Evaluation of a carcinogenic and non-carcinogenic health risks due to the quality of drinking water by springs in the arid zone

Abstract

Introduction. Chemical factors affect the emergence of carcinogenic and non-carcinogenic health risks when drinking water consumed in the arid regions of Russia and the world. Material and methods. The objects of the study are samples of water springs located in the city of Saratov. Methods of atomic-absorption spectrometry, spectrophotometry, and potentiometry were used to determine contaminants’ content in water of springs. The health and hygiene safety of spring water was assessed by calculating carcinogenic and non-carcinogenic risk, hazard level, and total hazard level. Results. The unacceptable level of non-carcinogenic risk (HI>1) was established to refer to the development of pathologies of the cardiovascular system and liver and the gastrointestinal tract, kidneys, skin, endocrine system. Nitrates are the greatest contributor to the formation of non-carcinogenic hazards of spring water from the sources studied. Discussion. The processes of rotting plant matter, agricultural activities, and exchange between water and underlying aquifer caused the exceeding of the admissible health risk of water springs located at higher elevations was mainly due to. The highest frequency and magnitude of excess non-carcinogenic sanitary and chemical indices are most often characteristic of springs at the highest elevations or located in the zone of active agricultural activity. The Ni2+ ion, with the highest amount of the total carcinogenic risk caused the carcinogenic effect mainly. It corresponds to springs located on the slopes near the freeways. Conclusion. Nitrates, nickel, cadmium, and iron, made the most significant contribution to the risk of non-carcinogenic exposure in drinking water from the studied springs have. The presence of nickel had a more pronounced carcinogenic effect. Toxic non-carcinogenic water action is directed mainly at the cardiovascular system and liver. The use of water from the springs studied decreases with the increase in the height of the source above sea level caused the probability of non-carcinogenic and carcinogenic effects. The exchange processes with the underlying aquifer of carbonate rocks, as well as the life of iron-healing bacteria during floods and rains, can explain the effect of the arid climate on the distribution of carcinogenic and non-carcinogenic risks in the spring water of Saratov.