Smog from ozone may cause a worsening of respiratory symptoms, such as coughing and shortness of breath, as well as a worsening of asthma symptoms and reduced lung function. It may also irritate the eyes, nose and throat. Relatively speaking, people with respiratory symptoms, children and the elderly are most sensitive to smog. Contact your GP general practitioner (general practitioner) or Municipal Public Health Service (GGD Gemeentelijke Gezondheidsdienst (Gemeentelijke Gezondheidsdienst)) if you experience symptoms.

Ozone forecast for the days ahead

On Tuesday, July 1, and Wednesday, July 2, ozone concentrations in the air will rise, which may lead to smog in some areas in the central and southern parts of the Netherlands. In the northern and southwestern regions, ozone concentrations will be lower. Due to changing weather conditions, ozone concentrations are expected to be lower starting Thursday.

Smog due to ozone

Smog due to ozone is the result of an accumulation of pollutants in the air on sunny days. This occurs in spring and summer when there is little wind (that is mainly blowing from the south-east). The pollutants include nitrogen oxides and volatile organic compounds, which the sunlight turns into ozone. This is also known as ‘summer smog’. In other seasons, the UV ultraviolet (ultraviolet) radiation is not high enough to create significant amounts of ozone concentrations.

EU Europese Unie (Europese Unie) information and alert thresholds for ozone

The EU has established information and alert thresholds for ozone. The EU information threshold is 180 micrograms per cubic metre of air. When this threshold is crossed (or about to be crossed), people who are sensitive to smog may start experiencing symptoms. RIVM will send out a warning when this happens. As per the Dutch air quality index, the air quality will be ‘poor’.

The EU alert threshold is 240 micrograms per cubic metre of air (air quality of ‘very poor’ according to the Dutch air quality index). When this

threshold is crossed, everyone may start experiencing symptoms. RIVM will change the warning to an alert before this happens.

More information

• Visit luchtmeetnet.nl (externe link) or NOS Nederlandse Omroep Stichting (Nederlandse Omroep Stichting) Teletext page 711 for current and expected smog levels.
• Visit rivm.nl for the maximum concentrations per hour or eight-hour period, as measured by the monitoring stations in the National Air Quality Monitoring Network over the last few days.
• You can also visit rivm.nl for more information about smog.
• Read more about lung diseases and air pollution on the website of Lung Foundation Netherlands (Longfonds (externe link)).