Lec 1- Enviro + Health Intro Jan 9Th

Front 1

What does environmental health encompass?

Back 1

aspects of human health: quality of life, that are determined by physical, chemical, biological, social and psychosocial factors in the environment

Front 2

What is Who's definition of environmental Health?

Back 2

the theory and practice of asserting, correcting, controlling and preventing those factors in the environment that can potentially affect adversely the health of present and future generations

Front 3

What are different kinds of environmental hazards?

Back 3

physical, biological or chemical or cultural

Front 4

Physical Hazards: def

Back 4

occur naturally in our environment

Front 5

Examples of Physical hazards:

Back 5

earthquakes, volcanoes, fire, floods, droughts,

Front 6

How can we prevent physical hazards?

Back 6

We can't! but we can prepare and reduce the risk!

Front 7

What are chemical hazards?

Back 7

synthetic chemical such as pesticides, disinfectants, pharmaceuticals

Front 8

What are biological hazards? examples

Back 8

result from ecological interactions.
- viruses, bacteria, pathogens
Infectious disease: other diseases that parasitize humans, fulfilling their ecological roles

Front 9

Cultural hazards? examples

Back 9

result from the place we live, our socioeconomic status, occupation, behaviour choices
smoking drug us, diet and nutrition, crime, mode of transportation

Front 10

Which is the easiest hazard to avoid?

Back 10

cultural because they can be controlled by our behaviours!

Front 11

Where are infectious diseases mostly found in relation to high death rates? why?

Back 11

15 mil people die a year
- half in developing countries
- because developed countries have better hygiene, access to med, and money

Front 12

Def Vector: ex?

Back 12

an organism that transfers pathogens to a host

ex: mosquito, transfer malaria to humans

Front 13

Why are diseases spreading? (3)

Back 13

- our mobility (travel)
- evolving resistance to anti biotics
- climate change will expand the range of diseases

Front 14

Radon: Def

Back 14

a highly toxic, radioactive gas that is colourless and undetectable without specialized kits,

causes lung cancer

Front 15

Lead poisoning

Back 15

- from water in lead pipes, lead based paint, toys

causes organ damage, learning problems, behaviour abnormalities, death

Front 16

PBDEs

Back 16

comps, TVS, pastics, furniture,


cause: endocrine disruption, brain + nervous system

Front 17

Toxicology: def

Back 17

study of the effects of poisonous substances on humans + other organisms

Front 18

Toxicity

Back 18

degree of harm a toxicant can cause

Front 19

what is toxicity analogous with

Back 19

pathogenicity, virulence

Front 20

toxicant

Back 20

any toxic agent

Front 21

What does environmental toxicology study?

Back 21

deals with toxic substance that are discharged in the environment

the health effects on humans, other animals and ecosystems

- focuses on humans with animals as test subjects

Front 22

Who published Silent Spring and what did it change?

Back 22

Rachel Carson, 1962
- presented the risks of DDT

Front 23

What are different kinds of toxicants?

Back 23

Cacinogens
Mutagens
teratogens
allergens
neurotoxins
endocrine disruptors

Front 24

Carinogens

Back 24

cause cancer

Front 25

Mutagens

Back 25

cause DNA mutations

can lead to severe problems

Front 26

teratogens

Back 26

cause birth defects

Front 27

Allergens

Back 27

over activate the immune system

Front 28

Neurotoxins

Back 28

assault the nervous systme

Front 29

endocrine disrupter

Back 29

interfere with the endocrine system

Front 30

What do endocrine disrupters do? what do they cause?

Back 30

mimic horomones

Cause:
-feminization of males
- drop in sperm
-testicular cancer
-breast cancer rates rise
-neurological problems

Front 31

What does water have toxicants concentrating in it?

Back 31

- runoff carries toxins from large land areas to small volumes of surface water
- chemical leach into soil
- chemical enter organisms though drinking or absorption (aquatic organisms are effecting pollution indicators)

Front 32

Pesticide drift:

Back 32

airbourne transport of pesticides

- synthetic chemical contaminates are found globally

Front 33

How does the persistence of toxicants vary? what effects it?

Back 33

some degrade quick others remain and persist for decades

- rates change: depending on sun exposure, moisture and temp

Front 34

breakdown products:

Back 34

toxicant degrade into simpler products



May be more or less harmful than the original substance.
DDT degrades into DDE, which is also highly persistent.

Front 35

Bioaccumulation

Back 35

toxicants build up in animal tissues

Front 36

Biomagnification

Back 36

toxicants concentrate in top predators

Front 37

What is important to remember about the types of toxicants

Back 37

not all toxicants are synthetic!!!


Chemical toxicants also exist naturally and in our food.
Don’t assume natural chemicals are all healthy and synthetic ones are all harmful.
Some scientists feel that natural toxicants dwarf our intake of synthetic chemicals.
However, others argue that natural substances are easily metabolized and excreted compared to synthetic chemicals which tend to persist and accumulate.

Front 38

What is a useful tool for collecting information on the effect of toxicants

Back 38

wildlife studies, looking at museum data, may have stuff collected before synthetic chemicals were used!
- can compare wild to controlled labs

Front 39

Case histories

Back 39

the process of observation and analysis of individual patients

Front 40

Epidememiology

Back 40

large scale comparisons among groups of people, generally for a long period of time
- studies between exposed vs. unexposed people last for years

Front 41

Manipulative experiments

Back 41

using animals, lab exposes subjects to toxicant and establish causation

Front 42

Dose

Back 42

amount of toxicant received

Front 43

Response

Back 43

type or magnitude of negative effects of the animal

Front 44

Dose- response curve

Back 44

the plot of dose given against response

Front 45

LD50/ED50:

Back 45

LD50/ED50= the amount of toxicant required to kill (affect) 50% of the subjects.

Front 46

Threshold

Back 46

the dose level where certain responses occur

Front 47

What are the three curves for dose response analysis?

Back 47

linear,
dose response curve with threshold]
- u-shaped dose response curve

Front 48

Why do people respond different to hazards?

Back 48

- affected by genetics, surrounding
- people w/ poor health
- sensitivity that varies with age, sex, weight

Front 49

Standard set by health canada are only valid for who?

Back 49

the average adult

Front 50

acute exposure:

Back 50

high exposure
- short period of time

- ingestion, oil spills, nucleur accident

Front 51

Chronic exposure

Back 51

low exposure,
- long period of time

- affects organs gradually,

Front 52

Which is easier to regocnize?

Back 52

acute, easier

chronis: hard to detect + diagnose, cause and effect may not be easily apparent

Front 53

Synergistic effects:

Back 53

interactive impacts that are more than or different from the simple sum of their constituent effect

Front 54

Pesticide drift:

Back 54

airbourne transport of pesticides

- synthetic chemical contaminates are found globally

Front 55

How does the persistence of toxicants vary? what effects it?

Back 55

some degrade quick others remain and persist for decades

- rates change: depending on sun exposure, moisture and temp

Front 56

breakdown products:

Back 56

toxicant degrade into simpler products



May be more or less harmful than the original substance.
DDT degrades into DDE, which is also highly persistent.

Front 57

Bioacumulation

Back 57

when toxicant build up in animal tissues

Front 58

Explain the fact that all toxicants are not synthetic!

Back 58

- chemical toxicant also exist naturally in our food
- natural toxicants probably drarf our intake of synthetic ones
- but natural ones my be more metabolized and excreted compared to synthetics

Front 59

Explain how using wildlife studies is a tool for studying toxicants?

Back 59

musuems do collections that provide data from times before synthetics
- measurements from animals in the wild can be compared to controlled
- concpicuous mortality events can trigger research

Front 60

Whats an example of wildlife research?

Back 60

1998 sea otters diet from toxoplasma from sewage run off containing cat litter

Front 61

case studies

Back 61

the process of observation and analysis of individual patients

Front 62

epidemiology

Back 62

large scale comparisons amount groups of people, generally for a long period of time

Front 63

manipulative experiments

Back 63

lab experiments that expose subject to toxicants to establish causation

- animals often used as modles

Front 64

dose

Back 64

amount of toxicant the test animal recieves

Front 65

response

Back 65

the type or magnitude of negative effects of the animal

Front 66

dose-response curve:

Back 66

the plot of dose given against response

Front 67

LD 50/ ED 50

Back 67

the amount of toxicant required to kill 50% of the subjects

Front 68

Threshold:

Back 68

the dose level where certain responses occur

Front 69

Why do people vary in their response to hazards?

Back 69

Affected by genetics, surroundings, etc.
People in poor health are more sensitive.
Sensitivity also varies with sex, age, and weight.
Fetuses, infants, and young children are more sensitive.

Front 70

Acute exposure =

Back 70

high exposure for short periods of time to a hazard.
Easy to recognize.
Stem from discrete events: ingestion, oil spills, nuclear accident.

Front 71

Chronic exposure =

Back 71

low exposure for long periods of time to a hazard.
Hard to detect and diagnose.
Affects organs gradually: lung cancer, liver damage.
Cause and effect may not be easily apparent

Front 72

Synergistic effects =

Back 72

= interactive impacts that are more than or different from the simple sum of their constituent effects.
Mixed toxicants can sum, cancel out, or multiply each other’s effects.
New impacts may arise from mixing toxicants.

Front 73

Toxicology:

Back 73

“Studies how environmental exposures lead to specific health outcomes, generally in animals, as a means to understand possible health outcomes in humans”.

Front 74

Environmental epidemiology:

Back 74

“Studies the relationship between environmental exposures (including exposure to chemicals, radiation, microbiological agents, etc.) and human health”.

Front 75

Exposure science:

Back 75

“Studies human exposure to environmental contaminants by both identifying and quantifying exposures.