Asthma is one of the most common chronic conditions in America, afflicting about 15 million people and causing 5,000 deaths annually, according to the National Institutes of Health. Asthma rates have been on the increase, rising by 75 percent from the early 1980s to the mid-1990s. Asthma disproportionately affects children and African-Americans, and is especially prevalent in low-income populations. The prevalence of asthma in Boston’s neighborhoods reflects national trends with higher rates in poorer neighborhoods. The rates of asthma hospitalization in Boston’s Roxbury section between 1994 and 1997 were the highest in the city, about six to eight times that in wealthier Back Bay. A new collaboration in Boston, called the Healthy Public Housing Initiative, combines a new spirit of tenant and management cooperation to attack public housing problems with a focused effort to improve sanitation, pest control, ventilation, heating, and indoor air quality linked to the onset of asthma. Jack Spengler, the Akira Yamaguchi Professor of Environmental Health and Human Habitation in the Harvard School of Public Health’s Department of Environmental Health, said the collaboration brings together groups that are often at odds, such as public housing management and tenant organizations.