1 AOP

Question 1

what is the introduction to chemicals?

Answer 1

-over 100,000 “new” chemicals have been introduced into the biosphere since the “chemical revolution”, with many more produced each year
-society has an increased awareness and concern for the limited or no hazard/risk information for most of these chemicals
-legislation: canadian environmental protection act (toxic substances list), toxic substances control act (TSCA; USA), registration, evaluation, authorization and restriction of chemicals (REACH; EU)
-recognized need for techniques with rapid throughput to evaluate toxicity of chemicals while limiting the use of animal models (e.g. in vitro, in silico approaches)

Question 2

what are the 21st century techniques for chemicals?

Answer 2

Question 3

what is the definition of an AOP?

Answer 3

-a framework that serves as a knowledge assembly, interpretation and communication tool designed to support the translation of pathway-specific mechanistic data into responses relevant to assessing and managing risks of chemicals to human and ecosystem health

Question 4

what is the framework of AOPs?

Answer 4

Question 5

what are the qualities of AOPs?

Answer 5

-AOPs: a given AOP can be relevant to multiple chemicals (e.g. xenoestrogens (ER) and dioxin-like chemicals (AhR))
-AOPs are not necessarily linear pathways, they can be networks (i.e. there can eb several KEs branching out from a single MIE (i.e. pleiotropy))
-homeostatic mechanisms may avoid AOs: the AOP may not progress from a MIE (or early KE) to an AO due to an adaptive response (e.g. upregulation of antioxidant defences)
-modifying factors can alter AOPs: genetic differences (intra- and inter-specific) underlying pathology, environmental factors can magnify responses
-the development of AOPs that involve complex biological and environmental factors can serve to generate hypotheses for further research

Question 6

what is the example of an AOP?

Answer 6

Question 7

what is a pest? what is a pesticide?

Answer 7

-pest=harmful, destructive or troublesome animals, plants or microorganisms

-pesticide=any chemical, physical or biological agent that will kill an undesirable plant, animal or microorganism pest
-goal: selective toxicity to certain species (pests) with decreased toxicity toward non-target organisms
-problem: highly conserved nature of cellular processes targeted by most pesticides (e.g. nervous transmission, electron transport chain, other cellular processes)

Question 8

what are the classes of pesticide?

Answer 8

-insecticides
-herbicides
-fungicides
-rodenticides

Question 9

what is the history of pesticides?

Answer 9

-sulfur: used since 1000 BC: still #1 by weight in california (21 million kg 2016)
-nicotine: first used in 1690 as an insecticide
-1930s: chemical revolution (extensive organochloride synthetic chemistry)
-1980s: integrated pest management (IPM)

-pesticides mainly used today in agriculture, forestry, veterinary medicine, human disease control, aquaculture, and domestic (home and garden)

Question 10

what is the scope of use of pesticides?

Answer 10

Question 11

what is the exposure to pesticides?

Answer 11

Question 12

what are the regulations of pesticides?

Answer 12