Mind, DisruptedPhoto
AboutThe ParticipantsThe ProblemFindingsToxic ChemicalsPolicy RecommendationsThe ScienceResources

Associations Between Health
Outcomes and Exposures

wheelchairThe Collaborative on Health and the Environment (CHE) maintains a Toxicant and Disease Database, compiling information on health effects of toxic substances. This information was used in the following summary of environmental chemicals known or suspected to contribute to adverse health outcomes.

The database codes the strength of the available evidence into three categories. The evidence of a link between exposure to a given chemical and a given health outcome was classified as “strong” if a causal association between exposure and outcome has been conclusively established in humans and is accepted in the medical community. Evidence is classified as “good” when exposure has been associated with a health outcome through epidemiological studies or through “some human evidence and strong corroborating animal evidence.” “Limited” evidence indicates that the chemicals listed have been mildly associated with a health outcome by limited case reports, human epidemiological studies with mixed or equivocal results, or from “reports clearly demonstrating toxicity in animals where no human data exist.” More information about the CHE database can be found here.

Attention Deficit and Hyperactivity Disorders (ADHD)

According to the National Institute of Mental Health (NIMH), ADHD is one of the most common childhood disorders and can persist throughout life. Symptoms include hyperactivity and difficulty staying focused, paying attention, and controlling behavior.69

Chemical exposures associated with ADHD:

  • Strong evidence: ethanol, lead, PCBs
  • Good evidence: manganese, solvents, tobacco smoke
  • Some evidence: multiple pesticides, cadmium, PBDEs

Cognitive disability / Intellectual disability / Developmental delays

Persistent, major delay in one or more areas of early childhood development, such as communication, social and motor skills.70

Chemical exposures associated with developmental delays:

  • Strong evidence: ethanol, lead, mercury, PCBs, tobacco smoke
  • Good evidence: carbon monoxide, multiple pesticides, solvents
  • Limited evidence: arsenic, cadmium, fluoride, PBDEs

Behavioral disorders

Chronic hostile, aggressive or disruptive behaviors.71

Chemical exposures associated with behavioral disorders:

  • Strong evidence: ethanol, lead, mercury, PCBs
  • Good evidence: nicotine
  • Limited evidence: multiple pesticides

Psychomotor delays / decreased coordination

A generalized slowing of physical and / or mental reaction.72

Chemical exposures associated with psychomotor delays:

  • Strong evidence: lead, mercury, carbon disulfide, acrylamide
  • Good evidence: multiple pesticides, solvents, aluminum, manganese, methyl bromide
  • Limited evidence: styrene, toluene

Psychiatric disorders

Any of a multitude mental illnesses including disorientation, hallucinations, psychosis, delirium, paranoias, anxiety/depression, emotional lability, mood changes, euphoria.73

Chemical exposures associated with psychiatric disorders:

  • Strong evidence: ethanol, lead, mercury, carbon disulfide
  • Good evidence: multiple pesticides, manganese, methyl bromide
  • Limited evidence: acrylamide, thallium