Air
The environment and human health benefit from good air quality. This is because air pollution can lead to health problems such as cardiovascular disease and asthma. In Europe there are therefore standards for the permissible concentrations of pollutants in the outdoor air. Wassenaar meets these standards, but does not yet meet all the guidelines (recommendations) of the World Health Organization (WHO). Even exposure to concentrations lower than the standards can cause damage to health. That is why we work continuously to improve and monitor air quality.
You can do this
Everyone can contribute to better air quality. This helps the environment, your neighbors and yourself.
- Via the Stookwijzer you can see whether this moment is suitable for burning wood, or whether it would be better to do so at another time (as far as possible). Together with traffic, wood burning is the largest source of air pollution in Wassenaar. Neighbors can also be affected. Therefore, it is important to consider when and how best to fire. It is also possible to set up a notification, so that you will automatically be notified about your address.
- For several years, Wassenaar has been measuring air quality via sensors at private homes, in public spaces and on municipal vehicles. The annual report of these air measurements can be downloaded at the bottom of this page. The results can also be viewed live for everyone via the app "Caeli" (downloadable from the Google Play Store and App Store). The app is improved at the end of 2024. It advises what is and isn't practical to do at this time, for example, burning wood, airing your home or exercising outside. Information can also be sent to the municipality. The more people use the app, the more visibility we will get on air quality.
Furthermore, you can find more information through the sources below.
- Also check the Atlas Leefomgeving for up-to-date information on air quality. This is produced by RIVM and the nearest sensor is in The Hague, where air quality is generally worse than in Wassenaar.
- The causes, consequences and severity of air pollution in the Haaglanden region was examined by the GGD in 2023. View GGD Haaglanden report, Air pollution in Haaglanden region.
- Through an annual monitor, all municipalities provide information to the national monitoring website CIMLK to see how air quality is developing in certain parts of the Netherlands. These are focus areas where concentrations of nitrogen dioxide and particulate matter can exceed permitted values. Wassenaar is part of the 'Leiden-Den Haag' focus area. Wassenaar will provide new data in 2025. Wassenaar does not have to update the monitor data annually because the chance of exceeding limit values is relatively small.
Causes and management of air pollution in Wassenaar
Traffic and households (especially wood burning) are the largest sources of air pollution in Wassenaar. The municipality therefore stimulates clean mobility, for example by installing public charging stations and tendering low-emission public transport. We also ask all Wassenaar residents to pay attention to how they light a fire in a fireplace, barbecue or open fire. A good stoker makes a difference to air quality. With the Stookalert or Caeli for example (see above), you can check whether stoking is responsible at that moment because of the current weather conditions. With warm weather or fog, smoke can linger, causing considerable discomfort or even complaints to neighbors, especially young children or people with lung problems. Read more about nuisance from wood burning. Finally, the municipality tests plans for spatial developments and environmentally harmful activities for their effects on air quality.
Annual air quality report Wassenaar 2024
At the bottom of this page is the Wassenaar 2024 Air Quality Annual Report. Herewith a brief summary of the 2024 air quality in Wassenaar.
Air quality in Wassenaar is measured in particulate matter (PM10 and PM2.5), nitrogen and ozone. In general, there are no significant changes in particulate matter concentrations between 2023 and 2024 in Wassenaar. The WHO recommendation threshold was exceeded on more days but the degree of exceedance remained limited. The exceedance may be due to weather conditions. Incidentally, this is an advisory and not a standard that must be met.
Nitrogen concentrations decreased significantly compared to 2023. Ozone concentrations have increased significantly compared to 2023.
The measurements in Wassenaar show a similar trend to that of the RIVM monitoring station in De Zilk. These trends correspond to known seasonal variations: concentrations of particulate matter and nitrogen tend to be higher in winter due to heat emissions, while ozone concentrations peak in summer under strong sunlight. The observed changes in air quality can be influenced by meteorological conditions and changes in local emission sources.
About the measurements
Determining air quality in the Netherlands is a combination of measurement and calculation. Background concentrations are measured; these are present on a large scale throughout the Netherlands, such as from traffic and even from abroad. On top of the background concentrations, calculated emissions from local traffic sources are added. This creates a picture of air quality at locations exposed to the largest emissions.