Air quality plays an important part in our daily life.Xi Jinping said, "People's yearning for a good and beautiful life is the goal for us to strive for." Undoubtedly, enjoying the fresh air is one of parts in a good and beautiful life.

It has been about 4 years since revised ambient air quality standards (GB3095-2012) were implemented. So, how is the air quality now? When it comes to air quality, we associate it with air pollutants. The less air pollutants are, the better air quality is.

According to Air quality report from China National Environmental Monitoring Center, in the first half of 2017, the concentration of PM2.5 and NO2 in the 74 cities increased comparing the same period last year. The concentration of PM10 was flat, but the concentration of SO2 decreased. The standard exceeding rate of CO and O3 increased comparing the same period.

Seventy four cities are the cities mainly from Pearl River Delta, Yangtze River Delta and Beijing-Tianjin-Hebei Urban Agglomeration,whose air quality was evaluated by revised ambient air quality standards(GB3095-2012) from 2013. Through the standards, we can know the situation of air quality in the 74 cities.

The cities with the best or the worst air quality

According to the composite index of city ambient air quality (the greater the value of the environmental air quality index, the heavier the overall pollution level), the 10 cities with relatively good air quality(from first to tenth) were Haikou, Lhasa, Zhoushan, Zhuhai, Huizhou, Lishui,Shenzhen, Fuzhou, Xiamen and Guiyang. Air quality of Haikou was the best, and it was the only one with a composite index under 3. Meanwhile, the 10 cities with relatively low air quality (from seventy-fourth to sixty-fifth) were Handan, Shijiazhuang, Xingtai, Baoding, Tangshan, Taiyuan, Zhengzhou, Hengshui,Xi'an and Ji'nan. Handan was the city with worst air quality, and it was the only one with index over 10.

The main pollutant in 58 cities was PM2.5,accounting for 78%, as the city with best air quality, the main pollutant of Haikou was still PM2.5. Also, as the city with worst quality, Handan was with the same main pollutant. Jiangmen was the only city that was with 2 main pollutants-O3 and PM2.5.

As for concentration of pollutants, Haikou was the city with a minimum concentration of PM2.5, PM10, SO2 and NO2. Urumchi was the city with a minimum concentration of O3-8H-90per but still with bad air quality because it ranked over 60 among the 74 cities with high concentration of PM2.5, PM10, NO2 and CO-95per.

The area with the best or the worst air quality

Developed by heavy industry, air pollution in Beijing-Tianjin-Hebei Urban Agglomeration is serious. On the contrary, Pearl River Delta Urban Agglomeration is with good air quality because it is developed by light industry.

In the first half of 2017, the rate of the number of days with good air quality in 13 cities in Beijing-Tianjin-Hebei Urban Agglomeration was between 32% and 74.3%, between 39.2% and 95.6% in the Yangtze River Delta and between 81.2% and 97.8% in Pearl River Delta.

From the data, Pearl River Delta was the area with best air quality and Beijing-Tianjin-Hebei Urban Agglomeration with worst air quality as usual.

Among the 10 cities with best air quality, 3 cities belong to Pearl River Delta Urban Agglomeration, and 2 belong to Yangtze River Delta Urban Agglomeration. Among the 10 cities with worst air quality, half of them belong to Beijing-Tianjin-Hebei Urban Agglomeration. Air quality in Beijing-Tianjin-Hebei Urban Agglomeration made people worried while people in Pearl River Delta and Yangtze River Delta Urban Agglomeration could enjoy a relatively good air.

The core city with the best or worst air quality

Beijing, Shanghai and Guangzhou are the core cities inBeijing-Tianjin-Hebei Urban Agglomeration, Yangtze River Delta and Pearl RiverDelta Urban Agglomeration.

The proportion of days with good quality in Beijingwas 55.3%, and in Shanghai was 79.3% and in Guangzhou was 81.2% in the firsthalf of this year.

Beijing was with severe pollution for 12 days and serious pollution for 4 days. There was no severe and more severe pollution weather in Shanghai. Guangzhou was with severe pollution for 1 day, and no serious pollution day was found.

From the number of days with good air quality,Guangzhou was the best city. While we find that Shanghai was the city with best quality from the ranks in the 6 months.

In the past 6 months, Beijing was the city with the worst air quality and Guangzhou ranked in front of Shanghai in April and May.From this data, Shanghai was the city with best air quality though Pearl River Delta was the best area with best air quality.

Air quality is related to control air pollutants. From 2006 to 2015, our country spends a lot in controlling the wasted gas in industry. From the chart, we can find that the investment in controlling wasted gas in industry is increased quickly in the recent three years.

The situation of air quality differs from cities and areas but all people want to breathe a fresh air. 74-city standards have been worked about 4 years up to now, but air pollution is still a problem in China especially in Beijing-Tianjin-Hebei Urban Agglomeration. When people can get silk and gold easier, they also want to enjoy lucid waters and lush mountains and fresh air.

So, balancing the relationship between economic development and environmental protection is the most important duty for us.

Data sources: National Environmental Monitoring Center (http://www.cnemc.cn/) 

Nation Bureau of Statistic of the People's Republic of China (http://www.stats.gov.cn/)

Reporter: 周倩欣