Lead, mercury and cadmium in umbilical cord blood and its association with parental epidemiological variables and birth factors
1 Environmental and Cancer Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health (Instituto de Salud Carlos III - ISCIII), Madrid, Spain
2 Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública - CIBERESP), Madrid, Spain
3 Instrumental Analysis and Environmental Chemistry Department, Organic Chemistry Institute, CSIC, Madrid, Spain
4 Madrid Regional Health & Consumer Affairs Authority, Madrid, Spain
5 Medical Genetics Department, Ramón y Cajal University Teaching Hospital, Madrid, Spain
6 Public Health Department, Miguel Hernandez University, Alicante, Spain
7 Health Prevention & Environmental Health Department, Madrid, Spain
8 Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA
BMC Public Health 2013, 13:841 doi:10.1186/1471-2458-13-841Published: 12 September 2013
In Spain, few studies have evaluated prenatal exposure to heavy metals. The objective of this study was to describe lead, mercury and cadmium concentrations in blood from a sample of newborn–mother-father trios, as well as to investigate the association between metals in cord blood and parental variables. We also explored the relationship between cord blood metal concentrations and child characteristics at birth.
Metal correlations among family members were assessed using Spearman Rank Correlation Coefficient. Linear regression was used to explore the association between parental variables and log-transformed cord blood lead and cord blood mercury concentrations. In the case of cadmium, tobit regression was used due to the existence of samples below the detection limit. The association between cord blood metal concentrations and child characteristics at birth was evaluated using linear regression.
Geometric means for lead, mercury and cadmium were 14.09 μg/L, 6.72 μg/L and 0.27 μg/L in newborns; 19.80 μg/L, 3.90 μg/L and 0.53 μg/L in pregnant women; and 33.00 μg/L, 5.38 μg/L and 0.49 μg/L in men. Positive correlations were found between metal concentrations among members of the trio. Lead and cadmium concentrations were 15% and 22% higher in newborns from mothers who smoked during pregnancy, while mercury concentrations were 25% higher in newborns from mothers with greater fish intake. Cord-blood lead levels showed seasonal periodicity, with lower concentrations observed in winter. Cord blood cadmium concentrations over 0.29 μg/L were associated with lower 1-minute and 5-minute Apgar scores.
These results reinforce the need to establish biomonitoring programs in Spain, and provide support for tobacco smoke and fish consumption as important preventable sources of heavy metal exposure in newborns. Additionally, our findings support the hypothesis that cadmium exposure might be deleterious to fetal development.