Blood cadmium determinants among males over forty living in Mexico City

Abstract

Background: Mexico City has air, water and food pollution problems; however, human exposure to cadmium and its sources have not been described.

Objectives: To determine the blood cadmium (BCd) level and its main exposure sources among males aged 40 years or older living in different areas of Mexico City.

Methods: After receiving informed consent, we interviewed 702 males aged ≥40 years to collect data on their sociodemographic characteristics, lifetime occupation, smoking history, and dietary habits, using a validated questionnaire. The BCd level (μg/L) was determined by atomic absorption spectrophotometry.

Results: The BCd mean level ± SD was 2.61 ± 0.82 μg/L, and 20% of men reported a potential cadmium occupational exposure. After adjusting for age and other potential confounders, the main determinants of the BCd level were the current smoking status at interview, with low (β_{≤8.5packs/year vs. non-smoker} = 0.46; 95% CI: 0.28-0.64 μg/L; p < 0.01) and high (β_{> 8.5 packs/year vs. non-smoker} = 0.71; 95% CI: 0.56-0.87 μg/L; p < 0.01) smoking intensity, and living in the Center (β_{Center vs. South} = 0.20; 95% CI: 0.02-0.37 μg/L; p = 0.02) or West area of the city (β_{West vs. South} = 0.40, 95% CI: 0.21-0.58 μg/L; p < 0.001). Moreover, the potential dietary sources of BCd included: liver (β_{Yes vs. No} = 0.13, 95% CI: 0.03-0.23 μg/L; p = 0.01), "Chorizo" (β_{>1-3servings/month vs. No} = 0.14, 95% CI: 0.01-0.26 μg/L; p < 0.001), sausage and ham.

Conclusions: The BCd levels observed in this population are high and only similar to those observed in workers from a sanitary landfill area in Southern Thailand. Potential environmental Cd exposure sources, such as industrial activity and previous land use, in the West and Center areas of the city should be explored in detail, especially in vulnerable population groups, such as children.

Keywords: Blood cadmium levels; Determinants; Diet; Mexico; Smoking.