RESUMEN
Persistent organic pollutants (POPs) present in the living environment are thought to have detrimental health effects on the population, with pregnant women and the developing foetus being at highest risk. We report on the levels of selected POPs in maternal blood of 155 delivering women residing in seven regions within the São Paulo State, Brazil. The following selected POPs were measured in the maternal whole blood: 12 polychlorinated biphenyls (PCBs) congeners (IUPAC Nos. 99, 101, 118, 138, 153, 156, 163, 170, 180, 183, 187, 194); dichlordiphenyltrichloroethane p,p'-DDT, diphenyldichloroethylene p,p'-DDE and other pesticides such as hexachlorocyclohexanes (α-HCH, ß-HCH, γ-HCH), hexachlorobenzene (HCB), chlordane derivatives cis-chlordane, trans-chlordane, oxy-chlordane, cis-nonachlor and trans-nonachlor. Statistical comparisons between regions were performed only on compounds having concentrations above LOD in 70% of the samples. PCB118 congener was found to be highest in the industrial site (mean 4.97 ng/g lipids); PCB138 congener concentration was highest in the Urban 3 site (mean 4.27 ng/g lipids) and congener PCB153 was highest in the industrial and Urban 3 sites with mean concentration of 7.2 ng/g lipids and 5.89ng/g lipids respectively. Large differences in levels of p,p'-DDE between regions were observed with the Urban 3 and industrial sites having the highest concentrations of 645 ng/g lipids and 417 ng/g lipids, respectively; ß-HCH was found to be highest in the Rural 1 site; the γ-HCH in Rural 1 and industrial; the HCB in the Rural 1 and industrial sites and oxy-chlordane and t-NC in the Rural 2 sites. An association between levels of some contaminants and maternal age and parity was also found.
Asunto(s)
Contaminantes Ambientales/sangre , Exposición Materna/estadística & datos numéricos , Bifenilos Policlorados/sangre , Adolescente , Adulto , Brasil , Clordano/sangre , Parto Obstétrico/estadística & datos numéricos , Diclorodifenil Dicloroetileno/sangre , Monitoreo del Ambiente , Contaminación Ambiental/estadística & datos numéricos , Femenino , Hexaclorobenceno/sangre , Hexaclorociclohexano/sangre , Humanos , Hidrocarburos Clorados/sangre , Plaguicidas/sangre , Embarazo , Adulto JovenRESUMEN
This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of São Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 µg L⻹, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 µg L⻹ (0.01-0.58 µg L⻹) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 µg L⻹ (0.06 µg L⻹-4.35 µg L⻹); median Pb level was 16.2 µg L⻹ (3.5-57.7 µg L⻹) and no differences between sites were observed for both metals. Median Mn level was 16.7 µg L⻹ (7.0-39.7 µg L⻹), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 µg L⻹ and 1.1 µg L⻹ (median 0.25 µg L⻹) and As level was 0.60 µg L⻹ (0.10-3.8 µg L⻹) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 µg L⻹ (36-233 µg L⻹), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in São Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.
Asunto(s)
Elementos Químicos , Embarazo/sangre , Adolescente , Adulto , Estatura , Peso Corporal , Brasil , Femenino , Sangre Fetal/química , Estado de Salud , Humanos , Recién Nacido , Estilo de Vida , Edad Materna , Paridad , Resultado del Embarazo , Factores Socioeconómicos , Adulto JovenRESUMEN
Environmental toxicants such as metals may be detrimental to foetus and infant development and health because of their physiological immaturity, opportunistic and differential exposures, and a longer lifetime over which disease, initiated during pregnancy and in early life, can develop. The placental mechanisms responsible for regulation of absorption and excretion of elements during pregnancy are not fully understood. The aim of this paper is to assess the correlation for selected toxic and essential elements in paired whole blood samples of delivering women and cord blood, as well as to evaluate the placental permeability for selected elements. Regression analyses used to assess this correlation in 62-paired samples of maternal and cord whole blood of delivering women show that the concentrations of mercury, lead, cobalt, arsenic and selenium in maternal and cord blood differed statistically. Lead, cobalt, arsenic and selenium appear to pass the placental barrier by a diffusion mechanism. It was also found that the mercury levels in cord blood were almost double those of the mother, suggesting that the foetus may act as a filter for the maternal mercury levels during pregnancy. Transplacental transfer for arsenic and cobalt was 80% and 45%, respectively, suggesting that the placenta modulates the rate of transfer for these elements. Cadmium, manganese, copper and zinc levels did not show statistically significant correlations between two compartments (maternal versus cord whole blood). The study confirms that most of the toxic metals measured have an ability to cross the placental barrier.