Pollution Principles and Processes TREN 1F90: Sustainability, Environment and Tourism.

Pollution Principles and Processes

Pollution Principles and Processes

TREN 1F90: Sustainability, Environment and Tourism

Note worksheetNote worksheet

Available for download athttp://www.brocku.ca/tren/courses/tren1f90/2006/Pollution Principles and Processes.pdf

http://www.brocku.ca/tren/courses/tren1f90/2006/%C2%A0Pollution%20Principles%20and%20Processes.pdf

Environmental PollutionEnvironmental Pollution

• Any physical, chemical, or biological alteration of air, water, or land that is harmful to living organisms

Two main groups of pollutantsTwo main groups of pollutants


____________ or _______ ______:

• pollutants which are harmful in almost any amount


Nonthreshold or Gradual Agents:





_________ ______:

• pollutants which have a harmful effect only above a certain threshold level




Threshold agents:

• pollutants which have a harmful effect only above a certain threshold level

DOSE / RESPONSE CURVESDOSE / RESPONSE CURVES• Illustrate the effects of toxic substances on

living organisms

Image credit: aquaticpath.umd.edu/.../ module1-factors.html

DOSE / RESPONSE CURVESDOSE / RESPONSE CURVES• Illustrate the effects of toxic substances on

living organisms

Response =detectable effect onorganism

Dose =amount ofsubstance

encountered

http://aquaticpath.umd.edu/appliedtox/module1-factors.html

Nonthreshold (Gradual) AgentNonthreshold (Gradual) Agent

DOSE

DOSE (ppm)

RE

SP

ON

SE

Any level of aflatoxin (dose) will increase the

lifetime probability of liver tumors in rats (response)

Threshold agentThreshold agent

DOSE (% in diet)

RE

SP

ON

SE

The lifetime probability of

bladder tumors in rats increases

once a 3% threshold in diet

is crossed

Types of pollutantsTypes of pollutants

Persistent

• Do not degrade in the environment

Types of pollutantsTypes of pollutants

Persistent

• Do not degrade in the environment

Non – persistent

• Break down in the environment (biodegradable / photodegradable / chemodegradable)

Forms of BIOACCUMULATIONForms of BIOACCUMULATION

Bioconcentration• Accumulation of substances (toxic or not) in the

living tissues of an organism• (e.g., iodine in thyroid gland of humans)

• Thyroid produces hormones(e.g., thyroxine (T4) andtriiodothyronine (T3) which regulate metabolism of many systems in the body

• Iodine is an essential component of T3 and T4.

• Iodine deficiency results in goiter (enlarged thyroid)

• Not just a developing-nation syndrome: US ‘goiter belt’ at turn of last century

• Controlled by introducingiodized salt in1924


Biomagnification• Buildup of substances in organisms

across successive trophic levels




1° PRODUCERS

1° CONSUMERS

2° CONSUMERS

3° CONSUMERS

4° CONSUMERS

4°- 5° CONSUMERS




Reasons:– trophic pyramid interactions – water insolubility / lipophilic action of many

biomagnifiable substances– slow biodegradability of substances– biological novelty of synthetic substances: no naturally occurring counterparts

==> no natural elimination mechanism

Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five

(nonexclusive) categories in order of increasing seriousness to humans:

1. _____________________________________________

2. _____________________________________________

3. _____________________________________________

4. _____________________________________________

5. _____________________________________________

The above classification system may be further subdivided to include more detailed biological responses at the organism, population, or community ecosystem levels.



1. Nuisance / Aesthetic Insult

2. _____________________________________________

3. _____________________________________________

4. _____________________________________________

5. _____________________________________________





2. Property Damage

3. _____________________________________________

4. _____________________________________________

5. _____________________________________________





2. Property Damage

3. Damage to Plant and Non-human Life

4. _____________________________________________

5. _____________________________________________





2. Property Damage


4. Damage to Human Health

5. _____________________________________________





2. Property Damage


4. Damage to Human Health

5. Disruption of Ecosystems


ToxicologyToxicology

Toxin:Toxin:

• A chemical substance which adversely affects living organisms

Image credit: www.eurekalert.org/.../ 2005-03/m-dna031505.php

Effects of ToxinsEffects of Toxins

Acute effects:• symptoms which appear immediately after

exposure to the toxin. Usually caused by fairly high concentrations of toxins during short‑term exposures.

Chronic effects:• delayed but long‑lasting responses to toxic

agents. Generally the result of low‑level exposure over long periods. Often difficult to diagnose, predict, and detect.

Image credit: www.nersc.gov/news/ greenbook/nersc3/node28.html

Carcinogen:Carcinogen:

• a cancer-causing agent

• E.g., polycyclic aromatic hydrocarbons and amines

(present in automobile exhaust, tobacco smoke, dyes, and barbecued meat and fish)

Image credit: www.nersc.gov/news/ greenbook/nersc3/node28.html

Carcinogen:Carcinogen:

• Cancer is initiated in the cell by attacking the DNA bases

(A, G, C, T)

• Once bound to the bases, they can alter the DNA shape (conformation).

• This change can profoundly impact on the normal functioning of DNA during replication.

Image credit: www.gcarlson.com/ immuno_metastisis.htm

Metastasis:Metastasis:

• The migration / spread of cancer cells in the body

Image credit: www.quarks.de

Teratogen:Teratogen:

• Agent which causes birth defects

Image credit: http://www.thieme.de/dmw/inhalt/engl_or/or18802.jpg



• e.g. alcohol

(fetalalcoholsyndrome)

Image credit: teratology.org/jfs/ ThalidomidePics.html



• e.g. thalidomide

Image credit: www.llnl.gov/str/ April01/Colvin.html

Mutagen:Mutagen:

• agent which causes genetic mutation

• e.g. radiation, certain foods and chemicals, some viruses

Gene / point mutation:• Alteration to the DNA base sequence

Clastogenesis:• Chromosomal breaks; gain, loss, or

rearrangement of pieces of chromosomes

Aneuploidy / Polyploidy:• Uneven separation of chromosomes during cell

division, or addition of entire chromosomes

Three main types of genetic alteration:Three main types of genetic alteration:

Gene / point mutation:• Alteration to the DNA base sequence

Clastogenesis:• Chromosomal breaks; gain, loss, or

rearrangement of pieces of chromosomes

Aneuploidy / Polyploidy:• e.g., Down syndrome (Trisomy 21)

Three main types of genetic alteration:Three main types of genetic alteration:

Image credit: sci.cancerresearchuk.org/. ../cap/capanal.html

Capping enzyme for mRNA(red) and reaction products

Modes of action of toxinsModes of action of toxins

1. disturbance of enzymatic activity to alter the functioning of a cell, tissue or organ

Enzyme: A protein that initiates or accelerates the rate of chemical reactions. Enzymes are catalysts that promote reactions repeatedly, without being damaged by the reactions.

The three-dimensional structure and composition of enzymes is critical to their effectiveness.

Image credit: www.eccentrix.com/members/ chempics/Enzymes.html





Examples:

• Mercury: binds with sulfhydryl and thiol groups found in most proteins and all enzymes, and interferes with normal fetal development → Minamata disease



Examples:

• Arsenic: induces skin lesions, neurological disorders, and chromosomal abnormalities leading to cancer

Image credit: www.leighday.co.uk/ doc.asp?cat=850&doc=563

Skin lesions from arsenic inwater supply - Bangladesh


2. Direct binding to cells or molecules within the cell, upsetting cellular metabolism

Image credit: dept.physics.upenn.edu/.../ subsection1_1_3.html


2. Direct binding to cells or molecules within the cell, upsetting cellular metabolism

Example:

• Carbon monoxide: binds to hemoglobin in blood → disrupts oxygen and carbon dioxide transport Hemoglobin molecule with

carbon monoxide attached


3. stimulate release of other naturally occurring cell substances that have an adverse effect when present in excess

Image credit:www.vetmed.wsu.edu/ medsci520/cell_injury.htm


3. stimulate release of other naturally occurring cell substances that have an adverse effect when present in excess

Example:

• Carbon tetrachloride: stimulates productionof adrenalin → overproduction results inliver damage

Centrilobular hepatic necrosis and fatty

change in a patient poisoned by carbon

tetrachloride

Factors affecting toxicity of chemicalsFactors affecting toxicity of chemicals

1. Dose and duration of exposure

2. Biological reactivity: how it reacts with enzymes and other cellular components. Inert substances are generally non toxic, with a few exceptions (e.g.silica dust, asbestos fibres)


3. Age: young, growing organisms generally more susceptible to toxins than are mature adults.

Examples: lead and mercury poisoning have severe effects on developing nervous systems)

4. Health Status: poor nutrition, stress, and diseases make individuals more susceptible to the effects of toxins


5. Synergism: different chemical substances may act together so that the toxic effect of the combination is greater than the simple sum of the two individual responses

e.g. alcohol and barbiturates: neither taken alone in small amounts is dangerous, but combination can be deadly==> synergistic effect.


6. Antagonism: different chemical substances may act together so that the toxic effect of the combination is less than what would be predicted from the individual toxicities

e.g., selenium reduces the toxic effects of organomercury compounds)


7. Mode of exposure:

• Percutaneous: skin

• Respiratory: nose, pharynx, trachea, bronchii, lungs

• Oral: mouth, esophagus, stomach, intestines

Pollution Principles and Processes TREN 1F90: Sustainability, Environment and Tourism.

Documents

Transcript of Pollution Principles and Processes TREN 1F90: Sustainability, Environment and Tourism.