PURPOSE:

We examined the relationship between maternal proximity to hazardous waste sites and industrial facilities and neural tube defect (NTD) risk.

METHODS:

Texas Birth Defects Registry cases were linked with their birth or fetal death certificates; controls (without defects) were randomly selected from birth certificates. Distances from maternal addresses at delivery to National Priority List (NPL) and state superfund sites and Toxic Release Inventory (TRI) facilities were determined for 655 cases and 4368 controls.

RESULTS:

Living within 1 mile of an NPL or state superfund site was not related to NTD risk (adjusted odds ratio [OR] = 1.0; 95% confidence intervals [CI] = 0.6, 1.7). Living within 1 mile of a TRI facility carried a slight risk (adjusted OR = 1.2; 95% CI = 1.0, 1.5). The effect was highest among mothers 35 years and older (OR = 2.7; 95% CI = 1.4, 5.0) and among non-Hispanic white mothers (OR = 1.8; 95% CI = 1.1, 2.8).

CONCLUSIONS:

Hazardous waste sites posed little risk for NTDs in offspring. Close proximity to industrial facilities with chemical air emissions was associated with NTD risk in some subgroups. Further investigation is needed to determine if the effects are real or due to unresolved confounding or bias.