Reducing Noise-induced Hearing Loss (NIHL) to Achieve Us Healthy People 2010 Goals

Abstract

Uranium is a heavy metal ubiquitous in the environment. The health effects of its chronic ingestion are uncertain. Research suggests that high exposure (>300 lg/L) can alter proximal renal tubular function. In 2002, levels of natural uranium (93-142 lg/L) above current guidelines (15 lg/L World Health Organisation, 30 lg/L United States Environmental Protection Agency) were found in a public water supply to an Irish town (population 2000). An epidemiological study was undertaken. Three groups were defined based on exposure to the supply: Group A, exposed 1989Group A, exposed -2002;; Group B, exposed 1989 Group B, exposed -1995;; and Group C, never exposed. All 143 households from Group A, and 75 each from groups B and C were offered screening. Data collection included a general health and exposure questionnaire, height, weight and blood pressure, spot urine for b2microglobulin (B2M), retinol binding protein (RBP), microalbumin and uranium, serum urea and creatinine. Household response rate was 71% and 545 persons were screened. The proportion of detectable B2M (~5%) and RBP (~0.5%) were similar in the three groups. Mean albumin/creatinine ratio was similar in the groups (~3.3 mg/mmol Cr) as was mean plasma creatinine (~94.1 mmol/L). No correlation was found between the markers of renal dysfunction and uranium exposure. 29 participants were referred to a nephrologist. No case of renal disease attributable to uranium exposure was diagnosed. We found no evidence that ingestion of natural uranium at these levels affected renal health. The findings support the upward revision of current guidelines for levels of uranium in drinking water.