Seven of the 10 worst cities in America for air pollution are in California, per the American Lung Association. The two worst—Bakersfield and the Visalia-Porterville-Hanford metro area—are trending down. The two bear much of the attack that California's drought is waging on the state's air quality. Their location at the southern tip of the Central Valley, where the sun beats down unobstructed, creates an "inversion layer" of warm air, trapping industrial chemicals beneath it.

China leads the world in deaths linked to air pollution, with some 1.6 million a year. (India has 1.3 million.) Burning coal, China's main source of energy, is the main culprit. A recent peer-reviewed study linked the industry directly to over 360,000 deaths a year, or about 22 percent of the total.

In 2013, Xi Jinping's government published a five-year plan that would curb coal emissions. It also eased restrictions on media reporting on the pollution crisis, and earlier this year ratified the Paris Climate Agreement. However, loopholes in Xi's policies and existing projects put the Chinese government on track to open an average of one coal plant a week for the next four years, found a Greenpeace report published earlier this year.

Why not purchase some lovely air from the Rockies, provided in "a convenient can" ($23.99 for "80 breaths of fresh air"). Or perhaps you'd prefer a jar of Welsh air, with "a morning dew feel to it, but enriched with vibrant and flavoursome undertones." A 12-pack of Australia's finest bottled air gets you Bondi Beach and Tasmania. All to service a growing market of people who live in polluted cities.