Basic Toxicology Tutorials-US Nat'l Library of Medicine

[Guest guest]

I received this from a friend of mine....excellent information and I wanted

to share it with the group.

Angel Huggzz

or Angel

===============

Hi ,

I thought you might be interested in this. I hope you are continuing to

improve from your recent pneumonia from Mold exposure.

Click this link to download the three zipped files.

http://sis.nlm.nih.gov/enviro/toxtutor.html

It's well designed in easy to learn increments with short (optional) quizzes

with no worry about grades. Toxicology does not cover effects on chemically

sensitive individuals. You'll learn that inhalation of chemicals bypasses our

bodies defense and can directly enter the bloodstream without detoxification by

our liver.

B. Olinsky, M.S. Environmental Specialist

Toxicology Tutorials

Toxicology Tutor I - Basic Principles

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox1/index.html

Toxicology Tutor II - Toxicokinetics

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox2/index.html

Toxicology Tutor III - Cellular Toxicology

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox3/index.html

You can run the tutorials locally from your computer without the need for

an Internet connection. Each tutorial is made up of about 800 files. Save the

zipped file to your computer, open the zipped file (double click on filename,

e.g. Tox1.zip), then double click on the index.htm file to open and run the

tutorial. You will need a utility such as WINZIP® to open the zipped file.

Tox1.zip 5.4 mb

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox1.zip

Tox2.zip 4.2 mb

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox2.zip

Tox3.zip 6.0 mb

http://sis.nlm.nih.gov/enviro/enviro/toxtutor/Tox3.zip

Last updated: 01 June 2005

First published: 21 April 2005

Copyright, Privacy, Accessibility

U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894

National Institutes of Health, Health & Human Services

Excerpts below. The 1st (of three) section didn't take me too long.

Respiratory Toxicity

Respiratory Toxicity relates to effects on the upper respiratory system

(nose, pharynx, larynx, and trachea) and the lower respiratory system (bronchi,

bronchioles, and lung alveoli). The primary types of respiratory toxicity are:

pulmonary irritation

asthma/bronchitis

reactive airway disease

emphysema

allergic alveolitis

fibrotic lung disease

pneumoconiosis

lung cancer

Toxic effects are primarily of two general types:

hepatic and nephrotoxic effects

carcinogenic or teratogenic effects

systemic or specific target organ effects

THAT'S CORRECT! Toxic effects are primarily systemic or specific target

organ effects. Systemic effects are those in which there may be numerous target

organs. For example, some agents will produce cancer in multiple organs rather

than one specific organ.

The primary difference between acute and chronic toxicity is:

Acute toxicity appears soon after an exposure whereas chronic toxicity

occurs many months or years later.

Different organs are involved.

Acute toxicity occurs only after a single dose whereas chronic toxicity

occurs with multiple doses.

VERY GOOD! The primary difference between acute and chronic toxicity is that

acute toxicity appears soon after an exposure whereas chronic toxicity occurs

many months or years later. The period of time between an exposure and onset

of chronic toxicity is known as the " latency period. "

Police respond to a 911 call in which two people are found dead in an

enclosed bedroom heated by an unvented kerosene stove. There was no sign of

trauma or

violence, a likely cause of death is:

Excess oxygen generated by the combustion of kerosene.

Acute toxicity due to uncombusted kerosene fumes.

Acute toxicity due to carbon monoxide poisoning.

EXCELLENT! Police respond to a 911 call in which two people are found dead

in an enclosed bedroom, which is heated by an unvented kerosene stove. Since

there was no sign of trauma or violence, a likely cause of death is acute

toxicity due to carbon monoxide poisoning. The binding of carbon monoxide to

hemoglobin is 245 times as strong as oxygen. Thus 0.1% carbon monoxide in air

will

bind 50% of the hemoglobin (since air contains 21% oxygen).

Interactions

Humans are normally exposed to several chemicals at one time rather than to

an individual chemical. Medical treatment and environment exposure generally

consists of multiple exposures. Examples are:

hospital patients on the average receive 6 drugs daily

home influenza treatment consists of aspirin, antihistamines, and cough syrup

taken simultaneously

drinking water may contain small amounts of pesticides, heavy metals,

solvents, and other organic chemicals

air often contains mixtures of hundreds of chemicals such as automobile

exhaust and cigarette smoke

gasoline vapor at service stations is a mixture of 40-50 chemicals

Normally, the toxicity of a specific chemical is determined by the study of

animals exposed to only one chemical. Toxicity testing of mixtures is rarely

conducted since it is usually impossible to predict the possible combinations

of chemicals that will be present in multiple-chemical exposures.

Xenobiotics administered or received simultaneously may act independently of

each other. However, in many cases, the presence of one chemical may

drastically affect the response to another chemical. The toxicity of a

combination of

chemicals may be less or it may be more than would be predicted from the

known effects of each individual chemical. The effect that one chemical has on

the toxic effect of another chemical is known as an interaction.

Piperonyl butoxide added to pyrethrum insecticide results in a pyrethrum

formulation having about 100 times the toxicity of pyrethrum alone. The

interaction of this combination is:

Additivity

Antagonism

Synergism

EXCELLENT! Piperonyl butoxide added to pyrethrum insecticide results in a

pyrethrum formulation having about 100 times the toxicity of pyrethrum alone.

The interaction of this combination is synergism. Synergists are used to enhance

the toxicity of several commonly used insecticides.