Prospective study of chemical exposures and amyotrophic lateral sclerosis

Background: Although environmental toxins, including pesticides, are suspected of contributing to the risk of amyotrophic lateral sclerosis (ALS), no data exist from large prospective investigations. This study assessed the association between exposure to chemicals and risk of ALS in a prospective cohort study. Methods: The relation between self-report of regular exposure to 11 different chemical classes or x rays and ALS mortality among over 1 million participants in the American Cancer Society’s Cancer Prevention Study II was prospectively assessed. Follow-up from 1989 through 2004 identified 617 deaths from ALS among men and 539 among women. Adjusted rate ratios (RR) were calculated using Cox proportional hazards. Results: The RR for ALS mortality among individuals exposed to pesticides/herbicides compared with that among unexposed individuals was 1.07 (95% CI 0.79 to 1.44), but somewhat higher after excluding those with missing duration of pesticides exposure (RR 1.44; 95% CI 0.89 to 2.31; p = 0.14). A non-significant increase in ALS mortality was found among individuals who reported exposure to formaldehyde (RR 1.34; 95% CI 0.93 to 1.92). Excluding those with a missing duration of formaldehyde exposure, the RR was 2.47 (95% CI 1.58 to 3.86), and there was a strongly significant dose–response relation with increasing years of exposure (p trend = 0.0004). Conclusions: There was little evidence for any association between pesticides/herbicide exposure and ALS. In contrast, evidence was found, suggesting an increased risk of ALS with formaldehyde exposure. Because of the longitudinal design, this result is unlikely to be due to bias, but it should nevertheless be interpreted cautiously and needs to be verified independently.

[1]  Houeto Jean-Luc.  [Parkinson's disease]. , 2022, La Revue du praticien.

[2]  E. Beghi,et al.  Descriptive epidemiology of amyotrophic lateral sclerosis: new evidence and unsolved issues , 2007, Journal of Neurology, Neurosurgery, and Psychiatry.

[3]  B. Traynor,et al.  Genetics of sporadic amyotrophic lateral sclerosis. , 2007, Human molecular genetics.

[4]  M. Norenberg,et al.  The mitochondrial permeability transition in neurologic disease , 2007, Neurochemistry International.

[5]  Ying Liu,et al.  Amyloid-like aggregates of neuronal tau induced by formaldehyde promote apoptosis of neuronal cells , 2007, BMC Neuroscience.

[6]  M. Turgut,et al.  Effects of formaldehyde exposure on granule cell number and volume of dentate gyrus: A histopathological and stereological study , 2006, Brain Research.

[7]  R. Pamphlett,et al.  Amyotrophic Lateral Sclerosis and Exposure to Environmental Toxins: An Australian Case-Control Study , 2006, Neuroepidemiology.

[8]  M. Thun,et al.  Pesticide exposure and risk for Parkinson's disease , 2006, Annals of neurology.

[9]  M. Thun,et al.  Prospective study of occupation and amyotrophic lateral sclerosis mortality. , 2005, American journal of epidemiology.

[10]  M. Kanter,et al.  Vitamin E against oxidative damage caused by formaldehyde in frontal cortex and hippocampus: Biochemical and histological studies , 2005, Journal of Chemical Neuroanatomy.

[11]  M. Thun,et al.  Prospective study of cigarette smoking and amyotrophic lateral sclerosis. , 2004, American journal of epidemiology.

[12]  Adriano Chiò,et al.  Acute migraine treatment with droperidol , 2003, Neurology.

[13]  C. Armon.  An Evidence-Based Medicine Approach to the Evaluation of the Role of Exogenous Risk Factors in Sporadic Amyotrophic Lateral Sclerosis , 2003, Neuroepidemiology.

[14]  T D Koepsell,et al.  Prognosis in amyotrophic lateral sclerosis , 2003, Neurology.

[15]  C. Armon.  Environmental Risk Factors for Amyotrophic Lateral Sclerosis , 2001, Neuroepidemiology.

[16]  M. Thun,et al.  Epidemiological research at the American Cancer Society. , 2000, Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology.

[17]  B. Brooks.  Risk factors in the early diagnosis of ALS: North American epidemiological studies , 2000 .

[18]  B. Brooks.  Risk factors in the early diagnosis of ALS: North American epidemiological studies. ALS CARE Study Group. , 2000, Amyotrophic lateral sclerosis and other motor neuron disorders : official publication of the World Federation of Neurology, Research Group on Motor Neuron Diseases.

[19]  JD Mitchell.  Amyotrophic lateral sclerosis: toxins and environment , 2000, Amyotrophic lateral sclerosis and other motor neuron disorders : official publication of the World Federation of Neurology, Research Group on Motor Neuron Diseases.

[20]  Wayne Spoo,et al.  Toxicological profile for formaldehyde , 1999 .

[21]  C. Visser,et al.  Amyotrophic lateral sclerosis: mortality risk during the course of the disease and prognostic factors , 1997, Journal of the Neurological Sciences.

[22]  G. Belle,et al.  Occupational exposures and amyotrophic lateral sclerosis. A population-based case-control study. , 1997, American journal of epidemiology.

[23]  A. Chiò,et al.  Accuracy of death certificate diagnosis of amyotrophic lateral sclerosis. , 1992, Journal of epidemiology and community health.

[24]  C. Warlow,et al.  Motor neuron disease in England and Wales, 1959-1979. , 1983, Journal of neurology, neurosurgery, and psychiatry.

[25]  P. Andersen.  Amyotrophic lateral sclerosis associated with mutations in the CuZn superoxide dismutase gene , 2006, Current neurology and neuroscience reports.

[26]  Lorene M. Nelson,et al.  Epidemiology of ALS. , 1995, Clinical neuroscience.

[27]  W. Kühnel,et al.  Mechanistic study on formaldehyde-induced hepatotoxicity. , 1989, Journal of toxicology and environmental health.