Abstract

Three areas in the province of North Holland have their own air quality monitoring networks: Haarlemmermeer, the western port area of Amsterdam and the IJmond region. Air quality monitoring in IJmond has been ongoing since the 1970s, while the other networks were established later. The National Institute for Public Health and the Environment (RIVM) conducted at the request of the province of North Holland an evaluation to determine whether these monitoring networks still meet current needs – for example, whether they measure the appropriate substances at the right locations. Input was also sought from various stakeholders, including municipalities, provincial authorities and local residents, regarding their expectations of these networks.

The networks have proven suitable for monitoring air quality trends over time. They can also assess whether the concentrations of certain substances remain below Dutch regulatory limits or the guidelines for air quality recommended by the World Health Organization (WHO).

The networks provide extensive data to help answer stakeholder questions about air quality. However, stakeholders have indicated they need more context to interpret the ‘raw’ measurement results effectively. Furthermore residents indicate that they are often unaware of where to find these results. The RIVM therefore advises the province of North Holland to share the measurement results and knowledge about air quality more actively with them. It is up to the province how this can best be done.

An air quality monitoring network is not suitable for formally verifying whether a company complies with its permitted emissions of polluting substances into the air. Many factors influence air quality beyond the presence of a single company. Nevertheless, measurements of an air quality monitoring network, combined with air quality modelling, can offer insight into a company’s impact on air quality. For these calculations, data from the company about emissions are used, among other things. If the difference between measurements and calculations is significant, this may be a reason for the competent authority to discuss this with the company concerned.

Some residents have requested more localised monitoring locations. The current combination of measurements and modelling provides a reliable picture of regional air quality. Adding more monitoring locations would not necessarily yield additional insights. RIVM advises against relocating long-standing monitoring locations, as fixed locations are essential for accurately tracking changes over time.

RIVM recommends that the province consider expanding existing monitoring locations in the IJmond and Haarlemmermeer networks to include ultrafine particle measurements. These measurements would offer greater insight into regional ultrafine particle concentrations and help estimate the levels inhaled by the Dutch population. Such data is important for understanding the potential health impacts of ultrafine particles.