Environmental Health Eoh 740

Front 1

ECOSYSTEMS

Back 1

The concept of nature as divided into
basic functional units called
ecosystems reflects the complex
manner in which organisms interact
with each other & with nonliving
components of their environment to
process energy & cycle nutrients.

Front 2

BIOTIC COMMUNITY

Back 2

Natural grouping of different kinds of
plants & animals within any given
habitat. (Biomes)

Front 3

Population

Back 3

Individuals of the same species living together within a given area.

Front 4

BIOMES

Back 4

Tundra
.. Taiga
.. Temperate Deciduous Forest
.. Grassland
.. Desert
.. Tropical Rain Forest

Front 5

Matter

Back 5

Matter Matter-Has mass and takes up space

Front 6

Atomic #

Back 6

# of protons

Front 7

Atomic Wt

Back 7

= # of protons and neutrons

Front 8

Isotopes

Back 8

= Same # of protons, various # N

Front 9

Ions

Back 9

Ions- charged particles (gain or lost electrons)

Front 10

Energy

Back 10

Ability to do useful work, comes in
many forms
– Heat, light, electrical, chemicaloo.c

Front 11

Types of Energy:

Back 11

potential
-kinetic
-chemical

Front 12

The First Law of Thermodynamics

Back 12

Conservation of energy

Front 13

The Second Law of Thermodynamics

Back 13

Entropy:
With every energy transformation,
there is a loss of usable energy (you
can can’t break even!).

10% Rule (Biomass a proxy for energy)ropy

Front 14

Producers

Back 14

Producers- large amounts of biomass
– Photosynthesis (Harness energy)
– 6CO 6CO2 +6H 6H20 = C 0 C6H12 1206 + 6O 6O2

Front 15

Consumers

Back 15

less biomass, obey
thermodynamic laws
– Respiration (releases energy)
– 602 + C6H12O6 = 6CO2 + 6H2O

Front 16

Environment is a living
System

Back 16

Elements
.. Compounds
.. Chemical Reactions/Physical Reactions
.. Producers/Consumers/Decomposers
.. Natural Cycles of Matter
.. Law of Conservation of Matter

Front 17

BIOGEOCHEMICAL CYCLING

Back 17

The cycling of earth materials through living systems and back to the earth.
..Nutrients
..Macronutrients
..Trace elements
..Water

Front 18

Carbon Cycling

Back 18

.. CO 2 in atmosphere (exhale please!)
.. CO 2 used by plants for photosynthesis
.. Converts from a gas to a solid (sugar)
.. Plant eaten by animal (solid to gas) via
cell respiration (enzymes)
.. Energy Energy…reduced to less useful form
.. Exhaled as CO 2
.. Global warming?

Front 19

Nitrogen Cycles

Back 19

.. Amino acids, peptides, nucleic acids,
proteins (all contain nitrogen)
.. Nitrate NO 3-, Nitrite NO , 2-, Nitrogen
, Molecule N 2 , Ammonium NH 4+, +,
Ammonia NH 3; Nitrous Oxide N 2O
.. Nitrogen fixing bacteria are key
.. Nitrates (NO 3-) most useful to plants

Front 20

Nitrogen: what it causes

Back 20

.. Controls primary terrestrial productivity
.. Eutrophication in lakes (aging)
.. Greatly altered by fertilizer use, burning
fossil fuels
.. Humans convert more nitrogen to ammonia
and nitrates than all natural land processes
combined!
.. Acid Rain (HNO HNO3) Nitric Acid along with Sn

Front 21

Phosphorous Cycle

Back 21

.. P leached from rocks
.. P has no gaseous form, usually liquid
.. Inorganic form incorporated into
organisms (plant), then passed onto
consumers.
.. Decomposition of consumers and
waste return (long time)=

Front 22

Phosphorous

Back 22

.. Fertilizers, Detergents and soaps
(cleaning agents)
.. In West US controls algae and plant
growth in lakes, blooms (aging)
.. Mostly discharged into waters as
“waste waste”l

Front 23

Biomes control plant ______

Back 23

Tolerances (heat, pH, nutriants, etc.)

Front 24

Relationship of Ecosystem to Biotic community

Back 24

All biotic communities w/i make up the biologic part of the ecosystems

Front 25

10% rule states that ...

Back 25

90% of energy is lost from one level to the next.

Front 26

1st Law of ecology ...

Back 26

you can never only do one thing.

Front 27

Energy levels for different levels of ecological pyramids.

Back 27

100% -> Producers ->
10% -> Primary consumers ->
1% -> secondary consumers ->
0.1 -> Tertiary consumers.

Front 28

Nitrogen fixation

Back 28

convert from biologically unavailable (N2) to biologically available (NO3)

Front 29

Nitrogen controls

Back 29

bottom level of food chain

Front 30

Phosphorus does not have a ______ form

Back 30

gaseous

Front 31

LIMITING FACTORS

Back 31

Environmental conditions that limit or control where an organism can live.i

Front 32

Law of the Minimum

Back 32

–“the growth of a plant is dependent on the amount of foodstuff which is presented to it in a minimum quantity”p

Front 33

Limits of Tolerance

Back 33

–Food, temp, water, pH, etc.

Front 34

Principle of Competitive Exclusiond

Back 34

When two species are competing for the same limited resources, only one will survive.
–Bighorn Sheep and “Wild”Burros

Front 35

ECOLOGICAL DOMINANTS

Back 35

Organisms which exert a major modifying influence on the community.

Front 36

Keystone Predators-

Back 36

greater than expected influence on the ecosystem (can be on the top or bottom) Wolves? Grasses?

Front 37

CHANGE IN ECOSYSTEMS

Back 37

..Ecological Succession
–Present ecosystems have their component communities changing in an orderly sequence within a given area.
..Pioneer Plants
..Primary & Secondary Succession
..Eutrophication
.. Climax

Front 38

What does this have to do
with Environmental Health?!

Back 38

.. The environment, which were are one part
of, is driven by living systems, cycles and
natural checks and balances designed to
maintain homeostasis.
.. Humans have disrupted ALL of these cycles,
resulting in changes to the health of the
systems and ALL the organisms living in
them.
.. Environmental Health IS Human Health!!!
– We all rely on the same systems, finite resources
and interactions with each other to survive.

Front 39

Limits to Growth

Back 39

In nature a given population of organisms tends to maintain relatively stable numbers over a long period of time

Front 40

Biotic potential

Back 40

Max number of offspring a female can potentially produce during her lifetime.ms-

Front 41

Environmental resistance

Back 41

something that retards the increasing number of members of a population: food, energy, space, water, etc.

Front 42

S-curve

Back 42

–Upper asymptote
–Carrying capacity -Max number of individuals that can be indefinitely sustained in a given area

Front 43

J-curve

Back 43

–Frequently results in population “crashes”
–Severe die-backs
–Preliminary “lag”phase

Front 44

Homeostatic Controls
•Self-regulating factors

Back 44

–Behavioral
–Physiological
–Social
•Rising levels of violence and aggression

Front 45

Doubling time

Back 45

–Numbers of years it takes a population to double in size
•70/Population Growth Rate (%) = D.T.
»70 / 2% = 35 years

Front 46

Urbanization

Back 46

•Urban explosion
•Third world slums
•Quality of life
•Disease outbreaks
•Pollution

Front 47

Population Projections

Back 47

•Decrease in growth rate vs. Population base
•Trends in fertility, mortality, and migration
•Replacement level –2 children per family
•“Constant fertility”

Front 48

Early Attempts at Family Limitation

Back 48

•Coitus interruptus
•Crude barriers to the cervix
•Herbal concoctions
•Condoms
•Breast feeding
•Abortion
•Infanticide

Front 49

Modern Family Planning Movement

Back 49

•Dr. Charles Knowlton
–“societies for the suppression of vice”
•Margaret Sanger
–Comstock Law
–National Birth Control League
–Planned Parenthood Federation

Front 50

Birth Control –Its Health Impact

Back 50

•Age of Mother
•Interval between births
–“maternal depletion syndrome”
•Total number of births
–More births = higher health risks

Front 51

Contraceptive Safety

Back 51

•Hormonal Contraceptives
–Birth-Control pill
–Norplant
–Depo-Provera
•Surgical Sterilization
•Intra-uterine device
•Spermicides
•Barrier Methods
–Vaginal Contraceptives
–Condoms
•Natural Family Planning)

Front 52

Family Planning in the Third World

Back 52

•Spreading the Word
•Motivation –the key to success
–High Infant Mortality Rates
–Children as “Social Security”
–Desire for sons
–Low Education and Economic Status of Women

Front 53

Population Policy: Moving Beyond Birth Control

Back 53

•Increasing availability of contraceptives
•Misperceptions about the health effects of certain contraceptives
•Cost
•Programs that focus on individual needs not numerical targets

Front 54

Factors Influencing Food Demand

Back 54

•Population Growth
•Rising personal income

Front 55

Extent of Hunger

Back 55

•Basal Metabolic Rate (BMR)
•The World Health Organization (WHO) estimates that every day 19,000 children die as a result of malnutrition and related ailments; malnutrition is the direct or indirect cause of more than half the deaths of children under age 5 in Third World Countries.

Front 56

Causes of Hunger

Back 56

•Uneven distribution of food
–Over past two centuries, food supplies have kept up with population growth
•Richer countries suffer over-nutrition
–20% of Americans seriously overweight
–Can past gains be indefinitely sustained
•Poverty
–Poverty is greatest threat to food security
•Chronic Hunger and Food Security
–Proportion of chronically hungry people in the world has stayed relatively stable, but total number has dramatically increased
•200 million children­

Front 57

Kwashiorkor

Back 57

protein deficiency; adiquate kcal.

Front 58

Marasmus

Back 58

both protein and cal deficiency .

Front 59

Xerophthalmia

Back 59

inability to produce tears - vit. A deficiency.

Front 60

Anemia

Back 60

lack of iron; vit B12; folic acid

Front 61

Goiter

Back 61

lack of iodine in diet (big throat growth [hypertophy of thyroid])

Front 62

Famines

Back 62

–Large-scale, acute food shortages
–Environmental problems usual trigger
•Politics and economics may prolong (i.e., war)
–People have survived these condition before
•Political boundaries now stop migration
•Food Aid policies are short-term solutions
•Feeding Camps are not efficient strategies
–Disease transmission

Front 63

Prospects for Reducing World Hunger

Back 63

•Expanding the amount of land under cultivation
•Increasing world fish catch
•Aquaculture
•Reducing Post-harvest food losses
•Eating lower on the food chain
•Improving yields per acre

Front 64

Three major crops for world nutrients:

Back 64

•Wheat, Rice, and Corn

–Other important staples
•Potatoes, Barley, Oats, Rye
–(High latitudes)
•Cassava, Sweet Potatoes
–(Moist, warm climates)

Front 65

Meat and milk distribution

Back 65

very inequitable
–90% of grain in NA used to feed livestock
•1 kg beef requires 16kg of soybeansprivate

Front 66

Fish and seafood

Back 66

important protein source for much of the world

•Most fisheries over-harvested
•On average, 1/4 unwanted by-catch

Front 67

Environmental refugees

Back 67

people seeking refuge abroad due to environmental problems at home

Front 68

Degradation of Land Resources

Back 68

•Overgrazing
•Soil Erosion (only top two layers have nutiants)
•Deforestation
•Desertification
•Wetlands Loss
•Loss of
Biodiversity

Front 69

Earth’s total land area: 132.4 million km2

Back 69

–Cropland11%
–Range / Pasture26%
–Forest / Woodlands32%
–All Other31%
•Humans have altered all parts of globe

Front 70

Annual Land Degradation

Back 70

–3 million ha cropland ruined by erosion
–4 million ha cropland turned into deserts
–8 million ha cropland converted to non-agricultural usese

Front 71

Overgrazing

Back 71

Historically, the US supported large herds of migratory mammals.
–Grazing effect can be mimicked by short-duration, intensive grazing strategy.

Front 72

Soil Erosion

Back 72

Nature of Erosion
–Important natural process
•Redistribution of geological weathering
•Sediment loading of waterways
... this intrupts rock cycle (P).

Front 73

Mechanisms of Erosion

Back 73

•Water
•Rill, Gully, and Stream bank Erosion

•Wind
–Can be equal to or greater than water
–Intensive farming exacerbates the problem
•Row Crops –Exposed soil
•Weed-free areas –Exposed soil

Front 74

Where Soil Erosion Occurs

Back 74

•Land Resources
–In developed countries (MDC’s):
•95% of recent agricultural growth has been result of Green Revolutions
–Less land cultivated now than before
–In undeveloped countries (LDC’s)
•Marginal lands still transformed for agriculture

Front 75

Soil

O HOrizon

Back 75

surface litter, patially decomposed organic debris

Front 76

A Horizon:

Back 76

Topsoil, organic matter (humus)living org., minerals (thisis lost in erosion)

Front 77

E Horizon:

Back 77

Zone of leaching disolved or suspended materials

Front 78

B horizon

Back 78

subsoil: accumulation of iron, aluminum, humic compounds, clay leached down from A & E horizons.

Front 79

C Horizon

Back 79

Weathered parent material, partially broken down inorganic materials

Front 80

R Horizon

Back 80

Bedrock, impneterable layer

Front 81

Three parts of soil:

Back 81

sand, silt, clay

Front 82

Diminishing Forests

Back 82

–Occupy 10% of land surface
•Contain 2/3 higher plant biomass
•Contain 50% of all species
Poor Soil
–Annual loss at 14.5 million ha / yr
•Cattle ranching
•Banana Plantations
•Illegal loggings

Front 83

Forest Distribution

Back 83

–4.2 Billion ha of forests and woodlands cover 33% of earth’s land surface
–Old Growth Forests
•39% retain original
growth characteristics

Front 84

Desertification

Back 84

•Caused by a variety of factors
–human factors -improper use of land resources including soil, vegetation and land water supplies

–environmental factors –temperature, precipitation levels, and wind

Front 85

Wetlands Loss

Back 85

Nature's waste management

Wetland Destruction–US Swamp Lands Act (1850) allowed individuals to purchase swamps and marshes for as little as $.10 / acre.–1930’s –1940’s US government promoted draining wetlands to produce farmland.•Not conserved again until late 1970’s–Lost over ½area

Front 86

–Genetic Diversity:

Back 86

Number of different versions of same gene within a gene pool

Front 87

–Species Diversity:

Back 87

Number of different kinds of organisms

Front 88

–Ecological Diversity:

Back 88

Richness and complexity of a biological community.

Front 89

Natural Extinction Forces

Back 89

99% of all species now extinct
•Most expired long before humans
•Humans have accelerated extinction rate

Habitat Destruction
–Habitat fragmentation

Front 90

Predators and Pest Control

Back 90

–Animal Damage Control (ADC)
•Annually take 700,000 birds / mammalsr

Front 91

Biological Pollution

Back 91

Exotic Species Introduction

Front 92

Genetic Assimilation

Back 92

Cross-breeding of closely related species
•Black Ducks and Mallardsn

Front 93

Benefits of Biodiversity:
Ecological

Back 93

–Human lives heavily linked to eco. services
–Complex –chaotic ecosystems self-regulatei

Front 94

Benefits of Biodiversity: Aesthetic and Cultural

Back 94

Nature Appreciation has economic value
•USFWS –American spend $104 Billion annually on wildlife-related recreation
•Ecotourism CAN be sustainable economic development

Front 95

Benefits of Biodiversity: Food

Back 95

–800,000 edible plant species in the world
•35 species make up human diet
–Land Destruction destroying food sources
•Overgrazing and Land Conversion

Front 96

Benefits of Biodiversity:
Drugs and Medicines

Back 96

–$35 Billion/ yr pharmaceutical products
–Pharmaceutical companies actively search for new prospects in tropical regions

Front 97

How many species are there

Back 97

1.4 Million currently catalogued
•3-50 Million estimated
–30 Million insect species alone ?
–Only 10-15% of world’s species live in North America and Europe

Front 98

Protecting Biodiversity:
Habitat Protection

Back 98

Ecosystem vs. Single Species Management
•Efficiency–Whooping Cranes–California Condors•ecies

International Wildlife Treaties–Convention on International Trade in Endangered Species (CITES)

Front 99

Protecting Biodiversity:
The Endangered Species Act (ESA)

Back 99

Spotted Owls
–1989 US Govt. sued
by environmentalists
•Old growth Forests vs. Spotted Owls

Front 100

Endangered Species Act (ESA) –1973–

Back 100

Endangered: Imminent danger of extinction–Threatened: Likely to become endangered (usually locally) within foreseeable future•Illegal to harass, kill, sell, or export species or their body parts.

Front 101

The key to intelligent tinkering ...

Back 101

is keeping all the parts.

Front 102

Mutation Definition:

Back 102

any change in the genetic material of cell
–Chromosomes
–Mitosis
–Chromatids
–Base pairs
•adenine-thymine
•guanine-cytosine
–Genes

Front 103

Types of Mutationsural:
“Point”Mutation

Back 103

Single change in base pair

Front 104

Types of Mutationsural:
Chromosomal Aberrations

Back 104

Change in "folding" or structure of chromosone so that it does not function properly (i.e., fragile X syndrome, cause of autism or "autistic-like" behaviors)

Front 105

Types of Mutations:
Change in Chromosome Number

Back 105

•Trisomy
•Amniocentesis/chorionicvillussampling

Front 106

Cause of Mutations

Back 106

Mutatgens

Front 107

Birth Defects: Teratology
Teratogens

Back 107

Chemical agent

Front 108

Birth Defects: Teratology
Folic acid

Back 108

lack of during pregnancy (nural tube defects)

Front 109

Birth Defects: Teratology
Thalidomide

Back 109

Phocomelia (flipper like limbs)

Front 110

Birth Defects: Teratology
DES

Back 110

diethylstilbestrol - It was first prescribed by physicians to prevent miscarriages. [edit] First generation
Women prescribed DES while pregnant are at a modestly increased risk for breast cancer. A new study shows DES daughters as having a 2.5 fold increase in breast cancer after age 40.
Women exposed to DES before birth (in the womb), known as DES Daughters, are at an increased risk for clear cell adenocarcinoma. (Prof. says, uterine and ovarian CA).

Front 111

Birth Defects: Teratology
Valproic acid

Back 111

a chemical compound that has found clinical use as an anticonvulsant and mood-stabilizing drug, primarily in the treatment of epilepsy and bipolar disorder.Valproate is relatively contraindicated in pregnancy due to its teratogenicity; women who become pregnant while taking valproate should be counselled as to its risks, take high dose folic acid and be offered antenatal screening (alpha-fetoprotein and second trimester ultrasound scans).It is a known folate antagonist

Front 112

Cancer facts:

Back 112

•Incidence rates continue to climb
•Cancer mortality rates aren’t climbing at the same rate
•Types of cancer vary across the globe

Front 113

Cancer Causes

Back 113

•Carcinogens
•Viruses
•Bacteria
•Heredity
–Predisposition
•Environmental Agents

Front 114

Cancer Development:
Initiation

Back 114

Exposure to environmental carcinogen.

Front 115

Cancer Development:
Adducts

Back 115

Result of initiation: Binds to gene = DAMAGE (can turn gene on, off or destroy it). (These are the "cancer" biomarkers). Not reverseable.

Front 116

Cancer Development:
Promotion

Back 116

Long term exposure of "Adduct-damaged" cells to "chemicals" (hormones) that signal multiplcation (increaseing the potential for growth of CA cells). Sometimes reversable (if hormone is removed).

Front 117

Cancer Development:
Latency period

Back 117

Time between exposure and CA development.

Front 118

Cancer Development:
Progression

Back 118

During the Latency period - additional Adducts (random) are accumulated (proto-oncogene, Tumor suppressor gene damage).

CA must have BOTH proto-oncogene and tumor-suppressor gene damage.

Front 119

Proto-oncogene

Back 119

signals a cell to divide. Damaged proto-oncogenes are called "onco genes" (Greek: lump)

Front 120

Tumor-suppressor genes

Back 120

tell cell to stop replication and to kill self (Apoptosis). Damage to this results in no stopping CA.

Front 121

Environmental Carcinogens

•Smoking:

Back 121

lung, nasopharynx CA

Front 122

Environmental Carcinogens –Sulforaphane:

Back 122

Sulforaphane is an anticancer and antimicrobial compound that can be obtained by eating cruciferous vegetables such as brussel sprouts, broccoli, cabbage, cauliflower, bok choy, kale, collards, broccoli sprouts, chinese broccoli, broccoli raab, kohlrabi, mustard, turnip, radish, rocket, and watercress.

Front 123

Environmental Carcinogens
•Dietary Factors:

Back 123

colon CA, inappropriate response to CA due to lack of nutriants (decreased immunity).

Front 124

Environmental Carcinogens
Alfatoxins:

Back 124

several different toxins produced by bacteria

Front 125

Environmental Carcinogens
Lycopene

Back 125

Early research suggested some amelioration of cardiovascular disease, cancer, diabetes, osteoporosis, and even male infertility

Front 126

Environmental Carcinogens
Air pollution

Back 126

Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies

Front 127

Environmental Carcinogens
•Occupational Exposure

Back 127

Route of contact with cancer causing agents (carcinogens).
•Asbestos
•Vinyl Chloride
•Anesthetic Gases
•Benzene
•Coke Oven Emissions
•Benzidine, naphythylamine
•Hardwood dust
•Radioactive mine dust

Front 128

#1 poisoning for children

Back 128

vitamins

Front 129

Cancer: factors

Back 129

•Reproductive/Sexual Behavior
–Late child bearing
–Early menstruation

•Preventing Cancer
–Proper nutrition
–Exercise

Front 130

•Toxicants

Back 130

Man-made toxins.

Front 131

•Routes Entering the body

Back 131

Oral
–Dermal
–Respiratory

Front 132

•Toxicology

Back 132

Study of toxicants and toxins and effects on environment/biological systems

Front 133

Toxins:

Back 133

bacterial made toxins.

Front 134

•Chronic Toxicity

Back 134

long term exposure to toxin/toxicants, usually at a low dose.

Front 135

•Lethal Dose (LD50)

Back 135

the amount of substance needed to kill half of the organisms exposed.

Front 136

A Horizon:

Back 136

Topsoil, organic matter (humus)living org., minerals (thisis lost in erosion)

Front 137

E Horizon:

Back 137

Zone of leaching disolved or suspended materials

Front 138

B horizon

Back 138

subsoil: accumulation of iron, aluminum, humic compounds, clay leached down from A & E horizons.

Front 139

C Horizon

Back 139

Weathered parent material, partially broken down inorganic materials

Front 140

R Horizon

Back 140

Bedrock, impneterable layer

Front 141

Three parts of soil:

Back 141

sand, silt, clay

Front 142

Diminishing Forests

Back 142

–Occupy 10% of land surface
•Contain 2/3 higher plant biomass
•Contain 50% of all species
Poor Soil
–Annual loss at 14.5 million ha / yr
•Cattle ranching
•Banana Plantations
•Illegal loggings

Front 143

Forest Distribution

Back 143

–4.2 Billion ha of forests and woodlands cover 33% of earth’s land surface
–Old Growth Forests
•39% retain original
growth characteristics

Front 144

Desertification

Back 144

•Caused by a variety of factors
–human factors -improper use of land resources including soil, vegetation and land water supplies

–environmental factors –temperature, precipitation levels, and wind

Front 145

Wetlands Loss

Back 145

Nature's waste management

Wetland Destruction–US Swamp Lands Act (1850) allowed individuals to purchase swamps and marshes for as little as $.10 / acre.–1930’s –1940’s US government promoted draining wetlands to produce farmland.•Not conserved again until late 1970’s–Lost over ½area

Front 146

–Genetic Diversity:

Back 146

Number of different versions of same gene within a gene pool

Front 147

–Species Diversity:

Back 147

Number of different kinds of organisms

Front 148

–Ecological Diversity:

Back 148

Richness and complexity of a biological community.

Front 149

Natural Extinction Forces

Back 149

99% of all species now extinct
•Most expired long before humans
•Humans have accelerated extinction rate

Habitat Destruction
–Habitat fragmentation

Front 150

Predators and Pest Control

Back 150

–Animal Damage Control (ADC)
•Annually take 700,000 birds / mammalsr

Front 151

Testing for Toxicity
Dose-response curve

Back 151

The science of toxicology is based on the principle that there is a relationship between a toxic reaction (the response) and the amount of poison received (the dose). An important assumption in this relationship is that there is almost always a dose below which no response occurs or can be measured. A second assumption is that once a maximum response is reached any further increases in the dose will not result in any increased effect.

Front 152

Testing for Toxicity
Dose-response curve
Threshold

Back 152

Prior to reaching the threshold, no reactions to the toxicants are noted. (No-observed-effect-levels (NOELs))

Front 153

Testing for Toxicity
Dose-response curve
Margin of saftey

Back 153

the amount of exposure from 0 to threshold.

Front 154

ED50

Back 154

Effective dose for 50% of those exposed (in Rx).

Front 155

Risk assessment

Back 155

Determining whether something suspected of presenting a human health threat is in fact dangerous.

Front 156

Risk fomula

Back 156

Risk = exposure X hazzard

i.e., Risk = exposure concentration+route X LD50

Front 157

Assessing Health Risk
Four step process:

Back 157

1.Hazard Identification
2.Dose-response assessment
–LOEL, NOAEL, and NOEL
3.Exposure assessment
4.Risk characterization
–Acceptable Daily Intakes (ADIs)

Front 158

Polychlorinated Biphenyls (PCBs)

Back 158

PCBs were used as coolants and insulating fluids for transformers and capacitors, stabilizing additives in flexible PVC coatings of electrical wiring and electronic components, pesticide extenders, cutting oils, flame retardants, hydraulic fluids, sealants (used in caulking, etc), adhesives, wood floor finishes, paints, de-dusting agents, and in carbonless copy paper.

Studies in workers exposed to PCBs have shown changes in blood and urine that may indicate liver damage. In 1968 in Japan, PCB contamination in rice bran oil caused a mass poisoning known as Yushō Disease in over 14000 people. Common symptoms included dermal and ocular lesions, irregular menstrual cycles and a lowered immune response.
Other symptoms included fatigue, headache, cough, and unusual skin sores. Additionally, in children, there were reports of poor cognitive development. associated with specific kinds of cancer in humans, such as cancer of the liver and biliary tract

Front 159

Chloracne

Back 159

Chloracne is an acne-like eruption of blackheads, cysts, and pustules associated with over-exposure to certain halogenated aromatic compounds, such as chlorinated dioxins and dibenzofurans. The lesions are most frequently found on the cheeks, behind the ears, in the armpits and groin region.

Front 160

Bioaccumulation & biomagnification

Back 160

increasing concentration of toxins/toxicants with each level of the food pyramid.

Front 161

Dioxin (TCDD)

Back 161

•“dioxin is the most toxic substance ever created by humans”
•Formed as a by product in production of certain herbicides and hexachlorophene
•Exposure may result in reduced fertility, fetal loss, changes in sexual behavior, thyroid dysfunction, and suppressed immune system

Front 162

Asbestos

Back 162

•Asbestosis
•Lung Cancer
•Mesothelioma
•Gastrointestinal Cancer
•Abatement
–Encapsulation
–Enclosure
–Removalg

Front 163

Lead

Back 163

•Biological effects
–Continuum of toxicity
•Lead Poisoning
–Chelation
–Environmental intervention
–Screening programs
–Pica/msword

Front 164

Mercury
Health Effects of Mercury Exposure
–Inorganic Metallic Mercury

Back 164

•Liver and kidneys
•Brain
–Mad Hatters’Disease

Front 165

Mercury
Health Effects of Mercury Exposure
Organic Mercury

Back 165

•Numbness in lips, tongue,
and fingertips
•Fish advisories

Front 166

What is a Pest?

Back 166

A purely human concept, any species that affects human interests
–Animal
–Plant
–Microbe

Front 167

Problems Caused by Pests
Resource Competition

Back 167

Responsible for the loss of an estimated 30-35% of the global harvest each year

Front 168

Problems Caused by Pests
Vectors of Disease

Back 168

–Mosquitoes
–Flies
–Cockroaches
–Body Lice
–Rat Fleas
–Ticks

Front 169

POPs

Back 169

•Many classifications, most all extremely persistent pesticides contain chlorine
•Now termed persistent organic pollutants or POPs. ( also called “Dirty Dozen”)
•List of 12 POPs, international treaty signed in 2001 to stop their use except for specific applications

Front 170

Pest control:
Non-specific

Back 170

Non-specific
–Often kill non-target species (honeybees)
–90% of pesticides never reach intended target

Front 171

Modern Pesticides - DDT history/legacy

Back 171

began with the invention of DDT in 1934
–Paul Mueller won Nobel Prize in 1948 for Dichloro-Diphenyl-Trichloroethane(DDT)
–DDT has possibly saved more lives than any other compound invented
–DDT use in banned 1974

Front 172

DDT problems

Back 172

DDT and DDE minimize the deposition of Calcium Carbonate into egg shells-thinning
–Rapid declines in predatory bird populations
–Residues of DDT today in most living organisms
–Malaria affects 500 million people per year!
–Bubonic Plague –rats
–Yellow Fever-Mosquito
–Almost eliminated by DDT

Front 173

Types of Pesticides:

Back 173

•Insecticides
•Stomach poisons
•Contact poisons
•Fumigants
–Inorganic insecticides
–Chlorinated hydrocarbons
–Organophosphates
–Carbamates
–Synthetic pyrethroids and other botanicals
•Neem

Front 174

Types of Pesticides

Back 174

•Herbicides
–Selective
–Non selective
•Agent Orange
•Rodenticides
–Provides the only effective long-term control of domestic rodent.

Front 175

Silent Spring
by Rachel Carson

Back 175

The book is widely credited with helping launch the environmental movement in the West. Silent Spring facilitated the ban of the pesticide DDT

Front 176

Environmental Impact of Pesticide Use

Back 176

–Cycle of Pesticide Resistance
•Inherited resistance (same as bacterial resistance formation)
–At present, more than 500 species of insects and mites are resistant to common pesticides
–Re-occurrence of Malaria epidemic

Front 177

Environmental Impact of Pesticide Use

Back 177

Killing of Beneficial Species
–Target pest resurgence –application is quickly followed by a sudden increase in pest numbers to a level higher than before
–Secondary pest outbreak –rise to prominence, species that hadn’t been of concern because natural enemies kept their populations down

Front 178

Environmental Impact of Pesticide Use

Back 178

•Environmental Contamination
–Pesticide residues are found virtually everywhere in the tissues of even extremely remote creatures
•Direct Killing of Organisms exposed to chemicals
•Indirect Killing Via depletion of food or habitat
•Groundwater contamination
•Indirect contamination via food chains
–biomagnification

Front 179

Pesticide: Hazards to Human Health

Back 179

•Acute pesticide poisoning
–May account for as many as 300,000 illnesses among American farm workers every year
–World Health Organization estimates 25 million annually in Third World countries
•Oral, dermal, and inhalation
–Usually, failure to comply with safety regulations or carelessness while handling are main causes of poisoning

Front 180

Hazards to Human Healths

Back 180

•Chronic pesticide poisoning
–Cancer
–Disruption of the endocrine and immune systems
•Dietary exposure
–Food Quality Protection Act of 1996
•Environmental Estrogens

Front 181

Alternatives to Chemical Pest Control
•Integrated Pest Management (IPM)

Back 181

–Low Impact Pest Control
–Low Impact Sustainable Agriculture
•Changing the crop changes the suitability for some species
•Natural Enemies
–Praying Mantis
–Ladybugs
•Pathogens and Parasites

Front 182

Alternatives to Chemical Pest Control

Back 182

•Sex Attractants
–Inhibit larval stages deterring development
–Alter sex ratios
•Insect Growth Regulators
–Chitin inhibitors
•Juvenoids
•Sterile Insect Technique
–Release of large numbers of sterile males

Front 183

Alternatives to Chemical Pest Control

Back 183

•Host Plant Resistance
–Bioengineering
–VFNT
•Verticillimwilt, Fusariumwilt, Nematodes, and Tobacco mosaic virus
•Transgenic varieties
•Sanitation
–Bug Vacuumash,

Front 184

Delaney Clause

Back 184

The Federal Food, Drug and Cosmetic Act of 1958 (FFDCA) under EPA prohibits the addition of any known cancer-causing agent to food, drugs or cosmetics