This site is 100% ad supported. Please add an exception to adblock for this site.

Environmental Toxicology

Start Studying!

Terms

undefined, object
copy deck
Atmosphere
Layer of gases that extends upwards 62,000 mi.
Source of oxygen, nitrogen and carbon dioxide.
Acts as a freshwater distillery.
Absorbs cosmic rays and UV radiation.
Insulates the earth – the “Greenhouse Effect.”
Hydrologic Cycle
sunlight evaporates water. It’s a distilling process. Water vapor condenses in the atmosphere and comes back down.
Cosmic Rays
Damaging rays. UV causes skin cancer.
Carbon Cycle
Two processes:
Photosynthesis
Plants. Take sunlight energy and combine CO2 and water into a sugar called glucose.
Provides energy for almost all organisms on the planet.
Respiration
We take sugar and combust it biologically and release energy. This is the energy we live on. We also release some waste. Plants take these back up, make more sugar, we combust, etc etc.
Infrared
Can't pass through glass. Sunlight passes through glass and gets converted to infrared energy.
Greenouse gasses
Triatomic or Larger
Carbon dioxide, water vapor, ozone, nitrous oxide, methane, freons, NOx, SOx, etc.
Need a central atom from which to vibrate.
Most atmospheric gases are diatomic (99%).
The central atom acts as a fulcrum so that the other 2 can vibrate against. Has to vibrate to re-radiate that energy after absorption occurs.
Global Warming
Increasing amounts of gases in the atmosphere. Temeperature changes are happening much faster than before
Industrial Revolution
Key determinant of increased levels of CO2
Carbon Seasonal Fluctuations
Carbon Cycle occurs more during the summer than winter.
Arrhenius
Estimated that doubling of CO2 would increase temp. by 5 - 6c. Pretty close.
Ice Melting
Huge problem w/ global warming. Results in sea leel rise. Over past 50 years, line starting to go exponential.
Removal of CO2
Takes on average 50 - 200 years for it to come back. Could take a while before we see an improvement.
Ways to reduce global warming
Reduce fossil fuel combustion for energy.
Switch to renewable sources of energy.
Enhance global photosynthetic capacity.
Sequester carbon dioxide in deep oceanic sites or geologic formations.
Four Belts of the Atmosphere
Troposphere: where we live (most molecules reside here.
Stratosphere: more elevation more thinner air
Mesosphere
Thermosphere
Wavelength
Longer - lower energy
shorter - higher energy
Ultraviolet light has more energy than infrared
UV A, B, C
UV A reaches the ground.
UV B tends to get better filtered
UV C is essentially all filtered out
The problem today is that the filtering process is becoming less efficient. UV B now comes through as well which means higher energy and more destruction to our skin.
Ozone in the troposphere
Can be quite destructive. Very corrosive to the lungs. Created by baked industrial processes, lawn mowers, trucks, and other volatile organic compounds.
Ozone in the stratosphere
Good. Filters harum ultraviolet rays.

Oxygen gets split up into atomic oxygen (highly reactive). Those react w/ other oxygens to form ozone. Goes from UV energy to infrared energy (lower form of energy). UV -> heat
Cholorfluorocarbons
Created by Refrigernats, spray propllants, plastic foam blowing (styrofoam).
CFS are great for refrigeration. Good compressibility and relatively inert.
With increase in CFC came drop in ozone because they started escaping (especially during fridge repairs).
Freons
Made of carbon and a halogen (chlorine or fluorine). Quite stable
Ozone depletion
Particularly acute at the poles
Ozone reduction by freons
CFC are source of cholrine radical. Freaon + UV = chlorine in form of free radical. Attacks ozone and converts it to Oxygen. Now you have one oxygen on cl. Atomic oxygen comes along to release Cl and to form oxygen (o2). Reaction starts all over again.
Acids
Donate an H+
Measured as pH
Strong acids donate readily.
Bases
Accept an H+ or donate -OH.
Acid rain
occurs in highly industrialized areas.
Winds can cause acid rain somewhere else even though it is caused in another area. Northa AMerica to Europe.
Acids that contribute to Acid Rain
Carbonic acid (from carbon dioxide) = water + CO2 - >weak
Sulfuric Acid (from sulfur dioxide)
Nitric Acid (from nitric acid)
Nitric and Sulfuric Acid comes from industry.
Calcium carbonate
Weak Base
Acidic soils
These are most sensitive to acid rain. Regeions w/ basic limestone rich soils are capable of buffering acid rain.
Remediate Acid Rain
Lake Liming: throw crushed limestone into acid lakes. Not a permanet solution.
Catalytic converters: convert nitric oxide in auto exhausts to nitrogen and oxygen gases. Expensive
Smokestack Scrubbers: convert sulfur dioxded to gypsum.
Hydrosphere
Includes water bodies and water atmosphere. Recycles itself via hydrologic cycle. All living organisms are living on 2% fresh water supply.
Water pollution
Organic: petroleum, dyes, detergents, pesticides
Inorganic: acids and bases, salts, nitrates, phosphates
Biological Water Pollution
Pathogenic - cause disease: bacteria, fungi, virus
Aquatic Weeds: plants that use nutriens and choke off waterways
Aquatic algae: excessive grwoth caused by excess nutrients: eutrophication.
chimeical Oxygen Demand
Amount of oxygen required for degradation of a pollutant over 5 days at room temp. Fish in the pond aphyxiate due to a rusting car.
Biological Oxygen Deamnd: Amount of oxygen required for degradation of a pollutant by microbes over 5 days at room temp.
Sewage treatment
reduce the oxygen demanding substances released in the environment
Accelerated Eutrophication
Nitrates and phosphates are plant fertilizers taht cause excessive plant growth in the summer. In the fall, plants die off and form deritus. Contributes to high BOD in the water. Microbes consume the detrius and oxygen.
Fish asphyxiate.
Oil
gets into our environment via pipelines, storage tanks, refineries, waste oils, cars, industrialzed sectors
Industrial waste is biggest source (not oil tankers)
Weathering
oil begins to dissolve when released in sea water (dissolution).
Aromatic hydrocharbons are most important chemicals in terms of toxicity.
Remediation technique
Recovery – removal via the use of booms, collecting agents (e.g. straw), and mechanical skimmers.
Burning – combustion only works well on fresh oil.
Sinking – use of agents that cause oil to sink to the bottom of the sea.
Dispersal – use of detergents (dispersants) to disperse oil into the water column and off the surface.
Bioremediation – Use of bacteria to degrade the oil.
MIcells
Break up oil into smaller and smaller portions until it is digested by bacteria.
Efficacy
mechanism or method by which a chemical acts
Aerobic Microbes
Utilize oxygen to perform aerobic respiration. We like these
anaerobic microbes
utilize sulfur or nitrogen to perform any anerobic respirtion. Givee off methane, hydrogen sulfide, ammonia. Gives off some toxic chemicals.
Bioremediation
use of biological organisms to alleviate the problems associated with toxic chemicals or other chemical wastes.
Organism Types – Selected organisms can be bacteria, fungi, plants, etc.
Natural Bacteria
bioremediation: tend to be adapted for the local environment; disadvantage is the products they produce from a waste may be unknown and toxic (intrinsic bioremediation).
cloned bacteria
Advantage is that they can be selected based upon the known non-toxic products they produce; disadvantage is that they might not be adapted for the local environment (enhanced bioremediation).
chemicals subject to bioremediation
TCE and other cleaning solvents in groundwater.
Pesticides such as DDT and atrazine in sediments.
Crude oil in coastal estuaries.
Gasoline in groundwater from station storage tanks.
Sewage – normal treatment and in groundwater from sewer pipe seepage.
Dinoflagellates
Swimming Plants.
Most toxic plankton are dinoflagellates – 24 spp.
They are photosynthetic.
They have whip-like flagella for swimming.
They are filter fed by fishes.
Produce light – bioluminescence (warning for native Americans
Alexandrium spp.
type of dinoflagellate
Saxitoxins (STX) - “ I can’t breathe!” (Taken up by molluscs)
Also known as gonyaulax toxin and paralytic shellfish poison.
Tends to arise in summer blooms – months without an “R.”
Filter fed by bivalves, anchovies and sardines.
Causes vomiting and respiratory paralysis.
California coast is quarantined annually.
Gymnodinium breve
Type of dinoflagellate
Brevetoxin (BTX) - “I can’t see!”
Causes neurotoxic shellfish poisoning (NSP).
Dissolves in water; the aerosol causes surfer’s cough.
Corrodes boat paint, fish gills, eyes and lungs of people.
Causes respiratory paralysis – manatees and dolphins
Dinophysis acuta, D. acuminata
Type of dinoflagellate
Diarrhetic shellfish poison (DSP) - “ I can’t …!”
Found in Europe and eastern Canada.
Okadaic acid and other dinophysistoxins.
Causes diarrhea, stomach ulcers and cancerous tumors.
Gambierdiscus toxicus
Type of dinoflagellate
Ciguatoxin (CTX)- “I can’t feel hot and cold!”
Also known as ciguatera poison.
Produced by a photosynthetic benthic dinoflagellate.
Found in the tropics, rests and grows on other algae.
Grazed upon by many tropical reef fishes and moluscs.
Causes nausea, vomiting, and paralysis (rarely lethal).
Reverses temperature sensation!
Diatoms
Tend to be needle-shaped single cells.
They are photosynthetic and have silica walls.
They exist in colonies of long chains.
They tend to bloom in the spring.
Pseudo-nitzschia spp.
Type of diatom
Domoic acid (DA) - “I can’t remember anything!”
It causes amnesic shellfish poisoning (ASP).
Found in Japan, Canada, California, etc.
Filter fed by bivalves, sardines and anchovies.
Causes loss of coordination and seizures.
Impacts seals, sea lions, pelicans, other birds, and humans
Tetrodotoxin
“I can’t move!”
Also known as fugu poison, produced by bacteria.
In red algae, some salamanders, and blue-ringed octopus.
Also in puffer fishes, sunfishes, and porcupine fishes.
In puffer fishes, TTX is concentrated in the ovaries and liver.
Causes respiratory paralysis, and is super toxic.
Fugu
Raw pufferfish, considered a delicacy in Japan.
A tingle in the mouth and tongue is considered desirable.
Prepared by licensed chefs.
Some 200 people per year die from bad fugu.
In puffer fishes, TTX is concentrated in the ovaries and liver.
Causes respiratory paralysis, and is super toxic.
Langerhans cell
protects from microbes. Allergy response
Melonacyte
pigment of the skin. Protect from UV light. When exposed to UV light, make pigment and donate pigment. Can be targets of melanoma.
Hydrated Skin
Makes it easier for things to get in.
Fossil fuels
Coal – A form of carbon that is derived from the heat/pressure degradation of swamp plants.
Coal – As determined by carbon and water content, found as anthracite, bituminous coal, or lignite.
Oil/Natural Gas – Hydrocarbon mixtures that are derived from the heat/pressure degradation of marine phytoplankton.
Oil consists of
Alkanes (hydrocarbons), Alkenes, Alkynes, Aromatics
Fractional Distillation of Crude Oil
Oil consists of literally hundreds of organic chemicals.
Carbon lengths vary from C1 to about C60.
Different size hydrocarbons have different uses.
Hydrocarbons can be separated into size “fractions.”
Separation involves using their unique boiling points.
Boiling point = the temperature at which a chemical transitions between as liquid and a gas.
Approximate Distilled Fractions
Natural gas (BP < 20C) – C1 to C4.
Petroleum ether (BP 20 to 60C) – C5 to C6.
Gasoline (BP 30 to 180C) – C5 to C9.
Kerosene (BP 180 to 230C) – C10 to C14.
Heating oil/diesel fuel (BP 230 to 305C) – C15 to C18.
Lubricating oil (BP 305 to 405C) – C19 to C25.
Asphalt (non-boiling) – C26 to C60
Petroleum “Cracking”
The splitting of larger hydrocarbons into smaller ones.
About 25 to 45% of a barrel of crude oil can be distilled into gasoline.
Used to make more gasoline (C5 to C9) from the heating oil (C15 to C18) fraction.
Commonly done to meet summer driving demand
Octane Rating of Gasoline
Gasoline consists of straight and branched alkanes.
If consisting of all straight alkanes, they ignite before the spark = premature ignition (“knocking”).
n-Heptane causes the most pre-ignition, so it is “0.”
Iso-octane (2,2,4-trimethylpentane) is the best burning branched alkane, so its rating is set at “100.”
Gasoline mixtures are rated by comparison to standard mixtures of n-heptane and iso-octane
Octane Enhancers
The octane rating of gasoline can be enhanced.
Reforming can be used to convert straight alkanes to branched alkanes.
Until 1975 TEL was used as a less expensive means.
Until recently MTBE was used.
Methanol and ethanol (gasahol) are now used.
Problems with Octane Enhancers
Branched alkanes are too expensive.
TEL simply degrades to lead, which is highly toxic and does not further degrade.
MTBE is both volatile and soluble in water, noxious, and has a low odor and taste threshold.
Methanol and ethanol (gasahol) are now used, but easily absorb water and are expensive.
toxicology
the study of the interations between organism and chemical
Ebers
Egyptian payrus that is the earliest toxicological document written
Discorides:
First to classify toxics into categories of animal, vegetable, mineral
Catherine de medicis
Middle ages: probably true first toxicologist. Used toxic procedure to study poisions

Time till onset
Potency
Specificity: where in the body does it take effect
clinical science: symptoms
Bombastic Paracelsus
Considred founder of toxicology
Percival Plott
Scrotal cancer + chimney sweeps
Orfilia
First to put out idea that if one sees toxic symptoms one must do analysis to find out if it was from a toxic cause
Rachel Carson
Silent spring: book envisions world of pesticide where no living thing exists.
Synthetic compounds
anthropogenic
natural compound in asprin
salicin
Normal chemical effects
predictable effects based on the physical/chemical properties
Abnormal effects
based on immunological properties
Acute effect
arise within 96 hours
sub Chronic effect
One week to a year
chronic
year or more
graded response
measured in single individual over time with increasing does
Quantal response
measured in population over time w/ increasing dose
Potency
amount of chemical needed to cause an effect
median effect level
does that will kill 50% of the population.
LD50
letahl dose
TD50
Sublethal dose for 50% of tested population
ED50
Therapeuitc dose for 50% of the population.
margin of safety
distance between toxic effect and therapeutic effect
Therapeutic index
TD50/ED50 or TD1/ED99
Threshold
chemical requires certain amount before there is a toxic effect
(as opposed to one hit theory w/ cancer)
Reference dose
Also known as accepted daily intake

= NOEL/(1+SF)
chemical risk
the inherent probability that a chemical exposure will resul in an adverse effect
Risk
Exposure/LD50

No exposure, no risk
phytotoxins
bioactive chemicals from plants
mycotoxins
bioactive chemicals from molds and fungi
analgesiscs
Drugs that cause temp. relief
Narcotic analgesics
produce sleep like painless state
anesthetics
block pain nerves
stimulants
stimulate activity
sedatives
produce general sedation
antimicrobials
cure infectious diseases
ergot alkaloids
caused by mold on grains.
Rye: one of the most common grains to suffer this condition.
mycotoxin example
penicillins; first expensively produced until it was relized that it was usable in patient's urine
Phytotoxin example
Opioids: dull senses and induce sleep. relieve diarreah. Narcotic. Used for dysentry. Comes from opium poppy dried sap. Morphine, codeine and papavarine isolated from the sap as well.
codeine:
Strong cough suppressant
Papeverine
similar to viagra.
morphine
combined w/ alcohol as laudanum: given for old war injuries
heroin
produced from morphine. also great cough suppresant.
Tropane alkaloids
stimulants that suppress appetite.
cocaine is an example. Numbness of the tongue; local anastethic.
-caine: related to cocaine.
Atropine
Belladonna
Tropane poison. Used as beauty aid to dilate pupils.
Sarin: war gas that kills within minutes, but atropine is an antidote.
scopolamine
Henbane poison
related to atropine, isolated from henbane, powerful sedative, used to treat motion sickness
contaminant
abnormal concentration of a chemical in an environment.
Pollutant
abnomral concentration of a chemical in the environment that is above the NOEL
Three physical environments/compartments
lithosphere
hydrosphere
atmosphere
also biosphere (organsims)
transport
movement of chemical within a compartment
percolation:
chemicals travel through water moving through soil
partitioning
when a chemical's movement travel between compartments
biomagnification
study of chemical movement in the
= bioaccumulation - bioconcentration
weaknesses of the model: chemicals can be lost through each level by excretion or detoxification; organisms can absorb chemicals not just through food.
bioconcentration
represents uptake of chemicals via water, soil, air
bioaccumulation
represents cheimcal uptake via all routes
strabo:
observed that miners who mined for arcenic died young
Beaver pelt hats
hats required mercuric nitrate. People who chronically wore the hats developed tremors.
solvents
alkanes(hydrocarbons). Made from crude oil. Generally used as solvents and fuels.
alochols
HO in their molecular structure
Methanol: causes blindness
glycols
related to alcohols; 2 HOs.
Two step process in the liver tuns ethylene glycol into oxalic acid and formic acid
Oxalic acid
crystallizes in your brain and kidneys
formic acid
causes blidness
Polycyclic aromatic hydrocarbons (PAH)
sic carbon rings w/ hydrogen.
2 types: pyrogenic and petrogenic
Lead
attacks nervous system and kidneys, carcinogen.
Nickel And Cadmium
commonly found in batteries.
Cadmium selectively ends up in kidneys and is carcinogen
Both are likely to replace calcium.
Cinnabar and Mercury
Fat soluble, found in sharks, swordfish, tuna. toxic to nervous system and kidneys.
Abestos fiber for insulation
form of silicon. When distrubed, breaks off into very small barbed particles. causes mesothelioma.
HERP risk values
human exposure over rodent potency.
Alkaloids
contain nitrogen rings
Oleander
Found on side of highway. Campers get easily poisoned by it due to unawareness.
Poison oak
Contains laccol, easily absorbed into the skin.
Peruvian lilly
similar to poison oak. Often found in bouquets and cut flowers
buttercup
kind of like poison oak. used in wwII to avoid draft.
Nettle
has heart shaped leaves that are gray-green in color. Underside of leaves contain tiny inorganic quartz needles which act like miniscule poison syringes.
Dumbcane
plant contains inorganic n eedles made out of calcium oxalate; slaves punished by being forced eat dumbcane; provided great pain and swelling of the mouth, lips, tongue, throat. Can cause asphyxiation.
Potato
Contains solanine when green.
celery
poison celery contains xanthotoxin is at its highest level. circulates around the blood ending up in the skin. Once exposed to sunlight, symptoms appear which are similar to that of poison oak
lima beans
little amounts of cyanide.
Lime
also has phototoxic effects
allelochemicals
Redwood and pyrethrium daisy.
glycosides
sugars attached to an alcohol (lima beans)
latones
cyclic ester (tulips)
oxalate
oxalic acid or its salts
phenols
benzen ring w/ at least one OH group (poison oak).
ACD
Allergic contact dermatitis: delayed skin reaction
allelochemical
naturla chemical that affects an organism other than that producing it.
cholinesterase inhibitor
chemical that binds to enzymes that regulate conduction of nerve impulses between enrve cells; often results in paralysis.
coumarin
class of chemicla with fuzed benzene and lactose rings
cyanogenic
capable of forming cyanide
ester
reaction product of an alcohol and an acid
lactone
cyclic ester
teratogenic
causing birth defects
Nicotine
phytochemical: made from ground tobacco in powder form. used to be a pesticide. Very toxic. Black leaf. Falls under category of nicotinoid
rotenone
made from the root of the plant derris; general pesticide. More toxic to fish than humans
pyrethroids
made from chrysantehmums; makes up about 40% of all insecicides used.
Initial extraction from chrysantehmum is called pyrethrum; an elixir of six pyrethrins.
organocholorine insecticide
classical is ddt.
orgonophospathe insecticide
react w/ water breaking down up contanct (hydrolisis).
carbamate insecticide
react w/ wather because of the carbon oxygen bond.
cholorphenoxy herbicide
agent orange is an example. used to erdicate the vietnamese jungle: mimics growth hormone of plants. stimulates uncontrollable growth and uses up the nutrients in theground.
Dioxin found to be an impurity of agent orange.
secondary carcinogen
one which the body has to convert in order for it to become carcinogen.
mutagen
chemical that directly reacts w/ DNA to cause a change in its function
carcinogen
a chemical that causes cancer by any means:
many carcinogens serve to cause cancer by non genetic means such as by supressing the immune system or naturally creasing cell divion rate.
genotoxic carcinogen
chemical that causes cancer by drieclty reacting w/ dna to cause a change in its function
epigenetic carcinogen
a chemical that causes cancer by non genetic means
malignant tumor
invades other cells.
PAHs in Puget Sound, Washington
cause tumors in fish
Sea turtles in hawaiian islands
suffered from fibropapillomas; expected to be caused by planktonic toxins or by viruses
carcinoma
cancer that arises from epithelial cells (covering body or tisssue surfaces)
sarcoma
cancer that arises from supporting or connective tissue
melanoma
cancer aht arises from pigmented cells of the skin
lymphoma
cancer atha rises from teh cells of the lymphatic system
class 1
plenty of human evidence and many animal evidence
class 2
weak human evidence, many animal evidence
class 3
weak human evidence, some animal evidence
class 4
data shows that it does not cause cancer
hematoxic
destory tissues by digesting proteins; either thinning or thickening of blood
neurotoxic
poisons that act at neuromuscular junctions
marine cnidarians
jellyfish, sea anemones; these have stinging nematocysts
necrotoxic
digests tissues
mollusks
harpoon like tooth filled w/ conotoxins
conotoxins
cause nerve paralysis, nausea, speech difficulties
proteolytic
digests proteins
bufonidae
toads: produce bufotenin, bufotenidin; cause hypertension and hallucination
dendrobatidae
(frogs)produce batrachotoxin which cause skeletal muscle paralysis.
Used as arrow tip poison.
venoms lost in captivity
Ichthyosarcotoxic
fishes that contain toxins following ingestion
ichthyootoxic
fishes that produce toxins in their gonads
Ichthyohemotoxic
fishes that have toxins in their blood
Ichthyovenomous
fishes that produce aggressive venoms (causes intense pain, cardiac failure, complete limb paralysis
hymenopterans
creatures can cause allergic reactions; venoms tend to be mixtures of enzymes and histamines.
endocrine disruptor
hormones which control many activiites, including development, reproduction, and behavior.
xenoestrogen
foreign chemical w/ estrogen properties
xenoandrogen
foreign chemical w/ androgenic properties
Hypothalamus and pituitary gland
responsible for the initial control of hormones
steroid hormones
naturally synthesized from cholestrol
agonist
foreign chemicals that can stimulate hormonal affects
antagonist
foreign chemicals that block receptors
Tributyltin and Marine Mollussk
TBT used in paint for boats. Kills mollusks and baranacles. Endocrine disruptor. Navy still uses it despite it being banned. whelks have suffered conversion of gentipic femalses to phenotypic males
Estrogens and reptiles
American alligators impacted by xenoestrogens. Chemicals come from oral contraceptives and natural estrogen from human excretions.
Genotypic femalses become phenotypic males
Nonylphenol and Fishes
Used for many years as pesticide solvent and detergent. Stimualtes the estrogenic receptor thus creates an overpoduction of the egg protein, vitellogenin in gentypic males. Males become feminized and infertile. Also cause hermaphroditism
Endocrine disruptors and human reproduction
Average sperm count has declined from 113 million/ml to only 66 million/ml
Males considered infertile when count declines below 20 million/ml
Category A
biological weapons
small pox:
fever, fatiuge
If sprayed, 90% inactivated within 24 hours.
practically eradicated.
Anthrax
fever,fatigue,
found naturally in soils, very stable.
bubonic plague
originally an naimla diseas w/ a rodent host and a flea vector.
characterized by buobes: nodules of tissue swelling filled w/ the bacterium
Typhoid fever:
contact w/ tissues of infected animals, bites inhalation, ingestion
viral hemorrhagic fevers
hemorrhagic is uncontrolled bleeding.
Hanninabl
hurled clay vases filled w/ venomous reptiles (184 BC)
Middle ages and black death
tarta soliders hurled cadavers of plague victims over the city walls
Smallpox
Pizarro gave indigenous people of south america small pox infected clothing
French and Indian wars
Give native americans loyal to the french small pox contaminated blankets
WWI
Germans shipped livestock to US and Russia infected w/ anthrax
WWII
Japanese biological wweapons programs used over 3,000 POWs for experimentation
Start Studying!

Deck Info

218

permalink