Assessment of Spatial Ambient Concentration of NH3 and its Health Impact for Mumbai City

Abstract

Generally, ambient Ammonia (NH3) concentration level is always under prescribed limit of government regulatory authorities but the concentration level tends to be higher in surrounding regions of a chemical fertilizer industry. There are many chemical fertilizer industries across the world and 9 public and 18 private fertilizers industries in India. Mostly, air quality monitoring is carried out for many gaseous pollutants and dust such as SO2, NO2, SPM, PM10 and PM2.5 but NH3 is monitored at only few selected locations. Maravali region of Mumbai city has a public sector fertilizer company and this region has maximum concentration of NH3 in Mumbai city. In this study, the spatial average concentration of NH3 was estimated for Mumbai city including and excluding the air quality monitoring site of Maravali, where fertilizer industry is present. The spatial average concentration of Mumbai city is 85 μg/m3 and 56 μg/m3 including and excluding Maravali respectively. The maximum concentration of NH3 is at Maravali and annual average concentration here is 342 μg/m3. This is 6.1 times more of spatial average concentration of Mumbai excluding Maravali. The same was visualized and represented in spatial concentration mapping using Inverse Distance Weighting (IDW) interpolation technique of ArcGIS tool. Also, health impact assessment was carried out for Mumbai city due to the concentration level of NH3. Local Concentration–Response (C-R) coefficient for Mumbai was used to assess health impact for ammonia. 3.4 and 6.8 Million people were exposed by phlegm and other chest illness respectively in Mumbai city. The economic cost of the health was also estimated for the phlegm due to ammonia which was 57 Million USD (3.9 Billion INR) for the year 2012 for Mumbai city.

Keywords

• nh3 concentration
• spatial distribution
• idw
• exposed population
• health cost