Trends in Particulate Matter

The uncertainty about the trend in the measured results is relatively large due to meteorological influences and also due to measurement uncertainties. In this study, several methods are presented for correcting meteorological effects that reduce uncertainties. For both emissions and measurements, the decreasing trends over the 1993-2000 period were obviously larger (typically 2 to 4%, annually) than over the period between 2000 and 2008 (0 to 2%, annually). A detailed study on traffic emissions, important with respect to health effects, has shown that any reductions due to cleaner car engines are cancelled out by the increase in total distance driven and the increasing weight of vehicles. The study has also shown that the uncertainty in the estimation of PM trends over short periods of time (<10 years) is too large for an unambiguous interpretation of the developments. After correction for meteorological influences, decreasing trends can be proven more early.

This study is a BOP publication produced under the auspices of ECN.

The Netherlands Research Program on Particulate Matter (BOP) is a national program on PM₁₀ and PM_2.5.. It is a framework of cooperation involving the Energy research Centre of the Netherlands (ECN), the Netherlands Environmental Assessment Agency (PBL), the Environment and Safety Division of the National Institute for Public Health and the Environment (RIVM) and TNO Built Environment and Geosciences.