FRIDAY, Oct. 12, 2007 (HealthDay News) -- Using household cleaning sprays and spray air fresheners just once a week can increase your risk of developing asthma, new research suggests.
Whether or not the cleaning products are a direct cause of asthma, or simply a trigger for people who already have the disease, isn't clear from this epidemiological study.
However, the European team involved in the study believes that spray cleaners can be a cause of new-onset asthma, because the people included in this study did not have asthma or asthma symptoms at the start of the study.
The use of spray cleaners as little as once a week increased the risk of developing the respiratory ailment by nearly 50 percent, the researchers found.
"Cleaning sprays, especially air fresheners, furniture cleaners and glass cleaners, had a particularly strong effect. The risk of developing asthma increased with the frequency of cleaning and number of different sprays used, but on average was 30 to 50 percent higher in people regularly exposed to cleaning sprays than in others," said the study's lead author, Jan-Paul Zock, a research fellow at the Centre for Research in Environmental Epidemiology at the Municipal Institute of Medical Research in Barcelona, Spain.
Results of the study were expected to be published in the second October issue of the American Journal of Respiratory and Critical Care Medicine.
The most important thing consumers need to know, cautioned Zock, is that "cleaning sprays -- for sale in all supermarkets -- are not harmless, and their use may involve serious health risks."
Previous research has found an association between asthma and being employed as a professional cleaner. Other studies have also noted a link between respiratory symptoms and certain cleaning products, but Zock and his colleagues wanted to learn if typical household exposures to cleaning products would have any effect on the development of asthma.
Drawing on a 10-country database, called the European Community Respiratory Health Survey, the researchers identified more than 3,500 people without any history of asthma or asthma symptoms. All reported being responsible for the cleaning of their homes.
After an average of close to nine years of follow-up, face-to-face interviews were conducted, and the study volunteers were asked about the types of cleaning products they used and how often they used them. They were also asked if they had been diagnosed by a physician as having asthma, or had been treated with asthma medications during the study period. The researchers also performed lung-function tests on the study volunteers.
Overall, 42 percent of the study volunteers reported using a spray cleaner at least once a week. Glass cleaning sprays were the most commonly used sprays, with about 22 percent reporting using them at least once a week.
Liquid multi-purpose cleaners were also frequently used -- just over 83 percent said they used such a product at least once a week. However, the researchers didn't find any association between asthma and properly used liquid cleaners.
Weekly use of a spray cleaner increased the risk of having current asthma by 45 percent in women and 76 percent in men. Among those who used the cleaning sprays at least four days a week, the risk of asthma was more than doubled.
Zock said it's too soon to tell people to swear off spray cleaners altogether, but added, "Nevertheless, from the perspective of precaution, we may recommend to use sprays only when really necessary. In most cases, it is possible to replace the spray by non-spray cleaning liquids and to do the cleaning properly. If [sprays are] used, people can protect themselves by opening windows, avoiding the application near the breathing zone, and by using masks or other types of personal respiratory protection."
"Cleaning compounds are generally just tested to make sure that they don't kill people or cause cancer," noted Dr. David Rosenstreich, director of the division of allergy and immunology in the department of medicine at Montefiore Medical Center and Albert Einstein College of Medicine in New York City.
"But, these products may not be safe for asthmatics to breathe in. And, if it's not safe for asthmatics, it's probably not safe for anyone else," he said. His advice: "Switch to liquid cleaning products rather than aerosols. If there's any difference in cleaning, it's a small sacrifice to be made in terms of protecting your respiratory health."
Zock did add one caveat, however. "Don't forget that old-fashioned liquid cleaning products can involve risks for respiratory disorders as well. The most notorious example is bleach, particularly when mixed with other cleaners -- something that should never be done."
To learn more about what causes asthma, visit the Asthma and Allergy Foundation of America.