People with asthma can be exceptionally sensitive to air contaminants, including those in ordinary cleaning products. A 2009 study led by Jonathan Bernstein, a physician and leading asthma and allergy researcher at the University of Cincinnati College of Medicine, measured worsening symptoms in asthmatic women after they had completed housecleaning tasks (Bernstein 2009).
In an asthma attack, the smooth muscles that line the airways to the lungs suddenly become swollen and inflamed and tighten up, obstructing or blocking the flow of air and causing chest tightness, wheezing, breathlessness and coughing. In people with the disorder, various circumstances can trigger an attack, including exposures to irritating or allergy-causing chemicals, stress or exercise. This chronic disorder has become increasingly common in recent decades for reasons that remain unclear.
According to the U.S. Centers for Disease Control and Prevention, overall asthma prevalence in the United States increased from 7.3 percent to 8.4 percent from 2001 to 2010, with even higher prevalence among children.
Scientists and doctors believe that asthma may be caused by a combination of environmental and hereditary factors. Various health organizations and government agencies have been investigating the association of the disorder with the inhalation of certain chemicals, often in occupational settings. Authoritative bodies such as the Association of Occupational and Environmental Clinics have compiled lists of chemicals, known as asthmagens, that have been reported to cause asthma.
EWG’s assessment of more than 2,000 cleaning products found that 438 contain at least one chemical that the AOEC has identified as an asthmagen.
A growing body of evidence suggests that using cleaning products can also cause asthma to develop in healthy people. A 10-country study of more than 3,500 individuals who were initially free of asthma found that nine years later, those who used spray cleaners at least once a week to clean their homes had a 30-to-50 percent increased risk of developing asthma during the study period (Zock 2007).