THURSDAY, June 16 (HealthDay News) -- No long-term decrease in lung function has been seen in 95 percent of the officers from the New York Police Department's Emergency Services Unit who responded to the 2001 terrorist attack on the World Trade Center, according to a new study.

Researchers analyzed the findings of annual lung function tests from 206 officers who responded to the attack and found that most had no change in lung function beyond expected age-related declines.

About 5 percent of the officers did have declines consistent with mild lung dysfunction, the researchers reported. Those most likely to have decreased lung function included officers with respiratory symptoms, those who were present when the towers collapsed and those who worked long hours at the World Trade Center site.

The greatest declines in lung function were seen in smokers and in the small number of officers who did not wear respiratory protective devices while working at the site.

Overall, the findings provide "encouraging expectations" that most police officers who were at the World Trade Center site won't develop long-term declines in lung function, the research team -- led by Dr. Eli J. Kleinman, supervising chief surgeon of the NYPD -- said in a news release from the American College of Occupational and Environmental Medicine. They plan to continue following the officers' health.

A report on their findings was published in the June issue of the Journal of Occupational and Environmental Medicine.

In terms of disaster planning, the researchers noted, the results of the study support greater use of personal protective gear and a limit on time spent at hazardous sites.

More information

The U.S. Department of Health and Human Services offers World Trade Center health resources.