Data health risk assessment of nitrate contamination in groundwater of rural region in the Yerraguntla Mandal, South India

The main objective of the present study was to determine the distribution levels of nitrate contamination in groundwater and its associated impact on human health risk in the Yerraguntla mandal, South India. For this 40 ground water samples were collected randomly during April 2018. Nitrate concentration in groundwater samples ranged from 2.50 to 760.12 mg/L, with a mean value of 86.13 mg/L. Most of the groundwater samples are exceeding the permissible limits of nitrate (45 mg/l). Hence health risk assessment of nitrate has been carried out. Hazard quotient (HQ) values for infants, children, male and female ranges from 0.05 to 14.25; 0.06 to 18.53; 0.04 to 12.18 and 0.05 to 14.62, respectively. The finding of data showed that HQ value was more than 1 in 42.5% of samples in groups of infants, children and female, and 35% of samples in group of male.


Value of the data
• The data of present paper revealed that the nitrate concentration in 45% of groundwater samples exceeding the maximum permissible limits (45 mg/L) according to world health organization (WHO) guidelines. • The findings of this study reveal that all the four groups i.e. infants, children, female and male are exposed to nitrate risk (HQ > 1). • High nitrate concentration in drinking water causes health risks on human body like methemoglobinemia in infants and stomach cancer in children.
• The findings of this study reveal the all the four groups i.e. infants, children, female and male are exposed to nitrate risk (HQ > 1). • Health risk assessment revealed that male, are less prone to risk than female. Hence proper precautionary measures have to be taken to control health risk in this area.

Study area
Yerraguntla is a limestone area located within the Kadapa district of the Andhra Pradesh. The study area lies between Latitudes N 14 °35 ˊ17.2 ˊˊ-N 14 °44 ˊ38.4 ˊˊand Longitudes E 78 °27 ˊ38.4 ˊˊ-E 78 °34 ˊ39.3 ˊˊ ( Fig. 1 ). In this area mainly Arenaceous consisting of conglomerate quartzite, Quartzite with shale formation of dolomitic lime stones are present. Groundwater quality may vary depending upon variations in geological formations. The total annual rainfall in the study area is 730.7 mm [1 , 2] .

Analytical data
Spatial distribution map of the nitrate shown in Fig. 2 ; revealed that most of the higher nitrate concentration fall eastern part of the study area. The concentration of nitrate and HQ values for infants, children, female, male shown in Table 1 . Table 2 show that the ranges of HQ for four groups. In the present study, 42.5% of the groundwater samples exceeding 1(HQ > 1) is referred as adverse non-carcinogenic risk for human health, for infants, children, female and 35% of samplers exceeding 1(HQ > 1) for male as shown in Fig. 3 .

Experimental design, materials, and methods
The Samples were collected from 40 points in the different villages of Yerraguntla Mandal ( Fig. 1 ). The samples were collected systematically during the month of April from bore/ hand pumps of study area. The samples were collected in acid washed 1 litter polyethylene bottles to prevent unpredictable changes in characteristic as per standard procedures [3] . Each of the groundwater samples was analyzed for nitrate. The nitrate concentration was measured using Spectro-photometer accordance standard methods for examination of groundwater [4][5][6][7] .

Human health risk assessment
In recent decades, groundwater quality has continued to deteriorate due to the various pollution sources such as chemicals and fertilizers [8] . And due to this there is an increased awareness of health risk on humans. Health risk assessment plays a crucial role in this new era. Health assessment insures and evaluates adverse human health effect on infants, children, female and male [9 , 10] . This study signifies the health risk assessment associated with NO 3 − in drinking water and around Yerraguntla Mandal. The chronic daily intake (CDI) and hazard quotient (HQ) were calculated by following formulas: Where CDI is the chronic daily intake (mg/kg/day), CPW indicate nitrate contamination concentration in groundwater (mg/L), Ingestion rate (IR) 2 L/day for male and female, 0.78 L/day for children, 0.3 L/day infants [11] . ED indicates exposure duration Years 40, 40,12 & < 1 for male, female, children, infants respectively [12] . EF indicates exposure frequency is assigned, 365days/year for male, female, children and Infants, ABW denotes average body weight of human body in kg 78 (male), 65 (female), 20 (Children), 10 (infants), AET denotes average exposure time Days, 14,600 for male and female, 4380 children and 365 infants. RfD indicates that reference of NO 3 − (1.6 mg/kg/d)were obtained from the database of Integrated Risk Information System (IRIS), and USEPA (2012) [13] . Hazard quotient value exceeding 1 is referred as adverse non-carcinogenic risk for human health, while HQ values less than 1 indicates acceptable limit of non-carcinogenic risk.