Addition of PM_2.5 into the National Ambient Air Quality Standards of China and the Contribution to Air Pollution Control: The Case Study of Wuhan, China

Table 3

Breakdown of the number of days in terms of primary pollutants.

Primary pollutant	Number of days	Percentage
PM2.5	125	73.10%
PM10	16	9.36%
O3	27	15.79%
NO2	6	3.51%
Total	171 ^a	100% ^a

aOn 8 March 2013, both PM_2.5 and PM₁₀ are listed as the primary pollutants as they had the same index value.