1.What was the purpose of the study?
The purpose of this study was to determine if maternal exposures to contaminants in drinking water at Camp Lejeune were associated with preterm birth and fetal growth retardation.
This study is a reanalysis of a previous study that incorrectly categorized as “unexposed” some maternal exposures before June 1972 based on information available at the time. Additionally, the Agency for Toxic Substances and Disease Registry (ATSDR) recreated monthly estimates of past levels of drinking water contamination using computer models. These estimates were not available when the study was originally conducted.
2. Who was studied?
The study included live singleton births 28-47 weeks gestation weighing 500 grams or more that occurred between 1968 and 1985 to women who resided on base at time of delivery. We compared birth certificate data for Onslow County, NC, in which Camp Lejeune is located, with Camp Lejeune housing records. A total of 11,896 births met these criteria.
3. Which conditions were included in ATSDR’s study?
The study included preterm birth and fetal growth retardation. Fetal growth retardation was measured by reduced mean birth weight (MBW), term low birth weight (TLBW), and small for gestational age (SGA). These birth outcomes have been previously found to increase the risk for negative health outcomes later in life.
- Preterm births were defined as births occurring at less than 37 weeks of gestation. We calculated gestational age using date of mother’s last menstrual period from the birth certificate.
- TLBW was defined as full-term babies (37 weeks gestation or more) weighing less than 2,500 grams at birth.
- SGA births were defined as births weighing less than the 10th percentiles using sex- and race-specific weight by gestational week norms.
- For the MBW analysis, only full-term infants were included.
4. Why does this study examine only the period from 1968 to 1985?
The study is limited to children born between 1968 and 1985. These years were selected because computerized birth certificates became available in North Carolina in 1968 and the contaminated wells on base were shut down in 1985.
5. What did you find?
ATSDR’s study results suggest associations between in utero exposure to PCE, TCE and benzene in Camp Lejeune drinking water and adverse birth outcomes.
The following effects were seen in births from 1968-1985 to women exposed to contaminated drinking water at Camp Lejeune. These findings also apply to women who gave birth before 1968 if they were exposed to similar levels of VOCs-contaminated drinking water.
- In utero exposure to PCE was associated with preterm birth.
- For PCE and preterm birth, the strongest association was observed for exposure during the 2nd trimester.
- In utero exposure to TCE was associated with SGA, TLBW and reduced MBW.
- The risk of TLBW increased with increasing levels of exposure to TCE during the 2nd trimester.
- The finding for SGA is consistent with a previous study conducted in Woburn, MA.
- In utero exposure to benzene was associated with TLBW.
- The risk of TLBW increased with increasing levels of exposure to benzene throughout the pregnancy.
6. How does this study help?
This study makes an important contribution to the scientific knowledge about the health effects of these chemicals. The information from this study, together with other information about the health effects of these chemicals, will play an important role in making decisions about setting acceptable levels of these contaminants in drinking water.
7. What does this study mean for the pregnant women and their children who were exposed to VOCs at Camp Lejeune?
This study attempts to answer some of the questions about the health effects of in utero drinking water exposures at Camp Lejeune. It also adds to the general knowledge about the health effects of these chemicals. The findings of this study might help the women and their children who were exposed to various contaminants in drinking water at Camp Lejeune better understand the association between their exposures and specific health outcomes.