Toxic Levels of Some Heavy Metals in Drinking Network Surface Water of 1 Damietta Governorate , Egypt 2 3

Abstract. In this paper, the heavy metals of the surface drinking water of Damietta governorate were evaluated. Damietta district, Farascore City, EL-Zarka City and Kafr Saad City are the main locations of drinking water pollution. The villages of the Damietta governorate have concentration values less than the permissible limits of World Health Organization (WHO) and Egyptian Ministry Health (EMH).


SAMPLING AND METHODS:
Drinking water samples were collected from different districts of Damietta governorate; Damietta, New Damietta City, Ras El-Bar, Kfr Saad, Farascore and EL-Zarka (Fig. 1).These samples collected from surface network water in each district, where the samples taken from public site in district.The samples randomly collected from each site in district.Heavy metals concentrations of drinking surface network water were analyzed by atomic absorption spectrophotometer (AAS) (Table 1).These metals are lead (Pb), zinc (Zn), copper (Cu), cobalt (Co), cadmium (Cd), nickel (Ni), chromium (Cr), iron (Fe) and manganese (Mn).The estimated values compared with WHO, 2011 andEMH, 2007 values to evaluate the studied drinking water.Where, this instrument available in the National Research Center for such studies.The pollution index (PI) was used in this study to evaluate the degree of heavy metal contamination in water samples (Chon, et al., 1991;Kim et al., 1998;Emoyan et al., 2005;Odukoya and Abimbola 2010).The tolerable level is the element concentration in the water considered safe for human consumption (Lee et al., 1998).Pollution index (PI) is based on individual metal calculations and categorized into 6 classes (Table 2) according the following equation (Caerio et al., 2005).

RESULTS AND DISCUSSION
The results are shown in Table 1 and 3. Where, the concentration of heavy metals in the drinking water and the pollution index of each site recorded in these tables.The values in Table 1 were compared with the permissible limits of Egyptian Ministry Health (EMH) permissible limits, 2007 and the permissible limits of WHO, 2011.As well as the pollution index were determined for each site or sample.
The drinking surface network water in Ras EL-Bar and New Damietta cities is suitable for drinking due to the whole values of heavy metals less than the permissible limits of EMH, 2007 andWHO, 2011 (Table. 1).Pollution index (PI) of these districts or cities in Damietta governorate showed that the degree of heavy metals contamination is no effect (<1) (Table . 2 and 3).
In Damietta district, Cd values of the samples are more than the permissible limits of EMH, 2007 andWHO, 2011.Cu values of the samples less than the permissible limits of EMH, 2007 and WHO, 2011 except in samples 9 and 12. Ni, Cr, Pb values are ≥ the permissible limits of EMH, 2007 and WHO, 2011.Co, Mn and Fe values are less than the permissible limits of EMH, 2007 andWHO, 2011.Pollution index of Damietta district is moderately affected category (2-3) (Table 2 and 3).
In Farascore district, the concentration values of heavy metals in Farascore city more than that in the villages of Farascore.Samples of Farascore city (14,15 and 16) showed that Cd, Ni, Cr and Pb values more than the permissible limits of EMH and WHO.The Cu, Co, Mn, Fe and Zn are less than the permissible limits of EMH and WHO.Samples of the villages of Farascore have values less than the permissible limits of EMH and WHO.Pollution index of the Farascore district showed slightly affected grad in samples 14, 15 and 16, while it is no affected grad in the other samples.
In EL-Zarka district, samples 25, 26 and 27 of Zarka city show that Cd Ni, Cr and Pb values more than the permissible limits of EMH, 2007 andWHO,2011.The Cu, Co, Mn, Fe and Zn are less than the permissible limits cof EMH and WHO.Samples of the villages of EL-Zarka have values less than the permissible limits of EMH and WHO.Pollution index of EL-Zarka district showed slightly affected grad in samples 25, 26 and 27, while it is no affected grad in the other samples.
In Kaf Saad district, the sample 30 and 31 of Kafr Saad city showed that Cd, Ni, Cr and Pb values more than the permissible limits of EMH, 2007 and WHO,2011, while the other metals are less than the permissible limits.Samples of the villages of Kafr Saad have concentration values less than the permissible limits of EMH, 2007 andWHO,2011.Pollution index of Kafr Saad district showed slightly affected grad in samples 30 and 31, while it is no affected grad in the other samples.
Thus the populations of Damietta City, Farascore City, EL-Zarka City and Kafr Saad City may be suffering from many diseases such as Liver Cirrhosis, Rental Failure, Chronic Anemia and Hair Loss.

Fig
Fig. (1): Location map for the different surface drinking water samples.Calculation of Pollution Index:The pollution index (PI) was used in this study to evaluate the degree of heavy metal contamination in water samples(Chon, et al., 1991; Kim et al., 1998; Emoyan et   al., 2005; Odukoya and Abimbola 2010).The tolerable level is the element concentration in the water considered safe for human consumption(Lee et al., 1998).Pollution index Heavy metal concentration in water; Si= permissible Level and Nm = Number of Heavy metals.Water sample with Pollution Index (PI) greater than 1 is regarded as being contaminated

Table . (3): Pollution Index of drinking surface network water in Damietta
pollution of surface drinking water of Damietta governorate by heavy metals in 140 most of villages less than that in the cities of the Damietta governorate.Pollution index is 141 ranged between no affected to moderately affected for whole station samples.142 143