ENSC 102 Test 3

VOCs

- A category of pollutants - carbon compounds with marked tendency to evaporate; these are liquids that evaporate to produce vapors.

initiation

- A cell is transformed by a mutation into a potential cancer

mutation

- A change in a gene or chromosome. -occur naturally all the time, caused by chemical/physical agents and by normal mistakes in cell division.

incidence rate

- A measure of the frequency with which an event, such as a new case of illness, occurs in a population over a period of time.

sarcoma

- Cancer of the supportive tissues, such as bone, cartilage, and muscle.

oncogenes

- Cancer-causing genes that are formed due to mutations - present in all cells and control cell division -say when to start dividing and when to stop

physical removal

- Depending on size and density, aerosol (particles) will exit the air via gravity.

methemoglobinreductase

- Infants lack the enzyme - a factor in blue baby syndrome - an enzyme that changes (reduces) the iron atom back to its normal form (methemoglobin becomes hemoglobin)

mixing height

- The altitude where the two lines cross

carbon dioxide

- a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.

carbon monoxide

- a colorless, odorless, and poisonous gas CO

state implementation plan

- a plan, required under the clean air act, that each state crates and implements for the purpose of meeting the national standards

catalytic converter

- a platinum, coated device that oxidizes most of the VOCs and some of the CO that would otherwise be emitted in exhaust, converting them to CO2. - a device that reduces carbon monoxide emissions from vehicles.

gas

- a state of matter in which the matter expands to fill the container and changes volume readily with changing temperature, pressure

promotion

- additional mutation or mutations occur that cause the cell to begin to grow uncontrollably

smoke

- aerosol produced by burning

aerosol

- airborne solid particles

methemoglobinemia

- an oxygen-carrying deficiency caused by the nitrate/nitrite oxidizing the iron atom in hemoglobin to methemoglobin

leukemia/lymphoma

- arise in blood-forming cells of bone marrow or lymph nodes.

excess deaths

- deaths exceeding the expected number - the actual number of deaths minus the expected number. observed-expected

central nervous system depression

- effect of overdose of ethyl alcohol.

sensitive/susceptible group

- groups likely to be affected by a disease

source density

- how many and how close together are the industry smokestacks, automobiles, etc - Factor affecting air concentration

vertical dispersion

- how well the pollutant can disperse, be diluted in the vertical. The higher, the better-pollutant rises through the atmosphere until it is denser than the surrounding air. "Hot air rises" because, being warmer, it has a lower density (mass per volume) than the air surrounding it.

horizontal dispersion

- lowering concentration by mixing and diluting - This is the result of the wind.

carcinoma

- most common cancer type - arise in epithelial cells (sheets of cells covering the surface of the body and linings of organs, glands) - examples: lung, breast, and skin.

criteria document

- multivolume reports containing health information about the pollutant

chemical removal

- pollutant reacts with other chemicals in the air to produce a third (or fourth or fifth...) chemical, destroying the original chemicals.

tumor registry

- receive reports of identified tumors - tracks cancer incidence rates

maximum tolerated dose

- the highest dose rate that the animal can stand without experiencing acute outward health damage.-A large fraction of all chemicals that have been identified as mutagens/carcinogens only have excess tumor growth in the group being exposed to the maximum tolerated dose.

maximum contaminant level

- units are in milligrams - The maximum permissible amount (by law) of a water pollutant that might adversely affect human health.

source strength

- what emission rate is each source (or the sources combined) producing - Factor affecting air concentration

combustion

- when oxygen combines with another compound to form water and carbon dioxide. - these reactions are exothermic, meaning they produce heat. An example of this kind of reaction is the burning of napthalene

dust

-aerosol produced by sanding, crushing, grinding, abrasive action.

Give the steps in setting an environmental quality standard. How is the endpoint chosen? For what group?

1. Dose-response information to identify susceptible/sensitive groups 2. Choose the endpoint 3. Find the threshold dose for the sensitive group or the No Observed Adverse Effect Level (this could also be a concentration in the air associated with an adverse effect, with the dose implied). 4. Apply margin of safety (if the threshold is 2 mg/day then set the standard to allow only 1 mg/day, e.g.)

How was the weather important to the London episode?

: it took the large number of relatively small sources during poor dispersion conditions to create the killing concentrations.

What's the difference between a gas and a vapor?

A gas is a state of matter in which the matter expands to fill the container and changes volume readily with changing temperature, pressure. A vapor, as used in air pollution and industrial hygiene, is a gas that exists largely as a liquid at normal temperatures and pressures. Thus we speak of water vapor, not water gas, but of methane gas, not methane vapor.

tumor suppressor genes

A gene whose protein products inhibit cell division, thereby preventing uncontrolled cell growth (cancer).

How does maximum tolerated dose relate to an increased cancer risk?

A large fraction of all chemicals that have been identified as mutagen/carcinogens only have excess tumor growth in the group being exposed to the maximum tolerated dose. The MTD causes chronic internal wounding. Internal wounding causes cell division to repair the wounds. The more cell division, the greater chance of genetic mistake mutation. There the higher tumor rates in animals at the MTD may very well be caused by the chronic wounding and not by the chemical's inherent ability to cause mutations and therefore cancer.

Why has London had no repeat of its infamous 1952 episode?

A natural gas distribution system in the city and laws discouraging the use of coal accomplished the switch to clean-burning gas; no major episodes have occurred since the 1950s.

respiration

A process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.

apoptosis

A type of cell death in which the cell uses specialized cellular machinery to kill itself- kills groups of cells that may be damaged

What are the two large categories of air pollutants?

Aerosols (airbone solid particles also called particulate Example; smoke) Volitale Organic Compound ( overexposure results in central nervous system depression; carbon compounds with marked tendency to evaporate)

nonattainment area

An area that does not meet air quality standards set by the U.S. Environmental Protection Agency for key pollutants

What are the adverse health effects of overexposure to VOC?

At high concentrations you would have CNS depression, fire/explosion hazards, at low concentrations you would VOC's would be ozone precusors and some VOC's are mutagens, carcinogens

What is the relationship between atmospheric pressure and altitude?

Atmospheric pressure decreases with increasing altitude-- altitude (+) , atmospheric pressure (-)

What are the two chemical products of complete combustion?

Carbon Dioxide and Water

Explain several control techniques for VOC.

Catalytic converter VOC + O2 -> CO2 and H2O, leak controls, change solvent- water- based paint instead of oil-based paint, activated carbon absorption- instead of passing water through activated carbon we run air through the carbon filters

constructed wetlands

Complexes of artificial marshes designed to filter and decompose waste.

What are the units for ambient concentration of a gas or vapor in air?

Concentrations, averaging times- volume/volume (ppm), mass/volume

ppm by volume

Gasses and Vapors are generally measured in...

What are the products of photosynthesis?

Glucose and oxygen

carboxyhemoglobin

Hemoglobin bonded to carbon monoxide is called __________.

Most cancers are environmental in origin. Define environmental here.

Here it means everything that happens to a human after conception: diet, hormones, occupation, smoking, alcohol consumption, medical care, background radiation, and, yes, environmental pollution.

What was the endpoint used to set the carbon monoxide NAAQS?

Increased frequency of angina attacks in the susceptible group.

How do Louisiana cancer rates differ from national rates?

Louisiana death rates from cancer are higher than the national averages in many categories. However, Louisiana incidence rates for cancers are lower than the national averages for most categories. A tumor is counted as part of the incidence rate when it is discovered; one is counted as a cancer death when his death certificate lists cancer as the cause of death. Incidence rates are tracked by tumor registries, which receive reports of identified tumors. The most common explanation for the generally lower incidence rates and generally higher death rates is that cancer victims are not identified in Louisiana until the cancer is advanced and treatment is less successful.

density

Mass / Volume

How can a drinking water contaminant cause blue baby syndrome?

Methemoglobinemia is a oxygen-carrying deficiency caused by the nitrate/nitrite oxidizing the iron atom in hemoglobin to the methemoglobin. In the methemoglobin form, the red blood cell cant carry oxygen. Infants are more susceptible because they lack the enzyme methemoglobineductase.

What do we mean when we say that VOC is a category of air pollutants?

Natural emissions of VOC are much greater than human, worldwide. VOCs do not have a NAAQS, but are an important category of air pollutants. VOC adverse effects

What, under current understanding, are the steps in formation of a tumor?

Oncogenes are present in all cells and control of cell divison. This causes cancer. If a physical or chemical agent damages oncogens and or tumor supressor genes it causes them to mutate and then they cant normally function any longer.

What units are used for the concentration of particulate matter in the air?

PPM, mass/volume

What is the difference between primary and secondary drinking water standards?

Primary drinking water are concerned with human health. Secondary are concerned with taste, odor, corrosivity, etc.

What did the studies on Japanese immigrants illustrate about the cause of cancer?

So the message of this chart is that environment is important to cancer risk (again, environment in the sense of everything not hereditary).

What were the pollutants that were in excessively high concentrations during the London episode?

Source of the two (main) pollutants in the London episode: fireplaces burning coal, producing sulfur dioxide and particulate matter (smoke).

Which kind of inversion is worse for air quality? Why?

Subsidence inversions can last days or weeks if high pressure system is persistent.

What is the usual relationship between air temperature and altitude?

Temperature decreases as altitude increases --- temperature (-), altitude (+)

What susceptible group did the USEPA choose when setting the carbon monoxide NAAQS?

The U.S. EPA NAAQS at 9 ppm to avoid an increased frequency of angina attacks in people suffering from it already. Heart Patients is the susceptible group.

What characteristics did those who died during the London episode have in common?

The fatalities experienced in the episodes were limited to therefore old and the ill (sensitive/susceptible groups) who were unable to adequately respond to the pollution's effect. The causes of death were cardiovascular and lung related, and those with preexisting heart and lung disease were those who were at risk of death from the high pollutant concentrations.

How does mixing height change?

The rising gases will continue to rise as long as they are warmer than the surrounding air. When they are the same temperature as the surrounding air (or cooler) they will no longer rise. Changes when the dashed and solid line change - the inversions

Give three reasons that workplace air quality standards allow higher concentrations than community air quality standards.

Time at work is 8 hours per day, 40 hours per week, with a rest/recovery time of 16 hours per day during the week plus the weekends. The community air standard must protect for 24 hours per day, 168 hours per week. -no children or very old in the workplace -no very sick in the workplace

What are the human sources of VOC?

VOC evaporation which include losses from petrochemical plants, oil based paintings operations, cleaning operations that use organic solvents, and unburned petroleum fuels

What are some natural sources of air pollution? Why are human sources more important?

Volitale Organic Compounds; Human Sources are more localized and concentrated therefore of more concern

primary drinking water standard

Water standards that are concerned with *human health*

secondary drinking water standard

Water standards that are concerned with taste, odor, corrosivity, etc.

subsidence inversion

When high altitude mass of stagnated high pressure air carries layer of warmer air over a region- Forms with a high pressure system. Winds in a high pressue system rotate clockwise, losing air at the edges. Air descends (subsides) in center of the high to replace the air lost at the edges. Subsiding air compresses the atmosphere slightly, and this increase in air pressure aloft causes the air at that height to be warmer. Therefore we have an inversion layer formed, warmer air above cooler air. Subsidence inversions can last days or weeks if high pressure system is persistent.

oxygenated fuel

a fuel with oxygen-containing additives, such as methanol, that increase the octane rating and reduce harmful emissions

vapor

a gas that exists largely as a liquid at normal temperatures and pressures

Which is a constant, atmospheric temperature profile or adiabatic lapse rate?

adiabatic lapse rate is a constant- constant cooling with increased altitude

criteria pollutant

carbon monoxide, particulate matter, sulfur dioxide, nitrogen dioxide, ozone, lead

What are the top causes of cancer in the United States?

diet & tabacco

What was the source of the pollutants in the London episode?

fireplaces burning coal, producing sulfur dioxide and particulate matter (smoke)

Carbon Dioxide

forms from incomplete combustion- carbon fuel + oxygen ---> carbon dioxide (CO2) + carbon monoxide (CO) + water vapor - sources - 2/3 automobiles - adverse health effects- because of its absorption to hemoglobin to form carboxyhemoglobin -- As air contains CO is inhaled the blood absorbs the CO, forming carboxyhemoglobin.

DNA repair

genes that fix non-lethal damage in genes, including proto-oncogenes, tumor suppressor genes and apoptosis regulation genes

What are the units for tailpipe emission standards?

grams/mile

radiation inversion

measured increase in air temperature just above the ground late at night or early in the morning, mainly formed from radiation cooling of the surface

What are the products of respiration?

oxygen and glucose are used to create ATP carbon dioxide, water

fume

small airborne solids from a metal that was melted, evaporated, condensed, then frozen (back to solid form). example : aerosol produced by welding.

atmospheric temperature profile

temperature declines with increasing altitude

Why is oxygenated fuel used as a control measure for carbon monoxide?

the oxygen in the fuel helps the complete combustion of gasoline to CO2

adiabatic lapse rate

the rate of temperature change with elevation

What are the natural sources of VOC?

vegetation

What is the preferred way of describing the adverse effects of air pollution on vegetation?

vegetation can be susceptible to certain pollutants or not. Certain plant may be susceptable to one form of pollution but not the other-- certain pollutants are more likely to harm certain crops

What factors affect the air concentration of a pollutant?

• Source density- how many and how close together are the industry smokestacks, automobiles, etc.? • Source strength- what emission rate is each source (or the sources combined) producing? • Chemical or physical removal,- how quickly is the pollutant exiting the air or being degraded? *• Weather is the most important factor determining day to day changes in air pollutant concentrations.*