Potential mercury exposure through diet in pregnant women and women of childbearing age

Placental transfer of Hg is known to cause brain damage in infants [Carpenter. D. Cell. Mol. Neurobio. 14(6):591, 1994]. Although environmental exposure is one of the common routes of Hg intoxication, pregnant women may be at risk through dietary fish and other seafoods. In order to conduct a survey of dietary Hg exposure which has never been performed in Gulf Coast areas, blood was collected from pregnant women and those of childbearing age at routine clinic visits at each of 3 centers in South Texas. Responses to a questionnaire provided demographic data and dietary and lifestyle information. Specific details were sought with regard to consumption of fish. Blood was analyzed for total Hg by cold vapor atomic absorption, following a digestion procedure. The procedure was sensitive to 5 ppt. Of 110 samples analyzed to date, the range of values (in ug/L) for blood Hg varied with the location of the centers: City of Galveston 3.50-62.00; Texas City 2.80-50-00; and the Port Lavaca areas 3.00-126.7. There was a positive association between the blood mercury level and frequency and the kind offish consumed. The highest shellfish consumed by study subjects was shrimp. Highest levels of Hg were found in the Port Lavaca areas which is in agreement with the fact that shrimp in Port Lavaca Bay have higher levels of Hg compared to those in other Gulf Coast locations [Palmer, S. J. et al. Bull. Env. Contam. Tox. 51:464, 1993]. Pregnant females appeared to show higher levels of Hg compared to women of childbearing age consuming similar amounts and kinds of fish.