Biodegradable waste produces methane and green house gases which are harmful for environment. Other harmful effects are that they can pollute water sources and spread diseases. Small insects like flies, mosquitoes, rodents harbour waste sites and spreads diseases.
Harmful effects of Non-biodegradable wastes
Long term exposure of these substances to air and soil may make them enter food chain and harm the organisms. e.g. Pesticides like DDT.
The non-biodegradable substances like radioactive wastes, lead, mercury etc. accumulate in the environment and cause life threatening diseases in humans and other living beings.
They also pollute water and harms the aquatic life. According to a survey, plastic debris in the ocean is responsible for the death of over 100,000 marine animals each year.