New research reveals that environmental factors in the home have a significant influence on the severity of symptoms experienced by children with asthma.
The study which looked at the living conditions of almost 1000 children diagnosed with asthma found factors suggestive of high pollution and mold exposure such as living on busy streets and having bedrooms at basement level were associated with poor control of symptoms.
Among children in developed countries roughly 1 in 10 suffers from asthma. The condition is the result of the muscles lining the airways contracting, triggering the airways to narrow and become inflamed which causes difficulty breathing and the other symptoms of asthma namely coughing, wheezing and tightness in the chest.
It is well established that a family history of asthma or atopic (allergic) illnesses such as hayfever and eczema increase the risk of a child developing asthma. The narrowing of the airways at the root of the condition requires an environmental trigger before symptoms become apparent or a child suffers an 'asthma attack' however.
Triggers include exposure to allergens, exercise (due to increased breathing rate) and changes in weather conditions such as extremes of temperature or humidity. Environmental factors associated with the living environment and human activity are also suggested to trigger asthma symptoms and influence their severity however - which is what this latest study investigated.
Researchers from the Université de Montréal, Canada, used the results from a respiratory health survey of Montreal children aged 6 months to 12 years involving a total of 7980 children to determine the associations between home environmental exposures and asthma control in 980 of the children in the survey who had active asthma during the year prior to the survey.
The results of the study showed that the home environment did indeed affect asthma control. A significant association was found between asthmatic children living in rented accomodation and severity of their condition. Asthma control was better in children whose families owned their own home. This link could be the result of a number of factors including location of rental properties and general state of upkeep compared to resident-owned properties.
The researchers found that the risk for poor asthma control in the children was increased by 35% as a result of living in areas of high traffic density and by 30% by bedrooms being located in basements. Traffic polution contains a cocktail of chemicals and particulate matter that can irritate the sensitive mucus membranes of the respiratory system and cause the airways to narrow, whilst basements are commonly damp and contain mold which is both an allergen and a source of toxic chemicals which again can trigger asthma symptoms.
This study suggests asthmatic children are likely to do better if living in quieter neighbourhoods with their bedrooms and main living space located above ground to reduce the risk of exposure to dampness and mold. Obviously this may require moving home for some families which is no small undertaking but simple measures such as keeping windows closed to prevent exposure to traffic pollution and ventilating basements properly could substantially improve a child's asthma.
Source: Değer L Plante C Goudreau S Smargiassi A Perron S Thivierge RL Jacques L (2010) Home environmental factors associated with poor asthma control in Montreal children: a population-based study Journal of Asthma 47(5):513-20