ASTHMATICS packed their inhalers yesterday and tried to avoid areas where congested traffic pumped more fumes into the air. Asthma Society secretary Tsang Ng Lai-fong said different factors sparked potentially fatal coughing fits in each sufferer. Some of the 700 members find themselves gasping for breath when the weather turns cold, and others are wracked with coughs when pollution levels rise. But a special class for children will teach them how to control their reaction to pollution, low temperatures or weather changes. 'Most of our work is to teach patients how to control asthma,' Mrs Tsang said. 'We have many courses and asthmatics can come and learn how to protect themselves.' Dr Lee So-lun of Queen Mary Hospital's Allergy Clinic said the worsening pollution level was bound to spark some asthma attacks. Many doctors have dismissed the theory that pollution causes asthma, but agree it can bring on violent attacks in those predisposed to the disease. Children are most vulnerable to their first attack at two or three years of age. 'It's because of the irritant gases such as sulphur dioxide or nitrogen dioxide; this can trigger an asthmatic attack in these children,' Dr Lee said. 'The exact point of how gases trigger these attacks is still not understood. It's similar to cases of people in a fire, breathing smoke. These children are more sensitive to inflammatory responses.' Parents are counselled not to panic and to calm their children when an attack starts, and give them medication. Treatment usually comes in the form of an inhaler which dilates the bronchioles, allowing more air to be drawn in. 'But they should try to avoid areas that are very polluted and the most important thing is to comply with the medication,' Dr Lee said.