February 2005

On December 23rd, 2004 the Times of London published a front-page article entitled, "Household Chemicals In Direct Link To Asthma Rise".  This article refers to a recently published study from the University of Bristol (UK) which confirms earlier studies linking household chemicals to childhood asthma.

The following technical update on the indoor environment is provided by R. Dixon & Associates of Brighton, Ontario; Consultants in Health, Safety and Environment. 

At premises where recent water damage has occurred, asthma-related symptoms and allergic reactions are often wrongly attributed to the presence of mould.  The fact is that exposure to other allergenic substances may be responsible.  It is for this reason that we draw your attention to the above research findings, which strengthen the association between exposure to trace amounts of chemicals in the home and workplace, and asthma-related symptoms.

Asthma of course does not only affect children.  It is a chronic disease that causes the inside walls of the airways of the respiratory tract to be inflamed.  This condition makes the airways very sensitive.  Both adults and children, when exposed to airborne allergens or irritants including dust particles, develop a sensitivity which causes the airways to become narrower, thus limiting the flow of air to the lungs.  The affected person has symptoms like wheezing, coughing, chest tightness and general breathing difficulties.  Asthma cannot be cured, but for most patients it can be effectively controlled.

In the course of our indoor environmental work, we notice a significant increase in reported cases of asthma-related symptoms among building occupants.  While it is clear that children are particularly susceptible, as evidenced by the growing use of "inhalers" among early school-age children, many adults are equally vulnerable.

For adults and children, there are two main factors involved:

• Increasing chemical sensitization due to increasing use of commercial chemical formulations in the home and workplace, such as cleaners and deodorants.
   
• A "cult of cleanliness" which limits an individual's exposure to antigenic materials such as organic dusts, animal dander and micro-organisms (including mould) found normally in the indoor environment.  This limitation of exposure restricts the development of a normally responsive immune system.

Therefore, when investigating allergy and asthma complaints in the workplace or in the home, factors other than mould exposure must always be considered.

Roger Dixon, an industrial hygienist and environmental health specialist, can be contacted at (613) 475-3572 or by email at rdixonconsult@sympatico.ca

Washington - Scientific evidence links mould and other factors related to damp conditions in homes and buildings to asthma symptoms in some people with the chronic disorder, as well as to coughing, wheezing, and upper respiratory tract symptoms in otherwise healthy people, say a new report from the Institute of Medicine of the National Academies of Science.

However, the available evidence does not support an association between either indoor dampness or mould and the wide range of other health complaints that have been ascribed to them, the report says.

This U.S. study was sponsored by the Centers for Disease Control and Prevention.  The Institute of Medicine is a private, non-profit institution that provides health policy advice under a congressional charter granted to the National Academies.

News release and report available online: national-academies.org