Cadmium exposure and associated factors among an adult population from Southern Brazil

Abstract

Introduction:Cadmium is a toxic metal widely distributed in the environment by geologic and anthropogenic sources. Even at low levels of exposure, cadmium is nephrotoxic and carcinogenic. The main sources of cadmium exposure in the general population are cigarette smoke, diet and ambient air near industrial areas. The aim of this population-based study was to evaluate the socioeconomic, environmental, and lifestyle determinants of blood cadmium in Brazilian adults. Methods:A total of 959 adults, aged 40 years or more, living in a medium size city in Southern Brazil, were randomly selected. Socioeconomic, dietary, lifestyle and occupation background was obtained by household interviews. Blood cadmium was measured by ICP-MS. We performed both crude and adjusted multivariable analysis on log-transformed blood cadmium to test for associated factors. Model 1 was adjusted for sex, age, race, education and income. Model 2 was further adjusted for smoking, alcohol intake, vegetables consumption, blood lead and occupation. Results:The geometric mean (GM) of blood cadmium was 0.39μg/L (95%CI,0.38-0.41). In the American adult population, cadmium levels of 0.36 and 0.42μg/L were reported (Navas-Acien et al. 2005; Tellez Plaza et al. 2008), respectively. In our crude analysis, blood cadmium was positively associated with male gender, non-white participants, smoking and drinking habits and more frequent vegetables consumption. In Model 1, only male gender was associated with blood cadmium, and in Model 2, the ratio for GM blood cadmium was significantly higher in former smokers (1.17;95%CI,1.04-1.30) and in current smokers (2.43;95%CI,2.14-2.76) compared with non-smokers, and was close to significance in participants with higher blood lead levels (1.09;95%CI,1.00-1.19). Conclusions:Low blood cadmium levels were found in adults living in an urban area. Biomonitoring studies should be encouraged to systematic evaluation and to examine trends of cadmium levels in urban areas.