The prevalence of fetal exposure to environmental toxins, specifically the heavy metals, has not been adequately studied due to the lack of an appropriate measure of exposure. We propose that meconium analysis is ideal for this purpose. For the first time, we present epidemiologic data on significant fetal exposure to lead, mercury and cadmium, based on meconium analysis, and the effects of this exposure. METHODS: Infants were randomly recruited from the nurseries of 7 private or public hospitals which collectively represented a cross section of the socioeconomic population of Manila, Philippines. Meconium was anonymously obtained from each infant and analyzed for lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As) by atomic absorption spectrometry. Pertinent clinical and demographic data were abstracted from the maternal and neonatal records. RESULTS: A total of 422 maternal infant dyads were studied. Meconium was positive (% of total infants) for the following heavy metals: Pb (26.9%), Hg (83.1%), Cd (8.5%). All samples were negative for As. Mean (sd) concentrations (per g meconium) were: Pb = 63.9 ± 74.5 μg/g (range= 4.1-301.5); Hg =1.9 ± 2.3 ng/g(range = 0.2-17.5); Cd = 7.02 ± 3.51 μg/g (range= 1.1-13.7). The Pb(+) group was associated with a significant (p<0.03) increase in the incidence of meconium stained fluid (15% vs 5%), multiple gestation (12% vs 4%), birth weight <2.5 kg (13% vs 7%); SGA (9% vs 3%) and parity >3 (15% vs 7%). High Pb conc in meconium (mean=254 mg/g) was also associated with lower gestational age (mean=35.6 wks, p<0.05, ANOVA). The Hg (+) group was associated with a significant (p<0.05) increase in thee incidence of gestation < 37 wks (16.2% vs 5.6%) and head circ <33 cm (59% vs 41%). The Cd (+) group was associated with a significant (p<0.02) increase in the incidence of parity >3 (22% vs 8%) and decrease in neonatal jaundice (11% vs 36%). Thus, meconium analysis is a useful, easy tool to detect fetal exposure to heavy metals. A high prevalence rate and significant hazardous effects from the exposure were observed in the study population.
