Impact of dust haze on acute and severe respiratory symptoms in Jinan, Shandong, January 2013

Objective To understand the impact of dust haze on acute and severe respiratory symptoms. Methods The study was conducted in Jinan, Shandong province, during January 2013, the results were compared with those during January 2012. And related data during December 2011 and December 2012 were used for sensitivity analysis. The daily meteorological data, including air temperature and relative humidity, and air pollution indicator (PM10) during all the periods were collected and the daily records of calling for emergency aid due to respiratory symptoms, including difficult breathing, breath holding, respiratory arrest and chest distress, during all the periods were collected from the medical emergency centers in Jinan to conduct descriptive analysis. The analysis of environment data was conducted with Kruskal-Wallis test. The symptom specific population based emergency calling rate (PECR), relative risk (RR) and 95% confidence interval were calculated during the study period and compared with those in reference period. Excel and Epi Info 3.5.1 were used for the statistical calculation. Results The median value of PM10 concentration was 316 μg/m3 (range: 80-602 μg/m3) during the study period, which was higher than national ambient air quality standard (150 μg/m3). Among the 4 respiratory symptoms, difficult breathing accounted for highest proportion (73.8%) with the PECR of 4.42 per million. and the PECR of breath holding was 1.19 per million. Difficult breathing increased obviously during the study period (RR=1.09,95% CI: 1.00-1.19). Breath holding and respiratory arrest increased too, but no consistence was found in sensitivity analysis. Conclusion The increase of difficult breathing was associated with air pollution caused by dust haze in Jinan.