1
Q
environmental toxicant
A
a chemical that is released into the environment and can produce adverse health effects on living organisms
2
Q
acute toxicity
A
refers to a single exposure to a chemical, and often a large dose of the chemical
3
Q
chronic toxicity
A
repeated exposure to small doses of a chemical over a long period of time (ex: eating a contaminated food)
4
Q
gaseous air pollutants
A
- class of air pollutant
- carbon monoxide and CO2
- nitrogen and sulfur oxides
- hydrogen sulfides
5
Q
particulate matter
A
- class of air pollutant
- mixture of tiny particles composed of non-gaseous pollutants
6
Q
natural sources of air pollutants
A
volcanoes, forest/prairie fires, dust storms
7
Q
anthropogenic air pollutants
A
- man-made air pollutants
- heating and power → combustion of fossil fuels releases CO2, CO
- automobile exhaust → releases smoke, lead particles
- industrial processes → release a wide range of pollutants
8
Q
human health and air pollution
A
primary health effect is chemical irritation of the respiratory tract
9
Q
tobacco smoke
A
exposure to environmental tobacco smoke carries the same health risks as directly smoking
10
Q
insecticides
A
chemicals used to kill insects or to make insects unable to reproduce or develop normally
11
Q
organochlorine insecticides
A
- type of insecticide
- increase sensitivity of neurons, resulting in increased CNS stimulation
- ex: DDT - insects developed resistance, levels in food were increasing
- developmental and reproductive effects on animals
12
Q
organophosphorus insecticides
A
- type of insecticide
- first synthesized in WWII
- requires metabolic activation to work
- relatively unstable and breakdown in the environment
- irreversibly inhibit acetylcholinesterase, leads to an increase in acetylcholine in nervous tissue
- results in decreased HR, difficultly breathing
13
Q
herbicides
A
- chemicals capable of killing or injuring plants
14
Q
agent orange
A
- herbicide used in Vietnam war as a defoliant to make it easier to spot targets hidden by trees
- mimics plant growth hormones, causing uncontrolled growth leading to plant death
- major concern is presence of TCDD (introduced during manufacturing process)
15
Q
TCDD toxicity
A
- binds to a receptor known as the aryl hydrocarbon receptor, which is involved in the expression of many genes required for normal cellular function
- manifests as aschloracne (severe acne)
- impairs liver and CNS function
16
Q
paraquat
A
- type of herbicide
- causes cellular damage, and when ingested, it causes immediate burns of the mouth and stomach
- primary target is the lungs, where cellular damage results in development of fibrous tissues that inhibit the ability to breath
17
Q
lead
A
- exposure sources: old paint, industry (lead-acid car batteries), and automobile exhaust (lead was used in gas as an additive until the 1970s)
18
Q
lead toxicity
A
- CNS → permanent brain damage
- motor nerves → degeneration of motor nerves
- kidney → kidney dysfunction
- anemia → decreases biosynthesis of heme
- treatment → chelating agents
19
Q
mercury
A
- can be found in water and air
- main source of contamination is industry (used in preparation of chlorine and sodium hydroxide)
- major source of exposure is ingesting fish from mercury contaminated water
20
Q
mercury toxicity
A
- methyl mercury → mercury is converted to methyl mercury by bacteria and fish in water; targets the CNS; leads to nerve cell death
- mercuric mercury → exposure is from vapors containing mercury; toxic to kidneys
- treatment → chelating agents for mercuric mercury poisoning; charcoal for methyl mercury poisoning
21
Q
bisphenol A (BPA)
A
- used to make clear hard plastic known as polycarbonate (water bottles, baby bottles)
- found in epoxy resins (line food cans)
- main source of exposure is through diet
- can bind to the estrogen receptors and mimic effects of estrogen
- could play a role in reproductive cancers and fertility problems
22
Q
BPA toxicity
A
greatest health risk is to infants
23
Q
how pharmaceuticals enter the environment
A
- human prescriptions to treat disease → admin and excretion of drugs
- inappropriate disposal of unused meds
- manufacturing processes → can accumulate in surface/ground water
- treatment of pets→ excreted into surface/ground water
- aquaculture → use of antibiotics in aquaculture
- use in agriculture → accumulate in ground water/soil
24
Q
neuroactive drugs
A
- antipileptics, antidepressants, antipsychotics
- detected in surface water, ground water, and soil
- sewage plants reduce, but don’t eliminate, this group of drugs
- exposure is minimal
25
steroid hormones
- steroid hormones of most concern are estrogenic compounds
- major concerns are the synergistic effect of human exposure to estrogens and the deleterious effect of low concentrations of steroid hormones on reproductive capacity and sexual maturation of aquatic animals
26
antibiotics
major source in the environment is in agriculture
27
hypertensive drugs
hard to determine concentration in seafood we eat
28
analgesics and anti-inflammatories
- most commonly observed in the environment
29
concentration of pharmaceuticals in the environment
- extent of use
- dose administered
- persistance in the environment
30
mitigation of risk
- reduce discharge from factories
- effect on the environment should be considered in the licensing process
- remove pharmaceuticals from sewage water
- unused pharmaceuticals must be taken back and properly disposed of
31
3 key features of all cancers
- cell growth and division → the ability to proliferate indefinitely
- invasion → ability to invade surrounding normal tissue
- metastasis → ability to spread throughout the body
32
carcinogenesis
initiation of cancer, multistage process
33
3 main steps of carcinogenesis
1. initiation → ultimate carcinogens react with a DNA molecule, damaging the DNA, if no DNA repair happens then permanent DNA damage, cells must divide to make the genetic change (mutation) permanent
2. promotion → selective growth of initiated cells, tumour promoters (hormones) induce changes in gene expression that control cell growth
3. progression → rapid growth of tumours once they are established
34
causes of cancer
- genetics
| - environmental factors → environmental chemicals, diet, infections
35
environmental factors → tobacco use
- smoking causes many cancers
| - development of cancer will depend on the tar content of the cigarettes smoked
36
environmental factors → diet/obesity
- saturated animal fat and red meat are strongly linked to cancer of the colon, rectum and prostate
- high intake of salt has been linked to stomach cancer
- fruits and veggies contain constituents that block cancer-inducing chemicals
37
environmental factors → occupational factor
carcinogens in the workplace are an extreme hazard
38
environmental factors → infections
- both bacterial and viral infections have been linked to cancer
39
cancer prevention
- get vaccinated
- eliminate use of tobacco products
- eat healthy
- avoid excess exposure to sunlight
- moderate alcohol intake
- improve exercise habits
40
goals of chemotherapy
- prevent the cancer
- cure the cancer
- control the cancer
- relieve symptoms
41
chemotherapy
- act by slowing the growth of rapidly dividing cells
- inhibit DNA synthesis, protein synthesis, or cell division
- alylating agents
- mitotic inhibitors
- hormones and hormone antagonists
- biologicals
42
principles of chemotherapy
- benefit-risk assessment
| - combination chemotherapy → development of resistance, occurrence of toxicities
PHAR 100
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