China's air pollution problem — which contributed to 1.2 million deaths in the country in 2010 — has gotten sharply worse in 2013. And the threat isn't contained to China. But things are still as ugly as ever in Beijing.

The study linking air pollution to deaths in the country came out over the weekend. As The New York Times reported, the death toll comprised 40 percent of all of the global deaths linked to air pollution. Another way of expressing the damage done is that, had all of those who died due to the pollution lived natural lives, it would have comprised an additional 25 million years of existence.

One of the primary ways in which air pollution kills is the presence of small particles, generally released from burning fossil fuels and other industrial activity. The Lung Association explains how particulate matter kills. The particles are generally measures in two sizes: those smaller than ten microns in diameter and those smaller than 2.5 microns — far, far smaller than the width of a human hair. "Particle pollution," the Association writes, "can be very dangerous to breathe. Breathing particle pollution may trigger illness, hospitalization and premature death, risks showing up in new studies that validate earlier research."

For all of the damage done in 2010 from pollution, 2013 could be worse. The Chinese government, which for years was reluctant to release pollution data, now suggest that particulate pollution this year has been 30 percent higher than the same period in 2012. Again, The Times:

Levels of the pollutants — nitrous dioxide and particulate matter that is between 2.5 and 10 micrometers in diameter, called PM 10 — appeared to have surged sharply in January, when they increased 47 percent over the same month last year, according to the report by The Economic Observer, a respected Chinese newspaper. The report cited as its source Chen Tian, head of the Beijing Municipal Environmental Protection Bureau. …

Mr. Chen said the main reason for the huge increase in two pollutants was high levels of emissions. Citing Mr. Chen, the report said “the emissions created by those living and producing in the city far exceed what the environment can take.”

The U.S. embassy in Beijing has a Twitter account, @BeijingAir, that releases regular updates on pollution in the city. (The account is widely credited with prompting the government to release its data.) Here are the readings for the past month:

Anything over 200 is considered "very unhealthy"; the air in Beijing exceeded that level 32 percent of the time. As the Lung Association notes, even brief spikes can be dangerous: "Deaths can occur on the very day that particle levels are high, or within one to two months afterward."

Early in February, the problem spread. Smog and soot pollution from China crossed the Sea of Japan and blanketed portions of that country for several days. Agence France-Presse reported on February 4 that "Air pollution over the west of Japan has exceeded government limits over the last few days, with tiny particulate matter a problem, said Atsushi Shimizu of the National Institute for Environmental Studies." Nor does it stop in Japan. Research conducted in 2007 and 2008 found that 29 percent of particulate pollution in California originated in Asia.

Making China's hazardous air pollution a problem for the rest of the world, as well.