Towards prenatal bio monitoring in Nanjing, China: Lead and cadmium levels in the duration of pregnancy

Background Prenatal lead and cadmium exposure will not only influence the mother's organ systems, but also will provide an environment that may influence the fetus and neonate in a harmful way. In the present study, we detected the blood lead levels (BLLS) and cadmium levels for the duration of pregnancy and 6-12 weeks after delivery and to analyze the influencing factors of BLLs in healthy pregnant women. Methods A cohort study survey was carried out. We recruited 174 healthy pregnant women without pregnancy or obstetric complications or abnormal pregnancy outcomes as the gravida group, and 120 healthy non-pregnant women as the control group. Results The lead concentrations in the three pregnancy trimesters and in the postpartum period were: (5.98 +/- 2.43), (5.54 +/- 2.01), (5.59 +/- 1.97), and (6.76 +/- 1.74) mu g/dl; and (6.75 +/- 2.13) mu g/dl in the control group. The cadmium concentrations in the three pregnancy trimesters and postpartum period were 1.61 +/- 0.45, 1.63 +/- 0.46, 1.64 +/- 0.49, and 1.67 +/- 0.57. We found that the BLLs in the gravida group were lower than in the control group during all three trimesters. Occupations, supplement nutritional elements (dietary supplements and nutritional (food) elements), and the time of house painting could affect BLLs in pregnant women. Lead-related occupations, using cosmetics, and living in a house painted more recently than one year previously are risk factors of high BLLs among pregnant women, while calcium, iron, zinc, and milk supplements are protective factors. Conclusions These findings may help people, especially pregnant women, to reduce lead exposure via supplements of calcium, iron, zinc, and milk or avoiding contacting risk factors.