Determinants of Blood Cadmium levels in Male Residents of Mexico City

Introduction:Cadmium (Cd) is a non-essential metal classified by IARC as a type 1 carcinogen. The main non-occupational exposure route is via inhalation of tobacco smoke or suspended particles. At a lesser magnitude the consumption of contaminated food may contribute to this exposure. The aim was to determine the main sources of Cd exposure in a sample of men aged 40 years or over and Mexico City residents. Methods:Information corresponded to 675 healthy men, aged between 40 and 91 years and residents for >1 year in different zones of Mexico City. Through a direct interview, we obtained information about sociodemographic characteristics, time of residence in the city, habitual occupation during lifetime, smoking history, and principal water source. Dietetic information of the previous 3 years was acquired through a validated food frequency questionnaire (127 foods). Blood Cd levels were determined by atomic absorption spectrometry. Results:Cd geometric mean in blood was 2.47±1.44 μg/L and 90.22% of the samples were above P95 for men reported in NHANES, 2007-2008. Around 20% were classified as occupationally exposed and their Cd concentrations were significantly greater than those not occupationally exposed (2.81±0.92 vs. 2.58±0.82 μg/L). Among non-occupationally exposed subjects, blood Cd levels increased with age, high consumption of sausages (3 portions/week) (β=0.20; 95%CI: 0.05; 0.34; p=0.007), >8 cigarettes/day (β=0.44; 95%CI: 0.27; 0.60; p<0.001), and longer residence time in Mexico City or living in the City’s western region (β=0.39; 95%CI: 0.17; 0.61; p<0.001). Conclusions:This study suggests that independently of tobacco, some foods such as sausages and probably atmospheric contamination can be relevant sources of Cd exposure in this urban zone. In children, sausage consumption is frequent and its role as a potential exposure source of Cd could lead to repercussions at the medium and long term in health of general population and of children.