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目的比较光散射法与重量法测定公共场所室内大气PM_(2.5)浓度的结果一致性,并探讨影响光散射法校准系数的因素。方法于2015年7—8月和11—12月,以南京4类30家公共场所(商场超市、影院、餐厅酒店、医院)为研究对象,用LD-6S光散射仪以重量法和光散法同时测定室内外大气PM_(2.5)浓度,并记录室内外温湿度、新风系统使用等信息,分析光散射法与重量法的相关性及光散射法校准系数的影响因素。结果光散射法与滤膜称重法对公共场所大气PM_(2.5)浓度的测定结果间呈线性正相关关系(r=0.873,P<0.01),但光散射法监测结果均值[(71±64)μg/m~3]低于重量法[(91±65)μg/m~3],差异有统计学意义(P<0.01)。夏季光散射法校准系数K(1.87±0.55)高于冬季(1.30±0.52),差异有统计学意义(P<0.01),且冬季K值与室内气温间存在负相关关系(P=0.011);未发现公共场所类型、室内大气PM_(2.5)浓度、室内相对湿度等因素对校准系数有影响(P>0.05)。结论光散射法与重量法测定的大气PM_(2.5)浓度具有良好的相关关系,但二者间存在系统偏差;光散射法校准系数受季节和公共场所室内气温的影响。
OBJECTIVE: To compare the consistency of light scattering and gravimetric methods for the determination of indoor PM_ (2.5) concentrations in public places and to explore the factors affecting the calibration coefficient of light scattering. Methods From July to August 2015 and from November to December 2015, four public places (shopping malls, cinemas, restaurants, hospitals) in Nanjing were enrolled in this study. LD-6S light scattering instrument was used to measure gravimetric method and light scattering method At the same time, indoor and outdoor atmospheric PM 2.5 concentrations were measured. The indoor and outdoor temperature and humidity and fresh air system were recorded. The correlation between light scattering and gravimetric method and the influencing factors of light scattering calibration coefficient were analyzed. Results There was a linear positive correlation between the light scattering method and the membrane filtration method for the determination of atmospheric PM_ (2.5) concentrations in public places (r = 0.873, P <0.01), but the mean value of light scattering method was (71 ± 64 ) μg / m ~ 3] was lower than that of gravimetric method [(91 ± 65) μg / m ~ 3], the difference was statistically significant (P <0.01). The calibration coefficient K (1.87 ± 0.55) of summer light scattering method was higher than that of winter (1.30 ± 0.52), the difference was statistically significant (P <0.01), and there was a negative correlation between winter K value and indoor air temperature (P = 0.011). The type of public places, indoor PM_ (2.5) concentration and indoor relative humidity were not found to affect the calibration coefficient (P> 0.05). Conclusions There is a good correlation between the light scattering method and the PM 2.5 concentration measured by gravimetric method, but there is a systematic deviation between them. The calibration coefficient of light scattering method is affected by the season and indoor air temperature in public places.