Variation and modifying factors of the exposure to lead and cadmium based on an epidemiological study.

Exposure to cadmium and lead was studied using a dietary survey. Data for 1348 individuals aged 25-64 years were collected using 3-day food records. In addition to the dietary intake of heavy metals, the effect of the following were also analyzed: smoking frequency, place of residence, occupation and age. Total cadmium and lead exposure was estimated by calculating intake from food plus that from inhalation, i.e. from urban air and smoking. Heavy smoking increased the cadmium exposure three-fold. The distribution curve of total cadmium exposure was bimodal due to the additional exposure caused by smoking. The distribution curve of the lead and cadmium exposure from food was also skewed, being mostly influenced by food intake. Contaminated urban air slightly increased the total exposure to lead. Occupation had a minor effect on the exposure to both metals. Housewives and retired persons were the least exposed groups. The distribution pattern and wide range of heavy metal exposure should be taken into account in risk assessment for contaminants in food. The additional exposure to cadmium and lead from smoking and from air and water should be considered.