Asthma has become an epidemic in the United States. In California alone, about half a million children suffer from the disease. Air pollution -- indoors and out -- is one of the primary triggers of asthma attacks, which may send sufferers to emergency rooms, and even result in hospitalization. Recently, these hospital visits have declined among children in the Bay Area. But it is difficult to evaluate the meaning of this decrease, since hospitalization rates tell only a small part of the story of childhood asthma -- and provide only a rough picture of the extent and severity of this disturbingly common disease.
NRDC researchers examined data on Bay Area children's hospitalizations for asthma, looking at discharge rates per 100,000 children under age 14. Scientists studying asthma often rely on hospitalization rates because no other data about the disease's occurrence are available. The data covered two periods: 1991 to 1994 and 1995 to 1997. From the first period to the second, hospitalization rates decreased in all nine Bay Area counties, from 4 percent to 36 percent, with the greatest decreases occurring in San Francisco, San Mateo, and Napa. By comparison, the statewide hospitalization rate declined nearly 6 percent.
San Francisco County had the highest asthma hospitalization rate in the period 1991 to 1994, but Alameda County surpassed San Francisco in 1995 to 1997. Marin County had the lowest hospitalization rate in 1991 to 1994; Sonoma had the lowest in 1995 to 1997. In the period 1991 to 1994, in Alameda, San Francisco, and San Mateo counties, hospitalization rates were higher than the rate for the state of California as a whole. In the later period, both Alameda and San Francisco counties continued to exceed the statewide average.
Alameda, Contra Costa, San Francisco, San Mateo, and Solano counties noted the race of the hospitalized children during both periods; Marin and Sonoma did in 1991 to 1994. (Some counties did not track this information because their nonwhite populations are small, and the results would be statistically insignificant.) Hospitalization rates for African-American children were consistently higher than the rates for other children. This disparity was also reflected in statewide figures: hospitalization rates among black children were generally three to five times higher than rates for white children, and even among other nonwhite groups, African-American children were consistently much more likely to be hospitalized for asthma.
In 1990, the U.S. Department of Health and Human Services set a target of reducing children's hospitalization rates to 225 per 100,000 or lower by 2000. Seven of the nine Bay Area counties achieved that goal in the period 1995 to 1997 (Alameda and San Francisco failed to do so). California's overall hospitalization rate during that period also met the U.S. goal. But for African-American children, the state fell far short: the rate was 678 per 100,000.