A smartphone user shows the Facebook application on his phone in the central Bosnian town of Zenica, in this file photo illustration from May 2, 2013. (Xinhua/REUTERS)

SAN FRANCISCO, Sept. 5 (Xinhua) -- The world largest social media platform Facebook is losing a large number of young users as about one in four of them had removed the app from their smartphones in the past one year, a new Pew Research Center survey said Wednesday.

The survey found that a whopping 44 percent of users aged 18-29 have removed Facebook's app from their phones in the past 12 months, and about 42 percent have taken a break from checking the platform for several weeks or more.

The findings coincided with Facebook Chief Operating Officer Sheryl Sandberg's appearance before a U.S. Congress hearing on Wednesday on how Facebook addresses political content on the platform.

Facebook has been under heavy scrutiny for the way it was handling privacy issues and misinformation activities over the past months since a scandal erupted earlier this year following revelations that a former British consulting firm Cambridge Analytica had illegally accessed data of more than 87 million Facebook users without their knowledge.

The Pew surveyed more than 3,400 U.S. Facebook users in May and June, and found that more than 54 percent of users aged 18 and older have adjusted their privacy settings.

The number of young people who deleted their Facebook app is about four times higher than that of users who are 65 years and older, with about 12 percent senior users quitting the app in the past 12 months, said the Pew study.

Older users were less frequently adjusting their privacy settings with only a third of them doing so, in comparison with the 64 percent of younger users more willing to do the readjusting.

An estimated 9 percent of Facebook users have downloaded the personal data about them after Facebook updated its privacy settings to make it easier for its users to download the data collected by the social media site, according to the Pew study.

Among the users who have downloaded their private data from the Facebook platform, nearly half of them, or 47 percent, have dropped the app from the cell phone, while the majority 79 percent chose a higher level of security options in their privacy settings in the wake of the Cambridge Analytica scandal, the survey said.