Summary of Work: We are collaborating with researchers from the National Institute of Diabetes and Digestive and Kidney Diseases and the American Dental Association of the risk of end stage renal disease among dentists exposed to mercury and nitrous oxide. We are comparing 138,000 U.S. dentists who graduated before 1977 with the U.S. renal disease registry to see whether general dentists who are highly exposed to mercury have higher rates of renal failure than orthodontists and other subspecialties who have lower exposures. We will also look whether oral surgeons and pedodontists who have elevated nitrous oxide exposures have increased rates. Initial analyses suggest that there is an excess risk of ESRD among general dentists compared to dental specialists which is consistent with the study hypothesis. Dr. Bjorkman (a research fellow at the Karolinska Institute in Sweden, Dr. Sandler, and I are analyzing data from NHANES I to look at the relationship between the number of dental amalgams in a person's mouth and their diastolic blood pressure. The hypothesis is that like lead, mercury might disrupt renal function and increase the risk of hypertension. Initial findings suggest an increased risk among young men and middle age women but are not elevated in any of the 4 other age-sex groups. This is therefore suggestive of a possible effect but so inconsistent that it may not be casually related.