TABLE ES-1 Summary of Findings in Occupational, Environmental, and Veterans
Studies
Regarding the Association Between Specific Health Outcomes and Exposure to
Herbicides
Sufficient Evidence of an Association
Evidence is sufficient to conclude that there is a positive association. That
is, a positive association has been observed between herbicides and the outcome
in studies in which chance, bias, and confounding could be ruled out with
reasonable confidence. For example, if several small studies that are free from
bias and confounding show an association that is consistent in magnitude and
direction, there may be sufficient evidence of an association. There is
sufficient evidence of an association between exposure to herbicides and the
following health outcomes:
Chronic lymphocytic leukemia (CLL) (category change from Update 2000)
Soft-tissue sarcoma
Non-Hodgkin’s lymphoma
Hodgkin’s disease
Chloracne
Limited or Suggestive Evidence of An Association
Evidence is suggestive of an association between herbicides and the outcome
but is limited because chance, bias, and confounding could not be ruled out with
confidence. For example, at least one high-quality study shows a postive
association, but the results of other studies are inconsistent. There is limited
or suggestive evidence of an association between exposure to herbicides and the
following health outcomes:
Respiratory cancer (of lung and bronchus, larynx, and trachea)
Prostate cancer
Multiple myeloma
Acute and subacute transient peripheral neuropathy
Porphyria cutanea tarda
Type 2 diabetes
Spina bifida in the children of veterans
Inadequate or Insufficient Evidence to Determine Whether an Association
Exists
The available studies are of insufficient quality, consistency, or
statistical power to permit a conclusion regarding the presence of absence of an
association. For example, studies fail to control for confounding, have
inadequate exposure assessment, or fail to address latency. There is inadequate
or insufficient evidence to determine whether an association exists between
exposure to herbicides and the following health outcomes:
Hepatobiliary cancer
Nasal or nasopharyngeal cancer
Bone cancer
Skin cancers (melanoma, basal, and squamous cell)
Breast cancers
Female reproductive cancer (cervical, uterine, and ovarian)
Testicular cancer
Urinary bladder cancer
Renal cancer
Leukemia (other than CLL)
Spontaneous abortion
Birth defects (other than spina bifida)
Neonatal or infant death and stillbirth