Himalayan Environment Research Institute

Mercury (Hg) is among the most toxic metals possessing a major threat to human health and aquatic ecosystems over the globe. However, measurement of Hg concentrations and seasonal variability remain poorly understood over the Indo-Gangetic Plain (IGP) in northern India. In this study, we present one-year data of particulate-bound mercury (HgP) in aerosol samples (PM10) collected from Kanpur to understand seasonal variability and factors influencing concentration, as well as dry deposition flux. The HgP concentration exhibit a large temporal variability and ranged between 100 (on 14 June 2007) to 4340 pg m−3 (on 4 March 2007) with an annual average concentration of HgP is 776 ± 846 pg m−3. The HgP concentrations and HgP/PM10 ratios showed a marked seasonality with the highest in winter (Dec-Feb) followed by post-monsoon (Oct–Nov) and summer (April–June) seasons. HgP and HgP/PM10 were positively correlated (r2 = 0.77, p < 0.05, N = 58) during the sampling period and the estimated dry deposition flux of HgP was 104.7 µg m−2 y−1. Although this study provides a comprehensive data set on HgP in an urban atmosphere of the IGP revealing high levels of HgP, measurement of gaseous Hg is needed for estimation of the total Hg budget. Therefore, future studies should focus on identification of different sources as well as emission characteristics of all forms of Hg (organic and inorganic forms) for better mitigation strategy to prevent health risks associated with toxic Hg in the region.

ABSTRACTThe concentration of 13 metals (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, and Hg) and their associated health risk assessment was performed for two Himalayan lakes, urban Phewa and remote Gosainkunda, from Nepal. Water Quality Index (WQI), Metal Index (MI), Hazard Quotient (HQ), Hazard Index, and Cancer Risk were calculated in order to evaluate the water quality of these lakes. Correlation analysis revealed that Mn and Fe were derived from natural geological weathering processes and Pb, V, Cr, Co, Ni, Cu, Zn, and Cd might have originated from anthropogenic sources. The results revealed that WQI of the remote lake fell into excellent water quality and urban lake fell into poor water quality, which is also supported by the MI calculation. Moreover, the HQ of Mn in urban lake showed values greater than unity suggesting its health risk to the local inhabitants. The cancer index values indicated “high” risk due to Cr, whereas Cd possesses “very low” cancer risk on local population residing nearby areas. This study provides the useful database and suggests for the regular assessment and policy formulation for safeguarding the natural water bodies in the region.

Nardostachys jatamansi, a perennial medicinal plant in Nepal, is valued for the rhizomes which have been traditionally used for a number of medical applications, including as a stimulant for the cardiac, respiratory, and nervous systems and as a carminative, stomachic, laxative, antispasmodic, diuretic, and emmenagogue. Extracts are generally prepared as an infusion for medical applications. The plant also has cosmetic uses in hair washes and hair oils.