Two days before the scheduled end of the door-to-door surveying of Beijing households ahead of the latest national population census, many enumerators who have been pounding the pavements are expressing concern that the exercise will not be finished on time.

Two census-takers fill in a questionnaire at the home of a resident in Beijing.

Some have even become so pressured by the monumental task they have quit their jobs.

Guo Yong, a spokesman at the census office in Dongcheng district, said enumerators have been leaving their jobs in every district. Guo said the city has called up an extra 5,000 enumerators to supplement the 100,000 initially recruited to carry out the work.

"We have been finding it more difficult to obtain accurate information this time compared to the previous five national censuses," Guo said. "People have more safety concerns nowadays when they are being asked to open their doors to a stranger."

Guo said the office has been working with the district's police, the industry and commerce department and city administration squads to try to reach some of those people who have been difficult to talk to, creating a team that has ventured into places including hair salons, construction sites and illegal apartments.

Li Zongying, director of the census office in Hepingli residential district, said two enumerators there had just resigned because of the pressure of work.

"We have just talked two university students into replacing them for the last two days," said Li.

Liu Zhan, a student majoring in social care at China Youth University for Political Sciences, told METRO he was pleased when he landed the job of census enumerator but it turned out to be too time-consuming.

"Since September, I've been staying late and working hard," he said. "It's my honor to work as an enumerator because it only comes around once every 10 years but it takes much more time that I expected. I didn't have enough time for studying so I had to quit."

Some enumerators said the process was being slowed down by the fact that so many of their colleagues were retired workers who are slower at putting data into the computer system.

But other enumerators said the door-to-door survey offers a way to get in touch with neighbors.

Ji Lao, 61, an enumerator who has lived in his community for decades, said many new people had moved into the area and he saw the job as an opportunity to get to know them.

"I tried to engage people in light conversation while asking the census questions," Ji said. "While the times have changed, it is still good to know who your neighbors are."

Li said he still needs to get around to talking to 23 households in the coming two days. Half of the residents were out when he called before or refused to open the door.

"The younger generation pays more attention to personal privacy," he said. "Even if they do accept the interview, they often answer my questions quickly without elaborating as we stand in the doorway and do not invite me inside."

Sun Ying, a researcher at East China Normal University, told METRO that population censuses are important tools for governments and other decision-makers.

"Given China's current national conditions, the door-to-door forms are still the most effective way to gather accurate information about the population, even though it can be inconvenient," Sun said.