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 – 2012

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 participant was conducted by ATSDR’s Geospatial Research, Analysis, and Services Program Office. CHEEC is linking geocoded residential addresses to water utilities, collecting DBP data for those utilities, and linking 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, is developing algorithms for models to account for spatial and temporal variability of DBPs.

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 – 2012

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 is examining 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 were 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 was 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 are being 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.

National Children’s Study
Collaborating Institutions:  University of Iowa (Pediatrics, Epidemiology, CHEEC, other units), Polk County hospitals and public health agencies
Funding Agency: National Institute of Child Health and Human Development
Project Period:  2008 – 2013
The National Children’s Study will examine the effects of environmental influences on the health and development of more than 1,000 children in Polk County (IA), following them from conception until age 21.

Water Quality Data for Private Wells for the Agricultural Health Study Cohort
Collaborating Institutions:  CHEEC, State Hygienic Laboratory
Funding Agency:  National Cancer Institute
Project Period:  2010 – 2012
This project will provide nitrate, pesticide and other water quality data for private wells and public water utilities across Iowa to use in modeling drinking water exposures for members of the Agricultural Health Study cohort.

Link to Archived Research