Unit 8: Aquatic and Terrestrial Pollution

Global HIV/AIDS Epidemic Case Study

- 34.2 million infected with HIV
- transmitted through exchange of bodily fluids

- 1.7 million deaths/year
consequences = orphaned children, diminished opportunities/access to education and health care, decreased food production and economic development (lack of adult workers)

Biological Hazard

living organisms that cause transmissible disease and non communicable disease

Chemical Hazard

harmful chemicals in air, water, soil, and food

Physical/Natural Hazard

fire, earthquake, flood, tornado, hurricane

Cultural/Lifestyle Hazards

smoking, unsafe working conditions, poor diet, drugs, drinking, unsafe sex, poverty, etc.

Top 3 Causes of Death by Infectious Diseases

1. lower respiratory infections
2. HIV/AIDS
3. diarrheal diseases

Ways to Prevent Death by Infectious Diseases

- understand capability of economy
- provide infrastructure and nutrition (food, clean water, etc.)

Epidemic

large-scale outbreak of an infectious disease in an area or country

Pandemic

global epidemic

Tuberculosis

1.5 million deaths/year
- major cause of death of AIDS patients (die from weakened immune system, not from AIDS itself)

big issues = screening is expensive, prohibitive - access for transportation in developing countries and treatment is lengthy and costly

Antibiotic Resistance

bacteria become resistant to antibiotics

How Antibiotic Resistance Occurs

- High reproductive rate/horizontal gene transfer
- Overuse, misuse of antibiotics in human and livestock
- Pesticide-resistant insects/other vectors
- More human travel and international trade

Malaria

- 212 million cases and
429,000 deaths (2015)

treatment: drugs, mosquito nets, use of insecticides

Reducing the Incidence and Deaths of Disease

- Vaccines
- Oral rehydration therapy
- Public health programs
- Access to clean water
- Reduce poverty and malnutrition
- Reduce unnecessary use of antibiotics

Ecological Medicine

track infectious disease that
potentially cross from animals to humans

crossover occurs from increased contact with wildlife,
practices of raising livestock, trade of wild species

Mutagens

cause mutations in DNA

Teratogens

causes birth defects to fetus or embryo

Carcinogens

promotes cancer

Effects of Chemical Hazards

immune system: leaves body vulnerable to allergens or infectious agents
- chemicals make body unable to fight infections thus making it weaker

nervous system (neurotoxin):
results in behavioral changes, learning disabilities, paralysis, death

endocrine system (hormonally active agents-HAA: DDT,
atrazine-herbicide): binds to hormone receptors
- hormone mimic
phthalates (plasticizers in PVC) and BPA (plastic) is a estrogen mimic

- hormone blockers
- others can disrupt production of hormone or other
pathways
perchlorates can compete with iodine for
production of thyroid hormone

PCBs Case Study

polychlorinated biphenyl
- organic compounds that are stable and nonflammable

US banned domestic production in 1977 after research showed it is a carcinogen and teratogen.
- lubricants, insulators, paints, preservatives, pesticides, etc.
take a long time to break down in environment + fat soluble
- 70% of all PCBs made in US still in the environment

Toxicology

effects of harmful chemicals on humans, wildlife and ecosystems

Toxicity

measure of how harmful a substance is in causing injury, illness or death

Dose

"the dose makes the poison"
LD50 + LC50

Genetics

are you more susceptible to certain toxins as it runs in the family?

Solubility

water soluble: move through the environment and body (urine)

fat soluble: accumulation in the tissue

Persistence

how long a toxin will remain in the environment for

Bioaccumulation

accumulation of a toxic chemical in the tissue of a particular organism

Biomagnification

increased concentration of a toxic chemical the higher an animal is on the food chain

Chemical Interactions

antagonistic vs. synergistic

increase when working together; old building materials promotes lung cancer but combined with smoking increases tremendously

Acute vs. Chronic Effects

short vs. long term effects of a toxin

Joseph V. Rodricks

"Toxicologists know a great deal about a few chemicals, a little about many, and next to nothing about most"

US National Academy of Sciences

estimates 10% of 85,000 synthetic chemicals in commercial use
screened for toxicity
2% to see if they are carcinogens, teratogens, mutagens

Precautionary Principal

only use things that are safe

"better safe than sorry"

dirty dozen are banned until they are shown that have negligible effect on environment

3M Company

"Pollution Prevention Pays"
- employees design programs to redesign equipment, use fewer hazardous raw materials,

recycle/sell toxic chemical outputs.
- prevented 1.4 million metric tons of pollutants
- saved $1.2 billion in waste disposal and material
costs

LD50

median lethal dose
- relative indicator of how toxic or how dangerous chemical is

dose that kills 50% of animals in a test population within certain period of time.
- measured in amount/kg of body weight

What is more toxic? Something with LD50 75 or 10?

LD50 10 is more toxic because it takes a smaller dose to kill half of the population

more toxic = lower LD 50

LC50

median lethal concentration
- concentration not dose

ex: fish in water

Graphing Data to Determine LC50

x axis: low to high concentration (10x)
y axis: % of organisms that die

plot curve and see where 50% die and then = LC50

semi log paper every big line = fold of 10 (10, 1, 0.1, 0.01, 0.001, etc.)
- nine lines between 10 and 1

Risk Assessment

evaluating probability of hazards and risk

Risk Management

determining options and making decisions about reducing or eliminating risks
- comparative risk analysis: ranking risks

Risk Communication

informing decision makers
and public

Epidemiological Studies

compares health of "experimental" group to "control" group to see if exposure to a particular chemical is statistically
associated
- limited by size of experimental group, length of time, isolating variables

can't be used to predict harm of new technologies/chemicals

High Risk Problems

chronic low problems

Low Risk Problems

mostly occur in isolated instances but media focuses on problems

What shortens life the most?

poverty shortens the most; hinders access to education, medicinal, nutrition

different hazard and life factors negatively affect life span

Non-threshold Dose-Response Model

demonstrates that any dosage of a toxic chemical causes harm that increases with the dosage
- higher the dosage the more harm it causes

Threshold Dose-Response Model

threshold dosage must be reached before any detectable harmful effect occur
- body will be able to repair the low dosage damage from certain substances

small doses are not harmful; certain doses are toxic at a certain level-due to the body's repairing operations

Challenges in Determining Toxicity

- application of the different models to low dosage supplements
- tests are done on animals = human physiology differs from that of animals
- exposed to a variety of chemicals which interact differently varying on the person

Dioxins

harmful chlorinated hydrocarbons made by various industrial processes as by-products
- compose of more than 75 compounds

dangers to humans: classified as carcinogens + disruption of the reproductive, endocrine and immune systems

Lichen Case Study

lichen is an indicator species - indicate various pollution

Structure of the Atmosphere

top - bottom
1. exosphere
2. thermosphere
3. mesosphere
4. stratosphere
5. troposphere

gravity increases going downwards = high density + pressure

Troposphere

layer closest to earth
- 78% N2
- 21% O2

weather and climate + nutrient cycling

temperature decreases with altitude: heated by
earth surface

Stratosphere

second layer
ozone layer: filters out UV radiation

temperature increases with altitude: absorption
of UV by oxygen molecules

Natural Pollutants

dust, ash and gasses from volcanic eruptions, VOCs (plants)

Human Pollutants

burning fossil fuels, industrial plants
- mobile and stationary sources.

Primary Pollutants

emitted directly into air

Secondary Pollutants

primary pollutants reacts with other chemicals in air to produce new pollutants

Carbon Monoxide (CO)

colorless, odorless gas
result of incomplete combustion of carbon
primary pollutant

sources: exhaust from cars, fires, open fires

effects: binds to hemoglobin and reduces ability of
RBC to transport oxygen
- long term exposure: can trigger heart attacks, worsen lung diseases

Carbon Dioxide (CO2)

colorless, odorless gas
primary pollutant

sources: burning of fossil fuels, clearing forests
and grasslands

effects: greenhouse effect, climate change

Nitrogen Oxide (NO)

nitric oxide
primary pollutant

source: formed when nitrogen reacts with oxygen
at high temperature in engines and coal burning
plants

contributes to photochemical smog, irritate
respiratory systems

Nitrogen Dioxide (NO2)

reddish-brown gas
primary pollutant

source: NO reacts with oxygen
- can react with water vapor in air to form nitric
acid (HNO3) and nitrate salts-components of
acid deposition

contributes to photochemical smog, irritate
respiratory systems

Nitrous Oxide (N2O)

source: emitted from fertilizers and animal waste, burning fossil fuels
primary pollutant

effects: greenhouse gas, irritate respiratory
systems, breaks down stratospheric ozone

Sulfurous Dioxide (SO2)

colorless gas, irritating odor
primary pollutant

source: sulfur cycle (reaction of hydrogen sulfide
and DMS, emitted from volcanoes)
- combustion of coal, smelting of sulfide ores, oil refining
- can react with water vapor in air to form sulfuric
acid (H2SO4) and sulfate salts-components of
acid deposition

effects: respiratory problems, damage wildlife

Suspended Particulate Matter

solid particles and liquid droplets that are small enough to remain suspended in the air
primary pollutant

natural sources: dust, sea salt, ash/dust from wild
fire

human sources: plowing, road construction, tobacco, smoke, coal burning power plants, motor vehicles

Particulate Matter Size

fine particles (diameter less than 10 μm) and ultrafine particles (diameter less than 2.5 μm)
are most harmful
- irritate airways, aggravate asthma and
bronchitis
- lead, cadmium, PCBs can cause cancer,
reproductive problems etc.

Ozone

tropospheric ozone is a pollutant
colorless, highly reactive
secondary pollutant

effects: Irritate respiratory system, worsen respiratory diseases, damage plants

VOCS

volatile organic compounds (vaporize easily):
hydrocarbons like isoprene, terpenes, methane
primary pollutant

natural sources: plants, wetlands, termites

human sources: rice paddies, landfills, oil and
natural gas wells, cows, chemical products (vinyl
chloride, benzene, dry-cleaning fluids, gasoline,
plastics, synthetic rubber, etc.)

effects: blood disorders, damage immune system

Radon-222

colorless, odorless gas produced by natural radioactive decay in rocks and soils
primary pollutant

- can enter homes through cracks in foundations and
walls, openings around pumps and drains, and hollow concrete blocks
- build up in homes

- can control by sealing
cracks, and increasing
ventilation

effects: naturally occurring radioactive gas + can cause lung cancer

uranium-238 --> radon-222 --> polonium-210

Effects of Air Pollutants

irritation of respiratory tract
- upper: nose, throat
- lower: lungs

results in shortness of breath, dizziness, headache
- aggravate asthma and bronchitis
- increased susceptibility to respiratory infections
- lung cancer

Industrial Smog

burning coal in industrial areas and
homes
ex: CO, CO2, SO2, H2SO4, (NH4)2SO4, soot

not a major problem in most developed countries - not as much heavy industry

major problem in China, India, Ukarine

Asian Brown Cloud

thick cloud of industrial smog that spans India, Bangladesh, and China
caused by coal and clearing forests

problems: mobile; circulate globe

effects: agriculture = reduced photosynthesis (less
sunlight and damage to plants) and acid rain, health = poor air quality, biodiversity = acid rain and other chemicals toxic.

Photochemical Smog

mixture of pollutants formed due to reaction with UV radiation
- worse on hot days

VOCs + NOx + heat + sunlight
+O3 + nitric acid
+ aldehydes
+ PANs (peroxyacyl nitrates)
+ secondary pollutants
+ other photochemical oxidants

effects: capable of inflicting damage on the lungs and heart

Factors that Reduce Outdoor Pollution

gravity: settles out particles

rain and snow: "washes" air

salty sea spray: "washes" air

winds: dilute/mix air

chemical reaction: formation of acid deposition can make it fall out of atmopshere

Factors that Increase Outdoor Pollution

urban buildings: slow down winds that dillute/remove pollutants

hills and mountains: reduces air flow in valleys

higher temperature: increase rate of chemical
reactions

VOC emission from trees/plants

grasshopper effect: carries pollutants to polar areas

temperature inversion: traps pollutants when
warmer air overlays cooler air
- in valley where cloudy/cold weather prevents
heating of air
- city with sunny climate and mountains on 3
sides and ocean! (LA)

Acid Deposition

wet deposition with pH less than 5.6 and acidic particles
- normal rain has pH~5.6 due to CO2

wet deposition: acidic rain, snow, fog
dry deposition: acidic particles

source: coal burning plants, ore smelters, industrial
plants, cars

local problem: emission of air pollution, reduced
with smoke stacks
regional problem: downwind of source

Harmful Effects of Acid Deposition

- chronic respiratory diseases
- leach toxic metals from soils and rocks that
contaminate fresh water
- damage buildings/metals
- aquatic systems
- farms/crops and forests* (mostly regional)
- leach nutrients and release toxic metals

Solutions to Acid Deposition

prevention > clean-up

prevention: reduce use of coal, increase use of renewable energy resources, remove particulates from gasses in smokestack

clean-up: limestone (CaCO3)

Exposure to Pollutants

levels of 11 common pollutants 2-5 times higher
inside US homes/buildings than outdoors
- exposure magnified by time spent indoors/in a car
- greater risk for smokers, infants and children, the
old, sick, pregnant women, people with respiratory
or heart problems and factory workers

Sick Building Syndrome

situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified (EPA)

Sources of Indoor Pollution

- cleaners
- stoves/heaters
- furniture
- aerosol sprays

living organisms: dust mites, cockroach
droppings, spores of mold
and mildew

Developed Countries Indoor Pollution

- spend more time indoors and in cars

- tobacco, formaldehyde, radon-222: seeps in from
soil/rock, particulates: pollen, pet dander, dust mites

Developing Countries Indoor Pollution

greater use of wood/biomass burning stoves

Health Effects of Air Pollution

respiratory system has natural defense mechanisms
- hair filters out particles
- mucus capture smaller particles
- sneezing/coughing expels air/mucus
- cilia move mucus

exposure to air pollutants can damage respiratory system

Deaths and Illnesses of Air Pollution

mostly from chronic (long term) exposure
- 3 million deaths world wide, mostly from indoor air pollution (2.2 million)

50-350 thousand deaths in US
- more productivity lost due to illness
- diesel fumes from busses, trucks, cargo ships

contribute to 125,000 cases of cancer in US
- more particulate matter
- EPA emission standards (effective 2007, full 2012)

Preventing and Reducing Air Pollution

1. national and international laws
- policy
- regulation and oversight
2. using the marketplace
3. clean up

National Ambient Air Quality Standards

6 criteria pollutants (common/widespread, and harmful): CO, NOx, SO2, suspended particulate
matter, O3, Pb

primary standard: protect human health

secondary standard: prevent environmental and property damage

188 Hazardous Air Pollutants (HAPS)

toxic release inventory: requires refineries, power plants, mines, chemical manufacturers, factories to report + release data about release of pollutants and waste management of toxic chemicals

Operating Standards for Major Polluters

stationary: power plants, factories

mobile: cars, trucks, trains (regulates both fuel and performance standards)

Clean Air Act

6 criteria pollutants
- states implement
- attainment v. non-attainment areas
- controlling air pollution at the source

identify polluters and new sources must meet program requirements to maintain air quality = BACT (best available control technology)
- permits must be obtained by new polluters, and must demonstrate it will meet maximum achievable pollution control requirement

Results of Clean Air Act

6 criteria pollutants decreased
- require power plants to install scrubbers, lower sulfur fuels, catalytic converters for vehicles

continued significant photochemical smog (need reduction in nitrogen oxides from industrial plants and vehicles)
- need for stronger pollution control of ground level ozone, particulates

Improving US Air Pollution Laws

US still relies on pollution clean up rather than prevention!***

- feebate program
- need for regulation of emissions from motorcycles, two-cycle gasoline engines, oceangoing ships
- need for air pollution regulation at airports, CO2, ozone (secondary), indoor air pollution
- better enforcement of Clean Air Act

Cap and Trade Program

CAA allows emission trading (cap-and-trade program)
of SO2
- buy and sell SO2 pollution rights

coal-burning power plant given credits (allowed emissions)
- emit less = sell

Issues of Cap and Trade Program

- self-reporting
- allow old power plants to buy their way out
- not producing as much emission reduction
- need to set lower initial cap and annual reduction

Electrostatic Precipitator

output solution

- remove 99% particulates
- uses a lot of electricity
- not effective in removing ultrafine particles
- toxic dust

Wet Scrubber

CaO or CaCO3
output solution

- remove 98% SO2 and particulate matter
- expensive
- not effective in removing
ultrafine particles
- sludge of CaSO3
produced

Input Solutions to Indoor Pollution

burn lower sulfur coal (found in the west, coal is burned in east)
- coal gasification (syngas)
- fluidized-bed combustion
- blow hot air into boiler to burn powdered coal + crushed limestone

- burns at lower temperature: NOx don't form
- can control sulfur dioxide emissions
- more efficient at health

Alternatives to Reduce Indoor Air Pollution

- clay or metal stoves to vent and burn fuels more efficiently
- burn biofuels
- solar cookers

Predicting Climate Change Case Study

volcanic eruption 1991 = Philippines
- NASA scientist predicts will cool earth 0.5 oC over 15 months -return to normal by 1995
- model accurately predicts changes in atmospheric temperature

significance = convinced people that climate model projections and impact of human actions should be taken seriously

Glacial and Interglacial Periods

Earth's climate has undergone series of changes over its lifetime due to many factors including: volcanic emissions, changes in solar input, moving of continents, large meteors

over 900,000 years, glacial and interglacial periods caused by:
- change in elliptical orbit of earth
- wobble of axis
- sun spots, solar magnetic cycles
- volcanic eruptions

Historical Temperatures

determined by proxy measures
- tree ring widths: thicker rings when warmer
- coral growths: amount of growth, and isotope of oxygen in calcium carbonate (cooler, heavier isotope)
- isotope in ice: O-18 condenses at higher temperature than O-16 = warmer periods results in more O-18 in higher latitude
- borehole temperatures
- pollen trapped at bottom of lakes and bogs
- analyze ice cores: levels of CO2 in troposphere correlate with temperature