Agrotóxicos e Transtorno de déficit de atenção com hiperatividade

Uma equipe de cientistas da Universidade de Montreal e da Universidade de Harvard descobriram que a exposição a agrotóxicos organofosforados está associada ao aumento do risco de Transtorno do Déficit de Atenção e Hiperatividade (TDAH) em crianças.


Publicado na revista Pediatrics, a pesquisa [Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides] descobriu uma ligação entre a exposição a pesticidas e a presença de sintomas de TDAH. O estudo foi realizado com 1139 crianças, de acordo com uma amostra da da população geral dos EUA, e mediu os níveis de pesticidas em sua urina. Os autores concluiram que a exposição a pesticidas organofosforados, em níveis comumente encontrados em crianças nos EUA, pode contribuir para o diagnóstico de TDAH.

“Estudos anteriores mostraram que a exposição a alguns compostos organofosforados causar hiperatividade e déficit cognitivo em animais”, diz o autor Maryse F. Bouchard, da Universidade de Montreal, Departamento de Meio Ambiente e Saúde do Trabalho no Sainte-Justine Hospital Research Center. “Nosso estudo encontrou que a exposição a organofosforados no desenvolvimento de crianças pode ter efeitos sobre os sistemas neurais e pode contribuir para comportamentos tipicamente diagnosticados em TDAH, tais como desatenção, hiperatividade e impulsividade.”

O estudo foi financiado pelo Canadian Institutes for Health Research e pelo National Institute of Environmental Health Sciences (EUA).

O estudo “Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides,” publicado na revista Pediatrics, foi elaborado por Maryse F. Bouchard, University of Montreal and Harvard University e por David C. Bellinger, Robert O. Wright, and Marc G. Weisskopf da Harvard University.

O artigo está disponível para acesso integral e gratuíto. Para acessar o artigo, no formato PDF, clique aqui.

Para maiores informações transcrevemos, abaixo, o abstract.

Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides

Maryse F. Bouchard, PhDa,b, David C. Bellinger, PhDa,c, Robert O. Wright, MD, MPHa,d,e, Marc G. Weisskopf, PhDa,e,f

Departments of aEnvironmental Health and Epidemiology, School of Public Health, Harvard University, Boston, Massachusetts; Department of Environmental and Occupational Health, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada; Departments of cNeurology and Pediatrics, School of Medicine, Harvard University, and Boston Children’s Hospital, Boston, Massachusetts; and Channing Laboratory, Department of Medicine, School of Medicine, Harvard University, and Brigham and Women’s Hospital, Boston, Massachusetts

Objective

The goal was to examine the association between urinary concentrations of dialkyl phosphate metabolites of organophosphates and attention-deficit/hyperactivity disorder (ADHD) in children 8 to 15 years of age.

Methods

Cross-sectional data from the National Health and Nutrition Examination Survey (2000–2004) were available for 1139 children, who were representative of the general US population. A structured interview with a parent was used to ascertain ADHD diagnostic status, on the basis of slightly modified criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.

Results

One hundred nineteen children met the diagnostic criteria for ADHD. Children with higher urinary dialkyl phosphate concentrations, especially dimethyl alkylphosphate (DMAP) concentrations, were more likely to be diagnosed as having ADHD. A 10-fold increase in DMAP concentration was associated with an odds ratio of 1.55 (95% confidence interval: 1.14–2.10), with adjustment for gender, age, race/ethnicity, poverty/income ratio, fasting duration, and urinary creatinine concentration. For the most-commonly detected DMAP metabolite, dimethyl thiophosphate, children with levels higher than the median of detectable concentrations had twice the odds of ADHD (adjusted odds ratio: 1.93 [95% confidence interval: 1.23–3.02]), compared with children with undetectable levels.

Conclusions

These findings support the hypothesis that organophosphate exposure, at levels common among US children, may contribute to ADHD prevalence. Prospective studies are needed to establish whether this association is causal.

PEDIATRICS (doi:10.1542/peds.2009-3058)
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