pesticide pollution

Question 1

list the properties of pesticides that cause pollution

Answer 1

1) specificity
2) persistence
3) bioaccumulation
4) biomagnification
5) mobility

Question 2

outline how pesticides affect the specificity of a pollutant b

Answer 2

1) pesticides are not specific to one species therefore will cause harm to other species
2) harm to non-target species is reduced by controlling dose

Question 3

outline how pesticides affect the persistence of a pollutant

Answer 3

persistent pesticides are more likely to remain in the environment long enough to disperse over larger areas and have more time to bioaccumulate

Question 4

outline how pesticides affect the bioaccumulation of a pollutant

Answer 4

1) liposoluble pesticides can dissolve in fats so organisms are unable to excrete or break them down fast enough so it accumulates in the body reaching toxic concentrations

Question 5

outline how pesticides affect the biomagnification of pollutant

Answer 5

pesticide conc may become more concentrated when they are eaten by predators

Question 6

outline how pesticides affect mobility of a pollutant

Answer 6

1) controlled by other properties such as solubility or ease of vaporisation
2) some pesticides may be transported via other animals

Question 7

what are the direct effects of pesticide pollution

Answer 7

1) harm to non-target species by being toxic and inhibit metabolic processes causing ill health
2) food chain impacts from DDT which affected birds as it became concentrated
- low does caused eggs to have thin shells
- higher doses causes sterility or death

Question 8

what are the indirect effects of pesticide pollution

Answer 8

1) a reduction in the population of one species affects the inter-dependant species
ie loss of food supply, pollinations, seed dispersal

2) some species populations increase as predation decreases

Question 9

what are the environmental impacts of organochlorines eg DDT

Answer 9

• used to control pests which transferred human pathogens
  1) high toxicity= deaths of non-target species ie bees and butterflies
  2) high persistence
  3) liposoluble= bioaccumulations and magnification

Question 10

what are the environmental impacts of organophosphates

Answer 10

• neurotoxins which inactivate enzyme acetylcholinesterase damaging nerve function
• took over from organochlorines
• low persistence and liposoluabilty= less bioaccumulation
• high mammalian toxicity- farm workers and risk and non-target species
• chronic exposure led to= impaired memory, depression and behavioural changes

Question 11

outline the environmental impacts of pyrethroids

Answer 11

• synthetic insecticide
  1) high insect toxicity and low mammal toxicity
  2) not persistent
  3) not liposoluble
  4) toxic to fish

Question 12

outline the environmental impacts of neonicinoids

Answer 12

• neuro toxin inhibiting acetylcholinesterase
  1) high insect toxicity but low vertebrate toxicity
  2) persistent and water soluble
  3) toxic to bees
  4) synergistic action with fungicides causing increased toxicity

Question 13

what are the methods to reduce pesticide pollution

Answer 13

1) restrict use
2) use of non-persistent pesticides
3) use of more specific pesticides
4) use of systemic pesticides
5) application timing
6) non-pesticide techniques