Current CHEEC research and data management projects:

Exposure Assessment Method for Disinfection Byproducts in Drinking Water in the National Birth Defects Prevention Study
Collaborating Institutions: CHEEC, NBDPS centers, U.S. EPA, University of North Carolina
Funding Agency: National Center on Birth Defects and Developmental Disabilities, CDC
Project Period:  2008 – 2009

The water exposure assessment subcommittee of the National Birth Defects Prevention Study (NBDPS) developed a detailed protocol and approach to assign disinfection byproducts (DBP) exposures in drinking water systems to residences in ten states. This project will enable the NBDPS, in conjunction with data on individual drinking water usage, to evaluate relationships between DBPs (trihalomethanes and haloacetic acids) in drinking water and select birth defects. The exposure assessment protocol includes linking the geocoded maternal address to the appropriate drinking water utility, obtaining all relevant DBP water quality data from that utility for that subject, and modeling water quality data to account for spatial and temporal variability. Centralized geocoding of the residences of NBDPS participants is being done by ATSDR’s Geospatial Research, Analysis, and Services Program Office. CHEEC will conduct the linkage of geocoded residential addresses to water utilities, collect DBP data for those utilities, and link the DBP data to the residences where the mother resided 1 month prior to conception through the first trimester of pregnancy. The University of North Carolina, in cooperation with US EPA, will develop algorithms for models to account for spatial and temporal variability of DBPs.

Comprehensive Assessment of Rural Health in Iowa: the Carroll County Well Water Study
Collaborators: Carroll County (IA) Environmental Health Department, CHEEC, Iowa Department of Public Health, University Hygienic Laboratory
Funding Agency: Iowa Department of Public Health, National Center for Environmental Health
Project period: 2007 – 2008

Intensive private drinking water well sampling in Carroll County, Iowa, will be conducted in 2007 – 2008 as part of the Comprehensive Assessment of Rural Health in Iowa (CARHI) project. This sampling will be a cooperative effort with the ongoing Iowa Statewide Rural Well Water Survey Phase 2 (SWRL2), a three year project (2006-08) conducted by CHEEC in collaboration with the Iowa County Health Departments and County sanitarians, the Iowa Departments of Public Health and Natural Resources, and other agencies. The intensive sampling effort in Carroll County will include 50 wells for the entire suite of SWRL2 compounds (nutrients, bacteria, metals, pesticides and herbicide degradates). Research questions of interest for this set of wells include are there seasonal variation for certain analytes in a confined geographic area (county), and what are the risk factors related to well characteristics/proximate sources of contaminants for poor water quality? An additional 100 wells will sampled and analyzed for total coliform bacteria, E. coli, enterococci, somatic coliphage, and chloride, as part of a special microbial monitoring study conducted by the University Hygienic Laboratory. The research objectives of the microbial monitoring study are to determine the incidence of enterovirus in private drinking water wells, to determine the occurrence of traditional and non-traditional fecal indicators in groundwater (e.g. somatic coliphage, chloride, and enterococci), and to determine whether the source of fecal pollution is human (by utilizing a human specific molecular marker).

Nitrates, Nitrites and Nitrosatable Drugs and the Risk for Selected Birth Defects
Collaborators: Texas A&M University, University of Iowa (CHEEC, Iowa Registry for Congenital and Inherited Disorders), National Birth Defects Prevention Study Centers.
Funding Agency: National Institute for Environmental Health Sciences
Project period: 2007 – 2011

Congenital defects are the greatest contributor to infant mortality in the U.S., but the causes for the majority of these defects are either unknown or poorly understood. Amine- and amide-containing (nitrosatable) drugs and other compounds react with nitrite in the stomach to form N-nitroso compounds, which have been found to induce a variety of congenital malformations in animal studies. Previous epidemiologic studies have focused on the separate effects of nitrates, nitrites, and nitrosatable drugs on risk of congenital malformations without consideration of their interaction in the formation of N-nitroso compounds. This study will examine the separate and joint effects of prenatal exposures to nitrates, nitrites, and nitrosatable drugs on the risk for neural tube defects, limb malformations, oral clefts, and heart defects. Cases and controls will be obtained from the National Birth Defects Prevention Study (NBDPS), a CDC-funded study that covers populations in 10 different states. Subjects' usual intake of dietary nitrates, nitrites, and nitrosamines will be calculated from a food frequency survey. The subject survey will also have information on medications taken one month pre-conception and during the first trimester; these will be classified as to their likelihood of nitrosatability based on the literature and chemical structure. Addresses of Iowa and Texas participants will be linked to community water systems and water nitrate sampling results. The separate and joint effects of nitrosatable precursors on risk of selected malformations will be analyzed. The effects of vitamins C and E (inhibitors of nitrosation) on the relations between nitrate/nitrite intake and nitrosatable drugs and risk of congenital malformations will also be examined. Use of over-the-counter medications is fairly common during pregnancy; several over-the-counter preparations contain nitrosatable compounds as active ingredients. This study will help us understand whether pregnant women who take nitrosatable drugs and also consume greater amounts of nitrates and nitrites are at increased risk of having offspring with birth defects.

SWRL Phase II:
Collaborators:   CHEEC, Iowa Department of Natural Resources, United States Geological Survey, University Of Iowa Hygienic Laboratory, UI College of Public Health, and County environmental health specialists.

CHEEC is the lead investigator in this three year research project sampling the water quality of Iowa’s private rural wells. The original SWRL (State-wide Rural Well Water Survey), completed in 1988-89, was a comprehensive statistically valid assessment of rural well water quality. The first phase of the SWRL II study identified, located and sampled more than 120 of the original SWRL wells. These will be used to assess water quality trends. In 2007 randomly selected wells across the entire state are being identified and sampled. Analysis and testing is for biological, inorganic and organic contaminants including commonly used pesticides and their degradates.

Link to Archived Research