Download PDFPDF

Mortality in chemical workers potentially exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) 1945–94: an update
Compose Response

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g.
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests


  • Responses are moderated before posting and publication is at the absolute discretion of BMJ, however they are not peer-reviewed
  • Once published, you will not have the right to remove or edit your response. Removal or editing of responses is at BMJ's absolute discretion
  • If patients could recognise themselves, or anyone else could recognise a patient from your description, please obtain the patient's written consent to publication and send them to the editorial office before submitting your response [Patient consent forms]
  • By submitting this response you are agreeing to our full [Response terms and requirements]

Vertical Tabs

Other responses

  • Published on:
    Re: Amyotrophic lateral sclerosis and occupational exposure to 2,4-D

    We appreciate the interest taken in our study by Dr. Freedman.[1] At the heart of the discussion are the interpretation of statistical significance in our study,[2] and the lack of statistical significance in others. A critical point in valuing causation is the weight of the evidence to be placed upon the nonsignificant increase of nonspecific exposures observed in human studies of amyotrophic lateral sclerosis (ALS) compare...

    Show More
    Conflict of Interest:
    None declared.
  • Published on:
    Amyotrophic lateral sclerosis and occupational exposure to 2,4-dichlorophenoxyacetic


    Burns et al.[1] report a significant excess of deaths due to amyotrophic lateral sclerosis (ALS) in a cohort of Dow employees potentially exposed to the herbicide 2,4-Dichlorophenoxyacetic (2,4-D), but then argue against the plausibility of a causal association, concluding that the association "is not consistent with previous human or animal studies".

    This conclusion and the authors' characterisatio...

    Show More
    Conflict of Interest:
    None declared.