PORTLAND — Underage Oregon girls are more likely than boys to drink alcohol, a survey shows.

The annual survey by the state Department of Human Services tracks students in the eighth and 11th grades. Roughly 16,000 students answered questions about their alcohol use.

Forty-eight percent of 11th-grade girls reported drinking beer, wine or liquor in the past month, up from 41.8 percent in 2001. Among 11th-grade boys, 46.8 percent said they had a drink in the past month, a slight increase from the 45.4 percent who reported doing so in 2001.

Alcohol use is growing at a faster pace among younger students. Thirty-three percent of eighth-grade girls reported drinking in the past 30 days, up from 24.8 percent in the 2001 Healthy Teens Survey. Twenty-seven percent of eighth-grade boys reported trying alcohol, up from 24.4 percent in 2001.

Among eleventh-graders, 81 percent said alcohol was “very easy” or “sort of easy” to get, while 58 percent of eighth-graders said the same.

Eighth-graders reported that the most common sources of alcohol are consenting parents, liquor cabinets and refrigerators at home, underage friends and parties.

The Department of Human Services plans to start an advertising campaign next month that will focus partly on parents and their attitude toward drinking.

The ads are to “increase their awareness of how, if they give their kids permission to drink, it’s probably not helping this problem,” said Bob Nikkel, an assistant director with the agency.

Another factor in the rise of alcohol use, anti-drinking advocates say, is a culture that romanticizes alcohol.

“We’ve got to understand that kids are being bombarded with messages,” said Judy Cushing, president of Oregon Partnership, a nonprofit alcohol and drug prevention group.

“Kids get the idea that everyone drinks, and everyone drinks all the time with no consequences, that it’s the perfectly normal thing to do, and it’s safe,” she said.