Our Environment
(Study Points)
Environment:
It is the sum total of all external conditions and influences that affect the life and development of an organism, i.e., the environment includes all the physical or abiotic and biological or biotic factors.
Biodegradable Substances:
These are those substances which are broken down into simpler, harmless substances in nature with due course of time by the biological processes such as action of microorganisms like certain bacteria.
Eg. Domestic waste products, urine and faecal matter, sewage, agricultural residue, paper, wood,
cloth and cattle dung.
Non-biodegradable Substances:
Non-biodegradable Substances are those substances which cannot be broken down into simpler, harmless substances in nature. These substances may be in solid, liquid or gaseous form and may be inert and accumulate in the environment or may be concentrated in the food chain and harm the organisms.
Eg. DDT, plastics, polythene bags, insecticides, pesticides, mercury, lead, arsenic, aluminium, radioactive wastes, etc.