10 modern pesticides

Question 1

what are pesticides?

Answer 1

“cide”=kill
-weeds=herbicide
-rodents=rodenticide
-fungi=fungicide
-insects=insecticide

Question 2

what was the evolution of pesticide use in north america?

Answer 2

Question 3

what are first generation pesticides?

Answer 3

-inorganic compounds: arsenic, mercury, strychnine
-plant botanical compounds: nicotine, chrysanthamum

Question 4

what are second generation pesticides (1940s)?

Answer 4

-organic synthetic compounds (ex: chlorinated hydrocarbons-DDT mirex)
-today more than 20,000 pesticides exist (canada has >700 actives and >6000 products registered for use)

Question 5

what is the global pesticide pollution risk?

Answer 5

75% of the global agriculture land (approx 28.8 million square kilometers) is at risk of pesticide pollution

Question 6

what is global pesticide use?

Answer 6

on the rise

Question 7

what is canada’s ranking?

Answer 7

ranks 5th for pesticide use per hectare

Question 8

what are the changes in pesticide use in canada 1981-2016

Answer 8

Question 9

what is saskatchewan?

Answer 9

SK is the largest pesticide user and higher insecticide use is linked to landscape simplification

Question 10

what are the significant benefits of pesticides?

Answer 10

1. crop protection against weeds, insects, disease (ex: pests destroy 1/3 of worlds crops)
2. economics: farmers save 3-5$ for every 1$ they spend on pesticides
3. disease control in humans: malaria, dengue, yellow fever, zika virus

Question 11

what is the graph of DDT and malaria control?

Answer 11

Question 12

what is pest resistance?

Answer 12

means there is a constant arms race between pests and chemicals
-but the rate of new commercial pesticides has slower to a near halt (ex; no new herbicide active have been developed in over 30 years)

Question 13

what are problematic pesticides?

Answer 13

pesticide properties that are undesirable for environment and human health
-water soluble: moves into surface/ground water
-lipid soluble: bioaccumulative
-persistent: resists breakdown/metabolism
-toxic: non-selective and high acute or chronic toxicity

Question 14

most pesticides are designed to be _____________

Answer 14

NON-SELECTIVE
-broad spectrum pesticide kills or deters a wide range of organisms
-ideal pesticide would be narrow spectrum or species (pest) specific
-for example: glyphosate, AKA roundup, is a non selective, broad spectrum herbicide

Question 15

where is glyphosate found?

Answer 15

herbicide commonly found in surface waters worldwide at levels above regulatory water quality guidelines (max allowed values)

Question 16

what is glyphosate herbicide used for?

Answer 16

-most widely used for weed control, is toxic to aquatic life including frogs

Question 17

what are other controversial pesticides?

Answer 17

-chlorpyrifos insecticide
-azole fungicides

Question 18

what are chlorpyrifos insecticide?

Answer 18

-most household uses were banned in 2000. Canada recently banned all used in dec 2023
-sprayed on wide range of food crops worldwide to combat roundworms, caterpillars, beetles and weevils and on golf courses to eradicate fire ants
-detected in human urine, maternal and cord blood, breast milk, cervical fluid, sperm and children’s hair
-commonly detected in food
-linked to autism, lower IQs, ADHD, and other neurodevelopmental problems in children

Question 19

what is azole fungicide?

Answer 19

-designed to control fungal disease on crop plants but have endocrine disrupting properties and frequently have negative effects on diverse soil and aquatic microbes

Question 20

what is the summary of pesticide concerns?

Answer 20

-resistance in target pests, outbreaks of non target pests
-economic costs from rising farm input costs
-long term soil degradation and crop yields
-mixture toxicity from formulated products with multiple active ingredients
-water and soil contamination with detrimental effects to invertebrate biodiversity
-direct and cascading indirect effects to biodiversity such as pollinators and birds
-human health concerns: neurotoxicity, developmental toxicity in children, immunotoxicity carcinogenicity, endocrine disruption (particularly in farm workers)