Groundwater is the main source for drinking in Egypt, especially in rural communities;
however, water quality of shallow aquifers is more susceptible to human activities. The
current work aimed at evaluating groundwater quality for drinking and associated health
risks in an area of the Nile Delta (30◦ 14′′ 47′′ to 30◦ 17′ 51′′ N and 31◦ 17′ 38′′ to
31◦ 20′12′′ E) in response to irrigation water quality. Thirty groundwater samples were
collected from three irrigated sites (ten samples from each site); the Nile freshwater
(NFW), the agricultural drainage water (ADW), and mixed wastewater (MWW) irrigated
sites. Overall, ranges of pH, Ca2+, Mg2+, F−, NO−
3 , Cu, Mn, Ni, and Zn were within the
permissible levels according to Egypt and WHO drinking water standards, while the
count of total and fecal coliform bacteria exceeded safety limits. The water quality index
indicated that samples from the NFW-, ADW- and MWW-irrigated sites had moderate
to good, low, and low to moderate qualities, respectively. On average, the hazard index
(HI) indicated no potential non-cancer risk for adults (HI < 1.0) in the three sampling
sites, while children in the MWW-irrigated sites would suffer adverse health risks (HI
> 1.0). The mean total cancer risk (TCR) was in the acceptable range (1.0 × 10−6 to
1.0 × 10−4) for adults in two sites (the NFW- and ADW-irrigated sites), while adults
in the MWW-irrigated sites and children in all sampling sites would suffer cancer risks
over the lifetime (TCR > 1.0 × 10−4). The potential cancer risk would be mainly due
to Ni exposure via the oral route, and thus further management studies should be
considered to mitigate the adverse effects. This study would provide a useful database
for decision and policymakers for protecting shallow groundwater quality and reduce
potential human health risks. |
