Health Update: Risk factors in asthma

USING a humidifier in a child's bedroom can increase the risk of asthma, according to US researchers. Humidifiers are often used in homes where central heating makes the air uncomfortably dry, but the moisture they introduce may encourage asthma. The study, published in the American Journal of Epidemiology, found other significant risk factors to be electric heating - which encourages the house dust mite - and the mother's smoking habits.