concern about/for/over

When conversation turned to prospects for 2008, however, the salesmen voiced concern about credit markets and warned that problems in the subprime market could spill over and hurt demand.

The reason for the stock market rout is a combination of fears over the sovereign debt crisis in Europe and growing concern about the US recovery.

The increasing concern over health has changed consumers' perceptions about their lives and needs. Consumers are becoming more anxious for healthy lives.