Effect of iron in drinking water on the morbidity rate in the population of the city of Orel

The population of the city of Orеl consumes drinking underground water of Zadonsko-Optuhovsky and Voronezh-Livny aquifers with natural iron content, annual mean levels of which over the observation period from 2007 to  2015 exceeded the maximum allowable concentration (0.3 mg/l) by 1.03 to 1.43 times, with a maximum of 3.67 to 17.7 times. Although an elevated iron content in drinking water has been considered primarily in terms of organoleptic changes, several sanitary studies of recent years have revealed the prolonged use of water containing iron in concentrations, which exceed the maximum allowable ones, to scale up overall morbidity as well as the development of blood, skin and subcutaneous tissue diseases, musculoskeletal problems, digestive,  urogenital system and allergic disorders. There are many reports concerning causes  and the harm to human organism due to iron overload, and largely explanation of the possibility of developing the above types of pathology. The purpose of the study is to identify relationships between levels of total iron content in drinking water and the morbidity rate of the population of the city of Orel. Investigations were executed with the use a correlation analysis. For the period from 2007 to 2015, there were revealed direct correlation relationships between the annual average concentrations of iron in drinking water and the total morbidity  rate of children and adults as well as 11 types of non-infectious pathologies, including diseases of the  respiratory and urogenital system, atopic dermatitis, reactive arthropathies and eczema in children; diseases of blood and blood-forming organs, reactive arthropathies, gastritis and duodenitis in adolescents, stenocardia, cerebrovascular diseases, diabetes mellitus, gastritis, duodenitis and liver diseases in adults. The correlation coefficients amounted to from 0.66 to 0.86, with an accuracy of 0.01-0.05. These relationships may be causal in nature, as it was proved by similar results obtained in the Tula region, Primorsky Krai, and Sverdlovsk region where the population uses ground water with a high iron content. Apparently, it should be more careful in the assessment of the elevated iron content in drinking water from a hygienic viewpoint and must focus, among other things, on its possible causal relations with the morbidity rates of the population, rather than scrutinizing primarily its impact on the organoleptic water properties.