The recent announcement that outdoor air pollution is carcinogenic to humans has caused huge reactions worldwide; provoking discussion in the press, within the scientific community, and among people in general.

The evaluation by the International Agency for Research on Cancer (IARC) is driven by findings from epidemiologic studies of millions of people living in Europe, North and South America, and Asia.

According to the IARC, there is sufficient evidence that exposure to outdoor air pollution causes lung cancer, and an increased risk of bladder cancer.

Predominant sources of outdoor air pollution are: transportation; power generation; industrial and agricultural emissions; and residential heating and cooking.

euronews’ Claudio Rocco interviewed one of the authors of the report, scientist Dana Loomis.

The air in China and India is known to be very polluted, but, surprisingly, the air in Northern Africa is, too.

“In China and in India much of what we see is due to coal burning,” explained Loomis.

“It’s industry and all the industrial development that is taking place in those countries. Here in Northern Africa, of course, is mostly desert, with few people. The particulate pollution that we see there is from windblown desert dust. So it’s quite different in character from the pollution coming from industry.”

Loomis added that desert dust is not as dangerous as other sources of air pollution. But, according to an Italian study, it does produce fine particles and can cause a wide range of health problems, including respiratory diseases.

He said the situation in Europe is very variable, with heavy pockets of pollution in certain areas and other, cleaner regions:

“In Europe the main sources today are related to transport. That is vehicles, airplanes, and so on. It used to be industry, and today if you go to China or India it is industry, because those are the countries that are industrialising, much as Europe did 200 years ago,” clarified Loomis.

When it comes to protection from polllution, Loomis explained, collective, rather than individual action needs to be taken:

“You know, air pollution is the classic public health problem, because the air belongs to everybody. We all breathe the same air, and so one person can’t do very much to improve the quality of their own air. You can cycle to work, you can reduce your use of fossil fuel, but it doesn’t help you very much. It helps the community. So it’s good if everybody does those things. But it’s also important for people to be aware of the problem, to recognize that it’s a collective problem and to expect solutions at a governmental and international level.”

The most recent IARC data indicates that, in 2010, 223,000 of the deaths from lung cancer worldwide were the result of air pollution.

But how can we be sure that air pollution was the cause of these deaths? A relevant point, according to Loomis:

“That’s a really important question. In fact, we can’t be sure,” he responded. “What we do is use statistical models to try to estimate the number of deaths that are due to a variety of different causes: air pollution; other environmental pollutions; cigarette smoking. We use data about large populations from epidemiologic studies. So, it’s an estimate, but we think it’s a good estimate.”