caa a22 4500 467902437 CHVBK 20180406152822.0 cr unu---uuuuu 170328e20060501xx s 000 0 eng 10.1007/s10661-006-7228-y doi (NATIONALLICENCE)springer-10.1007/s10661-006-7228-y Comparison of Nitrate Levels in Raw Water and Finished Water from Historical Monitoring Data on Iowa Municipal Drinking Water Supplies [Elektronische Daten] [Peter Weyer, Brian Smith, Zhen-Fang Feng, Jiji Kantamneni, David Riley] Nitrate contamination of water sources is a concern where large amounts of nitrogen fertilizers are regularly applied to soils. Ingested nitrate from dietary sources and drinking water can be converted to nitrite and ultimately to N-nitroso compounds, many of which are known carcinogens. Epidemiologic studies of drinking water nitrate and cancer report mixed findings; a criticism is the use of nitrate concentrations from retrospective drinking water data to assign exposure levels. Residential point-of-use nitrate data are scarce; gaps in historical data for municipal supply finished water hamper exposure classification efforts. We used generalized linear regression models to estimate and compare historical raw water and finished water nitrate levels (1960s--1990s) in single source Iowa municipal supplies to determine whether raw water monitoring data could supplement finished water data to improve exposure assessment. Comparison of raw water and finished water samples (same sampling date) showed a significant difference in nitrate levels in municipalities using rivers; municipalities using other surface water or alluvial groundwater had no difference in nitrate levels. A regional aggregation of alluvial groundwater municipalities was constructed based on results from a previous study showing regional differences in nitrate contamination of private wells; results from this analysis were mixed, dependent upon region and decade. These analyses demonstrate using historical raw water nitrate monitoring data to supplement finished water data for exposure assessment is appropriate for individual Iowa municipal supplies using alluvial groundwater, lakes or reservoirs. Using alluvial raw water data on a regional basis is dependent on region and decade. Springer Science + Business Media, Inc., 2006 cancer risk nationallicence exposure assessment nationallicence historical nitrate data nationallicence Iowa municipal water supplies nationallicence Weyer Peter Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut Smith Brian Department of Biostatistics, College of Public Health, The University of Iowa, Iowa aut Feng Zhen-Fang Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut Kantamneni Jiji Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut Riley David Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut Environmental Monitoring and Assessment Kluwer Academic Publishers 116/1-3(2006-05-01), 81-90 0167-6369 116:1-3<81 2006 116 10661 https://doi.org/10.1007/s10661-006-7228-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-006-7228-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Weyer Peter Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut NATIONALLICENCE 700 1- Smith Brian Department of Biostatistics, College of Public Health, The University of Iowa, Iowa aut NATIONALLICENCE 700 1- Feng Zhen-Fang Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut NATIONALLICENCE 700 1- Kantamneni Jiji Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut NATIONALLICENCE 700 1- Riley David Center for Health Effects of Environmental Contamination, The University of Iowa, N203 OH, 100 Oakdale Campus, 52242-5000, Iowa City, IA, USA aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 116/1-3(2006-05-01), 81-90 0167-6369 116:1-3<81 2006 116 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer