ON-SITE SCREENING FOR URINARY HG CONCENTRATIONS AND CORRELATION WITH GLOMERULAR AND RENAL TUBULAR FUNCTION

At the American Dental Association 1985 and 1986 Annual Sessions, an on-site screening for mercury was conducted as part of the Health Screening Program (HSP) to identify dentists having elevated urinary mercury concentrations. The data generated from this study were used to examine the relationship between elevated urinary mercury exposure and kidney dysfunction. Kidney dysfunction was assessed by measurement of serum and urine beta-2 microglobulin concentrations, serum creatinine, and creatinine clearance. The mean values found for urinary mercury were 5.8-mu-g Hg/L and 7.6-mu-g Hg/L for 1985 and 1986, respectively. Urinary mercury concentrations for this population were found to fall within the range of not detected to 115-mu-g Hg/L. Of the total number of participants assayed in 1985 and 1986, roughly 10 percent of the sample exhibited elevated mercury concentrations above 20-mu-g Hg/L. An analysis of the clinical markers indicated no clear relationship between elevated urinary mercury concentrations and kidney dysfunction. In addition to mercury testing, all dentists who participated in the 1985 and 1986 HSP were issued a questionnaire soliciting information as to their professional exposure. Those participants who were identified as having elevated urinary mercury concentrations in the 1985 HSP were issued a followup questionnaire that addressed psychological and neuropsychological symptoms. From these questionnaires three significant relationships were found. These relationships were associated with mercury/amalgam handling and skin contact, the number of amalgams placed by the dentist, and the number of hours of practice per week. The reported absence of a clear relationship between urinary mercury concentrations and potential kidney dysfunction is in agreement with other findings at the mercury concentrations tested. Based on the data generated from this study, these results support the use of an on-site screening procedure as a quick and accurate measure of total mercury excretion.