Dutch health institute triggers smog warning

Air quality in the Netherlands will be very bad in the coming days, public health institute RIVM warns. The institute therefore decided to issue a smog warning effective until Friday, ANP reports. People with breathing problems and the elderly are advised to stay inside, especially during the afternoon and early evening. People who work outside are advised to avoid physical exertion if possible. The smog is caused by a combination of little wind and a lot of pollutants in the air. Sunlight turns the pollutant substances into ozone, which can be hazardous to anyone with breathing and lung difficulties. In the Netherlands smog is most prevalent in spring and summer, as the other seasons do not have enough sunlight to form ozone.