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Washington StateThe Collaborative on Health and the Environment – Washington

A Partnership Network for Environmental Health
Established and Coordinated by the Institute for Children's Environmental Health

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Asthma is a reversible obstructive lung disease, caused by inflammation, constriction of the airways and excess mucous production. It is an increased reaction of the airways to various triggers. Asthma triggers vary from one individual to another, and may include: tobacco smoke, vehicle exhaust, ozone (or smog), carbon monoxide, airborne molds, pollens, dust, animal dander, many household and industrial products, air pollutants, wood smoke, perfume, exercise, and stress.

Proportion of Asthma Attributable to Environmental Contaminants

The World Health Organization has estimated that environmental exposures account for 44% of all asthma cases in its report on Preventing Disease Through Healthy Environments: Towards an Estimate of the Environmental Burden of Disease 2006". This does not include exposure to pollens.

Previously, Landrigan et al. estimated that 10-35% of acute exacerbations of childhood asthma are related to outdoor, non-biologic pollutants from preventable sources, such as vehicle exhaust and emissions from stationary sources. Asthma exacerbation due to household allergens, molds, second-hand smoke, infections or climatic conditions were not included in his estimate.


Summary of Information on Washington State

From National Organizations:

The Center for Disease Control and Prevention's (CDC) Behavioral Risk Factor Surveillance System (BRFSS) provides annual information on asthma in Washington State compared with other states and the nation as a whole. The database shows that in 2005, the lifetime prevalence of asthma in Washington was 14.6% and that Washington State had a current asthma prevalence rate of 9.2%. According to the CDC's National Center for Health Statistics, lifetime prevalence refers to people who have ever been diagnosed with asthma by a health care professional, as compared to current prevalence that tracks people who have asthma at the time of the survey.

The BRFSS also offers statewide asthma information broken down by gender, race, income and education for 2005:

Gender – A higher percentage of females report lifetime asthma prevalence in Washington State – 17.0% – as compared to 12.2% of males.

Race – There is a higher prevalence of lifetime asthma among MultiRacial populations in Washington State:


Lifetime Asthma Prevalence











Income – Washington State residents with an annual income of less than $35,000 tend to have a higher lifetime prevalence of asthma:

Annual Income

Lifetime Asthma Prevalence

Less than $15,000








$50,000 +


Education – Education levels do not seem to affect lifetime asthma prevalence in Washington State:

Education Level

Lifetime Asthma Prevalence

Less than High School


H.S. or G.E.D.


Some post-H.S.


College graduate


Specific studies from national organizations include:

From State Organizations:

The Washington Asthma Initiative Data Website provides information on asthma prevalence, hospitalization and mortality for different age groups. The most recent available data are from 1998.

The 1998 data show that prevalence of asthma in children increased with age:

Age (years)

Percent with asthma







(Adults) 18 +


The information on asthma related hospitaliztion in Washington State in 1998 show that rates were higher in the very young (ages 0-4 years) and the elderly (ages 65 + years). Data on asthma mortality suggests that rates were higher in 1998 for 35-64 year-olds than in younger populations, and highest for 65 year-olds and older.

According to the Department of Health's June 2005 report on "The Burden of Asthma in Washington State", about 400,000 Washington adults–one in ten women and one in fourteen men–currently have asthma, and approximately 120,000 Washington youth are currently affected by asthma. The report also found that asthma prevalence is higher for young boys than for young girls; and that by middle school age these differences reverse so that by high school and in later years rates are higher for women than for men.

Also according to the "Burden of Asthma" report, Stevens, Pend Oreille, and Columbia Counties had the highest hospitalization rates and adult prevalence of asthma in the State, but there were no obvious geographic patterns of county-level prevalence or hospitalization rates. For both adults and youth, there were no consistent differences in asthma prevalence by urban or rural community types.

The "Washington State Healthy Youth Survey", a collaborative effort of the Office of the Superintendent of Public Instruction, the Department of Health, the Department of Social and Health Service's Division of Alcohol and Substance Abuse, and Community Trade and Economic Development, offers additional details on asthma trends in 6 th, 8 th, 10 th, and 12 th grade students across the state in 2002 and 2004.

From Local Organizations:

Public Health Seattle & King County

In King County, there are about 9,500 children with asthma living in households with incomes less than 200% of the poverty level. Using data from the Seattle-King County Healthy Homes Study, it is estimated that close to 40% (3,800) of these homes have at least one smoker.

A study on "Childhood Asthma Hospitalizations – King County, Washington 1987-1998" conducted by the Public Health - Seattle and King County, found that youngest children and the poorest communities had the highest rates of asthma hospitalization. According the Public Health Seattle & King County’s asthma resources, asthma is the second most common reason for children to be admitted to the hospital.

From Academic Institutions:

University of Washington

University of Washington researchers have conducted a variety of studies on the links between particulate air pollution and asthma in children and adults in the Seattle area:

The Northwest Center for Particulate Matter and Health at the University of Washington is currently conducting additional studies on asthma and air quality.

Washington State University

Researchers at Washington State University are conducting a 7-year, time-series, epidemiologic study in Spokane that is examining the associations between ambient particulate constituents or sources and health outcomes such as emergency department visits for asthma or respiratory problems. A 2002 paper from the study on "Testing the Metals Hypothesis" looked at the relationship between metals and health outcomes.


Information on Washington State in Context

Washington State's 2005 lifetime prevalence of asthma – 14.6% – was higher than the national average of 12.6%. The State had the eighth highest lifetime prevalence rate for asthma in the US in 2005, up from the third highest in 2004.

In terms of current asthma prevalence, Washington State had a rate of 9.2% in 2005, as compared to 8.0% nationwide. In 2005, the State had the eighth highest current prevalence of asthma in the US.


Quality of Information on Washington State

The information available on asthma in Washington State is excellent. Asthma data for the State as a whole and its subpopulations are comprehensive, up-to-date and readily available.

Temporally, the BRFSS offers annual prevalence data, with the most current information from 2004, for Washington State State compared to other states. The BRFSS and the Washinghton Asthma Initiative both offer information on asthma prevalence across gender, age, race, and education levels.

The "Burden of Asthma in Washington State" report provides current asthma data, updated in 2005, for the entire state as well as at the county-level.


General Information Sources:

Hardcopy Sources:

Koenig JQ, Larson TV, Hanley QS, et al. Pulmonary Function Changes in Children Associated with Fine Particulate Matter. Environmental Research 1993; 63: 26-38.

Schwartz J, Slater D, Larson TV, et al. Particulate Air Pollution and Hospital Emergency Room Visits for Asthma in Seattle. The American Review of Respiratory Disease 1993; 147: 826-831.

Online Sources:

American Lung Association of Washington:

Asthma and Allergy Foundation of America:

Center for Disease Control and Prevention:

Environmental Health Perspectives:

Northwest Center for Particulate Matter & Health:

Public Health Seattle & King County:

Washington State Department of Health: