Biology note

• Pollution


  The release of food or harmful substance into the environment by their natural forces or man and other animals to an extent that it causes biological damage to man and its resources
• Pollution


  The release of harmful substances into the environment (water, air and land) in quantities or to the level that are harmful to man, animals and plants
• Types of Pollution


  • Air Pollution
  • Water Pollution
  • Soil or vegetation or land Pollution
  • Noise Pollution
• Air Pollution


  The release of unwanted material into the air by man to constitute danger to men's health and natural resources
• Pollutants


  Agents or causes of pollution
• Causes of Air Pollution

  • Dust particles from cement factories and environment
  • Smoke from industrial process e.g. burning of coal and cigarette
  • Sulphur (IV) oxide from burning of fuel containing Sulphur
  • Carbon (IV) oxide from incomplete combustion of fuels
  • Oxides of nitrogen produced by combustion of engines
  • Radioactive rays from nuclear power plants and nuclear reactions
• WAYS IN WHICH POLLUTION COULD AFFECT HUMAN RESPIRATORY TRACT
• 1.Inflamation

  2.Choking

  2. Irritation of the respiratory tract

  3. Reduction of oxygen carrying or the blood
• Effects of pollution on human respiratory system


  • Coughing
  • Sneezing
  • Lung cancer
  • Chronic bronchitis
  • Asthma
• Pollution


  Irregular sounds made up of groups of waves of random frequency and intensity or noise pollution which is also known as environmental noise with harmful impact on the activity of human or animal life
• Methods to control air pollution


  • Burning of smokeless fuels
  • Locating industries away from residential areas
  • Avoidance of air pollutants generally
  • Burning of refuse in incinerators
  • Use of chimney filters in industries
• Sources of noise pollution

  • Transportation noise (e.g. cars, trucks, planes etc.)
  • Industrial noise (e.g. construction sites, factories etc.)
  • Music and entertainment
  • Household appliances (e.g. generators, blenders etc.)
  • Construction and demolition
  • Lawn care and landscaping
  • Sirens and emergency vehicles
  • Thunderstorms
• Effects of noise pollution

  • Hearing loss/deafness
  • Cardiovascular problems (increased blood pressure)
  • Disturbance of sleep
  • Anxiety
  • Wildlife disturbance and stress
  • Changes in ecosystem structure and function
  • Damage to marine life
  • Decreased quality of life
• Methods to control noise pollution

  • Government establishing and enforcing noise pollution regulations
  • Noise reduction technologies such as sound proofing, mufflers and silencers
  • Creating quiet zones to reduce noise levels
  • Building noise barriers like walls or screens
  • Taking personal responsibilities to reduce noise levels in communities
  • Educating people on the dangers of noise pollution
  • Noise monitoring
  • Planning construction plans to prevent disturbances
• Dust Particles


  • Cause disease when inhaled
• Dust Particles

  • Causes asthmatic attacks
• Smoke


  • Causes discomfort to man
• Carbon Monoxide


  • Causes death
• Smoke

  • Causes eye irritation
• Smoke


  • Causes respiratory problems
• Oxides of nitrogen

  • Causes suffocation and lung irritation
• Water Pollution


  Contamination of water bodies, usually as a result of human activities
• Water Pollution is one of many types of Pollution which result from Contaminants being introduced into the natural environment (e.g. oceans, aquifers, lakes, rivers, groundwater)
• Water Pollution causes adverse change
• Major water Pollutants


  • Sewage
  • Pesticides
  • Fertilizers
  • Chemical wastes
  • Erosion
  • Crude oil spills
• Sources of Water Pollution


  • Sewage system
  • Pesticides washed from farms
  • Fertilizers from farms
  • Chemical wastes from industries
  • Erosion
  • Crude oil spills during loading/unloading of oil tankers
• Effects of Water Pollution


  • Supports growth of pathogens that cause diseases (e.g. cholera)
  • Makes water unfit for human consumption
  • Kills aquatic organisms
  • Produces odour
  • Leads to rapid vegetation growth that makes fishing and movement impossible
  • Destroys aquatic plants and animals
  • Affects food chain and leads to migration of species
• Methods of Purifying Water


  • Boiling
  • Addition of chemicals (e.g. alum or chlorine)
  • Filtration
  • Distillation
  • Sedimentation
  • Sterilization (e.g. by UV light)
• There should be efficient and proper sewage disposal system
• Dumping of refuse or petro-chemical products into rivers, streams or seas should be avoided
• There should be efficient techniques to deal with or prevent oil spillage
• Industries should be sited far away from residential areas
• Government or local authorities should strictly monitor all waste industries
• Industrial effluents should be recycled
• Boiling


  1. Heating water until it reaches its boiling point

  2. Microscopic bacteria are gone
• Addition of Chemicals


  1. Adding chlorine, fluoride, and pH adjustors to drinking water

  2. To make water safe and potable
• Filtration


  1. Removing impurities and contaminants by passing water through a filter or membrane

  2. To produce water that is safe and clean for drinking or other purposes
• Distillation


  1. Boiling water and collecting the condensed steam

  2. Produces water free from contaminants
• Sedimentation


  1. Allowing suspended solids and particulate matter to settle to the bottom of a container or tank

  2. Also known as settling or clarification
• Sterilization


  1. Eliminating all forms of microbial life, including bacteria, viruses, fungi, and protozoa

  2. To create water that is safe for drinking and medical use

  3. Involves boiling, UV-light, reverse osmosis, distillation, autoclaving, etc.