Breathing in diesel fumes may increase the risk of brittle bone disease among the elderly, research suggests.
A major study of more than 9.2million people found even small increases in air pollution led to an increase in osteoporosis and bone fractures.
The research, by experts at at Columbia University in New York, is the first to link air pollution to broken bones.
The paper, published in the Lancet medical journal, focused on exposure to microscopic sooty particles which are particularly linked to old diesel cars.
The research, by experts at at Columbia University in New York, is the first to link air pollution to broken bones
Just last week World Health Organisation data revealed 43 of 50 large towns and cities in Britain have dangerously high levels of these particles, which are known as PM2.5.
More than 40,000 people are thought to die early every year in the UK because of air pollution, which is known to contribute to heart problems, lung disease and dementia.
But the new research suggests it could also have a major impact of the quality of life of the elderly by raising the chance of crippling bone fractures.
The scientists tracked 9.2million people admitted to hospital in Northeast and Mid-Atlantic U.S. between 2003 and 2010.
They found people living in areas of higher PM2.5 pollution were 4 per cent more likely to suffer broken bones related to osteoporosis.
The scientists then looked in detail at 700 people in Boston and found those exposed to higher levels of PM2.5 and black carbon – another component of diesel exhaust – had lower levels of parathyroid hormones which bolster bone health.
The researchers believe air pollution causes oxidative damage and inflammation which accelerates bone loss.
Smoking is known to have a similar impact.
Osteoporosis, the most common reason for a broken bone among the elderly, is a disease in which bones become brittle and weak as the body loses more bone mass than it can rebuild.
It affects more than three million people in the UK, and 500,000 people suffer fragility fractures every year as a result.
Usually there are no symptoms before a break, which often happens spontaneously or from something as harmless as a hug.
Some 60 per cent of those suffer such a fracture never regain their independence.
Researcher Dr Andrea Baccarelli said: ‘Decades of careful research has documented the health risks of air pollution, from cardiovascular and respiratory diseases, to cancer, and impaired cognition, and now osteoporosis.
‘Among the many benefits of clean air, our research suggests, are improved bone health and a way to prevent bone fractures.’
Diesel cars had been promoted for decades as an environmentally-friendly choice because they emit less carbon dioxide, the greenhouse gas which causes global warming.
Tony Blair’s Labour government, in particular, used generous tax breaks to persuade drivers to buy diesel cars.
But in recent years scientists have realised that diesel also produces more of the tiny particles and nitrogen oxides that are damaging to human health.
Studies published this year alone have found this pollution can warp the structure of the human heart and raise the risk of an early death; it has been found to harm children while they are still in the womb; it raises the chance of developing dense breast tissue – a risk factor in breast cancer; and it may increase the risk of developing dementia.