But, health officials say, there are steps families can take to improve the air in their homes.
Madeleine Shea, an assistant Baltimore health commissioner, said her office is launching a program this month similar to the coalition's. The city got a four-year grant from the federal Centers for Disease Control and Prevention to do six home visits each with 250 Baltimore schoolchildren with asthma.
"A lot of assaults to health in homes are behavioral," Shea said. "Theoretically they should be easier to address."
While she knows change takes time, she thinks that once people know what improvements they can make on their own, they will. "Almost everyone really loves their child," she said.
Still, it can be very intrusive to have someone come inside your home and criticize your personal habits and your housekeeping.
"The issues are balancing privacy versus health," said Dr. Peyton Eggleston, a pediatric allergist at the Johns Hopkins Children's Center. "With ambient air quality control and water quality control and pollution control in general, there's not really a question. We all share the air. We all share the water.
"But when you get to the conditions inside someone's home ... you get to the conflict between individual rights and the rights of the community."
The Hopkins study, published in the journal Environmental Health Perspective s, looked at 150 asthmatic preschoolers in Baltimore over six months. It found that for every 10-microgram-per-cubic-meter increase in coarse air particle pollution, such as that produced by dusting and cooking, there was a 6 percent increase in the number of days of coughing, wheezing or chest tightness.
For every 10-microgram-per-cubic-meter increase in finer air particles indoors, there was a 7 percent increase in wheezing severe enough to limit speech, and a 4 percent increase in the number of days rescue medication was needed.
In many cases, the researchers found, the level of indoor fine particle pollution was twice as high as the standard for outdoor pollution established by the U.S. Environmental Protection Agency. There is no such standard for indoor air.
Diette points out that sometimes in the summer, officials warn of bad air quality days and suggest children with asthma stay inside.
"Depending on where you're staying inside," he said, "it may not be a better environment."
