title: Human exposure to uranium in groundwater.
abstract: High concentrations of uranium (mean=620 microg/L) were detected in water samples collected from private wells in a residential community. Based on isotopic analyses, the source of the uranium contamination appeared to be from naturally occurring geological deposits. In homes where well water concentrations of uranium exceeded the drinking water standard, the residents were advised to use an alternate water source for potable purposes. Several months after the residents had stopped drinking the water, urine samples were collected and tested for uranium. Elevated concentrations of uranium (mean=0.40 microg/g creatinine) were detected in urine samples, and 85 percent of the urine uranium concentrations exceeded the 95th percentile concentration of a national reference population. Urine uranium concentrations were positively correlated with water uranium concentrations, but not with the participants' ages or how long they had been drinking the water. Six months later, a second urine sample was collected and tested for uranium. Urine uranium concentrations decreased in most (63 percent) of the people. In those people with the highest initial urine uranium concentrations, the urine levels decreased an average of 78 percent. However, urine uranium concentrations remained elevated (mean=0.27 microg/g), and 87 percent of the urine uranium concentrations exceeded the 95th percentile concentration of the reference population. The results of this investigation demonstrated that after long-term ingestion of uranium in drinking water, elevated concentrations of uranium in urine could be detected up to 10 months after exposure had stopped.
authors.affiliation: Agency for Toxic Substances and Disease Registry, 1600 Clifton Road, MS-E32, Atlanta, GA 30333, USA. keo1@cdc.gov
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Orloff
authors.forename: Ketna
authors.initials: K
authors.lastname: Mistry
authors.forename: Paul
authors.initials: P
authors.lastname: Charp
authors.forename: Susan
authors.initials: S
authors.lastname: Metcalf
authors.forename: Robert
authors.initials: R
authors.lastname: Marino
authors.forename: Tracy
authors.initials: T
authors.lastname: Shelly
authors.forename: Eric
authors.initials: E
authors.lastname: Melaro
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Donohoe
authors.forename: Robert L
authors.initials: RL
authors.lastname: Jones
mesh_terms: D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005618:Fresh Water / Q000032:analysis*; D006801:Humans; D008297:Male; D013022:South Carolina; D013057:Spectrum Analysis; D013997:Time Factors; D014501:Uranium / Q000032:analysis* / Q000652:urine*
chemical_list: D014501:Uranium