Q 2: Lecture 2 Flashcards Preview

Y2 T1 Toxicology 200 > Q 2: Lecture 2 > Flashcards

Flashcards in Q 2: Lecture 2 Deck (12)
1

Pesticide in cigarettes?

Nicotine used as pesticide for 100's of years. Since late 1800's. Degrades relatively quickly.
High toxicity to mammals

2

How much nicotine in cigarettes?

1 mg on average 0.2-2.0 mg per canadian cigarette

3

Dafnia

(Water flees) like little shrimp

4

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.

5

Can be lethal at about __ to ___ mg

50, 100
a 60 mg dose= an oral LD50 of around 0.8 mg/kg

6

Neonicotinoids?

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

7

Is Neonicotinoids persistent?
Is Nicotine?

YES
No- Degrades fairly quickly

8

Neonicotinoids are ___ times more potent then Nicotine.

100

9

Neonicotinoid ban?

BEE DEATHS:
EU ban because of high rate of Bee Deaths
Ontario first in North America to ban

10

Next "silent spring" =

Neonicotinoids

11

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.
-Synergistic


12

Neonicotinoids additive or synergistic?

Synergistic