AN attempt to name and shame Glasgow as one of Britain's most polluted cities backfired on environmentalists yesterday, writes Ron MacKenna.

Friends of the Earth claimed the Government's air quality standards are being broken once a week in some towns and cities, and cited Glasgow as one of the main culprits.

However, the city's environmental health director Brian Kelly, while conceding the figures showed particulate levels in the city centre had breached levels on 20 days, said they were based on false results from a monitor.

''Our staff noticed there was something unusual with the results from the monitors in Hope Street,'' he said. ''And on checking the equipment, they discovered that heavy roadworks taking place in the immediate vicinity were affecting the readings.

''The readings were of high dust levels - a fact we have reported to the monitoring agency.''

So far during 1998, claim Friends of the Earth, levels of particulates - tiny specs released by traffic exhaust fumes - have risen above the official health standards on 30 days in Port Talbot, South Wales, 21 days in Central London and 20 days in Glasgow.

The group says urgent action is needed to cut car use.

Its call came as Transport Minister Dr Gavin Strang and comedian Ben Elton were launching a Don't Choke Britain campaign - a month of events to underline the need to walk - or switch to buses, trains and bicycles - rather than use cars.