The environment

• Weed killers - kills weeds

  BUTTT also other plants

  its not specific to weeds
• pH scale

  1 - strong acid

  7 - neutral

  14 - strong alkali
• Fair testing:

  • Same concentration/ volume of weed killer
  • same area of grass
  • same length of time between application and measuring effect
• indicator species

  • used to detect pollution (living organism)
  • mayfly nymph = no pollution
  • blood louse = high pollution
• Deforestation:

  • Destroyed for the land for farming or buildings
  • Destroys habitats/reduced biodiversity
  • increases carbon dioxide as less CO2 removed as there’s less trees
• Pesticides - kill pests

  Fertilisers - provide nutrients for growth of crops (NPK)

  Bioaccumulation - pesticides can enter food chain + Reach toxic levels
• Pesticides are:-

  1. Persistent / don’t break down
  2. accumulates in food chain
  3. to toxic levels
• Anything on land can leech/ run off into water when it rains
• Pest control:

  Chemical:

  Can pollute environment + harm many living things

  Biological:

  No pollution / use of chemicals