title: Nitrogen species in drinking water indicate potential exposure pathway for Balkan Endemic Nephropathy.
abstract: This study explored two hypotheses relating elevated concentrations of nitrogen species in drinking water and the disease Balkan Endemic Nephropathy (BEN). Drinking water samples were collected from a variety of water supplies in both endemic and non-endemic villages in the Vratza and Montana districts of Bulgaria. The majority of well water samples exceeded US drinking water standards for nitrate + nitrite. No statistically significant difference was observed for any of the nitrogen species between villages classified as endemic and non-endemic. Other constituents (sodium, potassium and chloride) known to be indicators of anthropogenic pollution were also found at elevated concentrations and all followed the order wells > springs > taps. This ordering coincides with the proximity of human influences to the water sources. Our results clearly establish an exposure pathway between anthropogenic activity and drinking water supplies, suggesting that the causative agent for BEN could result from surface contamination.
authors.affiliation: Institute of International Health, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Nedialka
authors.initials: N
authors.lastname: Niagolova
authors.forename: Shawn P
authors.initials: SP
authors.lastname: McElmurry
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Voice
authors.forename: David T
authors.initials: DT
authors.lastname: Long
authors.forename: Evangelos A
authors.initials: EA
authors.lastname: Petropoulos
authors.forename: Ivan
authors.initials: I
authors.lastname: Havezov
authors.forename: Karen
authors.initials: K
authors.lastname: Chou
authors.forename: Varban
authors.initials: V
authors.lastname: Ganev
mesh_terms: D000641:Ammonia / Q000009:adverse effects / Q000032:analysis; D001449:Balkan Nephropathy / Q000209:etiology*; D002031:Bulgaria; D002712:Chlorides / Q000032:analysis; D004326:Drinking; D019353:Endemic Diseases; D004781:Environmental Exposure / Q000009:adverse effects; D006801:Humans; D009566:Nitrates / Q000009:adverse effects / Q000032:analysis; D009573:Nitrites / Q000009:adverse effects / Q000032:analysis; D009584:Nitrogen / Q000009:adverse effects / Q000032:analysis*; D011188:Potassium / Q000032:analysis; D012423:Rural Health; D012964:Sodium / Q000032:analysis; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000009:adverse effects / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
chemical_list: D002712:Chlorides; D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D014867:Water; D000641:Ammonia; D012964:Sodium; D009584:Nitrogen; D011188:Potassium