The 131st Annual Meeting (November 15-19, 2003) of APHA

Abstract #59321

June M. Weintraub, ScD, Environmental Health Section, Health Inequities Research Unit, San Francisco Department of Public Health, 1390 Market St., Suite 910, San Francisco, CA 94102, 415-252-3973, June.Weintraub@sfdph.org

The influence of socioeconomic factors and water quality on low birth weight and preterm birth was studied in 36,369 singleton births with gestational age 20 to 42 weeks that occurred between 1996 and 2000 in San Francisco. Information on race, education, age, prenatal care, parity, infant’s sex, insurance, tobacco use, and preeclampsia were obtained from birth certificates. Water samples were collected quarterly at 16 locations throughout San Francisco and analyzed for trihalomethane (THM) concentration. Exposure was based on zip code; women were assigned one THM value per trimester of pregnancy. Multivariate models were used to calculate odds ratios and 95% confidence intervals (for preterm birth) and regression coefficients and standard errors (for low birthweight). Overall there was no relationship between THM levels and preterm birth or low birthweight. Stratification by race revealed some significant associations between higher THM exposure and lower birth weight for Hispanics. During the first trimester, Hispanic women in the highest quintile of exposure had babies weighing on average 35 grams less than those in the lowest quintile. In the second trimester, the difference was 31 grams. When THM values were averaged over the duration of the pregnancy, Hispanic women in the highest quintile of average exposure had babies weighing on average 41 grams less than those in the lowest quintile. The finding of a significant association between THM levels and low birthweight among Hispanics but not among other racial/ethnic groups should be explored further to address exposure misclassification, neighborhood level confounding, and socio-cultural differences.

Learning Objectives:

• At the conclusion of the session, the participant (learner) in this session will be able to:
• 1. Describe the influence of trihalomethanes on reproductive outcomes in San Francisco;
• 2. Recognize the methodological issues that must be confronted when using routinely collected water quality parameters and birth certificate data;
• 3. Identify social and demographic factors that may influence low birth weight and/or exposure to trihalomethanes among different ethnic populations.

Keywords: Low Birthweight, Environmental Exposures

Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: San Francisco Department of Public Health San Francisco Public Utilities Commission
I have a significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.
Relationship: I am an employee of the San Francisco Department of Public Health