1.挂虑的,担心的,不安的[(+about/for/over)]She is concerned about your safety. 她不放心你的安全。 2.有关的;参与的[(+in)]Everyone who was concerned in the affair regrets it very much. 参与此事的人对此都深感遗憾。 3.关心的,感兴趣的[(+about/for)][+to-v][+that]She's most concerned to solve this problem. 她很想解决这个问题。
To be concerned about something is to be 1. Interested and involved. For example I have sent a memorandum to those concerned.or2. Anxious or troubled. Example: We are concerned that children today do not receive enough English language instruction.