Assessment of exposure to trace metals in a cohort of pregnant women from an urban center by urine analysis in the first and third trimesters of pregnancy

Background: Prenatal exposure to trace metals, whether they are essential, non-essential or toxic, must be assessed for their potential health effects in the offspring. Herein is reported a preliminary approach to this end which involved collection of urine samples during the first and third trimesters of pregnancy from 489 mothers from Sabadell (Catalonia, Spain), a highly industrialized town. These samples were analyzed for cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), arsenic (As), molybdenum (Mo), cadmium (Cd), antimonium (Sb), cesium (Cs), thallium (Th) and lead (Pb). Results: An acid digestion method was developed and validated for Q-ICP-MS analysis of these 12 metals. The median concentrations of metals ranged from 0.13 to 290 μg/g creatinine, the highest levels were found for Zn and the lowest for Th. The mean concentrations of most metals except As, Ni, Th and Pb showed statistically significant differences between both trimesters. The concentrations of Mo, Se, Cd, Cs and Sb were higher in the first than in the third trimester, whereas the opposite was found for Co, Cu and Zn. The concentrations of all metals in both sampling periods showed statistically significant correlations (p