This is the 616th most frequent Korean word.
관련된
"Related" or "relevant."
'관련된' is used here as a modifier to describe '정보' (information), specifying its connection to '환경 문제' (environmental issues).
이 책은 환경 문제와 관련된 정보를 다룹니다.
This book deals with information related to environmental issues.
Here, '관련된' modifies '소식' (news) to denote its relevance to '그 사건' (that event).
그 사건과 관련된 소식을 들었나요?
Did you hear the news related to that event?
In this sentence, '관련된' describes '자료' (materials) to indicate their association with an implied topic.