Résumé
Objective To understand the relationship between the concentration of air pollutants and daily emergency department visits for different diseases (circulatory system disease, digestive system disease, nervous system disease and respiratory system disease) in Guangzhou, Guangdong Province. Methods The daily average concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2, carbon monoxide (CO) and PM2.5 and the daily maximum 8-hour concentrations of O3, the daily average temperature, the relative humidity and cause -specific emergency department visits of the four major diseases from 2015 to 2017 were collected in Guangzhou. Semi-parametric generalized additive model was used to analyze the relationship between the concentration of pollutants and daily cause-specific emergency department visits. Results The daily average concentrations of SO2, NO2, CO, O3 and PM2.5 during the study period were 13.24 μg /m3, 45.96 μg /m3, 0.97 mg /m3, 123.77 μg /m3 and 36.22 μg /m3, respectively. For circulatory system disease，the independently significant associations of SO2 with emergency department visits in single-pollutant models (2.91%, 95% CI: 1.00%-4.85%), and multipollutant models (4.39%, 95% CI: 1.22%-7.67%) were observed. Conclusion The ambient SO2 increases the risk of emergency department visits due to circulatory diseases in Guangzhou. Comprehensive prevention and control measures should be taken to reduce the emission of SO2.
Résumé
A strain ph 16 , that could effectively degrade phenol,was isolated from sewer sludge of printing and dyeing plant. The preliminary identification sugg ested that the strain belongs to Micrococcus sp. The strain could resist to phenol up to 1.5 g/L. The efficient biodegradation of phenol occurred when th e strain was cultured in the medium (pH 7.0) containing 1.0 g/L phenol under 35℃, wh er e the highest degradation rate reach 99.6% after 36 hours. This strain, when t re ated with some heavy metal ions such as Hg +、Co 2+ and Ag 2+ , showe d the significant inhibition of phenol degradation by 74.2%～100%. The kinetic s of phenol degradation during culture of the strain was also explored.