Dear student,
Harmful effects of synthetic polymers are:-
1)They are non-biodegradable waste(it cannot mixed in soil).
2)When they burn, they produce many toxic gases and pollute the environment and causes health hazard.
3)Disposal of the items made from synthetic polymers is a big issue.
WAYS TO REDUCE THE HARMFUL EFFECTS:
1)we should follow the principles of 3'R {reduce,recycle,reuse}
2)we should switch to items made from natural polymers.
3)Finding measures for their safe disposal
Regards