Robert Atkins, Minister of State for the Environment, asked people to use their cars only if they had to, and never to leave the engine running unnecessarily. The build-up of pollutants from car exhaust fumes, combined with sunshine and still conditions, produces large quantities of ozone, which can irritate eyes and lung and throat linings.
Children who suffer from asthma should not be allowed to take part in strenuous games. Anyone with asthma or a chest illness should avoid vigorous exercise.
People doing DIY work at home are asked to minimise use of solvent-based paints, varnishes and glues, which also help to form ozone in still, sunny conditions.
Ozone levels are also high in northern England. Yesterday's level of more than 89 parts per billion dramatically exceeds the 50 parts per billion level that air quality experts consider acceptable.
High ozone levels are a feature of summer smogs because the chemical reactions involved in forming the pollutant require plenty of sunlight. Although the introduction of catalytic converters on cars and plans to curb some types of ozone-exacerbating industrial pollutants should bring levels down, there is no prospect of keeping ozone levels permanently below the 50 parts per billion level.
Information on air quality and basic health advice is available on a freephone telephone number: 0800 556677. The levels of the main pollutants are on page 404 of Ceefax and page 187 of Teletext.Reuse content