Pesticides

Question 1

what’s the deal with pesticides? What does it aim to do?

Answer 1

• pesticides are a way of controlling unwanted pests
• there are 3 types of pesticides: fungicides, herbicides, and insecticides.
  fungicides: kills fungi
  herbicides: kills unwanted plants
  insecticides: kills unwanted insects
• it is

Question 2

what are pests?

Answer 2

species that compete with us for limited sources

Question 3

what were DDTs? the benefits and the harms? Why was it banned? why did people oppose the ban?

Answer 3

BENEFITS:

• was considered harmless to humans
• was inexpensive to make
• invented by Paul Muller, it was known as the greatest medicine invented because it killed off pests that could transmit diseases to humans(lice, mosquitoes)

HARMS:

• DDTs was a persistent insecticide that stayed in an ecosystem for years, it accumulated in their fat tissues,
• organisms higher in the food chain were affected the most, for example, the bird, their eggs were very thin they often died before hatching. Countries started to ban the use of DDTs when they realized the harms.

People opposed the ban because it killed off many diseases spreading pests, it was harmless to humans, it was effective and inexpensive.

Question 4

what are the challenges? what would make a good pesticide? Why are pesticides harmful to birds at or near the top of the food chain?

Answer 4

• inexpensive and effective
• tests for safety
• consumer use
  determining the effects of the chemicals on the environment

Question 5

what is “organic agriculture”?

Answer 5

the use of natural processes and cycles to reduce and minimize the environmental damage and optimize productivity

Canadian General Standards Board: “organic” is legislated.
- reduce or eliminate reliance on practices using natural or syntehtic compounds that may harm beneficial organisms within the soil. deplete non renewable resources, compromise water and air quality, and through misuse could endanger the health of agricultural workers, the agricultural community, or the consumer.

Question 6

what are some ways of reducing the use of pesticides in your homes/yards?

Answer 6

• handpick weeds
• plant varieties of plants
• biological control
• plant in cycles

Question 7

what is one example of a pesticide that caused harm to the whole food chain?

Answer 7

in 1955, the WHO sprayed Dieldrin on north Borneo, a pesticide similar to DDT, to control malarial mosquitoes. This lead to a chain reaction: the mosquitos almost completely wiped out-> all lizards that fed on mosquitos died->island cats that ate lizards died as well-> which led to the explosion of population of rodents that carried plague fleas. the issue was solved when the British Air Force(requested by the WHO) parachuted cats onto Borneo.

Question 8

what is bioaccumulation? Biomagnification? differences?

Answer 8

bioaccumulation refers to the accumulation of a chemical or substance in an organism. Biomagnification refers to the accumulation of a chemical or substance in a number of organisms

Question 9

what are toxins?

Answer 9

toxins are poisonous substances produced by living things

Question 10

is organic farming a better method of growing food than conventional farming? Why?
How can you reduce the use of pesticides?

Answer 10

Yes because it serves to preserve the water and soil quality as well as the organisms and the environment.
Handpicking weed
Planting varieties
Planting in cycles
Biological control