PM10: Results of a One-Year Monitoring Survey in the Netherlands

A comprehensive field assessment has been made of the measurement performance of PM10 inlets. Both precision and comparability are approximately 4 percent, complying well with the requirements of the proposed Federal Reference Method (FRM). Fluctuations in sampling efficiency play a dominant role. Hence, both comparability and precision can be interpreted in terms of changes in the 50 percent cutoff diameter D50. In this way a D50 performance of about 0.7 μm is deduced, clearly within the proposed FRM requirement of D50 = 10 ± 1 μm. There exists no fixed linear relationship between PM10 and TSP (total suspended particulate matter): different average situations yield different regression coefficients (Western Europe: 0.7 and USA: 0.5). Furthermore, there are different conversion factors, representative of average (0.5-0.7) or episodic situations of high concentration levels (0.8-0.9). Hence, TSP air quality standards should not be replaced by PM10 ones simply by using the regression results from various national studies because this could yield unequal stringent PM10 standards.