Respiratory disease surveillance in Hungary

In October 1989, the Hungarian National Institute of Hygiene initiated the Children's Acute Respiratory Morbidity (CHARM) Surveillance System to assess the association between nine reportable respiratory diseases and air pollution. The weekly number of physician-diagnosed, reportable respiratory diseases among four age groups of children (less than 1, 1-2, 3-5, and 6-14 years) was tabulated for Sopron, a city with 60,000 residents. We calculated the proportion of diseases occurring during weeks with low, moderate, and high sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations. The weekly averages of the 24-hour median SO2 concentrations were divided into thirds at less than or equal to 17.6, greater than 17.6 to less than or equal to 26.3, and greater than 26.3 micrograms/m3 (range: 0.9-79.6 micrograms/m3), and the NO2 concentrations at less than or equal to 29.8, greater than 29.8 to less than or equal to 44.1, and greater than 44.1 micrograms/m3 (range: 4.2-90.1 micrograms/m3). During 1990, 11,474 respiratory disease cases occurred among the 4,020 children less than 15 years of age living in Sopron and monitored by the CHARM system. The two most frequently reported disease categories were rhinitis/tonsillitis/pharyngitis (71.5%) and acute bronchitis (8.5%). Sixty-seven percent of pneumonia cases occurred when SO2 concentrations were highest. We found no association between levels of NO2 and respiratory diseases. The CHARM Surveillance System may characterize more fully which groups of children develop particular respiratory diseases following exposure to air pollution.