Influence of the new global air quality guidelines on Nantong's air quality attainment
Based on the monitoring data of the national air control point in Nantong from 2018 to 2022,according to the method of China's national standards,the national standard level 2,AQG2005 and AQG2021 limit concentrations were used to evaluate the air quality.The results showed that in the past five years,the air quality in Nantong was generally good,the ratio of good days showed a fluctuating upward trend.The average annual concentration of the other five indicators decreased year by year,and the average daily concentration compliance ratio increased year by year,except for the increase of the average annual concentration of O3 and the decrease of O3 average daily concentration compliance ratio.When using the national standard second-level evaluation,the rate of excellent days in 2022 reached 88.2%,the compliance rate of average daily concentration of PM2.5,PM10 and O3 reached 97%,99.4%and 84.1%,respectively,and the remaining three indicators reached 100%.When using AQG2021,the SO2 had a positive impact,while CO had no significant impact,and the remaining indicators were significantly reduced compared with the evaluation using AQG2005 and na-tional standards level 2.In order to further improve air quality,more demanding air quality management objectives need to be set.It is suggested that the annual and daily indicators of PM2.5 and PM10 in Nan-tong City can refer to the transitional target of AQG2021IT-3,and the annual and daily indicators of NO2 can take appropriate limits between AQG2021IT-3 and the guideline value,and between IT-2 and the guideline value,respectively.O3 still needs to take the second-level national standard as a reference.
NETL
NSTL
万方数据
