Effectiveness of Government Interventions to Reduce Arsenic Exposure in Punjab, India.

Abstract:

Groundwater in the Indus basin is contaminated with geogenic and anthropogenic pollutants. This study evaluates the access to safe water in 195 villages where a total of 11000 wells, mostly private, were previously tested using field test kits for arsenic (As), fluoride (F), nitrate (NO₃) along with pH and electrical conductivity (EC). The state government has installed 2327 reverse osmosis (RO) system in Punjab for safe water supply, and many smaller RO systems are used by individual households. In order to investigate the effectiveness of these interventions, the inflow and outflow of a subset of 108 reverse osmosis (RO) systems, including community and household RO systems were analysed using field test kits. The performance of these kits were evaluated in the lab and found effective in determining whether water meets World Health Organization (WHO) guidelines. The composition of untreated groundwater ranged from <1 to 60 µg/L for As, <0.1-11 mg/L for F, and 0.0-340 mg/L for NO₃. The conductivity of RO inlet ranged from 0.200 to 4 mS/cm and was higher than half that value in the outlet water of 30 out of 98 household systems and 1 out of 10 community systems, respectively. The inlet of 64 out of 108 RO systems did not meet the WHO guideline for either As, F, or NO₃. The outflow of 7 and 8, respectively, of these same 64 RO systems did not meet the WHO guidelines for As and NO₃. The results show that almost one third of household/community RO systems are insufficiently maintained despite the fact that they were recently installed. Mapping the allocation of community RO systems, mostly in the southern part of the state, suggest these were politically motivated rather than by taking into account actual water quality with respect to As, F, or NO₃. An intervention such as blanket testing of well should be prioritized before any much costlier centralized interventions are provided to reduce exposure.