Pollution in Biology — Full, Easy-to-Understand Overview
Pollution in biology refers to how harmful substances introduced into the environment affect living organisms—plants, animals, microbes, ecosystems, and even human health. It’s a major chapter in ecology and environmental science.
1. What Is Pollution?
Pollution is the introduction of contaminants into the environment that cause harm or life-disrupting effects. These contaminants can be:
Chemical (pesticides, metals, industrial chemicals)
Physical (plastic waste, heat)
Biological (pathogens)
Radiological (radioactive substances)
2. Major Types of Pollution
A. Air Pollution
Caused by:
Vehicle exhaust (CO, NO₂)
Industrial emissions (SO₂, particulate matter, heavy metals)
Burning fossil fuels
Smoke from biomass burning
Biological impacts:
Breathing issues in humans and animals
Acid rain → damages forests and aquatic ecosystems
Ozone depletion → UV radiation increase → DNA damage
Climate change → habitat shifts, species extinction
B. Water Pollution
Caused by:
Sewage
Industrial waste
Oil spills
Agricultural runoff (fertilizers, pesticides)
Plastics and microplastics
Biological impacts:
Eutrophication → algal blooms → oxygen depletion → fish deaths
Bioaccumulation & biomagnification of toxins (e.g., mercury in fish)
Waterborne diseases (cholera, typhoid)
Damage to coral reefs
Altered reproductive systems in aquatic organisms