Air pollution increases the risk of dying from breast cancer by 80 per cent.
The connection between pollution and the disease is firmly established but new research to be published this week highlights just how serious the link is.
A review of 27 studies has found that air pollution raises the danger of passing away from breast cancer by an alarming 80 per cent and other types of the disease by 22 per cent.
Professor Kefah Mokbel, a leading breast surgeon who conducted the research, says the results make air pollution "as significant a risk factor as smoking, obesity and alcohol".
The particulate matter 2.5 (PM2.5) - tiny fragments of pollution from exhaust fumes, wood-burning stoves and cooking - is of concern to scientists.
Professor Mokbel told Good Health: "At a time when we are seeing increasing numbers of women with breast cancer, particularly young women, people need to be aware that air pollution is a major risk factor for the disease.
"Long-term exposure to PM2.5 pollution not only raises the risk of breast cancer but also seems linked to a more aggressive disease and a poorer prognosis."