Lead, cadmium, and selenium in the blood of patients with sporadic amyotrophic lateral sclerosis.

We determined whole blood lead and cadmium levels, and serum selenium levels in patients with sporadic amyotrophic lateral sclerosis and age- and sex-matched controls. Disability due to the disease directly correlated with lead levels, and there was a strong inverse correlation with selenium concentrations. Lead and selenium concentrations tended to be similar in the cases and controls, both in the study population as a whole and after the removal from the analysis of the patients with the highest degree of disability. In the patients with limited disability, cadmium concentrations were higher than in the controls. Our findings lend limited support to a possible involvement of cadmium, but not lead, in the etiology of sporadic amyotrophic lateral sclerosis, and strongly suggest that short-term indicators of exposure are inadequate to investigate the relationship between selenium and the disease.

Observations on the use of plasma, hair and tissue to evaluate trace element status in cancer.

Selenium, zinc and copper were measured in plasma, hair and tissue of patients affected by either breast or lung cancer and their controls. A decrease in plasma Se and Zn in women affected by breast cancer was observed, whereas plasma Cu was increased in lung cancer. No significant modification was found in hair trace element levels adjusted for the main confounders, in particular for hair treatment which altered Se content. The examined elements were highly concentrated in cancerous vs normal tissue, but results changed according to the unit used to express results. The usefulness and significance of these biomarkers of trace element status are discussed in the light of the most recent literature data.