Fireworks Send Beijing Air Pollution Soaring Clouds of smoke from Lunar New Year fireworks sent air pollution in Beijing soaring under a new more sensitive measurement system, reports said Sunday. Readings of fine particulate matter called PM2.5 reached 1.593 milligrams per cubic meter on the Jan. 22 eve of the holiday, about 100 times worse than the amount considered good for 24-hour exposure, the city's environmental bureau said. The reading drew wide publicity in the local media on Sunday. The popular Beijing Youth Daily praised the city government for taking a more critical look at air pollution, while urging residents to consider the environmental effects of setting off fireworks. Readings on Saturday averaged around 0.07 before spiking again during the nightly new year fireworks barrage, hitting a height of 0.124 at 10 p.m. Concern has grown over air pollution from automobiles and other sources, prompting the city this month to begin announcing measurements of PM2.5 - particles less than 2.5 micrometers in size. That's about 1/30th the width of an average human hair. Because of their small size, the particles can lodge deeply in the lungs and are believed to pose the greatest risk to health. Beijing is frequently cloaked in yellow haze, with buildings a couple of blocks away barely visible. The city had previously only released readings of the coarser PM10 standard that indicated that pollution was "light," leading to accusations it was hiding the true extent of the problem. The U.S. Embassy has been independently monitoring PM2.5 from a device on its rooftop and releasing the results via Twitter. Some residents even tested the air in their neighborhoods and posted the results online. Beijing is now releasing hourly readings of PM2.5 that are taken from a monitoring site about 4 miles (7 kilometers) west of central Tiananmen Square.