RESUMO
Certain pesticides may affect children's neurodevelopment. We assessed whether pesticide exposure was associated with impaired neurobehavioral outcomes in children aged 6-9 years. We conducted a cross-sectional study in 140 children living near banana plantations and plantain farms in the Talamanca County, Costa Rica and assessed their neurobehavioral performance. Exposure was determined by analyzing urinary metabolites of chlorpyrifos (3,5,6-trichloro-2-pyridinol, TCPy), mancozeb (ethylenethiourea, ETU), and pyrethroids (3-phenoxybenzoic acid, 3-PBA). Repeated urine samples were obtained for 36 children. We estimated associations of pesticide concentrations with neurobehavioral outcomes using multivariable linear and logistic regression models. Median (25th-75th percentiles) TCPy, ETU, and 3-PBA concentrations were 1.4 (.7-3.1), 1.2 (.7-3.0), and .8 (.5-1.5) µg/L, respectively. Intraclass correlation coefficients (ICC) ranged between .32 and .67. After adjustment for potential confounders, higher urinary TCPy concentrations were associated with poorer working memory in boys (n = 59) (ß per 10-fold increase in TCPy concentrations = -7.5, 95% CI: -14.4, -.7); poorer visual motor coordination (ß = -1.4, 95% CI: -2.7, -.1); increased prevalence of parent-reported cognitive problems/inattention (adjusted OR per 10-fold increase in urinary concentrations = 5.8, 95% CI: 1.6, 22.9), oppositional disorders (aOR = 3.9, 95% CI: 1.0, 16.0), and ADHD (aOR = 6.8, 95% CI: 1.8, 28.6), and; decreased ability to discriminate colors (aOR = 6.6, 95% CI: 1.6, 30.3; the higher the score the worse). Higher ETU concentrations were associated with poorer verbal learning outcomes (ß = -7.0, 95% CI: -12.7, -1.3). Higher 3-PBA concentrations were associated with poorer processing speed scores, particularly in girls (ß = -8.8, 95% CI: -16.1, -1.4). Our findings indicate that children living near banana and plantain plantations are exposed to pesticides that may affect their neurodevelopment, which for certain domains may differ between boys and girls. We recommend the implementation of measures to reduce pesticide exposure in children living nearby banana plantations.
Assuntos
Benzoatos/urina , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/crescimento & desenvolvimento , Clorpirifos/urina , Maneb/urina , Praguicidas/urina , Zineb/urina , Criança , Comportamento Infantil , Costa Rica , Estudos Transversais , Feminino , Humanos , Masculino , Piridonas/urinaRESUMO
Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed and studied cognitive and behavioral disorder in school-age children. The etiology of ADHD and ADHD-related behavior is unclear, but genetic and environmental factors, such as pesticides, have been hypothesized. The objective of this study was to investigate the relationship between in utero exposure to chlorpyrifos, chlorpyrifos-methyl, and/or 3,5,6-trichloro-2-pyridinol (TCPY) and ADHD in school-age Mexican children using TCPY as a biomarker of exposure. The temporal reliability of repeated maternal urinary TCPY concentrations across trimesters was also explored (N=21). To explore associations with ADHD-related outcomes in children, third trimester urinary TCPY concentrations in were measured in 187 mother-child pairs from a prospective birth cohort. Child neurodevelopment in children 6-11 years of age was assessed using Conners' Parental Rating Scales-Revised (CRS-R), Conners' Continuous Performance Test (CPT), and Behavior Assessment System for Children-2 (BASC-2). Multivariable linear regression models were used to test relationships for all children combined and also stratified by sex. Intraclass correlation coefficients (ICC) calculations were based on a random effects model. The ICC was 0.41 for uncorrected TCPY, and ranged from 0.29 to 0.32 for specific gravity-corrected TCPY. We did not observe any statistically significant associations between tertiles of maternal TCPY concentrations and ADHD-related outcomes in children. However, compared to the lowest tertile we found suggestive evidence for increased ADHD index in the highest TCPY tertile in boys (ß=5.55 points; 95% CI (-0.19, 11.3); p=0.06) and increased attention problems for the middle tertile in girls (ß=5.81 points; 95% CI (-0.75, 12.4); p=0.08). Considering the continued widespread agricultural and possible residential use of chlorpyrifos and chlorpyrifos-methyl in Mexico and the educational implications of cognitive and behavior deficits, these relationships deserve further study.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/induzido quimicamente , Atenção/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Exposição Materna/efeitos adversos , Praguicidas/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal , Piridonas/efeitos adversos , Adulto , Agricultura , Criança , Comportamento Infantil/efeitos dos fármacos , Clorpirifos/efeitos adversos , Clorpirifos/análogos & derivados , Clorpirifos/urina , Feminino , Humanos , Masculino , México , Exposição Ocupacional/efeitos adversos , Praguicidas/urina , Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Piridonas/urina , Fatores Sexuais , Adulto JovemRESUMO
BACKGROUND: The US Environmental Protection Agency voluntary phased-out residential use of chlorpyrifos in 2001. In contrast, in Costa Rica, chlorpyrifos-treated bags are increasingly used to protect banana and plantain fruits from insects and to fulfill product standards, even in populated areas. OBJECTIVES: To evaluate children's exposure to chlorpyrifos in villages situated nearby banana plantations and plantain farms in Costa Rica. METHODS: The study targeted two villages with use of chlorpyrifos-treated bags in nearby banana plantations and plantain farms and one village with mainly organic production. For 140 children from these villages, mostly indigenous Ngäbe and Bribri, parent-interviews and urine samples (n=207) were obtained. Urinary 3,5,6-trichloro-2-pyridinol (TCPy) levels were measured as a biomarker for chlorpyrifos exposure. In the banana and plantain village also environmental contamination to chlorpyrifos was explored. RESULTS: Children from the banana and plantain villages had statistically significant higher urinary TCPy concentrations than children from the referent village; 2.6 and 2.2 versus 1.3µg/g creatinine, respectively. Chlorpyrifos was detected in 30% of the environmental samples as well as in 92% of the hand/foot wash samples. For more than half of the children their estimated intake exceeded the US EPA chronic population adjusted dose. For some, the acute population adjusted dose and the chronic reference dose were also exceeded. CONCLUSIONS: Our results suggest that children living nearby plantations with chlorpyrifos-treated bags are exposed to chlorpyrifos levels that may affect their health. Interventions to reduce chlorpyrifos exposure are likely to improve children's health and environment in banana and plantain growing regions.