RESUMO
Few studies have addressed co-occurring methylmercury (MeHg) from maternal origin and ethylmercury (EtHg) from Thimerosal-containing vaccines (TCVs) during infant's neurodevelopment. We studied children (n=1139) from the Western Amazon based on combined (low, intermediate, and high) exposure to chronic MeHg from fish consumption and acute TCV- EtHg. Neurodevelopment outcomes were age of walking and age of talking, and the Bayley Scale of Infant Development (BSID). The Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) were measured at six and 24 months of age. Median hair-Hg (HHg) at birth was 6.4µgg(-1) in mothers, and 1.94µgg(-1) in newborns; total (pregnancy and infancy) EtHg exposure ranged from 0 to 187.5µg. The combined (MeHg+EtHg) exposure showed significant differences for MDI but not for PDI; however, there was a significant decrease in both MDI and PDI scores at 24 months. The increase in BSID delays (scores <80) between six and 24 months was not discernible with regards to EtHg or MeHg exposure. We found a statistically significant increase in neurodevelopmental (BSID) delays related to the combined exposure to Hg (MeHg>EtHg). Neurodevelopment delays due to low-doses of organic mercury (albeit undiscernible) are not predictable but can be avoided by choosing low-Hg fish and providing Thimerosal-free vaccines.
Assuntos
Desenvolvimento Infantil/efeitos dos fármacos , Exposição Materna , Compostos de Metilmercúrio/efeitos adversos , Fala/efeitos dos fármacos , Timerosal/efeitos adversos , Vacinas/efeitos adversos , Caminhada , Animais , Pré-Escolar , Feminino , Peixes , Contaminação de Alimentos , Humanos , Lactente , MasculinoRESUMO
CONTEXT: Environmental mercury in the Amazon mostly originates from geochemical sources with some from artisanal gold mining (AGM). Geochemical-originated methylmercury (MeHg) reaches the aquatic food chain, ending up in fish. Inorganic Hg used in AGM is responsible for localised environmental contamination and occupational exposure of adults. In addition to this, iatrogenic ethylmercury (EtHg) derived from Thimerosal-containing vaccines (TCVs) exposes immunised infants. OBJECTIVE: To understand Hg exposure in the Amazon in relation to environmental fish-MeHg exposure, occupational AGM activities and low-doses of TCV-EtHg. METHODS: Medline and Thomson-Reuter Web of Science were searched to retrieve and select papers addressing Hg exposure and human health. RESULTS AND CONCLUSION: Environmental-Hg studies addressed health effects associated with birth weight, infant linear growth and neurodevelopment, while, in adults, environmental and occupational studies addressed immune and neurological issues. No widespread clinical toxicity was reported due to fish-MeHg. However, mixed results associated with Hg exposure can be found. Reducing children's exposure to EtHg is possible using Thimerosal-free vaccines, but it is difficult to interfere with fish consumption without consequences to riverine subsistence populations. Policies to diminish Hg exposure should focus on controlling and/or curbing widespread use of Hg (in gold amalgamation) and promotion of Thimerosal-free vaccines for pregnant women and young children.
Assuntos
Mercúrio/análise , Saúde Pública , Adulto , Brasil , Criança , Exposição Ambiental , HumanosRESUMO
BACKGROUND: Features of traditional living in the Amazon Basin (high fish consumption and long breastfeeding) are likely to expose children to Mercury (Hg). AIM: To study neurodevelopment in 690 children in relation to prolonged breastfeeding and mercury exposure. SUBJECTS AND METHODS: Three groups of breastfeeding children were formed: Group 1 (breastfed for 6 months), Group 2 (7-12 months) and Group 3 (extending up to 24 months). Neurodevelopment was assessed as age of walking, age of talking and the Bayley Scales of Infant Development-BSID. Mercury exposure was assessed from Thimerosal-containing vaccines and fish consumption from hair Hg (HHg). RESULTS AND CONCLUSIONS: HHg increased in children and decreased in mothers at 24 months. Frequency of fish consumption was significantly correlated with maternal HHg at birth (Spearman's r = 0.8583; p = 0.0001); likewise, there was a significant correlation between duration of breastfeeding and children's HHg (Spearman's r = 0.15; p = 0.0018). Extended breastfeeding did not influence the Mental Development Index-MDI or Psychomotor Development Index-PDI, but maternal education and HHg (marker of fish consumption) interacted positively and significantly with both. Frequency of maternal fish consumption and education had a positive association with BSID scores; it is speculated that maternal education and nutrients in fish have an opposing effect on Hg exposure.
Assuntos
Aleitamento Materno , Desenvolvimento Infantil , Comportamento Alimentar/fisiologia , Peixes , Exposição Materna , Mercúrio/análise , Sistema Nervoso/crescimento & desenvolvimento , Animais , Brasil , Feminino , Geografia , Humanos , Lactente , Análise de Componente Principal , Adulto JovemRESUMO
Methylmercury (from fresh-water fish) and ethylmercury [from thimerosal-containing vaccines (TCVs)] are the most prevalent source of neurotoxic exposure during early life in families consuming fish and using these vaccines. But children living in Amazonian mining environments are exposed to additional toxic metals in waste materials. We studied mercury (Hg) exposure and neurodevelopment in 294 children (105 boys and 189 girls) from Bom Futuro (Rondonia, Brazil), the epicenter of a tin-ore open-pit mine. Hair-Hg (HHg) concentrations and total ethylmercury (from TCVs) were taken from infants and respective mothers during pregnancy. We used bivariate analysis to determine the effect of sex and linear mixed models to assess the association of prenatal and postnatal organic Hg exposures with children's Bayley Scales of Infant Development (BSID) as psychomotor developmental index and mental developmental index (MDI) at 6 and 24 months of age as well as milestones achievements (age of walking and age of talking). Significant differences between boys and girls were observed for both MDI score (p = 0.0073) and MDI score (p = 0.0288) at 6 months but not at 24 months. Regression analysis showed that only in boys was there a significant interaction between MDI score with family income (ß = 0.288, p = 0.018) and with birth weight (ß = -0.216, p = 0.036) at 6 months; at 24 months, however, only boys showed a significant association of both MDI score (ß = -0.222, p = 0.045) and MDI score (ß = -0.222, p = 0.045) with neonatal HHg. In boys, age of walking was associated with HHg (ß = 0.188, p = 0.019) and breastfeeding (ß = -0.282, p = 0.000), whereas for girls, age of walking was only associated with breastfeeding (ß = -0.275, p = 0.001). In this mining environment, with only a weak association for prenatal Hg exposure, there was a significant sex difference in neurodevelopment, with boys showing more sensitivity related to BSID delays.
Assuntos
Desenvolvimento Infantil/efeitos dos fármacos , Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/análise , Mercúrio/análise , Brasil , Aleitamento Materno/estatística & dados numéricos , Pré-Escolar , Exposição Ambiental/análise , Poluentes Ambientais/metabolismo , Poluentes Ambientais/toxicidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mercúrio/metabolismo , Mercúrio/toxicidade , Mineração , Transtornos Psicomotores/induzido quimicamente , Transtornos Psicomotores/epidemiologia , Fatores SexuaisRESUMO
Neurological outcomes (Gesell development schedules [GDS]), age of walking, and age of talking were studied in 299 toddlers (12 to 24 mo) in relation to environmental (fish consumption and tin mining) exposure. Exposure to fish methylmercury (MeHg) consumption and iatrogenic ethylmercury (EtHg) in Thimerosal-containing vaccines (TCV) was quantified in toddlers from two rural villages (n = 91, Itapuã; n = 218, Bom Futuro) respectively populated by fishers and cassiterite miners. Median total hair Hg (HHg) concentrations of infants from Itapuã (3.5 µg/g) were significantly higher than those of infants from Bom Futuro (2.2 µg/g). Median EtHg exposure from TCV was also significantly higher in toddlers from Itapuã (137.5 µg) than in those from Bom Futuro (112.5 µg). There were no significant differences between groups for any of the Gesell schedules; however, there were proportionally more compromised toddlers (GDS < 70) in Itapuã than Bom Futuro. Median age of talking was not statistically different but median age of walking was significantly higher in Bom Futuro. In toddlers from both villages, of fishers and miners, HHg concentrations were significantly correlated with family fish consumption. A logistic regression model was applied to all infants after classification into two groups: above or below the median Gesell schedules. Overall, there was no distinctive pattern of neurodevelopment associated with either HHg or EtHg exposure; however, nutritional status was significantly associated with GDS. In conclusion, milestone achievement was delayed in toddlers from tin-ore mining communities. Despite significantly higher exposure to both forms of organic Hg (MeHg from maternal fish consumption, and EtHg from TCV) in toddlers from the fishing village, significant differences were seen only among the proportions of most severely affected toddlers (GDS < 70).
Assuntos
Deficiências do Desenvolvimento/induzido quimicamente , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/efeitos adversos , Compostos de Etilmercúrio/efeitos adversos , Compostos de Metilmercúrio/efeitos adversos , Saúde da População Rural , Brasil , Pré-Escolar , Estudos Transversais , Deficiências do Desenvolvimento/diagnóstico , Dieta/efeitos adversos , Inquéritos sobre Dietas , Exposição Ambiental/análise , Monitoramento Ambiental , Poluentes Ambientais/análise , Compostos de Etilmercúrio/análise , Feminino , Contaminação de Alimentos , Cabelo/química , Humanos , Lactente , Transtornos do Desenvolvimento da Linguagem/induzido quimicamente , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Modelos Logísticos , Masculino , Compostos de Metilmercúrio/análise , Mineração , Conservantes Farmacêuticos/efeitos adversos , Alimentos Marinhos/efeitos adversos , Timerosal/efeitos adversos , Estanho , Vacinas/efeitos adversos , CaminhadaRESUMO
We compared Pb concentration in human milk from 37 mothers living in a neighborhood of tin-ore smelters to that from 45 mothers living in a fishing community. The median breast-milk-Pb (BM-Pb) concentration was significantly (p = 0.0000001) higher (11.3 µg L(-1); ≤0.96-29.4 µg L(-1)) in mothers living in the vicinity of smelters than that of rural mothers (1.9 µg L(-1); ≤0.96-20.0 µg L(-1)). These mothers also showed a statistically significant correlation between length of residence and BM-Pb concentration (Spearman r = 0.6864; p < 0.0001). The estimated median exposure (for infants <6 months) was 3.0 µg kg(-1) b.w. for rural infants compared to 7.5 µg kg(-1) b.w. for infants in the vicinity of metal smelters. Overall, most BM-Pb concentrations (79 %) in the metal smelter area were above the critical limit of 5.0 µg L(-1) set by the WHO.
Assuntos
Poluentes Ambientais/metabolismo , Chumbo/metabolismo , Exposição Materna/estatística & dados numéricos , Metalurgia , Leite Humano/metabolismo , Adolescente , Adulto , Poluição Ambiental/estatística & dados numéricos , Feminino , Humanos , Mães , Análise de Componente Principal , Adulto JovemRESUMO
Environmental contamination by mercury (Hg) is a problem of global scale that affects human health. This study's aim was to evaluate Hg exposure among women of reproductive age residing in the Madeira River basin, in the State of Rondônia, Brazilian Amazon. This longitudinal cohort study used linear regression models to assess the effects on Hg levels of breastfeeding duration at 6 months, and of breastfeeding duration and number of new children at 2-year and 5-year. Breastfeeding duration was significantly associated with maternal Hg levels in all regression models (6 months, 2 years and 5 years) and no significant association was observed between the number of children and the change in maternal Hg levels in the 2-year and 5-year models. This longitudinal cohort study evaluated Hg levels and contributing factors among pregnant women from different communities (riverine, rural, mining and urban) in Rondônia, Amazon Region, for 5 years. A well-coordinated and designed national biomonitoring program is urgently needed to better understand the current situation of Hg levels in Brazil and the Amazon.
Assuntos
Mercúrio , Criança , Animais , Humanos , Feminino , Gravidez , Brasil , Estudos Longitudinais , Mercúrio/análise , Rios , Aleitamento Materno , Peixes , Monitoramento Ambiental , Exposição AmbientalRESUMO
Neurodevelopment as Gesell development scores (GDSs) in relation to mercury exposure in infants (<6 months of age) of one urban center and two rural villages, respectively, of fisherman and cassiterite miners. Mean total hair-Hg (HHg) concentrations of infants from Itapuã (3.95 ± 1.8 ppm) were statistically (P = 0.0001) different from those of infants from Porto Velho (3.84 ± 5.5 ppm) and Bom Futuro (1.85 ± 0.9 ppm). Differences in vaccine coverage among these populations resulted in significantly higher (P = 0.0001) mean ethylmercury (EtHg) exposure in urban infants (150 µg) than in infants from either village (41.67 µg, Itapuã; 42.39 µg, Bom Futuro). There was an inverse significant (Spearman r = -0.2300; P = 0.0376) correlation between HHg and GDS for infants from Porto Velho, but not for the rural infants from Bom Futuro (Spearman r = 0.1336; P = 0.0862) and Itapuã (Spearman r = 0.1666; P = 0.5182). Logistic regression applied to variables above or below the median GDS showed that EtHg exposure (estimated probability = -0.0157; P = 0.0070) and breastfeeding score (estimated probability = -0.0066; P = 0.0536) score were significantly associated with GDS. Conclusion. In nurslings whose mothers are exposed to different levels of fish-MeHg (HHg), a higher score of neurological development at six months was negatively associated with exposure to additional TCV-EtHg. Results should be interpreted with caution because of unaccounted variables.
Assuntos
Compostos de Etilmercúrio/intoxicação , Cabelo/química , Exposição Materna , Mercúrio/análise , Compostos de Metilmercúrio/intoxicação , Brasil , Aleitamento Materno , Deficiências do Desenvolvimento/induzido quimicamente , Dieta , Inquéritos sobre Dietas , Compostos de Etilmercúrio/farmacocinética , Feminino , Cabelo/metabolismo , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Mercúrio/farmacocinética , Compostos de Metilmercúrio/farmacocinética , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Desempenho Psicomotor/efeitos dos fármacos , População Rural , Fatores Socioeconômicos , População UrbanaRESUMO
Human occupation of the Amazon region has recently increased, bringing deforestation for agriculture and open-cast mining, activities that cause environmental degradation and pollution. Families of new settlers in mining areas might have a diet less dependent on abundant fish and their children might also be impacted by exposures to mining environments. Therefore, there is compounded interest in assessing young children's nutritional status and neurobehavioral development with regard to family fish consumption. Anthropometric (z-scores, WHO standards) and neurologic [Gesell developmental scores (GDS)] development in 688 preschool children (1-59 months of age) was studied. Overall, the prevalence of malnutrition [i.e., moderate stunting (≤2 H/A-Z), underweight (≤2 W/A-Z), and wasting (≤2 W/H-Z) were respectively 0.3% (n = 2), 1.6% (n = 11), and 2.5% (n = 17). Children's mean hair Hg (HHg) concentration was 2.56 µg/g (SD = 1.67); only 14% of children had HHg concentrations lower than 1 µg/g and 1.7% had ≥5 µg/g. The biomarker of fish consumption was weakly but positively correlated with GDS (Spearman r = 0.080; p = 0.035). In the bivariate model, attained W/H-Z scores were not significantly correlated with GDS. A moderate level of GDS deficits (70-84%) was seen in 20% of children. There was significant correlation between family fish consumption and children's hair Hg (HHg) (Spearman r = 0.1756; p < 0.0001) but no significant correlation between children's HHg and W/H-Z scores. However, the multivariate model showed that breastfeeding, a fish consumption biomarker (HHg), maternal education, and child's age were statistically significant associated with specific domains (language and personal-social) of the Gesell scale. In this mining environment, family fish-eating did not affect children's linear growth, but it showed a positive influence (along with maternal variables) on neurodevelopment. Health hazards attendant on a high prevalence of moderate neurodevelopment delays coexisting with exposure to multiple neurotoxic substances merits further investigation in poor environmental settings of tin-mining areas.
Assuntos
Encéfalo/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Dieta , Compostos de Metilmercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antropometria , Encéfalo/crescimento & desenvolvimento , Brasil , Aleitamento Materno , Pré-Escolar , Estudos Transversais , Monitoramento Ambiental/métodos , Peixes , Contaminação de Alimentos/análise , Cabelo/química , Humanos , Lactente , Compostos de Metilmercúrio/análise , Mineração , Análise Multivariada , Fatores Socioeconômicos , Estanho/análise , Poluentes Químicos da Água/análiseRESUMO
Birth weight data (22,012 live-births) from a public hospital in Porto Velho (Amazon) was used in multiple statistical models to assess the effects of forest-fire smoke on human reproductive outcome. Mean birth weights for girls (3,139 g) and boys (3,393 g) were considered statistically different (p-value < 2.2e-16). Among all models analyzed, the means were considered statistically different only when treated as a function of month and year (p-value = 0.0989, girls and 0.0079, boys) . The R (2) statistics indicate that the regression models considered are able to explain 65 % (girls) and 54 % (boys) of the variation of the mean birth weight.
Assuntos
Peso ao Nascer , Exposição Ambiental/estatística & dados numéricos , Incêndios/estatística & dados numéricos , Árvores , Poluição do Ar/estatística & dados numéricos , Brasil , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Recém-Nascido , Masculino , Modelos Estatísticos , População RuralRESUMO
OBJECTIVE: To assess the dependence on fish consumption of families and its impact on nutritional status and neurodevelopment of pre-school children. DESIGN: Cross-sectional study that measured children's hair mercury (HHg) as an indicator of family fish consumption, growth (anthropometric Z-scores, WHO standards) and neurological (Gesell developmental scores (GDS)) development. SETTING: Traditional living conditions among families residing in the area adjacent to the Samuel Dam (Western Amazon) hydroelectric reservoir. SUBJECTS: Two hundred and forty-nine pre-school children (1-59 months of age) from families transitioning from the traditional Amazonian lifestyle. RESULTS: Family fish consumption was significantly correlated with children's HHg concentration (Spearman's r=0.246, P<0.0001); however, HHg had no significant association with growth (Z-scores). Overall, the prevalence of severe malnutrition, i.e. stunting (height-for-age Z-score (HAZ)≤-3), underweight (weight-for-age Z-score (WAZ)≤-3) and wasting (weight-for-height Z-score (WHZ)≤-3) was 5.2% (n 13), 0% and 0.8% (n 2), respectively. The prevalence of moderate stunting (HAZ≥-3 to ≤-2), underweight (WAZ≥-3 to ≤-2) and wasting (WHZ≥-3 to ≤-2) was 8.8% (n 22), 2.4% (n 6) and 4.8% (n 12), respectively. Although 76% of the children showed adequate GDS (>85), multiple regression analysis showed that fish consumption (as HHg) had no impact on GDS, but that some variables did interact significantly with specific domains (motor and language development). CONCLUSIONS: The study showed that the families' shift in fish consumption had no negative impact on the growth of young children and that ensuing methylmercury exposure has not been a noticeable neurodevelopmental hindrance.
Assuntos
Desenvolvimento Infantil/efeitos dos fármacos , Transtornos da Nutrição Infantil/epidemiologia , Estilo de Vida , Compostos de Metilmercúrio , Alimentos Marinhos/análise , Animais , Brasil , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Estudos Transversais , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Feminino , Peixes/metabolismo , Contaminação de Alimentos , Cabelo/química , Humanos , Lactente , Masculino , Compostos de Metilmercúrio/administração & dosagem , Compostos de Metilmercúrio/efeitos adversos , Compostos de Metilmercúrio/análise , Estado Nutricional , Centrais Elétricas , Alimentos Marinhos/estatística & dados numéricosRESUMO
Young children are particularly vulnerable to the chronic sequelae of anemia, including poor nutritional status. The aim of this study was to assess intestinal parasitic-infections and nutritional status (anemia and linear growth) in preschool children living in contemporary Amazonian communities. A cross-sectional study measured children's intestinal parasites and hair-Hg (HHg)-biomarkers of fish consumption, hemoglobin levels, and growth (anthropometric Z-scores). Children came from traditional-living families (Itapuã), and tin-mining settlements (Bom Futuro) representing current transitioning populations. It covered 937 pre-school children (from 1 to 59 months of age) from traditional (247) and immigrant tin-mining families (688). There was a high prevalence of intestinal polyparasitic-infection in children from both communities, but mild anemia (hemoglobin concentrations) and moderate (chronic) malnutrition were more frequent in children from traditional families than in children from tin-mining settlers. Children from traditional families ate significantly more fish (HHg mean of 4.3 µg/g) than children from tin-mining families (HHg mean of 2.3 µg/g). Among traditional villagers, children showed a significant correlation (r = 0.2318; p = 0.0005) between hemoglobin concentrations and HHg concentrations. High rates of parasitic infection underlie the poverty and attendant health issues of young children in the Brazilian Amazon. The intestinal parasite burden affecting poor Amazonian children resulting from unsafe water, lack of sanitation and poor hygiene is the most urgent environmental health issue.
Assuntos
Anemia/epidemiologia , Anemia/etiologia , Enteropatias Parasitárias/epidemiologia , Estado Nutricional , Animais , Brasil/epidemiologia , Pré-Escolar , Estudos Transversais , Emigrantes e Imigrantes , Feminino , Humanos , Lactente , Enteropatias Parasitárias/complicações , Masculino , Mineração , Pobreza , Fatores de Risco , EstanhoRESUMO
OBJECTIVE: We evaluated the association between infant hair-Hg and Gesell schedules (GS). BACKGROUND: Longitudinal assessment of prenatal and postnatal Hg exposure during the first 60 months. METHODS: We used hair-Hg as a marker of postnatal Hg exposure (inorganic and methyl-Hg from breast milk, and ethyl-Hg from thimerosal) and GS measured at 6, 36, and 60 months. RESULTS: Hair-Hg at 6 months responded to events related to Hg exposure and breastfeeding. However, most neurodevelopment delays observed at 6 months were overcome with infant growth; at 60 months 87% of children showed adequate GS (>85). Length of lactation and hair-Hg were each significantly correlated with GS, but in opposite ways: length of lactation was positive and significantly correlated with all GS at 60 months; hair-Hg concentrations were negative and significantly correlated with GS at 6 months (r=-0.333; P=0.002) and 60 months (r=-0.803; P=0.010), but not at 36 months. Multiple regression models showed that the GS outcome at 60 months depended on GS at 36 months that in turn was influenced by infants' developmental and Hg exposure variables. GS at 6 months was significantly influenced by prenatal (maternal and infant hair-Hg at birth) and postnatal Hg exposure at 6 months. CONCLUSIONS: Until there is more refined approach to recognize children sensitive to Hg exposure, and in situations of uncertainty (EtHg exposure), the neurodevelopment benefit of breastfeeding should be recommended.
Assuntos
Aleitamento Materno , Desenvolvimento Infantil/fisiologia , Intoxicação do Sistema Nervoso por Mercúrio/patologia , Intoxicação do Sistema Nervoso por Mercúrio/psicologia , Adulto , Biomarcadores , Desenvolvimento Infantil/efeitos dos fármacos , Pré-Escolar , Estudos de Coortes , Deficiências do Desenvolvimento/induzido quimicamente , Deficiências do Desenvolvimento/psicologia , Compostos de Etilmercúrio/metabolismo , Compostos de Etilmercúrio/intoxicação , Feminino , Cabelo/química , Humanos , Programas de Imunização , Lactente , Recém-Nascido , Lactação , Estudos Longitudinais , Compostos de Metilmercúrio/metabolismo , Compostos de Metilmercúrio/intoxicação , Testes Neuropsicológicos , Gravidez , Análise de RegressãoRESUMO
Infant exposure to ethylmercury (EtHg) has not only increased but is starting earlier as a result of the current immunization schedule that uses thimerosal-containing vaccines (TCVs). Although vaccination schedule varies considerably between countries, infants in less-developed countries continue to be exposed to EtHg derived from more affordable TCVs. We studied the exposure of newborns to EtHg from hepatitis B vaccines; hospital records (21,685) were summarized for the years 2001 to 2005 regarding date of birth, vaccination date, and birth weight. Most of the vaccinations occurred in the first 24 hours postdelivery; over the 5 years, there was an increase in vaccinations within hours of birth (same day), from 7.4% (2001) to 87.8% (2005). Nearly 94.6% of infants are now being vaccinated within the first 24 hours. Range of mercury exposure spread from 4.2 to 21.1 microg mercury/kg body weight for those receiving TCVs with the highest thimerosal concentration; these exposure levels are conservative for 2% of children receiving vaccines within 2 to 3 postnatal days, when they are still going through physiological postnatal weight loss. Because of the particular timing (transitioning from in utero to ex utero metabolism) and specific aspects of exposure (i.e., parenteral mode, bypassing gastroenteric barriers) and dose (related to vaccine manufacturer and with variation in birth weight), this study reveals critical issues that can modulate toxicokinetics and toxicodynamics of organomercurials in neonates.
Assuntos
Vacinas contra Hepatite B/efeitos adversos , Hepatite B/prevenção & controle , Conservantes Farmacêuticos/efeitos adversos , Timerosal/efeitos adversos , Brasil , Estudos de Coortes , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Vacinas contra Hepatite B/administração & dosagem , Humanos , Incidência , Recém-Nascido , Masculino , Conservantes Farmacêuticos/administração & dosagem , Sistema de Registros , Medição de Risco , Timerosal/administração & dosagem , Timerosal/sangue , Vacinação/efeitos adversos , Vacinação/estatística & dados numéricosRESUMO
This data paper includes information of a cohort organized to study the health, nutrition, and development of Amazonian children [1]. Child development were evaluated by trained nurses and psychologists with the Bayley Scales of Infant Development (at 24 months), the Stanford-Binet Intelligence Scale (at 60 months) and also with questionnaires administered by trained interviewers to the mothers. Maternal food questionnaires were used to estimate fish consumption and the associations between levels of prenatal and postnatal hair mercury (from mothers and children) and scores of neurodevelopment.
RESUMO
Because of heavy dependence on fish, Amazonian riparian communities are chronically exposed to high levels of methylmercury (MeHg). We studied fish-MeHg exposure (total hair-Hg, HHg) as a determinant of neurocognitive scores of children living in two geographically distant, culturally distinct and isolated poor communities of non-urban environments: Amazonian riverines (Riparians, n=38) of the Puruzinho Lake community in the Rio Madeira Basin and rural agrarians from Iúna, Espírito Santo (Agrarians, n=32). Nutritional status was estimated by anthropometry (Z-scores) and individual cognitive abilities were assessed by the Wechsler Intelligence Scale for Children-III (WISC-III) and the Human Figure Drawings (HFD), both validated versions for Brazilian children. Anthropometric assessment showed slightly elevated Z-scores for the Agrarian children (not statistically significant) but median HHg concentrations were 14.4 and 0.25microgg(-1) respectively for Riparian and Agrarian children (p=0.000). Despite paradoxical MeHg exposures, both groups showed comparable HFD scores but very poor performance in WISC-III test battery; median of sum of WISC-III subtests scores (SigmaTOT) were 17.9 and 28.6 (p<0.000) for Riparian and Agrarian children, respectively (percentage scale). Spearman correlation between nutritional status (attained growth) and psychometric scores were statistically significant between height-for-age Z-score and Object Assembly subtest (r=0.269; p=0.043), SigmaTOT (r=0.319; p=0.016), Performance-IQ (r=0.311; p=0.019) and Perceptual Organization Index scores (r=0.302; p=0.023). In these isolated communities there are stronger determinants of neurocognitive poor performance than MeHg exposure. Global strategies for reducing human exposure to MeHg by curtailing fish consumption are unrealistic options for riverine subsistence populations and are not justifiable to prevent low cognitive scores.
Assuntos
Desenvolvimento Infantil , Peixes , Contaminação de Alimentos , Compostos de Metilmercúrio/análise , Psicometria/métodos , Características de Residência , Adolescente , Animais , Antropometria/métodos , Brasil , Criança , Feminino , Humanos , Inteligência , Testes de Inteligência , Masculino , Pobreza , População RuralRESUMO
The variance of variables associated with neurodevelopment at 180 days, pre-natal variables (Hg in placenta, blood and hair) and post-natal Hg exposure (including Thimerosal-containing vaccines, TCV) were examined in 82 exclusively breastfed infants using principal component analysis (PCA). This multivariate method was applied to identify hierarchy and sets of interrelated variables. The PCA yielded a two-factor solution, explaining 92% of variance and summarizing most of the relevant information in the dataset matrix: the first component represented birth weight and vaccine (first doses of Hepatitis B and DTP) variability and explained 57% of variance; the second component represented a gradient of neurodevelopment (Gesell scores) and explained 35% of variance. The third component explained only 3% of the remaining 8% variance. Beside CNS priming by breastfeeding, infant development (birth weight) and time of immunization with TCV should be considered in epidemiological studies. PCA can classify sets of variables related to vaccination and neuromotor development schedules, clearly discriminating between earlier and later TCV exposures of exclusively breastfed infants. In conclusion, the incommensurable concept of the chance of toxic risk caused by TCV-EtHg exposure against the proven benefit of immunization is in no way disputed here. However, infant neurodevelopmental (ND) disorders linked to Thimerosal-Hg stands in need of proof, but PCA points to the possibility of identifying exposure risk variables associated with ND schedules.
Assuntos
Deficiências do Desenvolvimento/etiologia , Mercúrio/efeitos adversos , Compostos de Metilmercúrio/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal , Timerosal/efeitos adversos , Adolescente , Adulto , Brasil , Aleitamento Materno , Desenvolvimento Infantil , Estudos de Coortes , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacina contra Difteria, Tétano e Coqueluche/química , Feminino , Vacinas contra Hepatite B/efeitos adversos , Vacinas contra Hepatite B/química , Humanos , Esquemas de Imunização , Lactente , Pessoa de Meia-Idade , Gravidez , Análise de Componente Principal , Adulto JovemRESUMO
BACKGROUND: Changes in fish-eating habits due to rapid urbanization in Western Amazon was used as model to investigate whether maternal fish-intake rate impacts on children's weight and height during the first 5 years. AIM: The study examined the growth of 82 breastfed children, and maternal fish consumption (hair mercury concentrations, HHg) during pregnancy and lactation. SUBJECTS AND METHODS: Fish consumption in mothers and children was estimated through HHg. The children were measured and weighed at birth and at 6 (exclusive breastfeeding), 36 and 60 months. RESULTS: Fish consumption rate (HHg) had no significant impact on children's growth at the specified ages (p = 0.35). After 6 months of exclusive breastfeeding, children had the highest proportion of Z-scores <-1 SD; however, weaning (with extended breastfeeding) had a substantial impact in moving up the attained growth at 3 years. The duration of breastfeeding was significantly correlated with attained Z-scores for weight-for-age (r = 0.26; p = 0.02) and weight-for-height (r = 0.22; p = 0.04) but not for height-for-age. At 3 years most children had improved Z-scores (>-1 SD) for height-for-age (70/82), weight-for-age (74/82) and weight-for-height (74/82). At 5 years, all but one child attained Z-scores >-1. CONCLUSION: The apparently good nutritional status of subjects is more likely due to a well balanced diet composition than to only one dietary protein source--fish.
Assuntos
Aleitamento Materno , Desenvolvimento Infantil/fisiologia , Dieta , Proteínas Alimentares , Estado Nutricional , Envelhecimento/fisiologia , Animais , Estatura , Brasil , Pré-Escolar , Comportamento Alimentar , Feminino , Peixes , Humanos , Lactente , Mães , Mudança SocialRESUMO
We studied trends in fish intake among pregnant women living in the Madeira River Basin in Rondônia State, Brazil, to investigate the influence of maternal fish intake on anthropometric indices of children followed up to 5 years. Maternal fish intake was assessed using hair mercury concentrations of mothers and children at delivery and 6, 24, and 59 months. Data analysis was performed using a linear mixed-effect model. Mothers were predominantly young, had low incomes and limited schooling, and breastfed for >6 months. Only 1.9% of children had low birth weight. Anthropometric indices in approximately 80% of the study population showed Z-score values ranging from ≥-2 to ≤1. The influence of maternal fish intake on anthropometric indices, including height-to-age (H/A), weight-to-age (W/A), and weight-to-height (W/H) were not statistically significant after model adjustments. However, higher income and larger birth weight had a positive influence on H/A and W/A, whereas W/H gain was favored by higher maternal educational status and breastfeeding duration. Other variables (hemoglobin concentration and maternal age) had a positive significant influence on anthropometric indices. Maternal fish intake (or its attendant MeHg exposure) did not affect children growth. Nevertheless, it is advisable to avoid mercury-contaminated fish during pregnancy and childhood.
Assuntos
Antropometria , Dieta , Exposição Materna , Alimentos Marinhos , Adolescente , Anemia Ferropriva/sangue , Animais , Peso ao Nascer , Brasil , Desenvolvimento Infantil , Pré-Escolar , Feminino , Peixes , Seguimentos , Contaminação de Alimentos/análise , Cabelo/química , Hemoglobinas/metabolismo , Humanos , Lactente , Masculino , Exposição Materna/efeitos adversos , Troca Materno-Fetal/efeitos dos fármacos , Mercúrio/análise , Gravidez , Fatores Socioeconômicos , Adulto JovemRESUMO
Pesticide exposure is a growing public health concern. Although Brazil is the world’s largest consumer of pesticides, only a few studies have addressed the health effects among farmers. This study aimed to evaluate whether pesticide exposure is associated with respiratory outcomes among rural workers and relatives in Brazil during the crop and off-seasons. Family farmers (82) were interviewed about occupational history and respiratory symptoms, and cholinesterase tests were conducted in the crop-season. Spirometry was performed during the crop and off-season. Respiratory outcomes were compared between seasons and multiple regressions analysis were conducted to search for associations with exposure indicators. Participants were occupationally and environmentally exposed to multiple pesticides from an early age. During the crop and off-season, respectively, they presented a prevalence of 40% and 30.7% for cough, 30.7% and 24% for nasal allergies, and 24% and 17.3% for chest tightness. Significant associations between spirometry impairments and exposure indicators were found both during the crop and off-season. These findings provide complementary evidence about the association of pesticide exposure with adverse respiratory effects among family farmers in Brazil. This situation requires special attention as it may increase the risk of pulmonary dysfunctions, and the morbidity and mortality burden associated with these diseases.