Hydrogeochemical characterization of groundwater and their associated potential health risks.

The present study assessed the human health risk exposure from the consumption of poor quality groundwater in the Lucknow area, a part of Central Ganga alluvial plain in India. Around 27 (n = 27) groundwater samples were collected from the study area. The analytical results of the samples (n = 27) collected indicate silicate and carbonate weathering is the dominant process along with cation exchange, sulfide oxidation, and reverse ion exchange. The type of groundwater is Ca2-Na-HCO3- type having all cations and anions within permissible WHO limits except for iron (Fe2+) and nitrate (NO3-). The high concentrations of Fe2 and NO3- in samples indicate the possibility of a non-geogenic point source for the same in an urban-influenced environment. The ionic concentration of dissolved constituents is used in weighted overlay analysis to generate the water quality index (WQI). WQI indicates that most urban areas (~ 98.52%) have fallen in the good to excellent category except few situated in the highly populated parts of Lucknow. The ionic concentrations of Fe2+ and NO3- have been further used to estimate human health risk by integrating regional urban population density data in Lucknow. The risk map shows alarming risks in the west-central part, where nearly ~ 35% of the total area is at moderate to high health risk.

GIS-based impact assessment and spatial distribution of air and water pollutants in mining area.

Mining is a significant part of the transforming economy, which is generally considered as essential as well as social evil at the same time. It is one of the potential contributors to air and water pollution and possesses long-term impact on their quality. Keeping in view the exponential mining activities, we have selected an iron mine area in Bailadila, Chhattisgarh, India, as a sampling site and investigated the impact of mining activities on the air as well as water quality by setting up seven air quality and thirty water quality monitoring stations. From the results obtained, it was observed that concentration of air pollutants such as SO2, NO2, PM2.5 and PM10 for the year 2015 lies in the range of 11.5-13.0 µg/m3, 11.5-13.0 µg/m3, 24.9-33.4 ppm and 61.6-74.2 ppm, respectively, while for the year 2018, it lies in the range of 10.3-11.7 µg/m3, 10.5-14.7 µg/m3, 18.3-50.8 ppm and 23.7-60.7 ppm, respectively. Furthermore, results obtained revealed that air pollutants such as SO2, NO2, PM2.5 and PM10 were within the permissible limits but they contributed towards the light air pollution (air pollution index: 25-50) at all the air monitoring stations. Moreover, PM10 was considered as criterion pollutant in the Bailadila, Chhattisgarh region. On the other hand, it was observed that groundwater quality was deteriorated in the subsequent years. Most of the water quality parameters were in the permissible limits except iron (Fe). Moreover, on the basis of water quality indexing, water quality was classified as "poor" in ~ 30% of the sites and "very poor" in ~ 34% sites. The water quality was "unhealthy for drinking" in 3% and 6% sites in the year 2015 and 2018, respectively.