Biodegradable substances are those substances which can be broken down by the action of microorganisms naturally.
Biodegradable substances would affect the environment in following ways :-
Biodegradable substances can become the breeding site for many disease causing microorganisms.
Longer accumulation of biodegradable substances in nature can cause discomfort in breathing due to its foul smell.
Final answer :-
Hence, these are the two ways in which biodegradable substances would affect the environment.