Objectives: In response to an anencephaly cluster along the Texas-Mexico border, we conducted an incident matched case-control study of Neural Tube Defects (NTD). Data are presented regarding the conception residences near interstate highways and biomarkers of exposures to six organo-phosphate metabolites, eleven organochlorine metabolites, and three metals. 

Methods: Maternal biological samples (blood, sera, urine, and hair) were obtained at the time of NTD diagnosis and a comparable time for unaffected pregnancies. Conception addresses of cases and matched controls were geocoded during residential visits for environmental sampling. 

Results: Infants with NTD were conceived significantly more often within ¼ mile from the interstate highways (OR=3.0, 95% CI 1.05, 8.83; p=0.041). A proximity to birthing clinic pattern was unlikely. Significant odds ratios for urinary metabolites of organophosphorus pesticides were associated with NTD (4th quartile ORs for creatinine-adjusted Diethyl phosphate (DEP), Diethyl thiophosphate (DETP), and Diethyl dithiophosphate (DEDTP) were 3.5, 2.8, and 2.9, respectively). Serum organochlorine pesticides were also significantly associated with NTD (4th quartile ORs for lindane, dieldrin, and trans-nonachlor were 11.1, 3.8, and 9.4). There was no parallel gradient for metals. Discussion: The increased odds for NTD, which we observed to be associated with increased concentrations of pesticide breakdown products in maternal specimens is consistent with disrupted cranium ossification and bifidum in the exposed human embryos. We invite attention to the risks from large-scale applications of pesticides in cropland, mosquito, weeds and  brush control along highways. Interstate highways have larger shoulders and herbicide treatment of these grassy spaces is more substantial than for minor roads. This is especially true for hot and humid climate in Southwest US. We have previously published fundings of significantly lower serum folate and vitamin B12 concentrations in NTD case mothers. We have now invite attention to significant confounding / interaction of odds for conception residences proximal to intestate highways and low serum folate/vitamin B12. We suggest  that observed exposures to agrochemicals might be bringing about reduced maternal serum folate/vitamin B12 levels seeing in NTD.

Irina Cech is a hydrologist and renowned American health scientist. She received her PhD from the University of Texas. She worked as Full Professor in the Division of Epidemiology, Human Genetics, Environmental, and Occupational Health sciences. Her research focuses on health consequences of pollutions, chemical, biological, and radioactive. She was awarded US Congressional Science Fellowship and worked as Special Assistant in the US Congress, House of Representatives, Oversight and Investigation Subcommittee of Energy and Commerce Committee (101 Congress).  Dr. Cech is multi-lingual and uses these skills as a speaker on behalf of USIA various countries.  She had a  honorary appointment with the University of Cuidad Juarez, Mexico. She was Principal Investigator/Project Director in the U.S.-Mexico Border Neural Tube Defect project, sponsored by the CDC/ATSDR. She served on the Expert Committee for the National Academy of Sciences/National Research Council, Water Sciences & Technology Board jointly with Mexican National Academy of Sciences.