Linking environmental hazards to childhood asthma

Undertaking epidemiologic/biologic studies that address the role of environmental exposure in childhood asthma and that enable a clearer understanding of why rates of asthma are increasing in children.

Participating in global efforts on asthma by collaborating in international research to identify the reasons for the increased prevalence of asthma. Promoting awareness of asthma and its public health consequences. Developing and promoting good practices in asthma management; Participating in the exchange of information and experience of asthma management and prevention strategies. Assessing air quality standards, taking into consideration the impact of air pollutants on children's health. Establishing pollution-free school areas, by limiting the access of vehicles, especially diesel-powered vehicles, and by restricting the siting of pollution-emitting sources around schools. Promoting awareness of the dangers of environmental tobacco smoke (ETS), as well as the risks of smoking during pregnancy. Strictly enforce the prohibition of smoking in areas frequented by children. Promoting interventions to improve housing conditions, especially such aspects as humidity and ventilation. Developing guidelines related to the quality of the home environment, in order to minimize risk factors such as house dust, humidity and moulds, cockroaches, pets and gas stoves. Creating allergen-free schools by banning wall-to-wall carpets, the use of irritant chemicals as cleaning products, and construction activities when children are present.

The incidence and mortality rates from asthma are increasing much more rapidly in urban and poor children than in children of other sectors of society.

There is a specific need for research that: (1) characterizes more precisely the linkages between air pollution and asthma, nd examines the interactions among components of air pollution in the aetiology of asthma; (2) examines the role of indoor air pollutants, including bioaerosols, in causing respiratory disease; (3) studies the synergy between indoor and outdoor air pollution and asthma risk; (4) examines the role of individual differences among children in their susceptibility to air pollutants; (5) follows prospectively large test groups of newborn children who live in both inner city as well as affluent environments to assess interactions among infection history and environmental exposures in the development of allergy, asthma and airway reactivity.

For many environmental allergens, such as the house dust mite, the higher the level of exposure, the higher the likelihood of a person producing "allergic" antibodies (called immunglobulin E or IgE antibodies). High allergen levels also increase a person's risk of becoming allergic and developing asthma. However, low-to-moderate amounts of cat allergen seemed to trigger allergy, but high amounts reduced both IgE antibodies and the likelihood of asthma. The children's immune systems made predominantly immunoglobulin G (IgG) and IgG4 antibodies rather than IgE. So high exposure to cat allergen appears to be protective for some children and a risk factor for others. This research sheds more light on the relationship between allergen exposure and asthma. When investigators further understand this process, it might lead to new treatments for asthma.