Asthma is a major urban disease and a substantial burden from the standpoint of both the quality of life for the many suffering from the disease and the economics of health care. The global increase in the prevalence of asthma in the last half of the 20th century has affected urban communities in many countries disproportionately. Asthma is an allergic disease for more than 50% of adults and 80% of children. The evidence for a relations- hip between allergic asthma and domestic exposure to cockroaches, mice and dust mites is strong. These pests are common in urban environments, especially impoverished com- munities, and play a significant role.
