In an interview with actress Candice Afia, she mentions working with Justin:

SheKnows:Professionally or personally, were there particular actors or actresses on the Grey’s Anatomy set that you felt a certain affinity with?

Candice Afia: I’ve had the opportunity to work with so many of them — equal amounts of time. I’ve really enjoyed working with Justin Chambers, who plays my resident. He’s such a sweetheart. It’s funny: His character is such a gruff bad-boy type. Before I joined the show, I didn’t really know what to expect. When I first met him, I was given the direction to be scared of him. He’s mean. [But] he’s so nice! He’s got five kids. He’s such a down-to-earth person.

Source
 

Celebrity Campers Share the Importance of the Camp Experience

     The American Camp Association® (ACA) is proud to announce the release of a public service announcement titled Because of Camp…™. This PSA highlights celebrities including Emma Roberts, Hill Harper, Lisa Loeb, Kerri Strug, Michael DeLorenzo, Justin Chambers, Paul Adelstein, James Pickens, Blair Underwood, Sharon Lawrence, Frank Sesno, Glynn Turman, Ashlan Gorse, and Lisa Raye sharing how their lives have changed Because of Camp…™.

Justin shows up around the 0:13 mark.