U.N. agency calls outdoor air pollution leading cause of cancer

The air we breathe is laced with cancer-causing substances and should now be classified as carcinogenic to humans, the World Health Organisation's (WHO) cancer agency said on Thursday. The International Agency for Research on Cancer (IARC) cited data indicating that in 2010, 223,000 deaths from lung cancer worldwide resulted from air pollution, and said there was also convincing evidence it increases the risk of bladder cancer. The WHO is a Geneva-based agency of the United Nations focused on international public health matters.