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. We are writing up the results of the ESRD study and an earlier study looking at the relationship between dental amalgam and blood pressure using NHANES I data. - dental, mercury, renal disease, childhood development, hypertension, high blood pressure, mercury vapor, - Human Subjects: Interview, Questionaires, or Surveys Only