Cadmium concentrations in hair in the population of the subjects of the Russian Federation: a systematic review

Abstract

Cadmium (Cd) is one of the most toxic trace elements. The most important sources of Cd contamination by burning fossil fuels as coal or oil and incineration of urban waste, including plastics and nickel-cadmium batteries. In all countries these sources make Cd contamination an important health issue worldwide. Cd can enter the body through smoking tobacco, eating and drinking food and water polluted with Cd, and breathong. Cd concentration in human hair, nails and blood is considered as an indicator of environmental pollution. However, there is little systemized information on Cd concentration in human tissues in Russia. This is a systematic review following PRISMA guidelines. We performed a systematic search and qualitative synthesis of scientific literature on Cd concentrations in hair across Russia between 2011 and 2021. PubMed and e-library were the main sources of scientific information in English and Russian, respectively. Initial search returned 1202 matches. Twenty-nine papers remained for qualitative synthesis after screening and eligibility analysis. Studies on Cd concentrations were performed in only 19 of 85 federal subjects (22.4%). No heterogeneity was observed in sample preparation while methods of laboratory analysis varied between the settings and included inductively coupled plasma mass spectrometry, atomic absorption spectrometry, and inversion voltammetry. The sample sizes ranged from 12 to 5908 individuals. The average Cd concentrations varied from 0.010 mg/kg to 0.164 mg/kg. The greatest concentrations of Cd were reported from Sibai in the Orenburg Region (0.164 mg/kg), in indigenous people of the Yamalo-Nenets Autonomous Okrug (0.15 mg/kg) and in residents of the Arctic part of the Sakha Republic (0.14 mg/kg); The maximum values on the abovementioned regions were 7.02 mg/kg, 0.52 mg/kg, and 0.51 mg/kg. High maximum concentrations were also found in the Republic of Bashkortostan (0,9 mg/kg) and in Yaroslavl (0,37 mg/kg). Conclusion. Data on Cd concentrations in human hair from 66 federal subjects are still needed for mapping of Cd concentration in Russia. Further data collection should be performed using representative and sufficient sample samples while presentation of the results should contain detailed information on methods of data collection and analysis to ensure reproducibility and comparability of the findings.