SOUTHAMPTON’S busiest roads have become so polluted that residents are to be sent alerts warning them when levels get dangerously high.

From next month, text and voice messages will be sent to asthmatics and people with breathing difficulties warning them to avoid going outside or to shut their windows.

About 28,000 people are being treated for asthma in the city and health experts say exhaust fumes can trigger potentially lethal attacks.

The £60,000 pilot scheme – called airAlert - launches as new research reveals air quality in many parts of the Southampton exceeds Government limits.

Cars and heavy goods vehicles (HGVs) have been blamed for the high nitrogen dioxide pollution levels that choke the city.

Redbridge Road – the city’s most heavily trafficked road – carries 76,000 vehicles each day, eight per cent of which are HGVs.

Worryingly, nearby Redbridge Community School was one of the areas that had the highest levels of pollution in the city.

Dr Graham Roberts, a paediatric consultant with the Southampton asthma and allergy research charity AAIR, said: “Pollution is an important cause of exacerbations of asthma. We get many parents who feel that their child’s asthma is worse around pollution.”

Southampton City Council, which has drawn up a plan to improve air quality, insists the city’s pollution levels are lower than other similar sized cities such as Portsmouth or Bristol.

However, according to the latest council figures, nitrogen dioxide levels exceed Government limits in 23 of the 55 locations tested with diffusion tubes in 2008.

The national target for nitrogen dioxide – a poison that forms whenever fossil fuels burn in the air – is for levels to not exceed 40 micrograms per cubic metre.

The city’s worst pollution hotspot, Cranbury Place, which runs between Onslow Road and Dorset Street in the city centre, had an average 59.7 micrograms per cubic metre.

Other hotspots included 148 Romsey Road (47mg/m3), Redbridge School (47), 66 Burgess Road (46.6 ), Ladbrokes on Millbrook Road (46.1), Regents Park Junction (44.5), 41-59 Onslow Road (43.8) and Bitterne Library (43.9).

Sites that exceed the Government limit must be declared formal Air Quality Management Areas (AQMAs) and have plans drawn up to cut fumes.

Southampton has eight AQMAs, compared with 13 in Portsmouth, three each in Eastleigh and the New Forest and one covering Winchester city centre.

That number could rise with new AQMAs being considered for Burgess Road, in Bassett, Victoria Road, Woolston, Princes Court, Northam, and St Andrews Road near Solent University.

Bassett Ward Councillor John Hannides blamed congestion on Burgess Road on the nearby University of Southampton campus and local shops.

He said the council was working to encourage more people to use public transport, but ruled out introducing a controversial London-style congestion charge.

“We must redouble our efforts to improve air quality, but the council has no plans to introduce a congestion charge,” the senior Tory councillor said.

“We think it would be bad for the city’s economy and bad for business.

The best way to minimise traffic is to give people a better choice of alternative transport.”

Residents living in the St Mary’s, Bevois Valley, Redbridge and Bitterne areas of city are to be targeted by the free, citywide airAlert service.

Data from the council’s air quality monitoring stations will be fed into a forecast system run by scientists at Kings College, in Sussex.

The initiative was welcomed by public health experts last night, but environmentalists have called for more to be done to get cars off the city’s roads.

Southampton Friends of the Earth spokesman Chris Bluemel said: “Monitoring air quality does no good if it’s not followed up by action. Reducing car use must be a priority.

“We need city-wide cycling infrastructure to ensure people can cycle from place to place without ever coming into danger.”

Readings from the city’s permanent monitoring stations showed that between 2006 and 2008 pollution had risen at Six Dials (36mg/m3) and Redbridge School (44.3), but dropped at Bitterne Road (39.2) and Onslow Road (51.4).

Simon Hartill, the council’s scientific officer, said Southampton had a “well managed integrated transport infrastructure system” and its coastal location helped to disperse pollution.

“We have learnt that localised areas of poor air quality do exist in the city, but these are restricted close to our busiest roads and potential health impacts will only arise where residential areas are very close to the kerbs,” Mr Harthill said.

“We learn more about local air quality every year and continue to find new areas that require further attention. This does not reflect a deterioration in air quality and it is anticipated that standards will improve.”

In bid to cut pollution further, the traffic flows in Bevois Valley will be studied to see if it can be manipulated to minimise congestion and reduce emissions. If successful, the scheme could be introduced across the whole city.

Mr Harthill added: “Road transport is the biggest contributor to poor air quality in the city and we encourage residents to do their bit, by considering sustainable alternatives to the private motor car, such as cycling, walking and public transport.”

Southampton’s public health director Andrew Mortimore said: “We believe the airAlert service will make a real difference to those people in the city with conditions such as asthma.”

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