大气PM2.5浓度的光散射测定法及湿度校正  

Determination of atmospheric PM2.5 by light scattering method with correction for relative humidity

作　　者：徐春雨[1] 王秦[1] 李娜[1] 林夏[1] 徐东群[1] 

机构地区：[1]中国疾病预防控制中心环境与健康相关产品安全所,北京100021

出　　处：《环境与健康杂志》2015年第2期151-154,共4页Journal of Environment and Health

基　　金：环境保护部国家环保公益性行业科研专项(201209008)

摘　　要：目的比较光散射法与重量法测定大气PM2.5质量浓度的一致性,分析相对湿度对光散射法的影响,并探讨校正相对湿度影响的方法。方法同时采用光散射法和重量法对大气PM2.5质量浓度进行平行测定,同时记录采样期间相对湿度。通过计算相对偏差、相关系数等指标分析两种方法测定结果的一致性,通过分组比较及相关分析探讨相对湿度对光散射法的影响,并采用湿度校正因子对相对湿度的影响进行校正。结果共获得40组有效数据,采样期间相对湿度为11%~94%;光散射法与重量法结果间呈正相关（r=0.853,P〈0.001）,光散射法测定结果高于重量法（P〈0.001）;光散射法与重量法测定结果的比值为1.92±0.97,范围为0.32~4.57。相对湿度〉60%时光散射法与重量法比值高于相对湿度≤60%时,光散射法与重量法比值与相对湿度之间呈正相关（r=0.538,P〈0.001）。采用湿度校正因子校正后,光散射法与重量法比值为0.99±0.34,范围为0.31~1.72,两种方法测定结果间差异无统计学意义（P=0.963）;校正后的光散射法与重量法比值与相对湿度间无相关性（r=0.190,P=0.241）。结论光散射法与重量法测定结果间存在正相关,但其一致性受相对湿度的影响,湿度校正因子可以有效校正相对湿度对光散射法测定结果的影响。Objective To assess the comparability of light-scattering method and gravimetric methods in the determination of atmospheric fine particles, and analyze the effect of relative humidity on light-scattering method. Methods Both light-scattering and gravimetric methods were used simultaneously to detect PM2.5. The data of real-time relative humidity during every sampling period were also collected and the statistical model was applied to correct the effect of relative humidity. Results A total of 40 sets of valid data were collected. The range of average relative humidity during the sampling periods was from 11% to 94%. PM2.5 levels measured by light-scattering method was correlated with that by gravimetrie method （r=0.853, P〈0.001）. However, the PM2.5 concentrations from light scattering method were significantly higher compared with gravimetric method （P〈0.001）. The mean ratio between light scattering method and gravimetric method was 1.92＋0.97, with the range of 0.32 to 4.57;The mean ratio in group with relative humidity〉60% during sampling periods was significantly higher than that in group with relative humidity ≤60% ;The ratios were significantly positive related to relative humidity （r=0.538, P〈0.001）.After correction for the effect of relative humidity, the mean ratio between light scattering method and gravimetric method was 0.99＋ 0.34, with the range of 0.31 to 1.72, and there was no significant difference between results from these two methods （P=0.963）. The correlation between relative humidity and the ratio of two methods became to be not significant （r=0.190, P=0.241）. Conclusion The relative humidity during sampling periods may have effect on the test results of PM2.5 measured by light scattering method and this effect can be effectively corrected through statistical model.

关 键 词：PM2.5 光散射法 相对湿度 测定方法 校正 

分 类 号：R122.2[医药卫生—环境卫生学]