worry about 是动词带介词结构
be worried about 是系动词+形容词表语+介词结构
意思基本一致,前者动词结构更侧重动作的发生,而后者系表结构更侧重一种状态,这里表示担心的状态
be concened about 更强调的是一种关注,关心某事
eg.Be concerned about enviroment.
Do we need to be concerned about that baby or is weight the whole story.