Pollution Principles and Processes TREN 1F90: Sustainability, Environment and Tourism.
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Transcript of 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
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
Two main groups of pollutantsTwo main groups of pollutants
Nonthreshold or Gradual Agents:
• pollutants which are harmful in almost any amount
Two main groups of pollutantsTwo main groups of pollutants
Nonthreshold or Gradual Agents:
• pollutants which are harmful in almost any amount
_________ ______:
• pollutants which have a harmful effect only above a certain threshold level
Two main groups of pollutantsTwo main groups of pollutants
Nonthreshold or Gradual Agents:
• pollutants which are harmful in almost any amount
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
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
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.
• Not just a developing-nation syndrome: US ‘goiter belt’ at turn of last century
• Controlled by introducingiodized salt in1924
Forms of BIOACCUMULATIONForms of BIOACCUMULATION
Biomagnification• Buildup of substances in organisms
across successive trophic levels
Forms of BIOACCUMULATIONForms of BIOACCUMULATION
Biomagnification• Buildup of substances in organisms
across successive trophic levels
1° PRODUCERS
1° CONSUMERS
2° CONSUMERS
3° CONSUMERS
4° CONSUMERS
4°- 5° CONSUMERS
Forms of BIOACCUMULATIONForms of BIOACCUMULATION
Biomagnification• Buildup of substances in organisms
across successive trophic levels
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.
Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five
(nonexclusive) categories in order of increasing seriousness to humans:
1. Nuisance / Aesthetic Insult
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.
Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five
(nonexclusive) categories in order of increasing seriousness to humans:
1. Nuisance / Aesthetic Insult
2. Property Damage
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.
Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five
(nonexclusive) categories in order of increasing seriousness to humans:
1. Nuisance / Aesthetic Insult
2. Property Damage
3. Damage to Plant and Non-human Life
4. _____________________________________________
5. _____________________________________________
The above classification system may be further subdivided to include more detailed biological responses at the organism, population, or community ecosystem levels.
Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five
(nonexclusive) categories in order of increasing seriousness to humans:
1. Nuisance / Aesthetic Insult
2. Property Damage
3. Damage to Plant and Non-human Life
4. Damage to Human Health
5. _____________________________________________
The above classification system may be further subdivided to include more detailed biological responses at the organism, population, or community ecosystem levels.
Effects of PollutantsEffects of Pollutants Miller (1990) classifies the effects of pollutants into five
(nonexclusive) categories in order of increasing seriousness to humans:
1. Nuisance / Aesthetic Insult
2. Property Damage
3. Damage to Plant and Non-human Life
4. Damage to Human Health
5. Disruption of Ecosystems
The above classification system may be further subdivided to include more detailed biological responses at the organism, population, or community ecosystem levels.
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: http://www.thieme.de/dmw/inhalt/engl_or/or18802.jpg
Teratogen:Teratogen:
• Agent which causes birth defects
• e.g. alcohol
(fetalalcoholsyndrome)
Image credit: teratology.org/jfs/ ThalidomidePics.html
Teratogen:Teratogen:
• Agent which causes birth defects
• 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
Modes of action of toxinsModes of action of toxins
1. disturbance of enzymatic activity to alter the functioning of a cell, tissue or organ
Image credit: www.eccentrix.com/members/ chempics/Enzymes.html
Modes of action of toxinsModes of action of toxins
1. disturbance of enzymatic activity to alter the functioning of a cell, tissue or organ
Modes of action of toxinsModes of action of toxins
1. disturbance of enzymatic activity to alter the functioning of a cell, tissue or organ
Examples:
• Mercury: binds with sulfhydryl and thiol groups found in most proteins and all enzymes, and interferes with normal fetal development → Minamata disease
Modes of action of toxinsModes of action of toxins
1. disturbance of enzymatic activity to alter the functioning of a cell, tissue or organ
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
Modes of action of toxinsModes of action of toxins
2. Direct binding to cells or molecules within the cell, upsetting cellular metabolism
Image credit: dept.physics.upenn.edu/.../ subsection1_1_3.html
Modes of action of toxinsModes of action of toxins
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
Image copyright 2000 by Nucleus Communications, Inc. All rights reserved. http://www.nucleusinc.com
See “Why is Carbon Monoxide so Poisonous?” at www.edinformatics.com/.../ carbon_monoxide.htm
Modes of action of toxinsModes of action of toxins
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
Modes of action of toxinsModes of action of toxins
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)
Factors affecting toxicity of chemicalsFactors affecting toxicity of chemicals
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
Factors affecting toxicity of chemicalsFactors affecting toxicity of chemicals
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.
Factors affecting toxicity of chemicalsFactors affecting toxicity of chemicals
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)