According to data released by Guangzhou Environmental Protection Agency, in 2011, there were 22 days whose PM 2.5 concentrations surpassed the national standard of 75μg/cubic meter, with an average annual concentration of 41μg/cubic meter. However, Yang Liu, Assistant Director of the Guangzhou Environmental Protection Agency, stated that this average may actually have been reported values up to 20% lower than the actual concentrations due to issues with equipment calibration. Mr Yang estimates that 2011’s average PM2.5 concentration was probably about 41μg/cubic meter- 49μg/cubic meter.
Mr. Yang explained that additional equipment must be installed to calibrate the American monitoring equipment to Guangzhou’s high humidity and temperatures. Failure to do so resulted in inaccurate readings. Currently, Guangzhou has set up 10 air monitoring stations that each conduct monitoring by one of two EPA-approved methods, but it is still difficult to guarantee accurate readings, with different laboratories often reaching different conclusions.
The American Consulate located at Shamian, Guangzhou also monitors and publishes PM2.5 air quality data, and results have been quite different from that of the Guangzhou Environmental Protection Agency. According to Mr. Yang, this may be because the American Consulate has not followed the monitoring requirements of the United States EPA.
The Beijing Municipal Environmental Protection Department also addressed the differences in its data with the US Consulate in Beijing this past February, saying that the Consulate’s equipment did not meet standards. According to the EPA stipulations, air quality monitoring stations should be located at least 50 meters from sources of pollution, while the US Embassy’s monitoring equipment is located near the side of road.
Translated and summarized by Theodore Lim