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122 Cards in this Set
- Front
- Back
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Additive exposure
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2+2=4
The combined effect of the chemical is equal tot he sum of each chemical acting independently Examples: organic solvents used together or multple pesticides used together. |
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Antagonistic exposure
example? |
2+(-1) =1
Two chemicals, when together, interfer with each other's action. Alcohol: ethanol preferentially metabolized over methanol Chelating agents (help pull metals out of the body) Atropine and organophosphates (nerve agents) |
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Synergistic exposure
example? |
2+2=8
The combined effect of two chemicals is much greater than the sum of the effect of each agent acting independently. smoking and asbestos acetaminophen (tylenol) and ethanol |
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Potentiating exposure
example? |
2+0=10
One substance that does not have a toxic effect on a certain organ system, when in combination with another chemical, makes the toxic effect greater. carbon tetrchloride and IPA |
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Carcinogens
as it relates to a dose-response curve? |
do not follow a dose-response curve. This is because of their long latency period and lack of threshold.
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Epigenetic
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Do not act directly on genetic material (asbestos and estrogen)
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Genotoxic / mutagen
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Acts directly by altering DNA (nitrosomines, epoxides, and nickel)
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Clastogen
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occurs at the chromosomal level
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Stages of cancer
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Initation: damage to cellular DNA
Latency period: remains dormant Promotion: induction of tumor cell growth Progression: progression of tumor tissue to neoplasm |
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A steep dose response curve indicates ?
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small varaibliy in reponse.
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Shallow dose response curve indicates ?
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wide varability
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General rule
If chemical has same degree of toxicity across specieis, |
then probably similar toxicity to humans.
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Carbon Tetrachloride uses.
acute effects: chronic effects: |
clear, colourless, volatile liquid with a characteristic, sweet odour. Used as a precursor to refrigerants and widely used as a dry cleaning solvent.
acute effects: CNS - excitability, dizziness, narcosis chronic effects: liver damage |
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Systemic toxicity
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adverse effects affecting whole system within the body.
i.e. organic solvents effect kidney & liver |
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Local toxicity
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adverse effects affecting soley site of exposure.
i.e. organic solves may cause dermatitis |
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What is an example of an additive effect?
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organophosphates: malathion and parathion
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What is an example of an antagonistic effect?
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Alcohols: ethanol preferentially metabolizes over methanol
Chelating agents: dimercaprol preferentially binds Pb, As, Hg. Atroine and organophosphates |
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What is an example of an synergistic effect?
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Asbestos lung cancer:5x.
Smoking lunch cancer:11x Smoking & asbestos: 55x Acetaminophen and ethanol |
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What is an example of a potentiating effect?
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TCE increases liver toxicity of CCl4
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In vitro
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Experiments conducted outside living bodies. Within a glass or test tube. Artificial environments.
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In vivo
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Experiments conducted within living bodies.
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Metabolism
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The transformation of chemicals in the body aka biotransformation.
i.e. make chemicals more water soluble for excretion. |
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What is an enzyme?
Give an example. |
Biochemical (frequently a protein) that speeds up a biochemical reaction.
CYP 450 system in liver generally "detoxifies" substances. Substance more easily excreted through kidneys (urine) or liver (bile). |
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Phases of metabolism
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Phase 1: conversion of compound to metabolites.
Phase 2: coupling of compound or metabolite to another endogenous substance. |
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Toxicokentics.
Study of what? |
The study of toxins through the body.
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General toxicology facts.
Water soluble compounds travel from? |
Water soluble go directly from small intestine to the liver via blood.
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Contact dermatitis
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Generally found in area of exposure.
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Photosensitization
examples? |
Photoactive chemical absorbed into skin, sunlight activates.
St Johnswort, horsebrushes, tetracycline, anthracene, pitch (tar) |
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Urticarial reaction
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Smooth, slightly elevated patches (wheals) that are redder or paler than surrounding skin.
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Lipid soluble (dissolved in fat) are absorbed _ compared to water solube substances.
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Lipid substance are absorbed much quicker than water soluble.
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Nonpolar substances are _ absorbed ?
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Readily absorbed.
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Tachydyrshythmias (abnormal heart rate) is associated with what chemicals?
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Chlorinated hydrocarbon, aromatic solvents, aliphatic hydrocarbons, halo-fluorocarbons.
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Cardiomyopathy (damage to heart muscle) is associated with what chemicals ?
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Lead, arsenic, cobalt, alcohol
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Carbon monoxide cause damage to?
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Blood vessels
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Lipid soluble (dissolved in fat) are absorbed _ compared to water solube substances.
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Lipid substance are absorbed much quicker than water soluble.
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Nonpolar substances are _ absorbed ?
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Readily absorbed.
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Tachydyrshythmias (abnormal heart rate) is associated with what chemicals?
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Chlorinated hydrocarbon, aromatic solvents, aliphatic hydrocarbons, halo-fluorocarbons.
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Cardiomyopathy (damage to heart muscle) is associated with what chemicals ?
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Lead, arsenic, cobalt, alcohol
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Carbon monoxide cause damage to?
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Blood vessels
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Epigenetic.
Ex. |
Does not act directly on generic material.
Ex: asbestos , estrogens |
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Genotoxic
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Acts directly by altering DNA.
Nitrosamines,epoxides, nickel |
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Clastogen
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Occurs at the chromosomal level.
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<4 carbons
5-6 carbons >16 carbons |
< 4 carbons: gas
5-6 carbons: liquid >16 carbons: solid |
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n-hexane causes
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Peripheral neuropathy. Demyelination of peripheral nerves.
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Carbon disulfide causes?
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Brain damage, peripheral neuropathy, neuobehavioral dysfunction, ocular and auditory effects.
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Benzene is used in ?
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Printing, paint, rubber, gasoline, adhesives.
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Benzene causes ?
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Aplastic anemia-bone marrow doesn't produce enough blood cells to replenish.
Leukemia Toxic to bone marrow. |
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Carbon tetrachloride
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"perfect solvent"
Liver damage. Fatty liver. |
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Vinyl chloride causes
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Angiosarcoma
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What are the primary uses of ethylene glycol?
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it is a colorless, odorless, syrupy liquid. It is used as anti-freeze in heating and cooling systems, to de-ice aircraft wings, as an industrial solvent and in paint and plastics.
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Toxicology
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The study of poisons. Studies how living organsims physically respond to positions.
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Xenobiotic
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Foreign chemical to the body not produced by the body or expected to be there.
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Toxin
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Substance that interferes with the normal functions of the body.
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Dose response curves.
Steep curve indicates ? Shallow curve indicates ? General rule: if chemical has the same degree of toxicity across species, then... |
Steep curve indicates small variability.
Shallow curve indicates wide varability in responses. General rule: if chemical has same degree of toxicity across species, then probably similar toxicity to humans. |
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Acute exposure
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Exposures over a short period of time, ie. minutes to hours.
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Subchronic Exposures
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Exposures of medium duration (days to weeks or months).
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Chronic Exposures
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Exposures over a long period of time.
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Carbon tetrachloride
Acute effects Chronic effects |
Acute: CNS: excitability, dizziness, narcosis.
Chronic: liver damage |
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Systemic toxicity
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Adverse effects affecting whole system within the body. Example, organics solvents effects kidneys and liver.
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Local toxicity
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Adverse effect affecting soley site of exposure. Example, organics solvents may cause dermatitis.
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Skin exposures.
_ _ are absorbed more quickly than water soluble substance. _ substances are readily absorbed. |
Lipid soluble (dissolved in fat) are absorbed more quickly.
Nonpolar substances are readily absorbed, |
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Nephrotoxins
Name 2 chemical groups and associated health effects. |
Kidney toxins.
Heavy metals- kidney vasoconstriction, block sulfhyxryl group. Halogenated aliphatic solvents-carbon tetrachloride & chloroform, metabolized to phosgene. |
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Neurotoxins.
Neuropathy is caused by ? |
Neuropathy (death to nerve cell)- organic & elemental Hg, trimethyltin, Al, Mn, methanol.
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Neurotoxins
Axonapathy is caused by? |
Axonapathy (damage to axons)- acylamide, n-hexane, carbon disulfide, organophosphate insecticides.
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Neurotoxin
Myelinopathy |
Myelinopathy (damage to the myelin)- trimethyltin, hexachlorophene,lead
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Common hepatoxins
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Liver toxins: CCl4, halothane, TNT, methylene dianiline (MDA), vinyl chloride -liver cancer, ethanol, acetaminophen.
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Immunotoxins
Examples. |
Damage to the immune system. Innate immunity is present at birth. Adaptive immunity is reaction to antigens. Example : benzene, perchlorate, anti-neoplasticism drugs, ionizing radiation, ethylene oxide.
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Acute poisoning remedies (3)
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Gastric lavage: insertion of a tube in to the stomach.
Activated charcoal- swallow activated charcoal powder, adsorbs toxins. Cathartic (saline)- increase stool output. |
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Irritation
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Inflammation, congestion, edema
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Asphyxiants
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Substances that prevent oxygen from reaching cells.
Simple asphyxiants : displace o2 in atmosphere. Ex- N2, Ar2, He Chemical asphyxiants: prevents o2 in blood reaching the cells. Ex- CO, HCN, H2S. |
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Teratogen
Examples |
Substances that cousr birth defects in developing fetus.
Ex: thalidomide, ethanol, lead. |
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Carcinogen
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Benzene
Cadmium Cigarette smoke Asbestos Vinyl chloride Radon Chromium Arsenic Soots Mineral oils Wood dust Beryllium Nickel compounds |
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Stages of cancer
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Initiation: damage to cellular DNA
Latency period: disease remains dormant Promotion: tumor cell growth begins Progression: tumor tissue becomes neoplasm (abnormal growth) |
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Ames test
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Test to determine mutagenicity of substance.
Bacteria salmonella typhimurium subjected to substance. DNA of bacteria is examined for damage. |
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Pneumoconiosis
Proliferative (progressive, complicated) |
Dusty lung disease
Silica: silicosis Asbestos : asbestosis Coal: black lung, anthracosis Bauxite (Al ore): shaver's disease |
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Nonproliferative (nonprogressive, simple)
Talc causes ? |
Talcosis
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Nonproliferative (nonprogressive, simple
Tin ore causes ? |
Stannosis
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Nonproliferative (nonprogressive, simple
Iron oxide |
Siderosis
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Biological pneumoconiosis
Cotton dust causes ? |
Byssinosis
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Biological pneumoconiosis
Moldy sugarcane causes ? |
Bagassosis
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Organophosphate
Basis for ? Examples? Interfers with? Causes ? |
Basis for many herbicides, pesticide & insecticides.
Ex: parathion, malathion Interferes with chloineaterase. Causes erratic signals from nerve endings. Sx- twitching, weakness, tremors. Irreversible. |
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Organochlorines
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Chlorinated hydrocarbons.
Examples: DDT, chlordane, aldrin, kepone. Stored in body fat. Nonpolar, lipid soluble Hepatoxins, nephrotoxic, neurotoxic |
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Metals
Organic metals are typically ? Are metals easily excreted from the body ? |
Organic metals generally more toxic than inorganic metals (methyl mercury,tetraethyl lead).
Metals not easily excreted. Most toxic (lead, arsenic) Chelation -binding of metals for excretion, also binds essential metals. |
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Cadmium
Uses? Acute health effects? Chronic health effects? BEI taken from ? |
Uses: Smelting, electroplating, soldering, welding.
Acute exposures: pulmonary edema Chronic exposures: pulmonary emphysema, lung cancer and kidney problems. BEI: blood and urine |
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Inorganic lead
Uses? Chronic exposures affect? |
Uses: smelters, battery production, firing ranges, lead paint removal, welding.
Chronic exposures affect nervous system, decrease male sperm count, accumulate in fetus. Affects metal development of children. BEI : lead in blood. |
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Inorganic arsenic
Uses? Exposure routes? Acute exposures? Chronic exposures? BEI? |
Smelting operations, battery production,
Exposure routes: inhalation, ingestion. Acute exposures may be lethal. Chronic health effects: Cancer -lung, liver, leukemia. Hepatoxin, Nephrotoxin. BEI: arsenic in urine end of workweek. |
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Beryllium
Used as ? Acute effects? Chronic effects? |
Very light weight used as hardening agent.
Acute exposures can cause pneumonitis. Sensitizer Chronic exposures: berylliosis, scarring of lungs. Lung cancer. |
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Asbestos
Uses? Types? Health effect? |
Used in commercial fire insulation. Still used in brake manufacturing.
Types: chrysotile, amosite, crocidolite, tremolite. Fibers enter the lung causing scar tissue to form. Health effects: asbestosis, mesothelioma, lung cancer. 30 years latency period. |
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Solvents.
Major effects on? CNS effects increase with ? |
Major effects on CNS.
lipophilic (fat loving)- seek fatty membrane of nerve. CNS effects increase with length of carbon chain. CNS effects increase with halogenated compounds, especially chlorine. Unsaturated compounds tend to enhance CNS depression. |
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Aromatic hydrocarbons
Contain ? Health effects? Polycyclic aromatic hydrocarbons (PAH) or polynuclear aromatics (PNA) contain? Health effects ? |
Contain a benzene ring
PAH or PNA contain 2 or more benzene rings. CNS, Hepatoxins, renal effects, bone marrow, blood forming systems. Many are carcinogenic. |
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Benzene
_ aromatic hydrocarbon Exposure routes? Carcinogen BEI |
Simplest aromatic hydrocarbon
Exposure routes: inhalation, skin absorption Metabolized in several steps- 60% becomes phenol. Carcinogen- leukemia BEI: S-phynylmercapturic acid in urine end of shift. T,t-muconic acid in urine end of shift |
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Coal tar pitch volatiles
Uses? Composed of? Health effects? |
Uses- coking, paving, roofing, al smelting.
Composed of - aromatic and PAH Health effects: lung, kidney, bladder, skin. Carcinogen in lungs, kidney skin |
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Halogenated hydrocarbons
Health effects? Chlorinated compounds? Carbon tetrachloride ? |
Health effects: CNS, Hepatoxins, nephrotoxins.
Chlorinated compounds most common. Carbon tetrachloride CCl4- potential Hepatoxin Methylene chloride CH2Cl2- metabolizes into CO. |
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Ethylene oxide
Uses? Physical properties ? Health effects? |
Uses- solvents, detergents, antifreeze.
Sterilizer in health care and other industries. Volatile, explosive and reactive. Health effects: Hepatoxin, Nephrotoxin, neurotoxin. Carcinogen causing leukemia, linked to miscarriages. |
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Formaldehyde
Uses? |
Preservative in medical labs, found in building materials, used ad fumigant.
Exposures: inhalation, skin absorption. Health effects: sensitizing agent can cause immune system response, nasal and lung carcinogen, lethal when swallowed, dermatitis. |
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Benzene
Acute exposures to high concentrations can results in? |
Acute exposure: irritation of the skin, eyes and respiratory system and in CNS depression.
Chronic exposure: bone marrow depression and leukaemia, particularly acute myeloid leukaemia, and possibly an increased risk of non-Hodgkin's lymphoma and multiple myeloma. |
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What does the term sequestration mean?
what are a couple examples? |
After exposure to a substance has stopped, it finds a way to hang around longer in the body and therefore increases exposure duration.
DDT and PCBs stored in fats Heavy metals stored in bones Dusts overloading lung capability to remove. |
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What are 4 OSHA regulated reproductive substances?
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Ethylene oxide
DBCP (dibromochloropropane) soil fumigant Radiation Lead |
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Urticarial reactions?
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reaction on the skin - smooth, slightly elevated patches (wheals) that are redder or paler than surrounding skin.
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What type of substances are absorbed more readily?
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lipid soluble (dissolved in fat) are absorbed more quickly than water soluble substances.
Nonpolar substances are readily absorbed |
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What is tachydyrshythmias?
what are a couple examples? |
abnormal heart rate
chlorinated hydrocarbons, aromatic solvens, aliphatic hydrocarbons, halo-fluorocarbons. |
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What is cardiomypathy?
examples |
damage to the heart.
lead, arsenic, cobalt, alcohol |
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What form of metal is typicaly more toxic?
organic or inorganic? |
Generally, ogranic metals are more toxic than inorganic.
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What are simple asphyxiants?
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Displace O2 in the atmosphere. Physiologically inert - argon, N2, He
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What are chemical asphyxiants?
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Prevents O2 in blood reaching cells,
CO, HCN (Hydrogen cyanide), H2S (Hydrogen sulfide) |
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Elemental Hg is not absorbed ot toxic when?
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ingested
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What is oliguria?
What is an example ? |
low output of urine.
Carbon tetrachloride |
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What are the halogens?
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fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
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Chronic health effects of ethylene glycol?
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possible teratogen and reporductive hazard.
Repeated exposures affect kidney and brain. |
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Following the ingestion of ethylene glycol what are the symptoms of poisoning?
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intoxication and vomiting, acidosis, cardiovascular dysfunction and kidney failure.
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General tox rules:
Non-soluble substances tend |
Non-soluble substances tend to be less toxic.
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General tox rules:
Chemicals tend to be most toxic through? |
exposure route permitting greatest entry (often the lungs).
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Organic metals are generally?
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more toxic than inorganic metals (methylmercury, tetraethyl lead)
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What is apoptosis?
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cellular suicide
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What is necrosis?
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inflamed cell death
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Cirrhosis (fibrosi) is the replacement of?
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functioning hepatocytes with fibrotic tissue
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Neurontrasmission toxicity (interrupt signal).
Anti-cholinesterase agents inhibit |
an enzyme from breaking down acetycholine, increasing the level and duration of action of acetylcholine (ACh). ACh is a neurotransmitter in both the PNS and CNS.
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Name 2 anti-cholinesterase agents ?
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organophosphate and carbomate pesticides.
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Neurontransmission toxicity
Name a chemical that acts as a blocking agent for blocking acetylcholine (neurotransmitter in PNS and CNS) ? |
Atropine.
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Neurontransmission Toxicity?
What results from exposure to a de-polarizing agent? Example of a de-polarzing agent? symptoms? |
the resting potential by altering ther permeability of the cell membrane.
Example: DDT, DDT partially depolarizes the membrane, as a reults, the neuron is in an almost continuous state of excitation. An individual may develop persistent tremors, irritablity, hypersensitiviey to external stimuli. |
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Methylene chloride metabolizes to form?
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CO
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Carbon disulfide causes?
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Organic brain damage, peripheral neuropathy, neuobehavioral dysfunction, ocular and auditory effects.
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