Won't fill out the 2010 census? Your ranks are getting smaller.

With the 2010 census under way, about 1 in 10 people may not participate in the population count, with many saying they see little personal benefit from the government survey or have concerns that it may be intrusive, according to a poll released Tuesday.

The Pew Research Center poll shows marked improvement in public interest since January. At that time a poll showed 1 in 5 might not mail back the census form. Still, the new poll highlighted lingering apathy toward the head count, particularly among young adults.

"There is an increased commitment to participating in the census, but disparities remain," said Michael Dimock, an associate director of the Pew Research Center for the People & the Press. "These include groups who have less-certain economic situations and who are often more mobile, which poses a challenge for the census count."

The poll comes as more than 120 million census forms arrive in mailboxes this week. The population count, conducted every 10 years, is used to distribute U.S. House seats and more than $400 billion in federal aid.

Stephen Buckner, a spokesman for the Census Bureau, said the increase in overall public awareness was heartening, noting that the government can save $1.5 billion in follow-up visits if everyone mails back their forms.

Buckner said for those who remain apathetic or reluctant to turn in their forms, the bureau will be closely monitoring mail participation rates and will increase advertising and outreach in the regions of the country that are lagging, including college campuses.

Beginning in May, the Census Bureau will also send census-takers to visit homes that do not return their forms.

"We're aware students are historically harder to count, and we are putting things in place to get an accurate count," he said.

Overall, nearly all of those surveyed by Pew were familiar with the census. About 87 percent reported they had already filled out their 10-question form, or definitely or probably would do so, often citing reasons that it was "important" or a civic duty.

Still, a majority of the people said they saw little personal gain from the census (62 percent) or expressed uncertainty as to whether the government was asking for more information than it really needed (55 percent). Many also said they still weren't confident that census information would be kept confidential and not be shared with other federal agencies for law enforcement, despite repeated assurances from Census Bureau director Robert Groves.

Broken down by age, adults 18-29 were least likely to say they would definitely or probably participate, at 71 percent. That's compared to 86 percent for adults 30-49; 92 percent for those 50-64; and 89 percent for people 65 and older.

Hispanics also were less likely to participate compared to other racial groups, although that gap has narrowed since January.

Pew interviewed 1,500 adults by cell or home phone from March 10-14. The poll has a margin of error of plus or minus 3 percentage points, higher for subgroups.