Air pollution is a leading cause of cancer, according to the World Heath Organization.
"Outdoor air pollution is a leading cause of cancer in humans, according to the International Agency for Research on Cancer (IARC), an arm of the World Health Organisation (WHO)," writes Al Jazeera.
There is now evidence that exposure to outdoor air pollution has caused and can cause lung cancer and raises the risk of bladder cancer.
The main sources of outdoor air pollution are: transport, power generation, emissions from factories and farms, and residential heating and cooking.
Japan has plenty of home grown sources of the above. However, in addition, tiny particulates blow in from China.
Diesel exhaust and these "particulate matter" have also been classified as carcinogenic by the IARC.
Time to pull out the bike mask - again.
Castelli Squadra Long Waterproof Jacket
Tags Japan Touring Kyoto Cycle Japaneset