Health risks associated with heavy metals in the drinking water of Swat,northern Pakistan

The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake （CDI） and health risk index （HRI） were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

Environmental sustainability of grey water footprints in Peshawar Basin:Current and future reduced flow scenarios for Kabul River

Assessing water pollution at basin level is a challenging task.In this study,the environmental sustainability of grey water footprints(WFgrey)of Peshawar Basin in Pakistan was analysed.The release of nitrogen(N)and phosphorus(P)from point and non-point sources during the period 1986 to 2015 were studied.Water pollution level(WPL)for normal and 10%-50%future reduced runoff in Kabul River as a result of construction of dams was considered.Methodologies described in Water Footprint Assessment Manual and Grey Water Footprint Accounting Guidelines were followed.Results showed that 30-year annual average of N and P discharges were 24.5×10^(3)t/a and 10.9×10^(4)t/a respectively.The discharge of N and P from non-point sources contribute 97%and 99%respectively.N related WFgrey was 50×10^(8)m^(3)/a and 50×10^(9)m^(3)/a for P.WPL of N was within the sustainable limit for all reduced runoff scenarios while P-related WPL for normal runoff exceeded sustainable limits and was worse in each reduced runoff scenario.This study confirms the deteriorated water quality of Kabul River and the findings may be helpful for future planning and water resource management of the basin.

Prevalent fecal contamination in drinking water resources and potential health risks in Swat, Pakistan

Fecal bacteria contaminate water resources and result in associated waterborne diseases.This study assessed drinking water quality and evaluated their potential health risks in Swat, Pakistan. Ground and surface drinking water were randomly collected from upstream to downstream in the River Swat watershed and analyzed for fecal contamination using fecal indicator bacteria（Escherichia coli） and physiochemical parameters（potential of hydrogen, turbidity, temperature, electrical conductivity, total dissolved solid, color, odor and taste）. The physiochemical parameters were within their safe limits except in a few locations, whereas, the fecal contaminations in drinking water resources exceeded the drinking water quality standards of Pakistan Environmental Protection Agency（Pak-EPA）,2008 and World Health Organization（WHO）, 2011. Multivariate and univariate analyses revealed that downstream urbanization trend, minimum distance between water sources and pit latrines/sewerage systems, raw sewage deep well injection and amplified urban,pastures and agricultural runoffs having human and animal excreta were the possible sources of contamination. The questionnaire survey revealed that majority of the local people using 10–20 years old drinking water supply schemes at the rate of 73% well supply,13% hand pump supply, 11% spring supply and 3% river/streams supply, which spreads high prevalence of water borne diseases including hepatitis, intestinal infections and diarrhea, dysentery, cholera, typhoid fever, jaundice and skin diseases in children followed by older and younger adults.