Answer:
Humans are responsible for the environmental pollution in many ways . Some of the points are as follows : 
1 ) People throw the wastes wherever they like instead of using dustbins .
2 ) The various types of gases from the industries which harms the nature .
3 ) Cutting off the trees . ( people can cut but also must plant a new one )
4 ) Farmers using different chemical substances in high amount in the crops .
5 ) Burning plastics , tires etc .
 
This was my way to answer the question , if you need then you can write in paragraph . 
let me know if its incorrect . :-)
 
        
             
        
        
        
The set of synonyms would be picked and took.