By Elizabeth Muller

By many measures, air pollution is the greatest environmental catastrophe in the world today –killing an estimated 3 million people worldwide every year. That’s more people than malaria, AIDS, diabetes or tuberculosis.
Even in the United States, the EPA calculates that air pollution kills an estimated 75,000 people every year – that’s about as many people as are killed by automobile accidents and gunshots combined. This is even though US measured air quality levels are typically ranked in the “good” to “moderate” categories.
Yet most environmental organizations are still ignoring air pollution. This is why, in March 2014, Berkeley Earth, the organization that I co-founded, took the strategic decision to begin a new study on air pollution. We started with China, since it has both horrific air pollution and good data publicly available. Last month our first scientific paper was published. The work received remarkable coverage in the media, including in the New York Times, the Economist, the Washington Post, the South China Morning Post, Atlantic Monthly, Sydney Herald, Thanh Nien Daily, Daily Pakistan, and hundreds more. The coverage has been uniformly positive for our work, although alarmed at the continuing tragedy.
We calculate that filthy air kills about 4400 people per day in China alone. That is 1.6 million deaths every year. The air quality in some Chinese cities is comparable to smoking a pack of cigarettes every day. Globally, smoking still kills more people than air pollution (6 million compared to 3 million), but as formerly impoverished countries begin generating more electricity from coal, air pollution is catching up. On an especially bad day (air pollution in the “hazardous” range), an hour of exposure will shorten a life by an average of about 20 minutes. And yet most people go about their lives, saying that they are not bothered by the pollution, and not even wearing a face mask to protect themselves. While visiting Beijing on such a “hazardous” day, I was shocked that almost no locals were wearing masks. The guy sitting next to me on the plane as we descended into the brown smog told me that as a foreigner, I should wear a mask, but he never does because he is “used to it”. On another trip, one where pollution levels were relatively low (but still far worse than we generally encounter in the United States), I wore a face mask the entire time I was there. My Chinese colleagues all thought I was silly to be wearing a mask in such better-than-average (for them) conditions.

The pollution in India is similar to that of China, but less well understood because measurements are generally not made public. Europe is much better than China and India, but still about twice as bad as the United States.
As we in the United States are warned during every smog alert or inversion, air pollution is especially harmful to “sensitive groups” – including children, people with asthma, chronic bronchitis, or emphysema, and also older adults and active people who work or exercise outdoors. The real killer is something called “PM 2.5” – something that most people still haven’t even heard of. PM 2.5 refers to particulate matter 2.5 microns in diameter or smaller. It’s the stuff that is so small that it gets right through your lungs and into your bloodstream.
PM 2.5 is now increasingly being monitored across the United States, but it is still challenging to find out pollution levels across the country. Our organization, Berkeley Earth, hopes to change that in the next few years adding much of the United States to our air pollution database and analyzing trends and impacts.
We do know that PM 2.5 is strongly affected by the presence of heavy industry, forest fires, and less so by cars and trucks. Of particular topical importance, the US Forestry Service says that “a large proportion of wildland fire smoke emissions is fine particulate matter (PM2.5) that can penetrate to the deepest parts of the lungs.” Given the fact that so much of the American West is now engulfed by fires, the name PM2.5 should become as well known as nicotine in states like Washington, Montana, and now California. I live in the Bay Area, and the Bay Area Air Quality Management District just issued its eighth Spare the Air Alert for smog in 2015. Good as their intentions are, however, I note that they are encouraging residents to walk or bike to work. Even those individuals who have no history of asthma or other lung conditions are cautioned against outdoor exercise in these conditions. Other options, such as carpooling or taking transit are more sensible recommendations.
Scientists are still working to better understand the different types of PM 2.5, and which ones are the most harmful. We do have reason to believe that PM 2.5 from coal is worse than other types of PM 2.5, but because forest fire smoke is unfiltered, it is best to assume that it can be very bad.
Any families with asthma should try stay indoors as much as possible if there are any major forest fires in the vicinity. Get a good HEPA air filter for your home, one that filters out even the smallest particulate matter. Avoid strenuous exercise outdoors, and when you do go out, wear a high-quality facemask that protects you from PM 2.5. Thankfully, here in the United States we can expect that the quality of our air will improve with time as the fires are put out. Our friends in China and India are not so lucky.
Elizabeth Muller is the co-founder and Executive Director of Berkeley Earth, a non-profit research organization. Elizabeth guided the strategic development of Berkeley Earth from global warming data analysis, to climate communications, to global warming mitigation, and now, PM2.5 and global air pollution. Elizabeth has authored numerous scientific and policy papers, as well as Op Eds in the New York Times and the San Francisco Chronicle, and made numerous TV and radio appearances. Prior to co-founding Berkeley Earth, Elizabeth was Director at Gov3 (now CS Transform) and Executive Director of the Gov3 Foundation. From 2000 to 2005 she was a policy advisor at the Organization for Economic Cooperation and Development (OECD). In these positions, she advised governments in over 30 countries, in both the developed and developing world, and has extensive experience with stakeholder engagement and communications, especially with regard to technical issues.