Xu Qin/Shanghai Daily news

For Xie Zhenhua, the fall from national hero to disgraced official came overnight.
For 12 years, he had been a much-admired crusader against pollution. But on December 2, he had to step down because of dereliction of duty.
Yes, he had ordered the closure of many plants polluting the nation's rivers and lakes, often in the face of entrenched local protectionism.
Yes, he had turned the country's environmental watchdog from being a "toothless" nonentity into a giant that could bite hard.
As the former head of the State Environmental Protection Administration, Xie was by no means a "rubber stamp" official.
In 2003, UN Secretary-General Kofi Annan awarded him the Sasakawa Environment Prize for that year, citing his great zeal and imagination in promoting sustainable growth in China.
However, this long-time campaigner in the cause of improving China's environmental health on November 13 missed the precious chance to stop major pollution in a river in Northeast China from worsening.
And that proved to be his water-loo.
On that day, a blast at a chemical plant on the Songhua River caused severe pollution. As a result, the city of Harbin had to suspend its tap water supply for four days leaving hundreds of thousands of people high and dry.
Had Xie acted earlier and done his due diligence, the pollution spill could have been tackled in a more timely manner to say the least.
Indeed, although his words and actions had been praiseworthy in the past, he was slow to act in this case.
From November 14 to November 17, when toxic chemicals contaminated the river and human life was at risk, no reports were received from Jilin's provincial authorities and this revealed an obvious lack of emergency reaction on the part of the local government.
Xie failed to detect the deliberate concealment and thus lost his best opportunity to act promptly.
His carelessness, or his blind trust in local reports, cost him, and the health of the river, dearly.
The poisonous slick finally passed the city on December 4 and made its way slowly through Heilongjiang Province toward the Russian border despite the freezing weather. The approach of the pollution also rang alarm bells in Russia.
The administration "as the main body for environmental protection did not pay enough attention and fell short in its evaluation of the possible severe results arising from the incident. Thus, it holds the responsibility for the losses," said China Central Television.
To blame everything on Xie in the case of the Songhua River pollution might be unfair to him.
But his resignation shows the sincerity of the central government in disciplining whoever is responsible in one way or another, even a high-ranking official - because the issues at stake are too high.
The signal of the central government is clear: No one shall be allowed to overlook the gravity of a pollution incident for even a second.
The job of an environment watchdog is around the clock. Anyone in that position must be vigilant all the time, not daring to close his or her eyes and ears for an instant.
The anti-pollution campaign needs more than fine words or short-term actions. It needs lifelong devotion.
To be sure, Xie's resignation alone won't automatically put an end to pollution.
But if we look at Xie's rise and fall from a different angle, he might not be such a tragic character after all.
In fact, both his glorious past and a sudden fall have allowed us to see a man of conscience and social responsibility.
When he did well, he deserved accolades. When he failed, he admitted generously that he was to blame.
Pollution will take generations to be fixed. The one and most important issue in that cause is conscience, a sense of responsibility and the courage to admit errors and to quit.
Xie is actually an amiable and easy-going person.
Many journalists like to call him "Lao Xie," meaning "Old Xie," a name that is usually used among peers or good friends.
You seldom see this kind of appellation in officialdom, as many Chinese officials like to be called by their glossy titles, such as "Minister This" and "Minister That."
No one is perfect and not everyone has Xie's courage to quit.
Otherwise not only pollution but all the safety problems as we see in one mine blast after another would have been tackled more efficiently.