Elevated nitrate levels in relation to bedrock depth, Linn County, Iowa, 1991-1996.
Ralston
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Linn County Health Department, Iowa, USA.
D006801:Humans; D007484:Iowa; D008377:Maps as Topic; D009566:Nitrates / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
D009566:Nitrates; D014874:Water Pollutants, Chemical