Air pollution in major cities in Asia exceeds the World Health Organisation’s (WHO) air quality guidelines and toxic cocktails result in more than 530,000 premature deaths a year, according to a new report issued on Tuesday.

Issued by the U.S.-based Health Effects Institute, the study found that elderly people with cardiopulmonary and other chronic illnesses were especially vulnerable and they tended to die prematurely when their conditions were exacerbated by bad air.

“In general, those susceptible to air pollution are people who are older, who have cardiopulmonary disease, stroke, conditions often related to aging,” the institute’s vice president, Robert O’Keefe, said by telephone.