Download health hazards- diseases, toxins and pollution ppt

Diseases, Toxins and Pollution
Types of Hazards
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Biological
Physical
Chemical
Cultural
 Lifestyle choices
 Hazard - Anything that causes:
 Injury, disease, or death to humans
 Damage to property
 Destruction of the environment
http://www.chathamjournal.com/weekly/moxiepix/a3463.jpg
Major Causes of Death in the World
and in the United States in 2005
Diseases
 Since 1900, and especially since 1950, the incidences of
infectious diseases and the death rates from such
diseases have been greatly reduced (antibiotics,
vaccines).
 However, it appears that the world today is becoming
more vulnerable to the outbreak of “new” diseases and
the re-emergence and spread of old ones.
 Since the 1970s, an average of one new emergent
disease has appeared each year.
 WHY?
Top 5 Infectious Diseases
1) Influenza
2) AIDS
3) Dysentery (diarrheal diseases)
4) Tuberculosis
5) Malaria
The World’s Seven Deadliest Infectious
Diseases Kill 12.5 Million People Annually
Diseases Hosts, Vectors and Reservoirs
 Lyme disease can be
processed to humans through
a bite from an infected tick
 Mosquitoes transmit malaria,
the vector for Plasmodium
 The protozoan of the genus
Plasmodium is the causative
agent of malaria
Disease Outbreaks
 Outbreaks result from change in a physical, social, or
biological environment of host, vectors, or disease
reservoirs.
 Vectors – agents of disease transmission; an
intermediate host of pathogens/parasites.
 Examples – mosquitoes, birds, fleas, ticks
 Disease-causing organisms can be spread by natural
disasters – floods, landslides, hurricanes.
 Katrina, Haiti, Japan
Tracking the Spread of Infectious Diseases
to Humans from Other Animals
 Human practices that encourage the spread of diseases
– i.e., global travel, animal feed consisting of dead
carcasses, an increasing human population.
 Emerging infections
 HIV
 SARS
 West Nile virus
 Lyme virus
Ebola virus
Bird flu
Historical Diseases
 Plague
 Tuberculosis
Malaria
Influenza
Cholera
Typhus
 Growing Global Threat from TB
Why is tuberculosis on the rise?
 Not enough screening and control programs
 Genetic resistance to a majority of effective antibiotics
 Person-to-person contact has increased
 AIDS individuals are very susceptible to TB
Case Study: Malaria
Malaria
Caused by
Plasmodium species
of protozoa
Carried by
Anopheles
mosquitoes
Symptoms = chills,
fever; enlarged
spleen
Change in disease
reservoirs
El Nino
Case Study: Malaria
Malaria decreased
sharply during mid1900s
 draining swamplands
and reservoirs
 Spraying mosquito
breeding areas with
insecticides (DDT)
 Using drugs/vaccines
to kill parasites
(Plasmodium) in the
bloodstream
 Malaria on the rise
since 1970
 Reservoirs for
hydropower have
increased
 Drug resistant
Plasmodium
 Insecticide resistant
mosquitoes
 Effect of climate change
 AIDs patients
particularly vulnerable
Increased Genetic Resistance to
Antibiotics
 Rise in antibiotic-resistant pathogens are attributed to
 Rapid reproduction rate of microbes allows for natural
selection for resistance
 Global travel allows for quick movement between
continents/countries
 Overuse of antibiotics; full prescription not always
followed to the end
 Use of antibiotics in cattle feed
 Overuse of pesticides
 Methicillin-resistant Staphylococcus aureus
(MRSA)
 Resistant to most antibiotics
 How will it be controlled?
Global Outlook: Distribution of
Malaria at Present
A Model for Increased Malaria Risk Due to
Climate Change
Disease
SARS
West Nile
Mad Cow
Disease
Malaria
Cholera
Tuberculosis
Category
E = Emerging
H = Historical
Mode of
Transmission
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
Disease
Category
E = Emerging
H = Historical
SARS
E
West Nile
E
Mad Cow
Disease
E
Malaria
H
Cholera
H
Tuberculosis
H
Mode of
Transmission
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
Disease
Category
E = Emerging
H = Historical
SARS
(Severe Acute
Respiratory
Syndrome)
E
West Nile
E
Mad Cow
Disease
E
Malaria
H
Cholera
H
Mode of Transmission
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
•Direct – animals to humans
•Destroy infected animals
Growth in human
population
ⱡ Human →human
- respiratory droplets
- person to person contact
ⱡ Wash hands frequently
Wear facial masks
Quarantine
Disease
SARS
West Nile
Category
E = Emerging
H = Historical
E
E
Mode of Transmission
E
Malaria
H
Environmental Factor
Contributing to
Emergence/Reemergence
•Direct – animals to humans
ⱡ Human →human
- respiratory droplets
- person to person contact
•Destroy infected animals Growth in human
ⱡ Wash hands frequently
population
Wear facial masks
Quarantine
• and ⱡ Bitten by infected
mosquitoes
•Reduce mosquito pop
- (insecticides, intro.
predators)
- eliminate standing
water
- Barriers – clothing,
screens, insect
repellant
ⱡ Blood transfusions
Mother to fetus
Mad Cow
Disease
Method of Controlling
Spread
- ↓ in mosquito predators
- Climate variability
- Global transport of
materials
Disease
Category
E = Emerging
H = Historical
SARS
E
West Nile
E
Mad Cow
Disease
E
Mode of Transmission
•Animal feed containing
remains of infected animals
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
- Destroy infected animals
- Protein mutation (ind.
cows_
- Adding ground-up
remains of dead cattle
and sheep to cattle feed
- Let cows eat grass!
ⱡConsumption of beef
containing prions
Malaria
H
Cholera
H
Tuberculosis
H
Disease
Category
E = Emerging
H = Historical
SARS
E
West Nile
E
Mad Cow
Disease
Malaria
E
Mode of Transmission
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
•Animal feed containing
remains of infected animals
- Destroy infected
animals
ⱡConsumption of beef
containing prions
• and ⱡ Mosquito bite
- Let cows eat grass!
- Protein mutation (ind.
cows_
- Adding ground-up
remains of dead cattle and
sheep to cattle feed
- ↓ in mosquito predators
- Climate variability
- Genetic resistance
H
ⱠBlood transfusions
Cholera
H
Tuberculosis
H
Ditto West Nile
Disease
Category
E = Emerging
H = Historical
SARS
E
West Nile
E
Mad Cow
Disease
E
Malaria
H
Cholera
Tuberculosis
H
H
Mode of Transmission
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
Ingestion of food or water
contaminated with human
feces
- Water treatment
- Standards for food
prep
- Boil water to kill
bacteria
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Lack of
sanitation/potable
water
Flooding
Climate variability
Disease
Category
E = Emerging
H = Historical
SARS
E
West Nile
E
Mad Cow
Disease
E
Malaria
H
Cholera
H
Mode of Transmission
Ingestion of food or water
contaminated with human
feces
Method of Controlling
Spread
Environmental Factor
Contributing to
Emergence/Reemergence
- Water treatment
- Standards for food prep
- Boil water to kill bacteria
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Tuberculosis
H
Respiratory droplets
(coughing, sneezing,
mucus)
- Immunization programs
- Quarantine
- Antibiotics if infected
Lack of
sanitation/potable
water
Flooding
Climate variability
- ↑ in population density
- Bacterial resistance to
antibiotics
Waterborne
Diseases
 Lack of access to safe drinking
water is a major cause of
disease transmission in
developing countries.
(cholera, giardia)
 Epidemiology is the study of
the presence, distribution and
control of a diseases in a
population
 Morbidity is the incidence of
disease in a population
 Mortality is the incidence of
death in a population
Waterborne Diseases – Protozoan Infections
Disease and
Transmission
Microbial Agent
Sources of Agent in
Water Supply
Amoebiasis (hand-tomouth)
Protozoan (Entamoeba
histolytica) (Cyst-like
appearance)
Abdominal discomfort,
Sewage, non-treated
fatigue, weight loss,
drinking water, flies in water
explosive diarrhea, bloating,
supply
fever
Cryptosporidiosis (oral)
Flu-like symptoms, watery
Collects on water filters and
diarrhea, loss of appetite,
Protozoan (Cryptosporidium membranes that cannot be
substantial loss of weight,
parvum)
disinfected, animal manure,
bloating, increased gas,
seasonal runoff of water.
nausea
Cyclosporiasis
Protozoan parasite
(Cyclospora cayetanensis)
Sewage, non-treated
drinking water
General Symptoms
cramps, nausea, vomiting,
muscle aches, fever, and
fatigue
Untreated water, poor
disinfection, pipe breaks,
leaks, groundwater
Protozoan (Giardia lamblia) contamination,
Diarrhea, abdominal
Giardiasis (fecal-oral) (handMost common intestinal
campgrounds where humans discomfort, bloating, and
to-mouth)
parasite
and wildlife use same source flatulence
of water. Beavers and
muskrats create ponds that
act as reservoirs for Giardia.
Parasitic infections
Sources of Agent in
Water Supply
General Symptoms
Schistosomiasis
Members of the genus
Schistosoma
Fresh water contaminated
with certain types of snails
that carry schistosomes
Blood in urine (depending
on the type of infection),
rash or itchy skin. Fever,
chills, cough and muscle
aches
Taeniasis
Tapeworms of the genus
Taenia
Drinking water
contaminated with eggs
Intestinal disturbances,
neurologic manifestations,
loss of weight, cysticercosis
Drinking water
contaminated with eggs
Abdominal pain, severe
weight loss, itching around
the anus, nervous
manifestation
Drinking water
contaminated with feces
containing eggs
Mostly, disease is
asymptomatic or
accompanied by
inflammation, fever, and
diarrhea.
Disease and species
Hymenolepiasis (Dwarf
Tapeworm Infection)
Ascariasis
Microbial Agent
Hymenolepis nana
Ascaris lumbricoides
Waterborne Bacterial Infections
Cholera
Spread by the bacterium
Vibrio cholerae
E. coli Infection
Certain strains of
Escherichia coli
Dysentery
Caused by a number of
species in the genera
Shigella and Salmonella
Legionellosis (two distinct Caused by bacteria
forms: Legionnaires' disease belonging to genus
and Pontiac fever)
Legionella
Drinking water
contaminated with the
bacterium
Water contaminated with
the bacteria
Water contaminated with
the bacterium
Contaminated water: the
organism thrives in warm
aquatic environments.
In severe forms it is known
to be one of the most rapidly
fatal illnesses known.
Symptoms include very
watery diarrhea, nausea,
cramps, nosebleed, rapid
pulse, vomiting (in severe
cases), at which point death
can occur in 12–18 hours.
Mostly diarrhea. Can cause
death in
immunocompromised
individuals, the very young,
and the elderly due to
dehydration from prolonged
illness.
Frequent passage of feces
with blood and/or mucus;
some cases vomiting of
blood.
Pontiac fever produces
milder symptoms
resembling acute influenza
without pneumonia.
Legionnaires' disease has
severe symptoms such as
fever, chills, pneumonia
The Current Leading Sources of Impaired Waterways in
the United States
Streams and rivers
Lakes, ponds and
reservoirs
Bays and estuaries
Causes of Impairment Sources of
Impairment
Bacterial pathogens,
Agriculture, water
habitat alteration,
diversions, dam
oxygen depletion
construction
Mercury, PCBs,
Atmospheric
nutrients
deposition, agriculture
Bacterial pathogens,
oxygen depletion,
mercury
Atmospheric
deposition, municipal
discharges including
sewage
Maximum Levels for Contaminants in
Drinking Water Allowed by EPA (ppb)
Contaminant
Category
Contaminant
Maximum
Contaminant Level
(ppb)
Microorganism
Giardia
0
Microorganism
Fecal coliform
0
Inorganic chemical
Arsenic
10
Inorganic chemical
Mercury
2
Organic chemical
Benzene
5
Organic chemical
Atrazine
3
Solutions
 Increase research on diseases and vaccines
 Reduce poverty
 Increase quality of drinking water
 Educate people about antibiotic use/reduce antibiotic
use to promote livestock growth
 Immunizations/vaccinations
Hazardous Wastes
 A class of waste materials that poses immediate or
long-term risks to human health or the environment
and requires special handling for detoxification or safe
disposal.
 Considered “hazardous” if it possesses one of 4
properties
Flammable
2. Unstable
3. Corrosive
4. Classified as a “toxic chemical”
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Carcinogenic, mutagenic or teratogenic
Electronic Waste
 E-waste consists of
toxic and hazardous
waste such as PVC,
lead, mercury and
cadmium.
Toxic Components in E-Waste
Some Metals in Cell Phones
Common Household Hazardous Wastes
 Motor oil
 Paints
 Batteries
 Antifreeze
 Fertilizers
 Computers
 Cell phones
Types of Chemical Hazards
 Toxic chemicals
 Neurotoxins
 Carcinogens
 Mutagens
 Teratogens
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Endocrine disruptors
Many can weaken or harm the nervous system, immune
system, and endocrine system
Toxic Chemicals
 Carcinogenic - cancer-causing
 Examples – cigarette smoke, radon, asbestos, PCBs
 Mutagenic – cause changes in DNA resulting in
mutations; can also cause birth defects
 Examples – exposure to radiation, viruses, high
temperatures
Toxic chemicals (cont.)
 Teratogenic – cause birth defects
 Examples – dioxin, PCBs, DDT, thalidomide, steroids,
bisphenol-A
 Include some endocrine disruptors or synthetic
hormone mimics
 Endocrine system – system responsible for growth,
reproductive development and much of our behavior.
Endocrine Disrupters
 Aka “gender benders”
 Organisms affected are mostly aquatic
 Can interfere with reproduction
 Case study – feminization of alligators in Lake Apopka, Orlando, FA
 Males produce eggs as well as sperm; however, they do NOT develop
female reproductive organs
 Interfere with normal hormone action
 i.e. – interfere with the production of testosterone
males have higher than normal levels of estrogen
 Can interfere with development
 Are often connected to cancer
 Are found in plastics and some pesticides
 Bisphenol A – estrogen mimic
Potential Pathways on Which Toxic Chemicals
Move Through the Environment
Case Study: PCBs Are Everywhere—A
Legacy from the Past
 Class of chlorine-containing compounds
 Break down slowly in the environment
 Travel long distances in the air
 Fat soluble – bioaccumulation in body tissues
 Biomagnification – amplified at higher trophic levels of
food chains and webs
 Banned, but found everywhere
 DDT accumulates in fat body
tissues of animals
(bioaccumulation)
 DDT – an insecticide used to
kill body lice, mosquitoes
 DDT is a persistent, synthetic
organic compound subject to
biomagnification in food
chains
Pesticide
Exposure
Mercury’s Toxic Effects
 2007: Hg hotspots identified
 How are humans exposed?
 Inhalation: vaporized Hg or particulates of inorganic
salts
 Eating fish with high levels of methyl mercury
 Effects of Hg on humans
 Who is most at risk?
Cycling of Mercury in Aquatic Environments
Many Factors Determine the Harmful
Health Effects of a Chemical
 Toxicology – a measure of how harmful a substance is
in causing injury, illness or death to an organism.
 Toxicity dependents on
 Dose – the amount of substance a person ingests, inhales or
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absorbs through the skin.
Frequency of exposure
Genetic makeup or sensitivity
Ability of body to detoxify (children)
Solubility and persistence of the chemical
Biomagnification
 Response – the type & amount of health damage that
occurs from exposure to a chemical or agent.
 Acute effect – high-level doses over short period
 Chronic effect – low-level doses over long period of time; can
effect immune, endocrine and nervous systems.
Dose-Response Curve Showing LD50 Level
• LD50 (lethal dose) or LC50
(lethal concentration) – the
amount of substance, given
all at once, which causes the
death of 50% (one half) of a
group of test animals.
• LD50 is one way to
measure that shortterm poisoning
potential (acute
toxicity) of a substance.
• Threshold level – the
maximum level of a
chemical (toxic substance)
before effects are observed
and no lethal effects are
apparent.
Toxicity Ratings and Average Lethal
Doses for Humans
Why are Children More Susceptible
to Toxic Chemicals?
 Eat, drink water, and breathe more per unit of body
weight than adults
 Put their fingers in their mouths
 Less well-developed immune systems and body
detoxification processes
Risks
Cultural hazard - a risk that a person chooses to
engage in
Risk
The probability of suffering (1, 2, or 3) as a
result of a hazard
Perception
What people think the risks are
The Greatest Health Risks Come from
Poverty, Gender, and Lifestyle Choices
 Risk analysis
 Often a person’s perception of actual risk may not match
reality
 Actual risk assessment is based on mathematical probabilities
 The US keeps data on various hazards which is used to
determine actual risk
 Assessing actual risk involves quantitative analysis
 Greatest health risks
 Poverty
 Gender
 Lifestyle choices
Cigarette Smoking
 Leading cause of cancer in U.S.
 Can cause cancer, lung disease, a bigger risk of
death in addition with other types of air pollution.
 Synergistic effect
 Radon and smokers
 Asbestos and smokers
 Highest health risk in U.S.
Comparative Risk Analysis: Most
Serious Ecological and Health Problems
Annual Deaths in the U.S. from Tobacco
Use and Other Causes in 2004
Global Outlook: Number of Deaths per
Year in the World from Various Causes
Comparison of Risks People Face in Terms of
Shorter Average Life Span
Air Pollution
 Criteria pollutants – Dirty half dozen
 Primary
 Secondary
 Indoor pollutants
Legislation Related to Toxic
Chemicals
 Toxic Substances Control Act of 1976 – US
legislation that provides for the regulation of many
chemicals by the EPA, not including pesticides, food,
and cosmetics.
 The Stockholm Convention of 2001 – an
international agreement that placed restriction on a
list of 12 chemicals, known as “the dirty dozen”.
 Referred to as POPs – persistent organic pollutants
 Include PCBs, dioxins and various pesticides
Legislation Related to Hazardous Waste
 Resource Conservation and Recovery Act (RCRA)
 US law that gives the EPA the authority to control hazardous
waste from “cradle-to-grave”, including the generation,
transportation, treatment, storage and disposal of hazardous
waste.
 Requires producers of hazardous waste to keep records of
how their wastes are disposed
 Requires all hazardous waste treatment and disposal and
facilities be built and operated according to standards that are
designed to prevent the facilities from polluting the
environment.
 Meant to protect human health and environmental integrity
by reducing source hazardous waste.
CERCLA and RCRA together directly address any and all
handling of hazardous waste.
Legislation Related to Hazardous Wastes
 Comprehensive Environmental Responsibility
Compensation and Liability Act (CERCLA)
 Federal law that specifically deals with the cleanup of
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abandoned hazardous waste sites.
The law imposes a tax on targeted industrial facilities and
then utilizes those funds for cleanup.
Gives the EPA the right to sue the owners of hazardous waste
sites who had illegally dumped waste.
Allows the EPA to force the owners to pay for cleanup
Some use of taxpayer’s money
Created a fund of money to pay for cleaning up abandoned
hazardous waste sites, thus
Also called the Superfund Act
Superfund Program – was implemented in reaction to Love
Canal incident.
Map of Superfund Sites in the Contiguous United States
Red – currently on National Priority List
Yellow – proposed cleanup site
Green – has been cleaned up
Phytoremediation
Indian mustard
Sunflower
Willow tree
Poplar tree
Brake fern
Landfill
Polluted
groundwater
in
Decontaminated
Soil
water out
Groundwater
Rhizofiltration
Roots of plants such as
sunflowers with dangling
roots on ponds or in greenhouses can absorb pollutants
such as radioactive strontium90 and cesium-137 and various
organic chemicals.
Phytostabilization
Plants such as willow
trees and poplars can
absorb chemicals and
keep them from
reaching groundwater
or nearby surface
water.
Oil
spill
Polluted
leachate
Phytodegradation
Plants such as poplars
can absorb toxic organic
chemicals and break
them down into less
harmful compounds
which they store or
release slowly into the air.
Soil
Groundwater
Multiple Choice Strategies
 If you don’t know it – circle it an go back to it later.
 When you go back, try to eliminate one or more
choices.
 Focus on key words
 Best suited vs. least suited
 Directly affected vs. not directly affected
 All of the following except
 Best example
FRQs
 Four questions
 Math
 Graphing
 Reading a passage
 General knowledge
TIMING
 AP Environmental test = 3 hours
 FRQ portion = 90 minutes.
 Four FRQs = 22 minutes per question
SCORING
 FRQs account for 40% of exam score.
 Each FRQ = 10% of overall grade.
 Each FRQ = 10 points
SCORING (cont.)
 FRQs consist of subparts (a,b,c…)
 Each subpart is typically worth 2-4 points, depending
on complexity or number of parts to the question.
 It is possible for points available to total more than 10,
but the maximum score given for any FRQ is 10.
PARTIAL CREDIT
 Some parts are more simple, so do not omit/skip the
entire question just because other parts may be
difficult.
 Partial credit is always available as long as knowledge
about the question being asked is demonstrated.
FRQ Math Questions
 You must show your work in order to earn points on
math questions.
 Answers with no work shown earn 0 points.
 Incorrect answers that show correct problem set-up
earn partial credit.
OTHER HELPFUL HINTS
 Use complete sentences – no bullets.
 Read the question carefully and be sure to follow the
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instructions.
Be concise
Label answers to subparts (a,b,c….)
Show your work and include units.
Mistakes don’t erase; cross out.
–
FRQ Commands
 List – short concise statements
 Describe – 2 to 3 sentences with vocabulary and
examples
 Discuss or Explain – elaborate reasoning