Study on Arsenic Presence in Drinking Water Resources of the Sabalan Area and its Relation with Skin Disorders

Abstract

Introduction and statement of problem Although water is known as the source of life, the existence of chemical and biological pollutants can make water quality inappropriate for drinking and even cause dangerous and fatal diseases. Among different pollutants, arsenic pollution of groundwater and surface water has been observed in different countries. Nowadays tens of millions of people all over the world especially in developing countries are influenced by the presence of arsenic in drinking water in level higher than guideline of world health organization (10 µg/L). Arsenic is mostly found in crust (1-2mg/kg) and exists as a partial element in soil, rock and sediments. The existence of arsenic in hot waters of different areas including hot water springs of parts of United States of America, Japan … has been reported. Skin is completely sensitive against arsenic and skin lesions and scars are the most common and of chronic non-malignant effects of being exposed with arsenic. In effects of chronic exposure to inorganic arsenic through drinking water first, skin pigmentation symptoms and then hyperkeratosis appears. Cancer is the last phase of reacting against long term exposure to arsenic which takes usually more than ten years to develop its effects. It is expected that there would be arsenic in northwest part of Iran soil and underground waters due to existence of volcanic activities in the area. Hence the aim of this investigation was to study existing arsenic in drinking water sources around Sabalan volcano and it's skin side effects. Research method Present study was carried out in two phase. First phase was data gathering, water sampling and measuring arsenic concentration by Graphite Furnace Atomic Absorption Spectroscopy and determination other physicochemical parameters of water in villages and cities and second phase includes epidemiologic study which was carried out by referring to a polluted village (Razlig) and a non-infected village (Farkush) to arsenic. In this study people disposed to arsenic through drinking water were studies from skin disease point of view. In both exposed and unexposed villages to arsenic studied samples more than ten years of residency were selected as control and case villages, respectively. They were examined from skin disease aspects through referring medical team. Results and findings Among 21 water samples from villages and 23 samples from cities around mount Sabalan, maximum amounts, minimum and measured average arsenic for villages was 93.6, 0and 7.7 µg/Land for cities minimum, maximum and average arsenic density in drinking water was 1.61 and 22.6 µg/L, respectively. During present study Razlig village with 130 people (26 make and 104 female) was selected as case village with highest arsenic level in drinking water and Farkush village with 149 subjects (56 male and 93 female) was selected as control village were studied with total 279 subjects. In case village with highest degree of pollution 130 people were examined for skin diseases. Average age of studied people was 41±19. According to chi square tests analysis results, there was a significant difference between studied population in two villages and number of studied males was more in Farkush village. Present study indicated that 27 cases of studied people (9.7%) were suffering from dermal pigmentation. Fromm this amount 18 cases (6.4%) were in Razlig village. Statistical analysis indicated that the chance for suffering from pigmentation in Razlig village which is exposed to arsenic is 2.5 times more than Farkush village. The continuation of analysis with entering different variables to model indicated that old and BMI has no significant effect but gender has significant effect in suffering from pigmentation. Between suffering keratosis, dermal decrements were observed just in 3 members (2.3%) of all statistical population. All sufferers were among studied males of Razliq village population exposed to arsenic. In Farkush village as controlling village keratosis decrement was not observed significantly. Conclusion and discussion In present study physicochemical parameters and arsenic concentration was measured in drinking water and its relationship was analyzed with dermal disease. Obtained results indicated ,except for some limited cases, there was no serious problem but the average arsenic concentration in Sarab, Ardebil and some other studied villages was higher than allowed maximum amount by WHO (10 µg/L). This can be considered as serious health concern in the area. From arsenic relationship with dermal disease aspect, the chance for suffering from pigmentation in Razliq village which is disposed to arsenic is 2.5 times more than Farkush village and for keratosis it was observed that all sufferers among studied population were from Razliq village exposed to arsenic. Considering close distance between control and case villages and considering the difference between arsenic amount and some other parameters in adjacent villages and areas more studies are required needed regarding pollution source and releasing arsenic to drinking waters.