In cleaners the decline in function is similar to smoking less than a pack of cigarettes a day compared to those women who shun the marigolds.
And it is because constant exposure damages the lung membrane speeds up the weakening of the lungs.
The lungs of men are not as damaged but this could be because they skimp on their duties or are less likely to work as a cleaner.
Professor Dr Cecile Svanes of the University of Bergen in Norway explained: “While the short-term effects of cleaning chemicals on asthma are becoming increasingly well documented, we lack knowledge of the long-term impact.
“We feared that such chemicals, by steadily causing a little damage to the airways day after day, year after year, might accelerate the rate of lung function decline that occurs with age.”
So the study followed 6,235 men and women from the average age of 34 over the next two decades as part of the European Community Respiratory Health Survey.
Smoking in terms of pack-years was included as a time-varying variable in the model in order to account for the effect of smoking over time on lung function decline.
Compared to women who did not do any cleaning, the forced expiratory volume in one second (FEV1), or the amount of air a person can forcibly exhale in one second, declined 3.6 milliliters (ml)/year faster in women who cleaned at home and 3.9 ml/year faster in women who worked as cleaners.
Forced vital capacity (FVC), or the total amount of air a person can forcibly exhale, declined 4.3 ml/year faster in women who cleaned at home and 7.1 ml/year faster in women who worked as cleaners. And for professional cleaners it was akin to smoking.
Prof Svanes said: “For comparison within our study population, similar models with similar adjustments showed that heavy smokers (more than 20 pack-years) had excess decline of 6.1 ml/year in FEV1 and 8.9 ml/year in FVC (as compared to the excess decline in occupational cleaners of 4.3 and 7.1 181 ml/year).
“The effect of occupational cleaning was thus comparable to smoking somewhat less than 20 pack-years. Most cleaning agents have an irritative effect on the mucous membranes of the airways.
“One possible mechanism for the accelerated decline in cleaners is the repetitive exposure to low-grade irritative cleaning agents over time, thereby causing persistent changes in the airways. Also, some cleaning agents may have sensitising properties through specific immunological mechanism; quaternary ammonium compounds are known to have sensitising effects in the airways, as well as also having an irritative effect.
“Repeated exposure could lead to remodelling of the airways, thereby over time causing an accelerated decline in FVC and FEV1. ”
Lead study author doctoral student Eistein Svanes said the level of lung impairment was surprising at first but added: “However, when you think of inhaling small particles from cleaning agents that are meant for cleaning the floor and not your lungs, maybe it is not so surprising after all.”
The study did not find the ratio of FEV1 to FVC used to diagnose chronic obstructive pulmonary disease declined more rapidly in women who cleaned than in those who did not.
Asthma was also more prevalent in women who cleaned at home at 12.3 per cent or at work at 13.7 per cent compared to those who did not clean at 9.6 per cent. The study also did not find that men who cleaned, either at home or at work, experienced greater decline in FEV1 or FVC than men who did not.
Mr Svanes concluded: “The take home message of this study is that in the long run cleaning chemicals very likely cause rather substantial damage to your lungs. These chemicals are usually unnecessary, microfibre cloths and water are more than enough for most purposes.”
The study was published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.