People breathing city air are likened to fish in an oil spill.

Alarming evidence for the way air pollution damages the cardiovascular system emerged on Monday at the American Association for the Advancement of Science meeting in Boston.

Although “clean air” legislation has cleaned up the most visible smog-like pollution in industrialised countries, Lung Chi Chen of the medical school at New York University said microscopic soot particles from vehicle exhausts killed an estimated 30,000-40,000 people a year in the US.

Breathing the air in New York City was similar to living with a smoker in terms of risk from heart disease, he said.

Several scientists said exposure to ultra-fine particles at levels found in city centres triggered heart disease in laboratory animals. Even the most modern diesel and petrol engines with efficient filters generated the most dangerous particles (less than 2.5 microns in diameter), Dr Chen said.

In addition, chemicals called polycyclic aromatic hydrocarbons pose a serious threat to human health according to John Incardona, researcher with the US National Oceanic and Atmospheric Administration.

Dr Incardona said PAHs, which affected fish exposed to oil spills, were also “prime suspects for cardiovascular impacts related to air pollution”.

Even in “safe” levels, particulate air pollution added to the cardiovascular health burden. “Estimates of toxicity based solely on measurements of particles are likely to dramatically underestimate the net health impact of complex emissions,” said Matt Campen of the Lovelace Respiratory Research Institute in New Mexico.

Source: Clive Cookson, Boston,dwp_uuid=cbc8c502-d316-11db-829f-000b5df10621,print=yes.html