Around six million people aged over 65 in England are at high risk of lung damage and asthma attacks because of toxic air, according to a new report.
It finds that older people and those with lung disease who are most vulnerable to the effects of pollution are often the most exposed.
The new document is from the British Lung Foundation (BLF) and Asthma UK.
It comes as MPs also demand the government sets tougher targets for air pollution.
Improving air quality needs to be "at the core" of the UK's post-pandemic rebuild, say members of a House of Commons committee that focuses on environmental issues.
The new report by two of the UK's leading respiratory charities finds that a quarter of all care homes and a third of all GP practices and hospitals in England are in places where particulate pollution exceeds the limits recommended by the World Health Organization (WHO), according to the new report.