Occurrence of 210po and biological effects of low-level exposure: The need for research

摘要

Background: Polonium-210 210po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210po are common in sediments, and segments of the public may be chronically exposed to low levels of 210po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, biokinetics, and toxicology of 210po and identified the need for future research. Methods: Potential linkages between environmental exposure to 210po and human health effects were identified in a literature review. Discussion: 210po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate 210po, the ovary may be the critical organ in determining the lowest injurious dose for 210po. 210po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to 210po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. 210po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of 210po. Conclusions: Much of the important biological and toxicological research on 210po is more than four decades old. New research is needed to evaluate environmental exposure to 210po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary.