Environmental Toxcicity Lec2

Question 1

What is toxicology

Answer 1

Toxicology is study of poison

Toxicology study of adverse effects of toxicant on living organism under specific condition or exposure 

Question 2

Which group of chemical are toxic

Answer 2

All substance  or poison there is none which is not poison

They write does differentiate the poison from remedy

Question 3

What are the factor affecting dose

Answer 3

Environmental concentration

Route of exposure

duration of exposure

Frequency of exposure

Body size

Question 4

What is environmental concentration?

Answer 4

The amount of chemical in air, water, food or other medium, which person is exposed

Question 5

Routes of exposure

Answer 5

Inhalation (lung)

Ingestion (gastrointestinal )

Dermal(skin )

Question 6

Duration of exposure

Acute

Sup acute

Sup, chronic

Chronic

Answer 6

Acute less than 24 hours

Sub acute several days in one month

Sup chronic. 1-3 month.

Chronic more than three months

Question 7

Frequency of exposure

Answer 7

How often the exposure takes place

Question 8

Absorbed does versus effective does

And what is the target tissue

Answer 8

Absorbed does the amount of toxic substance  absorbed into organism and distributed systematically, throughout the body

Effective dose. The amount of toxic substance reaching to tissue target tissue in the body is adversely affected by the toxicant

Target tissue the tissue which toxicant exerts its adverse effect

Question 9

Acute toxicity versus chronic toxicity

Answer 9

Acute toxicity adverse effect appears shortly after exposure

Chronic toxicity adverse effect appears after a long period of exposure 

Question 10

Local effect versus systematic effect

Answer 10

Local effect occurs at the site of first contract between biological system and toxicant 

Systematic effects occur after observed and distributed and even metabolised in the body

Question 11

Environmental toxicology

Answer 11

Is the branch of toxicology that the concern, with exposure of toxicant present in our general environment, 

Question 12

Source of natural pollution 

natural source

Anthropogenic source

Answer 12

Natural source, Volcanoes eruption 
forest, fire
Soil, erosion by wind

Anthropogenic sources due to human activity include industries, automobiles, agriculture, waste disposal 

Question 13

Bioaccumulation and biomagnification

Answer 13

Many chemical substance cannot break down and resist in the environment

bioaccumulation . These chemicals can enter the body of living organism and accumulate in there fatty tissue

Biomagnification, is increasing the concentration of substance from trophic level to the next food chain 

Question 14

Pharmacokinetics

Answer 14

Is the absorption distribution metabolism, excursion of chemicals through the human system

Question 15

Absorption

Toxicant may , absorbed from

Answer 15

Absorption natural mechanism by which the substance pass through the body membrane and enter the body 

Toxicant may absorbed by gastrointestinal
Lung
skin

Question 16

Biological membrane

Answer 16

Every compound that reach, the systemic circulation must cross the membrane barrier

All , biological membrane consists of phospholipid, bilayer, , and protein embedded between them 

Question 17

Distribution

The rate of distribution do the tissue depend on 

Answer 17

Distribution after absorption toxicant. In blood stream, they must live the blood and enter the body cell, and May reach any point in the body

Rate of distribution to the. Tissue depend on

Blood flow rate

The ease by which toxicant  crosses the biological membrane of tissue 

Question 18

Metabolism (biotransformation,)

The parent compound may be built up or broke down to form

The new metabolites , maybe more or less toxic then

The liver is by far the most important issue for

Answer 18

Sum of the processes, by which foreign substance is subjected to chemical change by living organism

Parent component maybe built in or broke down to form new metabolites

The new metabolites , maybe more or less toxic, then parent component 

Deliver is by far the most important issue for xenobiotic metabolism 

Question 19

Excursion 

The excretory organ

Answer 19

Toxicant  excreted eliminated from the body in form of parent compound, or there metabolism

Excretory organ

Lung liver, kidney

Question 20

Mechanism action of pollution

Answer 20

Distribution of cell structure,
combination with cell component
inhibition of enzymes initiation of secondary action 

Question 21

Distribution of cell structure

Answer 21

Inhalation of sufficient dose of nitrogen dioxide and sulfuric acid mist, can curse the damage of the surface layer of respiratory system 

High level of ozone can oxidise polyunsaturated  fatty acid of lipid protein, in biological membrane resulting to distribution of membrane structure 

Question 22

Combination with the cell component

Answer 22

Carbon monoxide combain
With blood haemoglobin to form carboxyhemoglobin
Which disrupt the exchange of oxygen and carbon dioxide between the blood lung and other body tissue causing asphyxia , and death

Question 23

Inhibition of enzymes

Answer 23

Enzyme are mostly proteins which serve as catalyst of reaction in a biological system many of enzyme consist of metal are you owns called cofactor

Organic molecule called coenzyme 

Question 24

Initiation of secondary action 

Answer 24

Entering Toxic pollutant in human body can result in the release of other substance those cause damage to the cell

Carbon tetrachloride release, epinephrine from the nerves, which raise, the blood pressure and cues damage to the liver