Flashcards in Q 2: Lecture 2 Deck (12)
Pesticide in cigarettes?
Nicotine used as pesticide for 100's of years. Since late 1800's. Degrades relatively quickly.
High toxicity to mammals
How much nicotine in cigarettes?
1 mg on average 0.2-2.0 mg per canadian cigarette
(Water flees) like little shrimp
How is nicotine a stimulant?
acts by binding to the nicotinic acetylcholine receptor on the post-synaptic membrane of neurons. Causes continuous firing of the nerve signal resulting in over stimulation.
Can be lethal at about __ to ___ mg
a 60 mg dose= an oral LD50 of around 0.8 mg/kg
Neonicotinoids used as pesticide since early 2000. It is Persistent
Most widely used category of pesticides on global basis(passed herbicides)
Low toxicity to mammals
Incredibly poisonous to insects
Is Neonicotinoids persistent?
No- Degrades fairly quickly
Neonicotinoids are ___ times more potent then Nicotine.
EU ban because of high rate of Bee Deaths
Ontario first in North America to ban
Next "silent spring" =
Neonicotinoids in Sask
65% of water bodies had Neonictinoids present
944 ng/L, nearly 1 mg/L in some places
Used on Canadian prairies as seed treatment
-Coats seeds, extremely water soluable(systemic)
- as plant grows it brings the pesticide into it protecting itself from insects.
-95% of pesticides leak out into wetland and isnt used by plants.
- Breaks down in sunlight, so in murky water you can get buildups after years.
- Millions of KG'S used per year in Canada
- SE Saskatchewan has most dense concentrations
- Levels that hurt Aquatic Invertibrates well below average in Saskatchewan Wetlands.