What is "grashopper effect"?

Mainly, it is a consequence of global warming. It is a phenomenon that allows pollutants to travel from one ecosystem to another. Because of high temperatures, the toxic chemicals evaporate and ride the wind until they reach colder temperatures where they ultimately condense and fall down to the ground. This is why the antarctic region gets it the most.
As a result, both human ingest the toxins and develop various diseases.
I also attached a picture which hopefully will give you a better view over the grasshopper effect.