Google Logo Search giant Google will begin storing the medical records of a few thousand people as it tests a health service. There is a strong likelihood that this service may raise more concerns about the volume of sensitive information entrusted to Google.

The pilot project announced on Thursday will involve 1,500 to 10,000 patients at the Cleveland Clinic who volunteered to an electronic transfer of their personal health records so they can be retrieved through Google’s new service, which won’t be open to the general public.

Each health profile, including information about prescriptions, allergies and medical histories, will be protected by a password that’s also required to use other Google services such as e-mail and personalized search tools.

Google views its expansion into health records management as a logical extension because its search engine already processes millions of requests from people trying to find about more information about an injury, illness or recommended treatment.

Marissa Mayer, the Google executive overseeing the health project, had previously said the service would debut in 2008.

The clinic already keeps the personal health records of more than 120,000 patients on its own online service called MyChart. Patients who transfer the information to Google would still be able to get the data quickly even if they were no longer being treated by the Cleveland Clinic.

“We believe patients should be able to easily access and manage their own health information,” Mayer said in a statement supplied by the Cleveland Clinic.

The Cleveland Clinic decided to work with Google “to create a more efficient and effective national health care system,” said C. Martin Harris, the medical center’s chief information officer.

Rival Microsoft Corp. last year introduced a similar service called HealthVault, and AOL co-founder Steve Case is backing Revolution Health, which also offers online tools for managing personal health histories.

It’s not yet clear how Google intends to make money from its health service.