The most important source of the gas nitrogen dioxide (NO2) in the Netherlands is traffic. It is therefore an important indicator for air pollution by traffic. Exposure to NO2 may cause a reduced lung function, an increase in respiratory complaints and asthma attacks and an increased sensitivity to infections.

The level of NO2 in the Netherlands is relatively low in the north. Relatively high levels are measured in the middle of the country and, most importantly, in the Randstad conurbation in the west. Levels are relatively high particularly in the morning due to a combination of the morning rush hour and weather conditions. In 2017 the limit value for nitrogen dioxide was exceeded several times at locations with a lot of traffic.

Nitrogen dioxide contents can also be excessive inside. The indoor levels of NO2 may even be higher than those outside due to the use of flue-less geysers and gas-fired stoves.


Measures relating to traffic, industry and the energy sector have, in recent years, led to a decline in the levels. However, during the last few years this decline has slowed for a number of reasons. For example, the share of nitrogen dioxide in exhaust fumes has increased due to measures to lower particulate matter quantities. In addition to this the number of kilometres driven has increased.

Concentration of NO2 since 2013.

Health effects of nitrogen dioxide

NO2 can penetrate into the deep into the lung. Exposure to NO2 will lead to a reduced lung function and sometimes to an increase in respiratory complaints and asthma attacks and increased sensitivity to infections. These effects are observed at levels below the current limit values for short-term exposure. It is unclear whether the health effects are really due to NO2 or other substances in exhaust fumes. In any event NO2 quantities in the air are a marker of the exposure to air pollution due to traffic.


Two limit values have been established for nitrogen dioxide: one for the annual average level and one for peak levels.

  • The annual average limit value is 40 micrograms/m3.
  • The hourly average (peak) limit value is 200 micrograms/m3. It is not allowed to exceed the peak limit value more than 18 times per year in the case of roads with at least 40,000 vehicles per day.

More policy information is available in the umbrella air quality theme. The Nitrogen Action Programme (PAS) is relevant to nitrogen. The aim of PAS is to reduce nitrogen in nature reserves.

Things you can do yourself

You can, for example, opt for environmentally friendly transport, or for a cycling route which takes you past less contaminated areas, or reduce your energy consumption at home. The Environment Centre provides more practical tips on how to reduce air pollution levels yourself.

Taking part in sporting activities outside? Please take the location or route into account. Avoid busy roads with high-rise buildings and numerous trees where pollution tends to accumulate. You should also avoid busy crossroads. However, you should not forget that the positive effects of sporting activities more than outweigh the detrimental effects of air pollution.

Read more about taking air quality measurements yourself.