Changsha and Zhuzhou began to release PM 2.5 data on December 1 and 2, 2012 respectively.
PM2.5 stands for particulate matter with a diameter of 2.5 micrometers or less, which can invade even the smallest airways. The international standards for PM2.5 emission are 75μg per cubic meter every day and 35μg per cubic meter every year on average.
Zhuzhou started monitoring PM2.5 on a trial basis. The real-time data at 11:00 a.m. on December 1 were lower than the international standards, marking good air quality of the city at that time. Visitors can log in the website of the Zhuzhou Environmental Protection Bureau (www.zzshbj.gov.cn) to learn the real-time PM2.5 data per hour at each operational station. The city will officially release the data per hour and the daily average data from January 1, 2013.
Changsha also released its PM2.5 data on the real-time release data system of Changsha environment and air quality (trial operation) on the website of the Changsha Environmental Protection Agency (hbj.changsha.gov.cn) at 0:00 on December 2. The air quality at eight stations was at third grade, while that at Yuhua station was good. According to the Changsha Environmental Protection Agency, the real-time monitoring data will be released each hour unless the force majeure such as machine and power failure happens.