A relational analysis of acute wheezing and air pollution

Objective To correlate hospital attendance forwheezing treated with nebulizer therapy withpollutant levels recorded in ambient air inColombo.Setting Emergency treatment unit (ETU) of theLady Ridgeway Hospital, Colombo.Design A prospective observational case controlstudy.Method Attendance at the ETU for nebulizertherapy was recorded daily for 12 months. ETUattendance for conditions other than wheezingserved as controls. The case and control attendancerates were correlated with daily maximum andminimum one hour average levels of sulfur dioxideand oxides of nitrogen in ambient air as measuredby the continuous pollution monitor situated in theFort, Colombo.Results 30,932 children needed nebulizer therapyin the ETU (median daily attendance 85) during theperiod of 12 months. The control population was10,100 children (median daily attendance 28). Thepattern of pollutant levels and attendance rates forwheezing showed a correlation on a time series.Conclusion Air pollution levels in Colombo correlatedsignificantly with hospital attendance rates forwheezing needing emergency treatment. The highestrecorded levels of sulfur dioxide and oxides ofnitrogen in ambient air showed a significantcorrelation with the highest hospital attendancerates, and the lowest pollutant levels with thelowest hospital attendance rates. We conclude thatvehicle related pollutants in ambient air inColombo are affecting the respiratory health ofchildren.Sri Lanka Journal of Child Health, 2001; 30: 66-8(Key words: Hospital attendance, severe wheezing, sulfur dioxide, oxides of nitrogen, ambient air) doi: 10.4038/sljch.v30i3.847