ZHENGZHOU - Sun Ximeng gets his kicks by picking up blood on the go, heading a mobile collection squad that drives around the city of Zhengzhou, Henan province.

In September, when the blood supply in the province fell short and a number of surgeries reportedly had to be deferred, the 56-year-old became extremely worried.

It wasn't until after many donors, learning of the problem from the media, finally came and rolled up their sleeves that he could relax again.

Zhu Xianzhou, 33, arrived early one morning after driving about 17 km with his cousin's family.

"Donating blood in needy times is the responsibility of citizens," said Zhu, a first-time donor.

According to Sun, many donors like Zhu came with their families, parents taking their children and brothers and sisters coming together.

"Such scenes move me," said Sun, whose work includes repeating almost identical questions to every donor while helping them to fill in the forms.

"I enjoy it. I can talk to different people," said the jovial man, with a voice gone hoarse after a busy morning, but showing no trace of tiredness.

Though their work normally ends before lunch, staying with the carriage is hard work, said Sun's colleague Ma Xuedong.

"We have to travel a lot despite bad weather. Visiting the suburbs is especially hard," Ma said.

Some donors who had lined up for a long time or had been turned away for health reasons were likely to complain. In the suburbs, villagers walk a long distance to donate but may be refused because donation staff is in short supply.

"They'll ask 'why would you refuse me? I don't want money!'" Sun said. "Then I need to explain patiently. They may not understand us, but we should understand them."

Sun, who had given blood 114 times since 1996, gave his last donation in October, three days before he turned 55, the oldest age allowed for donations.

"It's regretful that I can't donate blood anymore," he said.

"Many of my colleagues are active blood donors," Sun added.

Sun said the public might have mistakenly connected the blood center to recent scandals in China's charity scene.

"The public has some misunderstandings about blood donation," he explained.

Sun says he wanted to set an example and tell people blood donation is harmless, and hoped more people will join him.

Yuan Jincheng contributed to this story.