Genetic characteristics such as atopy, which is a predisposition to develop antibodies to environmental allergens, and environmental exposures increase the risk of developing asthma. A 2000 report from the Institute of Medicine reviewed evidence on indoor air exposures and asthma, finding sufficient evidence that house dust mites and environmental tobacco smoke causally increase asthma risk and exacerbation, especially in children. Cockroaches were also associated with increased asthma risk in preschoolers.

1. Risk Factors for Developing Asthma
 Genetic characteristics
 Occupational exposures
 Environmental exposures

2. Risk Factors for Developing Asthma:
Genetic Characteristics
Atopy
The body’s predisposition to develop an antibody
called immunoglobulin E (IgE) in response to
exposure to environmental allergens
Can be measured in the blood
Includes allergic rhinitis, asthma, hay fever, and
eczema

3. Risk Factors for Developing Asthma:
Environmental Exposure
Clearing the Air:
Asthma and Indoor Air Exposures
http://www.iom.edu (Publications)
Institute of Medicine, 2000
Committee on the Assessment of Asthma and Indoor Air
Review of current evidence about indoor air exposures
and asthma

4. Clearing the Air:
Categories for Associations of Various
Elements
Sufficient evidence of a causal relationship
Sufficient evidence of an association
Limited or suggested evidence of an
association
Inadequate or insufficient evidence to
determine whether an association exists
Limited or suggestive evidence of no
association

5. Clearing the Air:
Indoor Air Exposures & Asthma Development
Biological Agents
 Sufficient evidence of causal
relationship
 House dust mite
 Sufficient evidence of association
 None found
 Limited or suggestive evidence of
association
 Cockroach (among pre-school aged
children)
 Respiratory syncytial virus (RSV)
Chemical Agents
 Sufficient evidence of causal
relationship
 None found
 Sufficient evidence of association
 Environmental Tobacco Smoke
(among pre-school aged children)
 Limited or suggestive evidence of
association
 None found

6. Clearing the Air:
Indoor Air Exposures & Asthma Exacerbation
Biological Agents
 Sufficient evidence of causal
relationship
 Cat
 Cockroach
 House dust mite
 Sufficient evidence of an association
 Dog
 Fungus/Molds
 Rhinovirus
 Limited or suggestive evidence of
association
 Domestic birds
 Chlamydia and Mycoplasma pneumonia
 RSV
Chemical Agents
 Sufficient evidence of causal
relationship
 Environmental tobacco smoke
(among pre-school aged children)
 Sufficient evidence of
association
 NO2, NOX (high levels)
 Limited or suggestive evidence of
association
 Environmental Tobacco Smoke
(among school-aged, older children,
and adults)
 Formaldehyde
 Fragrances