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Asthma Increasingly Affecting North American Children
By Michael D. Lebowitz

Over the past 15 years, asthma has reached epidemic proportions in large areas of North America, children being particularly severely affected by the disease. When the Commission's Council adopted a resolution on Children’s Health and the Environment in June 2000, asthma was first among the health issues chosen as a starting point for cooperation between the partners. Michael D. Lebowitz explains why children are particularly susceptible  to asthma and notes the spread of   the disease among disadvantaged children.

Asthma is a disease that inflames and narrows the airways, causing difficulty in breathing. The primary cause is thought to be sensitization to allergic and related agents. Outdoor air pollutants such as diesel exhaust and indoor pollutants such as tobacco smoke appear to contribute to the process of sensitization. Allergens and air pollutants are also among the many factors that can trigger asthma attacks.

Lifestyle changes and worsening air pollution put many children at risk for asthma.

Children are more susceptible to asthma than adults because of the possibility of early sensitization, when their immune system is not fully developed, and because their lungs and airways are still developing. One of the major concerns is that asthma in childhood frequently results in reduced ability to breathe that persists into adult life, and appears to be associated with the likelihood of lung diseases later in life.

Asthma rates have been increasing remarkably in the past 25 years, especially in children: currently the disease occurs in up to 12% of all children in North America, and about twice as frequently in children living in poorer conditions, such as inner cities. (Disadvantaged children are more often exposed to allergens, tobacco smoke, and outdoor air pollutants, and also may have weaker immune systems. Moreover, asthma has been associated with low birth weight and with respiratory problems at birth, both of which occur more frequently in disadvantaged children.)

Asthma is responsible for increasing numbers and proportions of emergency room visits and hospitalizations, with some increase in deaths as well. These outcomes have been seen especially in children and in disadvantaged children more markedly still. The use by children of asthma medication, particularly inhalers, has become very frequent.

Thirty years ago, asthma was not often seen in Native Americans or in those of Mexican descent, but the increase in asthma rates in these ethnic groups has been especially noticeable. Many think that this is related to the spread of western and urban lifestyles (as noted by studies in developing countries).

Asthma and asthma attacks have been associated with various types of air pollution, especially those related to vehicle exhaust and the resulting photo-oxidant pollution. Various studies have also linked cigarette smoke, diesel exhaust and sulfate pollution with asthma. Greater fluctuations in airway narrowing, reduced lung function, and more serious respiratory symptoms from exposure to such pollution are more frequently found in disadvantaged children. Studies around the US-Mexico border have demonstrated that border children, mostly of Mexican descent, have clearly shown such effects.

One can conclude from various studies in North America and elsewhere that asthma in children is a major and growing concern, that vehicular air pollution is an important contributor, and, thus, that transportation corridors significantly influence the occurrence and seriousness of asthma and other related respiratory conditions in children.