A continuing environmental issue in Chiang Mai is the incidence of air pollution that primarily occurs every year towards the end of the dry season between February and April. In 1996, speaking at the Fourth International Network for Environmental Compliance and Enforcement conference—held in Chiang Mai that year—the Governor Virachai Naewboonien invited guest speaker Dr. Jakapan Wongburanawatt, Dean of the Social Science Faculty of Chiang Mai University, to discuss air pollution efforts in the region. Dr. Wongburanawatt stated that, in 1994, an increasing number of city residents attended hospitals suffering from respiratory problems associated with the city's air pollution.