The US Environmental Protection Agency (EPA) and World Health Organization (WHO) suggested a maximum level of 10µg/L inorganic arsenic level in groundwater is viewed as safe for drinking purpose (ATSDR, 2005; Rakib et al., 2013; WHO, 1993). Arsenic was positioned as number one general human health impact on its substance priority list by United States Agency for Toxic Substances and Disease Registry considering it as a carcinogen causing cancer of lung, kidney, bladder and skin (ATSDR, 2005). International Agency for Research on Cancer grouped inorganic arsenic as class I human cancer-causing agent, which means adequate evidence supported their classification (IARC, 2012; Martinez et al., 2011; WHO, 2011). The Joint Food and Agriculture Organization of the United Nations/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) re-examined the risks of arsenic exposure and found evidence of adverse impacts in regions with drinking water arsenic concentration ranging between 50 to 100µg/L (WHO, 2011).
An estimated 200 million individuals are exposed to arsenic level unquestionably more than the permissible limit, caused different arsenic related diseases (Naujokas et al., 2013; IARC, 2004; Gregori et al., 2003; Nordstorm, 2002; Smith et al., 2000). A new report in 2012 assessed that around 20-45 million individuals are at high risk of arsenic exposure more than 50μg/L concentration (Flanagan et al., 2012). According to a recent study, cancer risk is related with normal day by day utilization of 2 litres of drinking water with more than 50µg/L inorganic arsenic. The main source of inorganic arsenic exposure is mostly through drinking water and water-based products (Sinha et al., 2003; Anetor et al., 2007; Chung et al., 2014). The present study revealed the highest groundwater arsenic concentration found to be 244.20µg/L in studied area which is around 24 times greater than the WHO maximum permissible limit. Around 61% of the handpumps were found to be contaminated with more than 10µg/L arsenic concentration that is problematic situation for the residing population. The highly elevated arsenic levels were found between 60-80 feet of handpump depth range.
The arsenic toxicity symptoms primarily manifest on skin along with disturbances in other cellular process of organ systems. The arsenic caused skin manifestation appears with hyperpigmentation, hyperkeratosis, hypermelanosis of the palm and sole (Li et al, 2011; Melkonian et al., 2012). In the present study also, many arsenic exposed subjects exhibited the symptoms of arsenicosis like hyperkeratosis, hyperpigmentation and melanosis in their palm and sole.
Hair and nail reflect the long-term exposure of metals. The arsenic concentration in hair and nails reflect its average level in the human body for a period of 2-5 months in hairs and 12-18 months in nails (Yoshinaga et al., 1990, Nowak and Kozlowski, 1998). USEPA, WHO and Atomic Energy Agency (AEA) recommended the use of hair as an important biomarker for worldwide environmental arsenic monitoring (Druyan et al., 1998; Morton et al., 2002). Generally arsenic persists for longer time duration in hairs (Gebel et al., 2000). Blood arsenic moves into hairs and retain there by binding with the sulfhydryl groups of keratin and finally moves toward the hair shafts (Hindmarsh, 2002). Our present study explored the highest arsenic level in human hair samples that was 35.52mg/Kg among the studied population. Even the younger age group from village were also having high arsenic concentrations in their hair. Arsenic also persists for longer time duration in nails just like hairs. The present study showed that the nail samples retain lower values of arsenic concentration with the maximum of 9.419mg/Kg in comparison with hair samples.
The studied population’s health status was very poor as they were suffering from health issues like asthma, anaemia, hepatomegaly, diabetes, cardiac problems, fungal infection on skin, breathlessness and mental disability. Regular consumption of drinking water contaminated with elevated arsenic levels resulted in the high risk of skin, bladder, lung, liver and kidney cancer (Chowdhury et al., 2000; GuhaMazumder et al., 1998; Berg et al., 2001; Chen et al., 1999; Ferreccio et al., 2000). Long term arsenic exposure led towards early onset of diabetes (Benbrahim-Tallaa and Waalkes et al., 2008). In our present study some diabetic cases were found and the most unfortunate part of the study was the finding of few cancer cases of renal, skin, breast and cervix. Hence, arsenic in the present scenario is enhancing the disease burden in the arsenic exposed population. However, after the installation of the arsenic filter in this village will definitely change the scenario in this village and will also change the health status of the exposed population. Hence, from the present study, it can be concluded that, arsenic contamination in drinking water is causing lot of health-related problems in the exposed population of village Sabalpur. The disease burden in the studied village population is very high. However, after the installation of the arsenic filter in the village will definitely play the major role to control the disease burden in the coming years.