Evaluating Groundwater Quality for Sustainable Drinking and 1 Irrigation Purposes and Assessing Nitrate Risks on Human 2 Health in rural areas

Groundwater quality has specific importance for domestic, agricultural, and drinking 20 water supply. Therefore, the objective of the current paper is to investigate groundwater 21 quality for drinking and irrigation purposes, as well as studying health hazard effects of 22 nitrate-containing groundwater on age groups living in rural areas. Two water quality 23 indices were used for checking groundwater suitability for drinking and irrigation 24 purposes. For drinking water quality index (DWQI), 88% of groundwater wells were 25 poor water, whereas 12% were good water for drinking. The values of irrigation water 26 quality index (IWQI) showed that the suitability of groundwater for irrigation uses was 27 ranged from high to medium. In addition, this paper also included a risk assessment of 28 nitrate-containing groundwater on rural resident's health. calculating oral hazard quotient 29 (HQ oral ) for nitrates showed that 94% of the groundwater wells of the study area were less 30 than 1, indicating no adverse health hazards on infants and children, whereas 6% of total 31 wells were above 1, suggesting there are health risks. Regarding health effects on adults, 32 all HQ oral values were less than 1, indicating no adverse health hazards. The Hazard 33 Quotient via dermal contact (HQ dermal ) for nitrates was much less than the safety factor 1, 34 indicating no health hazards on age groups via bathing.

nitrate-containing groundwater on age groups living in rural areas. Two water quality 23 indices were used for checking groundwater suitability for drinking and irrigation 24 purposes. For drinking water quality index (DWQI), 88% of groundwater wells were 25 poor water, whereas 12% were good water for drinking. The values of irrigation water 26 quality index (IWQI) showed that the suitability of groundwater for irrigation uses was 27 ranged from high to medium. In addition, this paper also included a risk assessment of 28 nitrate-containing groundwater on rural resident's health. calculating oral hazard quotient 29 (HQoral) for nitrates showed that 94% of the groundwater wells of the study area were less 30 than 1, indicating no adverse health hazards on infants and children, whereas 6% of total 31 wells were above 1, suggesting there are health risks. Regarding health effects on adults, 32 all HQoral values were less than 1, indicating no adverse health hazards. The Hazard factors [5]. 48 The Water Quality Index (WQI) is considerably used to estimate the fitness of surface 49 water, as well as groundwater for drinking and agriculture [6]. The water quality index is 50 defined as a ranking, reflecting the composite impact of various water quality parameters 51 [7]. By specifying the suitable weightage to the parameters, WQI can be determined 52 precisely [8]. 53 The large-scale applications of nitrogenous fertilizer and application of animal manure 54 are considered as the essential source of nitrate (NO3) contamination to the groundwater 55 in many rural areas [9], [10], which have harmful influences on human healthiness and 56 the environment [11]. Inorganic nitrogen occurs in the forms of nitrate (NO3), nitrite 57 (NO2), and ammonia (NH4) in soil, and the most easily obtainable forms for plants are 58 NO3 and NH4. Nevertheless, both NO2 and NH4 generally exist in groundwater at very 59 little concentrations because they are readily converted to NO3 [12]. Repeated exposure 60 to nitrate, as one of the main contaminants in aquifers, leading to harmful health impacts 61 like methemoglobinemia (blue-baby syndrome), and particularly in infant's categories 62 [13]. Because of the severe impacts of nitrate on human health, a guideline of 50 and 15 63 4 mg L -1 for adults and infants, respectively, in drinking water, was recommended by the 64 World Health Organization (WHO) [14]. 65 The main objective of the study is to 1) determine the suitability of groundwater for 66 drinking and irrigation purposes via applying drinking water quality index (DWQI) and 67 irrigation water quality index (IWQI), and 2) assessing human health risk due to nitrate 68 exposure. The study area is located in Hemrin -Makhul Subzone or foothill zone which 80 characterized by a thick cover of sediments. The formations exposed in the area belong to  were rinsed with water samples three times and filled to the neck. For determining trace 96 elements, the samples were filtered using a 45µm membrane filter to get rid of colloids 97 and hen acidify them to a pH value less than two with high purity HNO3 acid [18]. All of 98 the collected samples were kept in a cool box in the field and then stored in a refrigerator 99 (4 -6 °C) before sending it to the laboratory. The water quality index is a worthy and distinctive parameter for determining the water 102 quality and its sustainability for drinking uses. It represents the combined effect of 103 various water quality parameters and provides water quality data to governmental 104 decision-makers and the general populace [19]. For calculating WQI four steps are 105 pursued as follows: 106 6 1. Each of the used parameters has been assigned a weight (wi) according to its relative 107 significance in the total quality of water for drinking uses. The minimum weight assigned 108 is one (the least effect on drinking water quality), and the maximum weight assigned is 109 five (the highest effect on drinking water quality) ( The quality and the quantity of the dissolved components in the irrigation water are used 129 to determine the water quality [24]. The permeability and infiltration hazard takes place 130 when elevated sodium ions minimize the rate at which irrigation water gets in the soil's 131 lower layers, and therefore, the crop cannot withdraw sufficient water from the soil, 132 which lessens agriculture production [25]. The SAR value of irrigation water defines the 133 relative ratios of Na + to Ca 2+ plus Mg 2+ and is calculated as: Where the concentration of Na, Ca and Mg are expressed in meq L -1 .

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In this paper, Irrigation Water Quality Index ( (Table 4) 138 were chosen, all five groups were included at the same time in the analysis and were 139 integrated to form a single value, which is then evaluated to define the suitability of the 140 groundwater for irrigation purposes. In the indicator methodology, each of the hazard 141 groups (Table 4) is given a particular weight from 1 (least considerable group in quality 142 of irrigation water) to 5 (most considerable group in quality of irrigation water). Based on 143 their importance for assessing the quality of irrigation water, the maximum weight of 5 144 has been assigned to EC, whereas the minimum weight of 1 has been allocated to pH, 145 HNO3 and NO3. The other hazard categories were designated a weight between 5 and 1 146 based on their significance in the overall irrigation water quality. The scale of quality 147 rating is ranged from 3, high suitableness for irrigation, to 1, low suitableness for 148 8 irrigation, for each component as in Table 4. The IWQI, to evaluate the integrated 149 influence of irrigation water quality parameters, is calculated as: where i is an incremental indicator, W is the contribution of every one of the five hazard 153 classes that are important to estimate the irrigation water quality, represents the weight 154 value of each hazard class, N is the overall number of water quality parameters in each 155 hazard class, and R is the rating value of each parameter as listed in Where CDI is the exposure represented by a mass of a substance per unit weight of body 166 per unit time (mg kg -1 d -1 ); Cw is the concentration of nitrate ion in water (mg L -1 ); IR 167 represents person ingestion rate of water (d -1 ); EF represents the exposure frequency (d 168 9 yr -1 ); ED indicates the exposure duration (yr); AT is the averaging time (AT=365×ED, d), 169 and BW is the average body weight (kg).

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The intake of a probable toxic substance by the human body via the dermal contact 171 pathway can be assessed by calculating DAD. The Eq. for calculating DAD is as follow

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[11]: Where DAD indicates the dermal absorbed dose of nitrate (mg kg -1 d -1 ); SA is the skin 175 surface area available for contact (cm 2 ); EV is the bathing recurrence (times/day). DA  Table 8.
Non-carcinogenic impact of nitrate in groundwater via oral and dermal contact pathways 184 can be expressed as hazard quotient (HQ) using Eq.s (11) and (12)

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The results of different physicochemical parameters of groundwater are listed in Table 9, 196 and the trace elements are presented in Table 10. Irrigation water was categorized based on IWQI given in Figure 3. For HQdermal, all values were much less than 1 for infants, children, and adults ( Figure 5), 214 suggesting no adverse health risks due to bathing by nitrate-containing groundwater.

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The values of THQ showed a very minor change when compared with HQoral values 216 ( Figure 6).

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In the current research, the suitability of groundwater for drinking and irrigation 219 utilization was evaluated using two water quality indices, as well as assessing the health This work was supported by the authors' self-efforts.