The city of Nanjing, Jiangsu Province was entirely shrouded by yellow haze along with a smell of burning in the air on Sunday, as was Wuhan, Hubei Province yesterday.

Local meteorological observatories issued visibility warnings, pointing out that the visibility of Nanjing was less than 1,000 meters and that of  other several cities in Jiangsu Province was less than 3,000 meters. And it will remain the same for the following days. Prospects for air conditions in surrounding provinces such as Shandong, Henan and Anhui are also looking bleak.

As air quality concerns everyone, cyber space has been filled with complaints of this abnormal situation. In the past two days, over 1.5 million posts in Weibo focused on this topic.

According to the Nanjing and Wuhan environmental protection bureaus, the main culprit for the abnormal air condition is crop straw burning, coupled with unfavorable meteorological factors. 

Crop straw burning is a long-term nagging problem that has persisted in China's countryside. Every year from early summer to autumn is the peak season for farmers to burn crop straw. Compared with pollution controls for factories in rural areas, ending the burning of crop straw is a much harder challenge.

It was reported that local governments often establish interim offices to fight against crop straw burning during harvest seasons and send administrative staff to patrol the farmland, but this cannot prevent farmers from burning crop straw at night and during weekends.

The reasons are complicated. Few factories are devoted to collecting crop straw. Many farmers use the ash as fertilizer.  But the fundamental reason is that people still have low awareness of environmental protection and are reluctant to abandon traditional methods of production that are environmentally hazardous.

Crop straw burning damages the air quality and threatens people's health. According to estimates by environmentalists, under the air conditions of Nanjing on June 10, the hazard to people's health is equivalent to smoking 15 packets of cigarettes.

The Chinese public has much higher expectations for air quality than they used to. There are more and more questions and complaints about why Chinese cannot have clean air, and the Chinese public has successfully urged local environmental protection authorities to accelerate their steps in monitoring and publicizing PM 2.5 data. But improving air quality is not merely the responsibility of the authorities, but needs the public to adopt an environmentally friendly lifestyle. 

China's deteriorating air quality is a result of many details that overlook the environment. Improving the environment has to be realized by everyone, from the top through to the bottom of society.