Quality assessment of roof-harvested rainwater in the West Bank, Palestinian Authority

摘要

Rain harvesting is becoming more common in the Palestinian Territories as a result of drinking waternscarcity. Although it might pose serious human health risk, this water is being consumed withoutntreatment in many areas of the West Bank. The present study evaluates the physicochemical andnmicrobial quality of harvested rainwater that is used as potable water in the West Bank. Samplesnfrom roof-harvested rainwater storage tanks (n ¼ 42) were collected in summer (SS) 2006/wintern(WS) 2007. Physicochemical parameters measured were: temperature, pH, electrical conductivity,nsalinity, total dissolved solids, turbidity, nitrate, copper and lead. With few exceptions, all thesenparameters were within WHO guideline values. All samples (100%) were found to contain coliformsnand to be heavily contaminated with heterotrophic bacteria. About 67% of all samples werencontaminated with fecal coliforms. Specific PCR technique confirmed the presence of fivenpathogenic microorganisms that can be ordered according to their prevalence as: Citrobactern(83%)>Acinetobacter (78%)> Aeromonas (52%)> Pseudomonas and Campylobacter (7%).nPrevalence of microorganisms in SS was higher than in WS. Although the physicochemical quality ofnmost harvested rainwater samples was in accordance with WHO guidelines for drinking water,nstored rainwater was significantly contaminated with bacteria resulting in significant human healthnrisk from infectious diseases.