Introduction to Toxicology

A toxin is best described as:

A toxicant is exclusively a chemical agent and does not include physical agents like radiation or noise.

Define 'toxicity' in the context of toxicology.

According to Paracelsus, the dose makes the ______.

Which of the following characteristics define a hazardous material?

A substance's toxicity is solely determined by its inherent properties and is not influenced by the dose.

List three factors that determine how well the body accepts a substance.

__________ is the accumulation or increase in concentration of a substance in living tissue as it moves through the food chain.

Which of the following is an example of a chemical element that can undergo biomagnification?

Inhalation, ingestion, absorption, and injection are all possible routes of exposure for toxicants to enter biological organisms.

List two routes of exposure for toxicants to enter biological organisms.

Toxicants can enter the body through routes such as inhalation, __________, and absorption.

Which route of exposure would likely result in the most rapid increase in blood level concentration of a toxicant?

Dermal exposure typically results in a more rapid increase in the blood level of a toxicant compared to inhalation.

Name two common measurements of toxicity.

__________ refers to one part of a substance in one million parts of a solution.

Which of the following represents the smallest concentration?

LD50 refers to the lethal concentration of a substance that kills 50% of a test population through airborne exposure.

Define LD50 and explain what it measures.

__________ is the concentration of a material that kills half of the test animals during the period of exposure, typically referring to airborne dosages.

The Threshold Limit Value (TLV) is defined as:

The Threshold Limit Value (TLV) is typically used for environmental exposure determinations rather than workplace exposure determinations.

What organization sets the TLV values?

The upper limit of a toxin concentration to which an average healthy person may be repeatedly exposed on an all-day, everyday basis without suffering adverse health effects is known as __________.

The TLV-TWA is:

TLV-STEL refers to the ceiling concentration that should not be exceeded, even instantaneously.

Define TLV-C.

TLV-__________ is a short-term exposure limit, representing the 15-minute time-weighted average exposure that should not be exceeded.

According to the TLV example values, which of the following toxicants has the lowest TLV?

All toxicants have a measurable threshold limit value.

For flammables what proportion of the lower flammable limit is the TLV?

According to the 'Exposure Model', after safe exposure, the next level is __________.

In toxicology experiments with rabbits, what is the initial step in determining a response curve?

When plotting a dose-response curve, using the log of the dose is less useful than using the raw dose values, especially at low doses.

In analyzing dose-response relationships, what mathematical transformation is used to change an S-shaped curve into a straight line for easier analysis?

In order to see low doses more clearly in a dose-response graph, we should take the __________ of the dose.

Match the following toxicity measurements with their definitions:

If Chemical A's dose-response curve shifts significantly to the left compared to Chemical B's, what does this indicate?

If Toluene has a value of -6.79 under K1 and 0.41 under K2, and Phosgene has -19.27 for K1 and 3.69 for K2, as seen in a toxicity table, we can say that Toluene is more dangerous than Phosgene.

What is the typical unit used to measure TLV in the air for gaseous substances?

If you have one molecule of a substance, swimming in a trillion molecules of water, then that concentration can be expressed as 1 ______.