Levels of the noxious gas nitrogen dioxide are said to be "dangerously high" at most airports in England, including one in the North-East.

According to a report, levels at Newcastle International Airport have exceeded recommendations by the EU, which states nitrogen dioxide (NO2) levels should stay below 40 micrograms per cubic metre of air.

Newcastle, with Heathrow, Gat-wick and Birmingham airports, exceed this recommendation by up to 75 per cent, said the report, published by the Chartered Society of Physiotherapy (CSP). It said Durham Tees Valley airport also had levels above the EU recommendation.

Respiratory physiotherapists say the consequences of being exposed to NO2 can be especially severe among people with existing lung conditions, such as asthma, bronchitis and emphysema.

CSP spokesman Professor Grahame Pope said: "The effects of airport emissions on air quality and public health are of serious concern to physiotherapists.

"It's not just NO2 polluting the environment around airports - our study reveals high ozone concentrations at some sites too."

He added: "There's no doubt that aircraft contribute to the problem, but it should be noted that cars, buses and taxis ferrying passengers to and from these sites are dominant sources of pollution.

"Several airports want to expand capacity. We would urge the Government to consider ways of balancing passenger convenience with improving public health when looking at these (expansion) proposals."