Final Review Flashcards
1
Q
What is “The Environment”?
A
The environment is the aggregate of surrounding things, conditions or influences, especially as affecting the existence or development of someone or something. This generally refers to the physical environment around us; the air we breathe, the water we drink and the lands, oceans, rivers and forests that cover the earth
2
Q
What are the two categories that categorize sources of anthropogenic environmental change?
A
Changes associated with land use.
Changes induced by emissions
or from products and industrial processes.
3
Q
What is the role of Engineering in regards to environmental issues?
A
Engineers are primarily involved in problems related to technology development and deployment.
4
Q
What are the three sources of environmental impacts?
A
Materials Selection
•
Manufacturing Processes
•
Energy Use
5
Q
What is Industrial Ecology?
A
means by which humanity can maintain a desirable carrying capacity, given continued economic, cultural, and technological evolution
6
Q
What is Sustainable development?
A
Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs
7
Q
What is environmental engineering?
A
Environmental engineering is the application of science and engineering principles to improve the environment hence allowing future generations to meet their own needs.
8
Q
What is the basis for all environmental concerns?
A
Human Health
•
Human Welfare
9
Q
How is human health effects classified?
A
Acute
Short term exposure results in immediate response in the human body
•
Chronic
Long term exposure results in long-term response in the human body
•
Carcinogenic
Exposure leads to cancer
10
Q
How is human welfare effects classified?
A
Aesthetic qualities
such as good visibility free from air pollution
11
Q
Name things that affect the air
A
Particulate Matter (Diesel Combustion, Mills)
•
Sulfur Dioxide (Combustion of coal and oil)
•
Carbon Monoxide (Carbon Containing materials are not completely combusted)
•
Nitrogen Oxides (Fuel Combustion and Industrial Chimneys)
•
Tropospheric Ozone (Photochemical reactions between sunlight and nitrogen oxides)
•
Lead (Combustion of Leaded Gasoline
12
Q
What is particulate matter?
A
Particulate matter refers to a mixture of small solid or liquid particles suspended in air.
•
Cardio Vascular, Lung Disease, Carcinogenic
13
Q
What is Sulfur Dioxide?
A
SO2 is emitted primarily from the combustion of coal and oil, which contain sulfur as an impurity
14
Q
What is Carbon Monoxide?
A
CO is a colorless, odorless gas that is produced when fossil fuels or other carbon carbon-containing materials are not completely combusted
15
Q
What are Nitrogen oxides?
A
Nitrogen oxides oxidize in the atmosphere to for Nitrogen dioxide (NO2) which is a reddish- brown gas that is toxic in very high concentrations. Nitrogen oxides are primarily produced through fuel combustion
16
Q
What is tropospheric ozone?
A
Tropospheric ozone or ground-level ozone is formed from complex chemical reactions in the atmosphere involving nitrogen oxides and hydrocarbon gases. These chemical reactions are triggered by summer sunlight, which provides the energy to initiate the photochemical reactions
17
Q
What is acid rain and describe how acid rain is produced
A
Acid rain (also known as acid deposition) refers to the fallout of acidic particles through precipitation. Acid rain is produced when sulphur oxides (SOx) and nitrogen oxides (NOx) react with water in the atmosphere to form sulphuric acid and nitric acid. The sulphur and nitrogen oxides are primarily released through the burning of fossil fuels.
18
Q
What are the effects of Acid Rain?
A
Acidification of freshwater lakes and streams and result in the death of aquatic organisms.
•
Contributes to the decline of some species of trees
•
Soil acidification disrupts the complex soil chemistry that provides nutrients to vegetation and indirectly affects soil erosion, sedimentation of waterways, and changes in animal habitat.
•
Deterioration of some building materials and monuments made of limestone or marble
19
Q
What is Stratospheric Ozone Depletion?
A
Stratospheric Ozone Depletion is the depletion of the ozone by human-made chemicals, most notably the family of compounds known as chlorofluorocarbons.
20
Q
Name things that affect the water
A
Pathogens (Human and animal feces)
•
Organic matter/waste (biodegradable organic wastes)
•
Nutrients (Agriculture and Detergents)
•
Toxic Organic Chemicals (Synthetic Organic Compounds)
•
Toxic Metals (Mercury, Arsenic, Lead) •
Sediments (Land Erosion from human activities)
•
Acidity (Sulphuric acid, when sulphur-bearing minerals react with water)
•
Salts (industrial and municipal discharges)
•
Heat (Electric Power Plants
21
Q
What are Pathogens?
A
Pathogens are disease-causing agents such as bacteria, viruses, protozoa, and parasitic worms called helminths. These microorganisms are commonly found in the intestines of infected people or animals, and then are excreted in the feces that enter the sewer systems or fall onto the ground
22
Q
What are Organic Wastes?
A
Organic wastes are the main source of
oxygen-depleting substances
in surface water. (Biodegradable chemicals)
23
Q
What are Nutrients?
A
Nitrogen and phosphorous are two essential nutrients needed to support vegetation and other forms of life. These chemicals are widely used in fertilizers and household detergents
24
Q
What are Toxic Organic Chemicals?
A
Synthetic organic chemicals, which contain addition substances like chlorine, are potentially toxic to people, plants, and animals.
25
What are Toxic metals?
Mercury, lead, arsenic
26
What are sediments and Suspended Solids?
Sediment consists of soil particles that enter a water body and eventually settle to the bottom
27
What are salts?
salts refer to compounds of elements, including calcium, magnesium, sodium, and potassium, that produce positively charged ions in solution. Salts dissolve naturally into water bodies as water flows over rocks and soils. Human-made sources enter waterways via industrial and municipal discharges and urban runoff
28
What is implied by heat?
Thermal pollution, primarily from waste heat generated at electric power plants, creates a plume of warmed water that can be detrimental to fish and plant life
29
What is the percentage of leaking underground gasoline storage tanks?
12%
30
What are the standards for drinking water based on
Total Coliform bacteria
•
Fecal Coliform and E. Coli
31
Name three things that affect the soil
```
Solid Waste (Paper and paperboard)
•
```
```
Hazardous Waste (Wastewater treatment)
•
```
Radioactive Waste (Uranium mining, milling, and refining)
32
What are Solid Wastes?
Solid wastes, also known as non-hazardous wastes, are wastes that have not been designated as Hazardous wastes
33
What is Hazardous Waste?
Hazardous waste is a solid waste or combination of solid wastes which because of quantity, concentration, or physical, chemical, or infectious characteristics may
•
Cause, or significantly contribute to, an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness; or
•
Pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed
34
Name the four characteristics of hazardous waste
Ignitability
–
An ability to burn easily or cause or enhance fires
•
Corrosivity
–
Strong acids and bases, or substances able to corrode metal.
•
Reactivity
–
An ability to react violently or cause explosions, including reactions with water.
•
Toxicity
–
An ability to threaten water supplies and health, as determined by a
laboratory test of leach-ability
35
What is the Toxicity Characteristic Leaching Procedure
If the metals and other chemical compounds specified in the TCLP are leached in amounts above specified thresholds, the material is considered toxic and hence hazardous
36
What are Radioactive Wastes?
Two key attributes distinguish radioactive wastes:
•
Its harmful effects on living organisms are induced by radiation rather than by chemical mechanisms; and
•
Radioactive wastes remain dangerous up to hundreds of thousands of years
37
What is High-level Radioactive Waste?
High-level radioactive waste is the most dangerous. High level waste is characterized not only by the
intensity of its radioactivity
but also by its
very long half-life.
38
What is Transuranic Waste?
Waste containing more than 100 nanocuries of alpha-emitting transuranic isotopes per gram of waste with half-lives greater than 20 years, except for high-level waste...
All TRU elements are heavier than uranium, have several isotopes, and are typically man-made
39
What is Low-level Radioactive Waste?
Any radioactive waste that is not officially classified as high-level waste, transuranic waste, or by-product waste from uranium mining and milling is called
low-level waste
40
What are the 3 purposes for humanity’s use and consumption of the Earth’s natural
l resources?
As a source of food
•
As a source of energy, and
•
As a source of raw materials for structures, devices and other human endeavours
41
What are the two general categories of natural resources?
Renewable resources
–
Which have the capability to be replenished
•
Non-renewable resources
–
Which exist only in finite amounts
42
What is an Ecosystem?
The term ecosystem is used to refer to any biological community that functions as a cohesive unit within its physical environment
43
Name some greenhouse gases, but not the important ones
```
CO2 Carbon Dioxide (important )
•
CH4 Methane (important )
```
N2O Nitrous Oxide ( Laughing gas)
CFC-11, CFC-12, CFC-113, Halocarbons
O3 Tropospheric Ozone
44
What is the definition of climate
Climate is not synonymous to weather. It is more commonly defined as the “average” weather,
patterns typically over a 30-year averaging period. Climate is determined by complex interactions of many factors that together constitute the
global climate system
45
What is the heat flux?
The heat flux is the expression of radiative energy in terms of the rate per unit surface area: Heat flux = (Total Rate of heat flow)/(Total surface area)
q=Q/A
46
How to find the Radiative heat transfer from a black body?
q=5.67(10^-8) T^4
| Where T is the temperature in Kelvins (Celsius + 273)
47
What would be the average temperature of earth if the greenhouse effect did not exist?
-19 degrees Celsius, the average temperature of earth, however, is 15 degrees Celsius
48
Explain the Greenhouse Effect
The greenhouse effect is the trapping of radiation within the atmosphere, which warms the planet. Just as in a greenhouse, most of the incoming radiation (as ultraviolet) gets through to
warm the earth’s surface, and most of the outgoing radiation (as Infrared) is blocked or absorbed
by the atmosphere. Gases that absorb infrared radiation are defined as
greenhouse gases
49
What is the Tropopause?
The Tropopause is the upper boundary of the troposphere approximately 10km above the
Earth’s surface
50
What is Radiative Forcing?
The term
radiative forcing
is used when any change in the net radiative balance will
force the climate system to readjust so as to ultimately restore equilibrium
∆F = ∆q
(out or in)
51
What does radiative forcing depend on?
Wavelength
•
Speed
•
Frequency
52
How is the Net Forcing from Atmospheric Changes determined?
∆F = ∆q(out) -∆(qin)
53
What is the climate sensitivity factor γ?
The climate sensitivity factor is known as the ratio of the final temperature change, ∆Te, to the
change in radiative forcing, ∆Frad
54
Where were the tests performed to determine possible past effects of climate change?
Vostok, Antarctica.
55
How much of a reduction of emissions are required to stabilize atmospheric CO2 levels?
The international goal of stabilizing atmospheric CO2 levels will require anthropogenic emissions to roughly 60 to 80% below the 1990 emission rates
56
What are the factors affecting CO2
| Emissions Growth?
Population Growth per year
–
This reflects the size of the population and effect of population growth. Increasing population generates greater demand for food, clothing, shelter, and other human needs.
•
GDP per Capita
–
This measures aver
age affluence. As this term grows, an individual’s
demand for goods and services also grows.
•
Energy Intensity (energy use / per GDP)
–
This is most related to technology and technological change.
•
CO2
emissions per unit energy
–
This depends principally on how the energy is being generated.
Multiply all of these together to get the CO2 Emissions Growth.
57
What is carbon Sequestration?
Carbon sequestration is the natural ability of biomass to absorb CO2 from the atmosphere. This however cannot achieve the sizeable long-term reductions needed to stabilize atmospheric concentrations in the face of global energy demands
58
What are the greatest failures of the International society to date?
Kyoto Protocol
•
Copenhagen
59
Describe the Inventory analysis
Description of all inputs (raw materials, energy) and outputs (products, wastes, energyt
60
Describe the Impact analysis
Description of effects on the environment for each input and output identified in inventory analysis
•
61
Describe Improvement analysis
Description of needs and opportunities to reduce adverse effects identified in impact analysis and inventory analysis.
•
62
What are the principal routes of human exposure to trace metals?
Inhalation of air
•
Ingestion of water
•
Ingestion of food
•
Ingestion of dust
63
How to find the mass of trace metal absorbed by the body/time?
MASS OF TRACE METAL ABSORBED BY BODY:
A= C*U*F
C= Concentration of the trace metal in the medium
U= Uptake rate of the medium
F= fraction of the trace metal absorbed by bloodstream
64
What is the “dose” and how is it determined?
D= A*t….. A= Total Absortion rate from all exposure rates
| T= time of exposure
65
What are the 3 steps in a life cycle analysis?
1- Inventory Analysis
2- Impact analysis: Determine impacts on environment from inputs and outputs
3- Improvement analysis→ Tradeoffs… sometimes saving raw materials may be of higher priority than saving energy
66
What are Trace Metals?
As we manufacture products, we release metals into the environment. We refer to them as Trace Metals
67
What are the F (fraction of the trace metal absorbed by bloodstream) values for air, water, food and dust?
air=0.3
Water= 0.5
Food=0.5
Dust=0.3
68
In the United-States, how many fatalities per year are caused by traffic accidents
40,000
69
What was the increase in automobiles from 1900 to 2000?
Automobiles have increased from 8,000 to 135 million
70
What is SMOG?
emissions of hydrocarbons reacting with sunlight
→Hydrocarbons get trapped by surrounding mountains and “cook” in the sun. They produce ozone and other chemical compounds called PHOTOCHEMICAL SMOG
71
Impacts of cars on air quality is growing because of:
1- Increasing vehicle Population
2- Increasing travel per vehicle… VMT (VEHICLE MILES OF TRAVEL) has grown at an average rate of 3.1% over the last 15 years
3- General on road emissions are generally higher than federal test cycle values
4- Greater use of light trucks…. More gas consumed and more CO, HC and NOx emissions
72
What percentage of the energy used in Transportation is Petroleum?
97%
73
How much of an automobile is recycled and how much is wasted at its end of life?
Around 75% of car’s materials are recycled and 25% disposed
74
What are other environmental impacts caused by automobiles?
Lead Emissions
•
CFC Emissions
•
Waste Motor Oil
•
Other Life Cycle Impact
75
How is the Energy Efficiency mathematically described?
n= (Useful energy delivered for motion) / (Total fuel energy input)
76
How is Engine Efficiency calculated?
nengine= (Useful energy out) / (Total energy in)
77
How is “useful energy out” calculated?
ntrain= E / Eshaft
78
What is Incomplete Combustion?
Incomplete combustion occurs when there isn’t enough air or temperature not high enough to combust all the fuel in the cylinder
79
What are normal products of most combustion reactions?
NOx
80
How is the final energy supplied to the drive wheels calculated?
n= n(engine) x n(train)
81
How is fuel consumption calculated?
E(fuel)= E / η
| Or expressing in terms of the fuel needed to drive a given distance d
Efuel) / d = (1/ n) (E/d
82
What is Risk
Risk = (probability of a specific
| undesired consequence) x (Size of loss)
83
How does one assess risk?
Subjective (as opposed to objective) personal opinion
•
Understanding (we cannot assess what we do not understand)
•
Exposure to the risk (over time, quantity)
84
What is a Hazard Assessment?
A hazard assessment is determining whether there is any potential problem from exposure to a given chemical
85
What is the Dose-Response assessment?
If a chemical can cause some type of health effect
→ Carcinogenic effect:
- Any exposure to carcinogenic substance is considered to increase lifetime risk of cancer
→ Non-Carcinogenic effect:
86
What is the Exposure Assessment?
Quantifies dose received in particular situations
| --> Most frequent pathway through which humans can be exposed to chemicals is through inhalation
87
What is Risk Characterization?
Combine results from exposure and dose-response for each chemical
88
How is Chronic Daily Intake calculated?
CDI = (Average daily dose (mg/day) / (Body weight (kg)
89
What is the potency factor?
PF= Incremental Cancer Risk for a Chronic Daily Intake of 1 mg/kg-day
90
How is the incremental risk of lifetime cancer risk calculated?
Incremental lifetime cancer risk = (CDI) (PF)
91
What level of risk is acceptable for a known or suspected carcinogen?
10^-6 (one chance in a million) or less can generally be regarded as acceptable or inconsequential, whereas a lifetime risk of 10^-3 (one chance in a thousand) or greater is considered serious and is a high priority for attention
92
What is the reference dose and how is it measured?
The reference dose is a key parameter used in risk assessments to characterize the safe dose of a non-carcinogenic chemical.
RfD = (NOAEL) / (UF) (MF)
Where, UF is the uncertainty factor and MF is the
modifying factor . NOAEL is No Obeservale Adverse side Effects Level
93
What is the hazard quotient and how is it measured?
The Hazard quotient is the metric used in risk assessments to compare an actual dose of a chemical to the reference dose. HQ = ADD / RfD, where ADD is Average Daily Dose, and Rfd Reference Dose
94
What is the hazard index?
The hazard index is the sum of all hazard quotients.
95
What are the options to dealing with unacceptable risks?
1- Source of risk can be reduced or eliminated: Removing contamination, closing facility, installing environmental control tech.
2- Exposure Pathway can be modified or avoided: installing engineered barriers
3- Human Exposure to contaminants can be reduced or eliminated: relocating population
4- Effects can be treated or compensated for after they occur: Medical treatment or monetary compensations
96
What are the different methods of decision analysis?
An influence diagram is a way of visualizing the important connections among different elements of a problem. (symbolic shapes may be used)
•
A decision tree is designed to highlight the ramifications of alternative decisions and uncertain events. The process of solving the tree is known as folding back the tree
97
Forecast vs. Scenario, what are the differences?
Forecast predicts a future outcome using a model
| Scenario is a hypothetical outcome derived from a set of circumstances that follow logical assumptions
98
Define the various time frames
TIME FRAME:
- Near-term: Within a decade
- Mid-term: Between 10 to 30 years
- Long term: 30+ years
99
What is the Spatial Scale of Concern?
local, regional, national or global
100
What are the primary drivers of environmental change?
Population
•
Standard of Living
•
Technology
101
What are some of the Population Growth Models?
Annual Growth Rate Model
–
Quantifies the growth of a population assuming a constant annual growth rate.
•
Exponential Growth Rate Model
–
Quantifies the growth of a population assuming that at any given point in time the rate of change in population is proportional to the total population at that moment.
•
Logistic Growth Model
- Quantifies the growth of a population assuming the same thing as an exponential growth rate model, but it also depends on the size of the current population relative to the carrying capacity Pmax
Demographic Model
Growth Rate = (Birth Rate)- (Death Rate) + (Immigration Rate)
102
What are some limitations to Forecasting?
- Doesn’t account for fertility, mortality and immigration rates
- Rates are usually generalized and not localized (i.e. poorer areas will has higher mortality…)
103
What are some of the Economic Growth Models?
Activity Coefficients
Total cars = (Cars / Person) (Population)
•
Economic Growth and Energy Use
Attempting to correlate changes in GDP with other changes in the economy that have a bearing on environmental impacts.
•
Input-Output Models
This type of model quantifies the value of goods and services that each sector requires from other sectors (the inputs) in order to make its own product (the output).
•
Macroeconomic Models
This model concerns itself with the structure and performance of national economies and the effect of government policies on aggregate economic activity
104
What are the different types of technological change?
1- Improvement to a current technology design: Cars with improved catalyst emitting lower HC’s
2- Substitution of an alternate technology: Replace gas by electric
3- New classes of technology: Designing whole new ways of doing things… airplane for displacement is an example
4- Change in technology utilization
105
What are some models to measure the rates of technology adoption?
Specified Rate of change
–
The most direct method of introducing a new technology is to specify its rate of adoption or diffusion into the economy.
•
Specified Market Share
–
Specifying the market share at different points in time
•
Consumer Choice Models
–
Introduce new technologies based on consumer preferences
106
BOD
Biological Oxygen Demand
107
COD
Chemical Oxygen Demand
108
MACT
Maximum Available Control Technology
109
TRI
Toxic Release Inventory
110
MCL
Maximum Contaminant Levels
111
NPDES
National Pollutant Discharge Elimination System
112
TCLP
Toxicity Characteristic Leaching Procedure
113
EIS
Environmental Impact Statement
114
GCM
General Circulation Model
115
GWP
Global Warming Potential
116
VMT
Vehicles-Miles of Travel
117
CDI
Chronic Daily Intake
118
NOAEL
No Observable Adverse Effects Level
119
LOAEL
Lowest Dose with Observed Adverse Effects Level
120
UF
Uncertainty Factor
121
MF
Modifying Factor
122
ADD
Average Daily Dose
123
RfD
Reference Dose
124
HQ
Hazard Quotient
125
HI
Hazard Index
126
SWDA
Safe Water Drinking Act
127
FWPCA
Federal Water Pollution Control Act
128
RCRA
Resource Conservation and Recovery Act
129
AEC
Atomic Energy Act
130
NWPA
Nuclear Waste Policy Act
131
NEPA
National Environmental Protection Act
132
CAA
Clean Air Act
133
NAAQS
National Ambient Air Quality Standard
134
NSPS
New Source Performance Standards
135
LUST
Leaking Underground Storage Tanks
136
MSW
Municipal Solid Waste
137
TRU
TRansUrenic
138
WIPP
Waste Isolation Pilot Plant
139
LLW
Low-Level Waste
140
HAP
Hazardous Air Pollutants
141
CFC
Chlorofluorocarbons
142
VOC
Volatile Organic Compound
143
ROG
Reactive Organic Gases
144
TSP
Total Suspended Particulates
145
TSS
Total Suspended Solids
146
TDS
Total Dissolved Solids
147
HHV
Higher Heating Value
148
LHV
Lower Heating Value
149
LEV
Low Emission Vehicle
150
ESP
ElectroStatic Precipitator
151
FGD
Flue Gas Desulfurization
152
SCR
Selective Catalytic Reduction
153
SNCR
Selective Non-Catalytic Reduction
154
CHP
Combined Heat and Power
155
IGCC
Integrated Gasification Combined Cycle
156
PWR
Pressurized Water Reactor
157
BWR
Boiling Water Reactor
158
PF
Potency Factor
159
GDP
Gross Domestic Product
160
EPA
Environmental Protection Agency
161
IPCC
Intergovernmental Panel on Climate Change
162
WCED
World Commission on Environment and Development
163
DOE
Department Of Energy
164
NRC
National Research Council
165
WMO
World Meteorological Organization
166
UNEP
United Nations Environmental Program
167
Give two benefits of designing a product to fit into a life cycle
1- Minimizes adverse impacts of waste
| 2- It reduces use of raw materials to make new products
168
Define MCL for drinking water
one contaminant per million units of water
169
Why has mercury been the subject of so much research lately; what are its impacts on the human body?
1- Damages Nervous system
2- Exposure to high enough concentrations can be fatal
3- Bioaccumulation
170
What is "eutrophication?"
Over-enrichment of water by nutrients such as nitrogen or phosphorus
171
What are the three steps of life cycle analysis?
Inventory Analysis
Impact Analysis
Improvement Analysis
172
Give two reasons why the life cycle analysis is not more widely used?
- Gathering the data is time consuming and expensive. This only gets worse as the LCA is more comprehensive
- There is no universally accepted methodology. The assumptions made might be subjective.
173
What is bad ozone and its source?
It is ozone present at the ground level and is the main component of smog. Created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) from motor vehicles, industrial facilities in the presence of sunlight.
174
5) Explain the difference between a response curve for carcinogenic and non- carcinogenic chemicals?
Carcinogenic chemicals typically assume a linear relationship with no threshold. Any dose above zero results in some risk.
Non-carcinogenic chemicals exhibit a flat horizontal line until a certain threshold, above which adverse effects are observed
175
Name three things that are affected by global warming?
- Rise of Sea level, and the flooding of low-lying regions
- Changes in weather patterns (increased droughts, floods, severity of storms)
- The viability of plant and animal life attempting to cope with rapid changes.
176
What is global warming potential (GWP)?
It is a measure devised to compare different emissions in terms of an equivalent mass of CO2, to determine its contribution to global warming in terms of its radiative forcing and atmospheric lifetime.
177
What are three uncertainties associated with risk assessment?
Lack of information on source location(s)
-Poorly known history of contaminant releases
-Unknown variability in mass or concentration distributions of contaminants
-Complexity in the chemical composition of contaminants
178
What are Fuel Cells?
It is a gas-powered electrochemical battery that takes hydrogen and oxygen and mixes them to produce electricity. The byproduct of this reaction is water. They’re very expensive
179
How to Calculate CDI?
Average Daily dose (mg per day)/ Mass (kg)
180
How to Calculate PF?
Incremental Cancer Risk for a Chronic Daily Intake of 1 mg/kg-day
181
How is the incremental risk of lifetime cancer risk calculated?
CDI x PF
182
Te?
Equilibrium Temperature
183
Describe some of the "uncertainties" in assessing risk for non-carcinogens
When assessing the risk, there is a key value called the uncertainty factor (UF). It can be affected by a lack of NOAEL data or an extrapolation of NOAEL from animal testing data. Uncertainty in risk assessment results from the lack of knowledge on toxicity to the target population for a substance.
184
Name the 4 steps in risk assessment
1- Hazard Assessment
2-Dose-Response Assessment
3- Exposure Assessment
4- Risk Characterization
185
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act
186
PCB
Polychlorinated Biphenyls
187
Name three things that can affect the carbon cycle
- Deforestation
- Burning of fossil fuels
- Cement production
188
Two major contaminants of groundwater and their sources?
- Petroleum contaminants from Leaking Underground Storage Tanks (LUST)
- Nitrates, from agricultural fertilizers
189
What are three uncertainties associated with risk assessment?
- Lack of information on source location(s)
- Poorly known history of contaminant releases
- Unknown variability in mass or concentration distributions of contaminants
- Complexity in the chemical composition of contaminants
