Asthmatic children exposed to traffic pollution before getting a viral infection have more serious asthma attacks. In children, about 80 percent of attacks are due to viruses -- most of them from the common cold virus. Researchers have discovered that exposure to nitrogen dioxide (NO2) from vehicle exhaust exacerbates the attacks. NO2 is common but the main sources indoors are gas stoves and, outdoors, traffic pollution.
With up to 150 million people worldwide suffering from asthma and cases expected to rise by 50 percent every 10 years, the findings could have important public health implications. These effects are occurring at levels (of pollution) that are currently considered to be safe by international quality standards. So it has an important bearing on what we should set as targets for air quality.
Asthma affects the airways -- small tubes that carry air in and out of the lungs. It occurs when the tubes swell up and go into spasm, blocking the free passage of air in and out of the lungs. People with the illness suffer from coughs, wheezing and shortness of breath. A very severe attack may kill. Colds, the flu, cigarette smoke, pollen, stress and pollution can trigger an asthma attack. There is no cure for asthma but it can be controlled with drugs.