I was searching for a quick lesson activity to teach one lesson on pollution and its effects on the food chain when I found another TPT activity! I ended up modifying it to fit my lesson, but I must thank the original author for the work! (original link: http://www.teacherspayteachers.com/Product/Pollution-147563)
I like how students have two visual organizers to help with this concept. I linked this worksheet with BrainPop Pollution videos.
Hope it helps!