A water-damaged workplace may trigger Asthma and other breathing problems in employees, and be a substantial source of sick days, new research suggests.

In a study of workers at one leaky, mold-contaminated office building, U.S. government researchers found that the rate of adult-onset asthma among employees was more than three times the norm for the general population. Two-thirds of these cases were diagnosed after the employees had started working in the building.

The researchers estimate that up to 12 percent of employee sick days in a year could be attributed to the health effects of the building.

Indoor water damage can set the stage for organisms like molds, bacteria and dust mites to thrive, as well as spur the release of chemicals from building materials. Damp indoor settings are known to trigger symptoms in people with allergies and asthma, and research suggests that such conditions can cause asthma to develop in previously healthy people.

“We feel our study adds to the evidence that Asthma can develop in damp indoor environments,” Dr. Jean M. Cox-Ganser, a researcher at the National Institute for Occupational Safety and Health, told Reuters Health.

In addition, she said, the findings bring attention to the “whole picture of burden in terms of health, quality of life, and lost productivity.”

The study, published in the journal Environmental Health Perspectives, followed employees at one large office in the northeastern U.S. that had sustained water damage from extensive leaks. Starting in 2000, repairs were made to shore up the leaky exterior and plumbing and to remove mold from the inside of the building.

However, the study found that many employees continued to have breathing problems into June 2002.

In an initial survey of workers’ respiratory health in 2001, Cox-Ganser and her colleagues found that 103 of 888 employees had adult-onset asthma - a rate more than three times higher than average. Workers also had higher-than-average rates of wheezing and nasal and eye symptoms.

Nine months later, in follow-up survey of 248 employees, the researchers found that 81 percent of those who initially had asthma or other respiratory ills continued to suffer from the conditions. Only two percent were free of respiratory symptoms. And among workers who had originally been symptom-free, about half had developed asthma or at least some respiratory symptoms by the second survey.

Workers with respiratory conditions missed an average of 7 days of work over the previous year due to respiratory symptoms, compared with the average of 2 days that their co-workers missed for such symptoms.

Cox-Ganser and her colleagues estimate that “building-related effects” may have been behind 12 percent of employees’ sick days that year.

The exact triggers of workers’ breathing problems are not clear, according to the researchers. Allergic reaction to mold is one possibility, Cox-Ganser said, but damp environments can create a number of exposures potentially irritating to the airways.

SOURCE: Environmental Health Perspectives, April 2005.