Environmental Health Perspectives.
The findings also suggest that probably longer exposure of the older mothers may be involved in their higher risk of having babies with the defect.
These results contribute to a body of evidence that PAHs may be teratogenic but further studies are needed to support the findings.
Women exposed to a group of chemicals called PAHs during pregnancy are more likely to have babies with gastroschisis, a rare defect of umbilical cord.
Gastroschisis is a type of hernia in which an infant's intestines stick out of the body through a defect on one side of the umbilical cord.
Prior findings have tied the rare birth defect with combustion of fossil fuels. However, now researchers for the first time have linked work place exposure to polycyclic aromatic hydrocarbons or PAHs during early pregnancy with the health problem.
PAHs are a group of approximately 10,000 compounds which most of them are resulted from incomplete burning of carbon-containing materials like oil, wood, garbage or coal.
PAHs are also developed in some cooked foods for example, in meat cooked at high temperatures such as grilling or barbecuing, and in smoked fish. Low doses of PAHs are also found in products such as mothballs, blacktop and even skin creams and anti-dandruff shampoos that contain coal tars.
Philip J. Lupo of the University of Texas and colleagues used data from the US National Birth Defects Prevention Study to find any association between PAHs and gastroschisis in human beings.
Their findings revealed that mothers who were exposed to PAHs during early months of pregnancy had 1.5 times the risk of having a baby with gastroschisis compared to women who were not exposed to PAHs at work.
The association was only found in women older than 19 years of age, which is notable because young maternal age is a known risk factor for this birth defect, according to the report published in the journal