In most types of housing, the Federal Fair Housing Act prohibits discrimination against people with disabilities, which is defined as having a physical or mental impairment which substantially limits one or more of such person's major life activities; having a record of such an impairment; or being regarded as having such an impairment. Breathing is a major life activity.
If you have a disability, you may be able to ask for "reasonable accommodations" to allow you to use your housing just like everybody else. Reasonable accommodations include structural modifications and changes in the rules, policies, and practices that would allow you to have equal access to your housing. In the case of secondhand smoke, this could include a no-smoking rule, being moved to a non-smoking building, separate ventilation, or sealing off your apartment. The only way to avoid the health hazards of secondhand smoke is to live in a completely smokefree building. An analysis of how the Fair Housing Act applies to secondhand smoke (PDF) explains more about requesting reasonable accommodations. If you live in public or subsidized housing, please read this analysis (PDF) of the authority of Housing Authorities and Section 8 multiunit housing owners to adopt smoke-free policies in their residential units.
Please talk to the Fair Housing Council of Oregon for more information on requesting reasonable accommodations. The Fair Housing Council of Oregon serves Clark County, Washington as well as Oregon.