Grantee Research Project Results

2004 Progress Report: Dose-Response of Nitrate and Other Methemoglobin Inducers on Methemoglobin Levels of Infants

EPA Grant Number: R829781
Title: Dose-Response of Nitrate and Other Methemoglobin Inducers on Methemoglobin Levels of Infants
Investigators: VanDerslice, Jim
Institution: Washington State Department of Health
EPA Project Officer: Page, Angela
Project Period: September 2, 2002 through September 1, 2005 (Extended to September 1, 2007)
Project Period Covered by this Report: September 2, 2003 through September 1, 2004
Project Amount: $594,934
RFA: Health Effects of Chemical Contaminants in Drinking Water (2001) RFA Text | Recipients Lists
Research Category: Drinking Water , Human Health , Water

Objective:

The objectives of this research project are to: (1) estimate the intake of methemoglobin inducers (i.e., nitrate, copper, chlorination products, and medications) by infants and their effects on methemoglobin levels; (2) estimate the effect of potential endogenous production of nitrite (i.e., symptoms of infection and gastrointestinal distress) on the level of methemoglobin in infants; and (3) examine mothers’ knowledge and attitudes regarding the risks associated with the use of private well water for infants.

Progress Summary:

This project is designed to generate data from a cross-section of young infants with varying levels of nitrate exposure and illness to assess the relationship between these primary risk factors and the level of methemoglobin in the study of infants’ blood. The study also will gather data about the well water use practices and knowledge of the risks of well water for infants among the mothers and other caregivers of these infants.

The implementation of this research project was delayed significantly because of difficulties in hiring field staff. The original administrative partner responsible for hiring staff and managing field operations withdrew because of internal staffing problems. At that time, the Washington State Department of Health (DOH) could not hire staff because of hiring restrictions in the state government. We were able to work out an agreement with Central Washington University, located in Ellensburg, Washington, to employ the field staff.

Staff training consisted of four 2-day sessions, including performance testing for each part of the data collection process. A data system was implemented to receive weekly reports of new births in the study area provided by the DOH Center for Health Statistics. Each birth is geocoded and spatially joined to a geographic information system coverage of public water supply service areas to identify those families that are not likely to be served by a large public water system. These infants are then assigned a randomly selected target interview date. The names of the selected infants are compared to the Early Notification of Childhood Death database to eliminate any infants who have died since birth. Recruitment letters are generated and sent weekly.

Recruitment began in early September 2004. Three field teams, consisting of a nurse and a bilingual technician, are currently conducting weekend home visits in rural areas of eastern Washington State. The home visit consists of a structured interview, in Spanish or English, covering recent symptoms, a 24-hour diet history, water treatment, and attitudes about the quality of their tap water. Nitrate levels of the household’s tap water and any other water given to the infant are determined using an ion-selective probe. Bacteriological quality is assessed using a presence/absence for total coliforms and Escherichia coli. Each infant is weighed and measured and a sample of blood is obtained using a heel stick. The blood is tested to determine the level of methemoglobin. Another 100 ml sample is collected and sent to Baylor University to determine the activity level of methemoglobin reductase, the enzyme that converts methemoglobin back to hemoglobin. The results are explained to the families and a packet of other information about infant health is presented.

All instruments and educational materials have been prepared in English and Spanish because about one-half of the study participants are Spanish speaking. All study protocols and instruments have been approved by the Washington State Institutional Review Board.

A field coordinator manages logistics and resupply of the teams, and a recruitment coordinator schedules home visits. Our target is to complete 24 visits each weekend (4 per day, per team). As of the end of September 2004, about 20 visits have been completed per weekend. There have been difficulties with refusals because some of these families are reluctant to have a team from a government agency come to their house. In addition, travel presents a challenge as each team serves a large area, with some travel times exceeding 2 hours.

The completed instruments are mailed to the DOH, where they are being entered into a Microsoft Access^© database using a set of custom forms designed to look like the data instruments. Validation rules help to ensure the accuracy of the data entry process.

Future Activities:

The primary objectives for the next year are to complete data collection from 1,000 infants, complete data entry, and begin data analysis. We expect that the data analysis will go beyond the original project period.

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this project

Supplemental Keywords:

drinking water, nitrate, infants, methemoglobinemia, “blue-baby” syndrome, exposure assessment, health effects, nitrites, microbiologic contamination, health, water, analytical chemistry, biochemistry, children’s health, environmental chemistry, epidemiology, health risk assessment, risk assessments, assessment of exposure, chemical contaminants, chemical exposure, children, children’s environmental health, children’s vulnerability, dietary exposure, dietary ingestion exposures, drinking water contaminants, exposure, exposure and effects, groundwater, human exposure, human health, human health effects, human health risk, methemoglobin, methemoglobin formation, nitrate contamination,, RFA, Health, Scientific Discipline, Water, Health Risk Assessment, Risk Assessments, Environmental Chemistry, Analytical Chemistry, Children's Health, Biochemistry, Drinking Water, health effects, human health, dietary exposure, other - exposure, methemoglobin formation, nitrate contamination, water quality, human exposure, chemical contaminants, dietary ingestion exposures, chemical exposure, children, drinking water contaminants, exposure, groundwater, methemoglobin, children's vulnerablity, human health effects, human health risk, assessment of exposure, exposure and effects, exposure assessment

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.