Background and aim Lead, mercury and cadmium are widely exposed environmental pollutants throughout the world. In this study, we aimed to investigate the level of exposure to lead(Pb), mercury(Hg) and cadmium(Cd) during intrauterine life.
Methods We included 123 mother-infant pairs between December 2006 and January 2007. Umbilical cord blood collected immediately after delivery while breast milk and newborn hair samples collected between 3–10th postpartum days. All the specimens analyzed by Inductively Coupled Plasma Mass Spectrometry.
Results Cord blood samples Pb was present in 99.2%(the mean 1.66±1.6µg/dl) while Hg in only 1.7% and Cd in 19.8%(ranged 0–6.71µg/L). Cord blood Pb was higher than ≥2µg/dl in 29% of the samples. Pb, Hg and Cd were detectable in all the newborn hair samples. Among breast milk samples 83.2% had detectable lead levels(mean 14.5±12.1µg/L). Presence of Hg and Cd in breast milk samples were 53.3% and 9% respectively. Cord blood lead levels were significantly higher when maternal age >35 years. Breast milk Cd levels were significantly higher in women who were residing close to the major city waste site. Cord blood Cd levels were significantly higher in women consuming more than two fish weekly. Maternal exposure to environmental tobacco smoking(ETS) resulted increased newborn hair Pb and Cd levels.
Conclusion Intrauterine heavy metal exposure is an important concern for pediatricians. Most samples had detectable levels for Pb, Hg, Cd indicating long term maternal exposure and considerable number exceeds the present accepted safety levels at cord and breast milk samples. Preventing ETS, limiting fish consumption and improved living conditions for pregnant women may decrease exposure levels.