European researchers have found that using household cleaning sprays and air fresheners as little as once a week can raise the risk of adults developing asthma.
The use of spray cleaners and air fresheners has already been linked to increased asthma rates in cleaning professionals, but a similar effect in non-professional users has been found now.
Researchers conducted a study, which included more than 3,500 subjects across 22 centers in 10 European countries. Subjects were assessed for current asthma, current wheeze, physician-diagnosed asthma and allergy at follow-up, which took place an average of nine years after their first assessment. They were also asked to report the number of times per week they used cleaning products.
During the research, it was found that two-thirds of the study population who reported doing the bulk of cleaning were women, about six percent of who had asthma at the time of follow-up. Fewer than ten percent of them were full-time homemakers.
The findings showed that the risk of developing asthma increased with frequency of cleaning and number of different sprays used, but on average was about 30 to 50 percent higher in people regularly exposed to cleaning sprays than in others.
Therefore, the researchers found that cleaning sprays, especially air fresheners, furniture cleaners and glass-cleaners, had a particularly strong effect.
"Our findings are consistent with occupational epidemiological studies in which increased asthma risk was related to professional use of sprays among both domestic and non-domestic cleaning women," Dr. Zock said.
"This indicates a relevant contribution of spray use to the burden of asthma in adults who do the cleaning in their homes," Dr. Zock added.
Researchers said that this risk could be due to a number of factors, including the possibility that asthma is partially irritant-induced, that sprays contain sensitizers that are specific to asthma, and/or that an inflammatory response is involved in asthma development.
"There is a need for researchers to conduct further studies to elucidate both the extent and mechanism of the respiratory toxicity associated with such products," Dr. Zock said.
Despite the uncertainty of the biological mechanism, the findings have important clinical relevance.
The epidemiological study appeared in the American Thoracic Society's second issue for October the American Journal of Respiratory and Critical Care Medicine