly for pisciculture, vegetable as well as paddy cultivation and manure production. Amaranthus caudatus, Amaranthus blithum and Spinacia oleracea grown at ECW were analyzed for their accumulation of elements using Energy Dispersive X Ray Fluorescence (EDXRF) and compared to those grown in south eastern parts of West Bengal (Midnapur). The objective was to analyze the health hazard, if any, underlying the use of wastewater and solid waste for cultivation of green leafy vegetables at ECW. The following results were obtained upon comparing the data collected from the two different sites: (a) higher accumulation in ECW grown plants of elements like Ca, Cu and Pb in Amaranthus caudatus; of Ca in Amaranthus blithum; of Cl and Cu in Spinacia oleracea, (b) for the same species grown in non-ECW site, higher concentration of elements like Mn and Fe in Amaranthus caudatus; of Cl, Mn and Br in Amaranthus blithum; of Ca, Mn, Fe and Br in Spinacia oleracea. The net consumption of the aforementioned elements per person per day was calculated and found to be much below the Recommended Dietary Allowance (RDA) levels in all cases. Thus the vegetables grown out of integrated resource recovery mechanism at East Calcutta Wetland appear to be safe for human consumption. This further corroborated by the healthy appearance of these vegetables. This result has profound implications of far reaching significance for environmental management and health economics.