Introduction to Toxicology: Occupational & Environmental Flashcards
EFFECT: Dose
AFFECT: CNS
EFFECT: Duration of Exposure
AFFECT: Liver & Kidneys
EFFECT: Vulnerability of individuals
AFFECT: Reproductive System
“safe“ chemical exposure limits for workers
Permissible Exposure Limits
deals with the effects of chemicals found in the workplace.
Occupational Toxicology
deals with the deleterious impact of chemical pollutants in the environment, on living organisms.
Environmental toxicology
ability of chemical agent to cause injury/disease in a given situation or
setting
Hazard
expected frequency of the of the occurrence of an undesirable effect
arising from exposure to a chemical or physical agent
Risk
what are the Routes of Exposure
Industrial: Inhalational > Transdermal Route > Oral
An exposure to a toxic substance that is
absorbed by the target human or animal
results in a _____
Dose
single exposure or multiple exposure over a brief period of time
Acute Exposure
single or multiple exposure over a longer period of time
Chronic Exposure
__________ exhibit environmental persistence and can accumulate.
Poorly degraded chemicals (by abiotic or biotic pathways)
Methyl mercury discharges –>
neurotoxic
Lipophilic substances:
organochlorine pesticides
bioaccumulate in body fat –>
endocrine disruption, neurological disorders, and carcinogenesis
_____ concentrates the chemical in organisms
Biomagnification, higher on the food chain
Colorless, tasteless, odorless and nonirritating gas
Carbon Monoxide (CO)
Byproduct of incomplete combustion
Carbon Monoxide (CO)
Has teratogenic potential
Carbon Monoxide (CO)
acquired through gas stoves; generators and other gasoline powered equipment; automobile exhaust and tobacco smoke
Carbon Monoxide (CO)
CO combines tightly but
reversibly with the oxygen
binding site of _____, resulting in ______
hemoglobin (Hb), Carboxyhemoglobin
CO affinity
220x oxygen
most affected organs by CO poisoning
Organs with the highest
oxygen demand (Brain,
Heart and Kidneys)
Symptoms of hypoxia
Carbon Monoxide (CO)
Psychomotor impairment
Carbon Monoxide (CO)
Headache and tightness in the temporal area
Carbon Monoxide (CO)
Confusion and loss of visual acuity
Carbon Monoxide (CO)
Tachycardia, tachypnea, syncope, and coma
Carbon Monoxide (CO)
specific antagonist for CO
oxygen
Deep coma, convulsions, shock and respiratory failure
Carbon Monoxide (CO)
____ concentrations of oxygen for a ___ amount of time only
high, short
Treatment for CO poisoning
Hypothermic therapy
Colorless irritant gas
Sulfur Dioxide (SO2)
Generated primarily by the combustion of sulfur containing fossil fuel
Sulfur Dioxide (SO2)
eye, nose and throat irritation, reflex
bronchoconstriction and increased bronchial secretions
Sulfur Dioxide (SO2)
May initiate or exacerbate Bronchial Asthma
Sulfur Dioxide (SO2)
Delayed onset pulmonary edema
Sulfur Dioxide (SO2)
Treatment for SO2
Treatment is supportive, non specific
high solubility of SO2 in ______
moist membranes forms sulfurous acid.
severe irritant on the eyes, mucous membranes, respiratory tract and skin
Sulfur Dioxide (SO2)
90% of inhaled form is absorbed in the ____, causing ____
Upper Respiratory tract causing Acute Irritant Asthma
Brownish irritant gas associated with fires
Nitrogen Oxides (NO2)
Farmers exposed to fresh silage, Miners exposed to diesel equipment, automobile and truck traffic emissions
Nitrogen Oxides (NO2)
Relatively insoluble deep lung irritant
Nitrogen Oxides (NO2)
Inhalation to this gas damages the lung infrastructure that produces the ____ necessary to allow smooth and low effort lung alveolar
expansion
Nitrogen Oxides (NO2), surfactant
Irritation of eyes and nose, cough, mucoid or frothy sputum production , dyspnea and chest pain; Pulmonary edema, fibrotic destruction of terminal bronchioles
acute effects of Nitrogen Oxides (NO2)
Emphysematous changes
chronic effects of Nitrogen Oxides (NO2)
Nitrogen Oxides (NO2) treatment
Supportive, non specific
Bluish irritant gas naturally found in the earth’s atmosphere
Ozone (O3)
caused by Burning of fossil fuel
Ozone (O3)
Emitted from power plants, motor vehicles
and other sources of high heat compounds
Ozone (O3)
Irritant of mucous membranes
Ozone (O3)
Formation of reactive free radicals
Ozone (O3)
Ozone produces _____ irritation to ____ irritation with ____
upper respiratory tract, deep lung, pulmonary edema
Shallow, rapid breathing and decrease in pulmonary compliance is an effect of ____
Ozone (O3)
Irritation and dryness to throat, changes to
visual acuity, substernal pain and dyspnea, ARDS
acute effects of Ozone (O3)
Chronic Bronchitis, Bronchiolitis,
Emphysema
chronic effects of Ozone (O3)
Ozone (O3) treatment
Supportive, non specific
found in industrial solvents, degreasing agents and cleaning agents
Halogenated Aliphatic Hydrocarbons
Carbon tetrachloride, trichloroethylene, chloroform, tetrachloroethylene and 1,1,1 trichloroethane
Halogenated Aliphatic Hydrocarbons
some are associated with renal, prostate and testicular cancer
Human Carcinogens
CNS depression, kidney injury, liver injury,
cardiotoxicity, arrythmia are effects of _____
Halogenated Aliphatic Hydrocarbons
Impaired memory, peripheral neuropathy are effects of ____
Chronic exposure to Halogenated Aliphatic Hydrocarbons
component of gasoline
Benzene
CNS Depression, Nausea, Euphoria,
Locomotor Problems and Coma; Vertigo, Drowsiness and Headache
acute effects of Benzene
Bone Marrow Injury (Aplastic Anemia,
Leukopenia, Pancytopenia, Thrombocytopenia…)
chronic effects of Benzene
targets of benzene
Pluripotent Bone Marrow Stem Cells
it is known as a Potent Clastogen
Benzene
known as Methylbenzene
Toluene
found in paint thinners, nail polish remover, glues, and correction fluid; explosives
Toluene
True or False : Toluene has myelotoxic properties
false, it has No myelotoxic properties
CNS depressant, skin and eye irritant, fetotoxic
Toluene
Associated with rapid loss of consciousness, severe fatigue, ataxia
Toluene
known as a dimethylbenzene
Xylene
Colorless, sweet smelling agent
Xylene
Substitute for benzene in solvent degreasing operations
Xylene
True or False : Xylene has no myelotoxic properties
true
Aryl, carbocyclic or heterocyclic compounds with chlorine substituents
Organochlorine Pesticides
4 classes of Organochlorine Pesticides
- DDT ( chlorphenothane ) and
- Benzenehexachlorides
- Cyclodienes
- Toxaphenes
Known endocrine disruptors in humans and animals
Organochlorine Pesticides
domestic mosquito elimination in malaria
infested regions of Africa
DDT
MOA of ____: interfere with inactivation of the _____ in excitable membranes and cause rapid repetitive firing in most neurons; _____ is inhibited
Organochlorine Pesticides; sodium channel; calcium ion transport
In DDT, ____ is the first manifestation
Tremor
Used against large variety of pests
Organophosphorus Pesticides
acquired through Either via direct contact or via plant systemics
Organophosphorus Pesticides
Based on warfare chemicals like sarin, soman and tabun
Organophosphorus Pesticides
Absorbed via the skin, respiratory and GI tract
Organophosphorus Pesticides
MOA: inhibition of acetylcholinesterase through phosphorylation of the esteratic state
Organophosphorus Pesticides
M U D D L E S:
miosis, urination, diarrhea, diaphoresis,
lacrimation, excitation of the central nervous system, and salivation
If Organophosphorus Pesticides is not reversed, patients will develop ____
neuromuscular transmission failure cardiorespiratory failure, weakness of respiratory muscles and death
Specific treatment and useful antagonists of Organophosphorus Pesticides
physostigmine, pralidoxime
Highly halogenated biphenyl compounds
Polychlorinated and Polybrominated Biphenyls
Used for insulation, fire retardancy
Polychlorinated and Polybrominated Biphenyls
Potent endocrine disruptors; associated with reproductive and teratogenic effects on animal studies
Polychlorinated and Polybrominated Biphenyls
Coolant materials in air conditioning systems
Perfluorinated Compounds (PFCs)
Used as oxygen carrying materials in clinical studies
Perfluorinated Compounds (PFCs)
Used as heat –, stain –, and stick resistant coatings for cookware, fabrics and other materials ( i.e. Teflon)
Perfluorinated Compounds (PFCs)
Human half life of Perfluorinated Compounds (PFCs)
3 years
Long term adverse effect on reproductive function, cellular proliferation and other cellular homeostatic mechanisms
Perfluorinated Compounds (PFCs)
Associated with proliferation of breast cancer cells; renal, ovarian,prostate and Non Hodgkin’s lymphoma
Perfluorinated Compounds (PFCs)
Associated with cholesterol and uric acid abnormalities
Perfluorinated Compounds (PFCs)
causes Polymer Fume Fever
Perfluorinated Compounds (PFCs)
Mimic, enhance or inhibit a hormonal
action
Endocrine Disruptors
Estrogen like or antiandrogenic effects; some affect thyroid functions
Endocrine Disruptors
Includes plant constituents like phytoestrogens, mycoestrogens
Endocrine Disruptors
Synthetic forms are industrial chemicals, persistent organochlorine agents (DDT), PCBs and brominated flame retardants
Endocrine Disruptors
Causes progressive fibrotic lung diseases, lung cancer, mesothelioma
Asbestos
Synergistic effect with cigarette smoking and exposure to radon daughters
Asbestos
Light alkaline metal
Beryllium (Be)
Used in ceramics and alloys; computers; dental equipment; devices that requires hardening like missile ceramic nose cones
and heat shield tiles in space vehicles
Beryllium (Be)
route of Beryllium
inhalation
what class of human carcinogen is beryllium
class 1
Characterized by progressive
pulmonary fibrosis
Beryllium (Be)
what kind of metal is Cadmium (Cd)
transition metal
Found in pigments, low melting point eutectic materials; insolder; in television phosphors; and in plating operations; semiconductors and plastics
Cadmium (Cd)
route of Cadmium (Cd)
Inhalation and ingestion
Chronic exposure to Cadmium (Cd) may lead to ___
progressive pulmonary fibrosis, renal failure
what class of human carcinogen is cadmium
class 1
Any material, natural or manufactured, bearing a size of at least one dimension that lies between 1 to 100 nm in size
Nanomaterials
Gold, silver, cadmium, ceramic, aluminum oxide nanowears , carbon, silicon, and germanium nanotubes, zinc oxide nanocrystal, gold nanowafers, and copper oxide nanocubes
Nanomaterials
routes of exposure of nanomaterials
Inhalational, oral, dermal, parenteral
kidney toxicity
Silica
hepatocellular damage
Zinc oxide
cytotoxic in humans
Multiwalled carbon nanotubes
toxic to lungs and other organs
Titanium dioxide