A new study shows that chemical sprays used for cleaning in the majority of homes may cause up to 15% of new cases of asthma in adults.
Most people are now aware of a link between urban air pollution and allergic respiratory conditions such as asthma, but new research suggesting domestic cleaning products are also a major trigger may surprise many.
The study, which is published in the American Journal of Respiratory and Critical Care Medicine, suggests that the use of cleaning sprays and air fresheners may account for up to one in seven, or 15%, of new asthma cases in adults. The study found no link between asthma and domestic cleaning products that are not sprayed.
The conclusions of the study are based on a review of data from the European Community Respiratory Health Survey, one of the largest epidemiologic studies of respiratory disease in the world.
A total of 3,503 people aged 20 to 44 from ten European countries were included in the study. All participants regularly used cleaning sprays and air freshener products. The study was longitudinal, meaning that the participants were followed over a period of time to determine how many developed symptoms of asthma. They were first assessed 9 years before the final report.
Of the study participants around two thirds were women but the researchers reported that only 9% were looking after the home full time by the time the study period ended.
The results show that 6 per cent of the participants had developed asthma symptoms by the end of the study and that there was a link between the disease and using sprays in the home at least once a week. More detailed analysis showed that 42% of those involved in the study used sprays in the home at least once per week, and this increased the risk of asthma symptoms by 30-50%.
The researchers found that: Consistently positive associations for most asthma definitions were observed for cleaning sprays in general, and glass-cleaning, furniture and air-refreshing sprays in particular.
This will probably not be such a big surprise to most people as the strongest smelling chemicals tend to be the most irritating and cause most symptoms and discomfort.
Domestic cleaning sprays and air fresheners contain a cocktail of chemicals such as aldehydes, ammonia, benzene derivatives, and chlorine-releasing agents. Commenting on why only the spray form of these products seemed to be implicated in asthma cases, researchers suggested that the chemicals being released into the air significantly increased exposure to the chemicals for people nearby. This way much more of the chemicals would be breathed in.
It's also likely that the extra chemicals needed for sprays may be involved, the most obvious example being propellants. The most common propellants are all petrochemicals.
In the past those who clean for a living have been shown to be at risk of developing asthma due to cleaning sprays but this is thought to be the first time an association between every day use of cleaning sprays and increased risk of asthma has been demonstrated.