Brown Richard J C, Woods Peter T
Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK.
J Environ Monit. 2012 Jan;14(1):165-71. doi: 10.1039/c1em10751h. Epub 2011 Nov 18.
A comparison of various averaging techniques to calculate the Average Exposure Indicator (AEI) specified in European Directive 2008/50/EC for particulate matter in ambient air has been performed. This was done for data from seventeen sites around the UK for which PM(10) mass concentration data is available for the years 1998-2000 and 2008-2010 inclusive. The results have shown that use of the geometric mean produces significantly lower AEI values within the required three year averaging periods and slightly lower changes in the AEI value between the three year averaging periods than the use of the arithmetic mean. The use of weighted means in the calculation, using the data capture at each site as the weighting parameter, has also been tested and this is proposed as a useful way of taking account of the confidence of each data set.
针对欧洲指令2008/50/EC中规定的计算环境空气中颗粒物平均暴露指标（AEI）的各种平均技术进行了比较。这是针对英国各地17个站点的数据进行的，这些站点在1998 - 2000年及2008 - 2010年（含）期间有PM(10)质量浓度数据。结果表明，在所需的三年平均周期内，使用几何平均值得出的AEI值显著更低，并且与使用算术平均值相比，三年平均周期之间AEI值的变化略小。还测试了在计算中使用加权平均值，以每个站点的数据捕获量作为加权参数，并且建议这是考虑每个数据集可信度的一种有用方法。
