Abstract

In 2018, the concentrations of particulate matter and nitrogen dioxide in most parts of the Netherlands were below European limit values.

The limit value for nitrogen dioxide is still being exceeded on a number of busy inner city streets. However, the number of locations in which the limit is being exceeded is decreasing. This trend is expected to continue in the coming years. However, the pace of this decrease is difficult to predict.

The average concentration of particulate matter in the Netherlands increased in 2018 in comparison to 2017, after a decreasing trend in the previous years. The limit values were not exceeded in most of the country, with the exception of a few locations in areas with intensive livestock farming. The number of times that the limit value was exceeded in these locations increased in comparison to 2017. This is in part due to the fact that the municipalities submitted more livestock farms for inclusion in the calculations for 2018. Another possible factor was the very unusual weather conditions in that year, such as the lack of rain.

The average concentration of particulate matter to which the population is exposed is expected to decrease in the coming years. However, as is the case for nitrogen dioxide concentrations, the extent of this decrease is uncertain. Lower concentrations of nitrogen dioxide and particulate matter improve public health, even when they are already below European limit values.

These conclusions can be drawn from the monitoring activities carried out as part of the National Air Quality Cooperation Programme (NSL). Government entities need to provide updated data on road traffic and livestock farms to facilitate calculations by RIVM. In recent years, the quality of this data has improved substantially. A strong focus on data quality continues to be of importance in order to provide a reliable picture of air quality.

In several locations, the concentrations of nitrogen dioxide and particulate matter are close to the European limit values. As a result, small changes in these concentrations can have a strong impact on the number of locations where the limit values are breached. Uncertainties in the calculations therefore also have an effect on the number of breaches.