Researchers from Texas have reported the results of a case-control study assessing the association between ambient air levels of benzene, toluene, ethylbenzene, and xylene (BTEX) and the prevalence of neural tube defects (spina bifida and anancephaly) among children.

They obtained data on these birth defects from The Texas Birth Defects Registry in infants delivered between 1999 and 2004, and data on BTEX levels from the U.S. EPA’s 1999 Assessment System for Population Exposure Nationwide (ASPEN).  They found that mothers living in census tracts with the highest benzene levels were more likely to have offspring with spina bifida compared to women living in census tracts with the lowest levels (OR = 2.30; 95% CI: 1.22 – 4.33), but the risk of anancephaly was not increased.  The researchers concluded that their study – the first study to assess the relationship between environmental levels of BTEX and neural tube defects – found between maternal ambient exposure to benzene and spina bifida, and contributed to the growing body of evidence regarding air pollutant exposure and adverse birth outcomes.

Lupo, P.J., et al., “Maternal Exposure to Ambient Levels of Benzene and Neural Tube Defects among Offspring, Texas, 1999-2004,” Environ. Health Perspect. advance pub. (Oct. 5, 2010).