The researchers then ranked the sites and problems by " disability life-adjusted year, " or DALY, which measures both early death and the impact of pollution-related disease.

The biggest pollution-related killers were heart disease, stroke, pulmonary disease and lung cancer.

Fruit and vegetables are rich in carotenoids, which are known to protect against cell damage from pollution and UV rays, and can also prevent age-related diseases including heart disease and cancer.