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ESM 693 Final Exam
I suggest you download this file and splice your answers after the appropriate sub-paragraphs. When you finish, send it to me via the dropbox. If anything is unclear on the exam, please email me. Also, if any glitches in the exam turn up that might affect an answer, I will post the correction in the Announcements, so you should check Blackboard from time to time before you hand the exam in. The exam must be in by May 10th, but there is no problem with sending it in early.
It is an "open book" exam, so you can use any non-human resource, including any electronic resources that are not specific to this examination.
The exam has several picture files, gif files, in it. These should open in Word as you get there. If there is a problem, let me know. Several of the gif files show results from two runs of RISC. That should be all you need for the questions. If you wanted to see the RISC output, the files are also in this exam sub-folder, and you are welcome to look at them, but you should not need them to complete the exam.
The exam will be graded out of 250 points, then scaled to 100 points, per the syllabus.
1. You are the newly hired "hazardous materials specialist" for the Alaska Department of Transportation. You get a call from the State Troopers. A railroad tank car of MethyEthylGoopanol, (MEG) a chemical you have never heard of, derailed and spilled its 40,000 gallons into a drainage ditch whence it flowed toward the Parks Highway. Fortunately the culvert under the highway was blocked. Unfortunately this formed a pool near the highway. The troopers have blocked traffic and are keeping well back from the pool. They want to know if the material in the pool is "safe" to drive past. Traffic is backing up. You tell them you will get back to them in "about half an hour." Answer the questions below in 5 or 6 paragraphs, read all sub-questions before answering any. Also, I have put a few hints in square brackets. These words might help you answer the question.
1.A. (10) A co-worker who overheard all this says, "Chemicals released into the environment never hurt people." Do chemicals released into the environment harm humans?
Yes and no. It depends upon the chemical concentration and/or the length of exposure time of the chemical with humans as well as the amount. Small, regular intakes of water is good for a person each day but drinking too much water at one time or over a short period of time can actually kill a person, if taken to the extreme. For exposure, small or even barely traceable amounts of chemicals such as DDT can affect the health of humans over a long period of time. Also, never say never. . 7 I was looking for a few examples of harm: Bhopal, Minamata Karen Wetterhahn
1.B. (15) You have the standard DOT emergency response booklets and data, including a CD, but they do not mention MEG. (The only visible placard on the tank car just said the name of the chemical, no other help. You called the emergency response number, but there was no answer.) How might you proceed to learn something about MEG? What kinds of things do you need to know, at this time?
Find the MSD (the list of chemicals and important
information about the chemicals that were being transported. Things to know: L/ED50
(might try the slash, although I've never seen it that way. ED includes LD,
volatility, does the chemical easily evaporate into the air and if so, how long
to do so, affects to water and air, human health risks, safety zone. Also, which way is the wind blowing, current
temperature, expect temperature later that day. Find solubility, density and flammability. good 15
1.C. (20) From Step 1.B, you now find lots of information on MEG. Prepare a "back of the envelope" risk assessment for your boss. Discuss in a general way the different types of hazard, receptors, fate and transport issues. [accident, illness, ecological]
There is a large concentration of
the chemical in liquid form, which is quickly evaporating. Is there anything that could possibly react
with the chemical vapors such as car exaust, the combustion of an engine,
residual residues of chemicals that may have been in the culvert in previous
times from runoff pollution, someone smoking a cigarette? The combustion of an engine is the most
likely to be the largest hazard, though someone lighting a cigarette is also
very likely. The first people to
respond to the accident could possibly inhaled high concentrations of the
chemical. They should be checked by a
medical personnel. Check to see if
there are possibly any one in their vehicles that may be sensitive to the
chemical such as children, elderly and/or people with respiratory
problems. Take liquid samples on the
other side of the highway to see if the chemical is leaking through the culvert
and at what rate. Check local
vegetation for stress or death to use as a possible health hazard indicator to
humans. Attempt to keep animals out of
the chemical pool such as waterfowl.
Make sure that people stay up-wind of the chemical, no one tries to
drink the chemical thinking that it is water since the chemical is most likely
clear. You
are grading over into risk management. 15
1.D. (15) Your boss asks, "Does this stuff cause cancer?" You found out that the EPA considers MEG a "Group 2B" chemical. So you answer her in one sentence. Then your boss asks, "What the hell does that mean?" Explain in more than one sentence. [MTD]
It possibly could.
What I mean is that if someone was to stand down-wind or nearby and
inhaled large amounts of the chemical vapor, or if someone was to drink the
chemical, or if someone was to take a bath in the chemical pool or even eat a
large amount of ducks for a period of time that swam in the chemical pool, then
this could possibly cause cancer. 7
1.E (10) In quick risk assessment (1.C above) you determined that the levels of MEG to which the nearby residents might be exposed was less than 10% of the concentration that OSHA says are legal for workers. Is this a good criterion for assuring the residents that MEG will not be a problem for them?
No, because the local residents were exposed to 40,000
gallons of the chemical at one distinctive period in time. People who work with this chemical probably
don’t work in an environment with 40,000 gallons of the chemical. 40,000 gallons of anything is a lot,
especially when trying to convince people that they and their children and dogs
will not be harmed by 40,000 gallons of a chemical.7,
see solutions.
Question 2
2. (50) The material in the barrels was dumped off the truck of a "midnight dumper." most of the barrels were open and the material spilled to the ground. The barrels contained four substances: Aroclor 1242, a hydrocarbon mix that is mostly benzene, acrylonitrile, and tetrachloroethylene. Describe in one paragraph for each of those four substances: the likely exposure pathways to the farmer and the likely fate of the substance. [You could use Level I and/or RISC for some information, but I am not looking for quantitative answers from those programs. Some of the substances you will have to search for, they are not in the RISC or Level I database. A neat way to organize your answer is to start with a five column table that has those 4 substances as the column labels, and the important parameters as row labels, then put numbers or descriptions. Then your descriptions may be shorter.]
Tetrachloroethylene: this chemical is highly regulated by
the government due to the high toxicity of the chemical to human health. Vaporization of the chemical is a likely
pathway as well as leaching through ground.
If the time of year is cool, the chemical will slowly if at all vaporize
which will lessen the human health hazard.
If the time of year is warm, then possibly/hopefully there is enough
distance between the chemical release and the farmer for the chemical vapor to
dilute (the solution to pollution is dilution). As the chemical is released into the ground and since the
chemical is insoluble in water, the chemical will separate out of the water and
either float at the top of the water table or sink to the bottom. By making a SWAG, I would say the chemical
would settle toward the bottom of the water table. But to do so, the chemical would have to travel through the water
table. Several hydrological factors can
be played through here but will not be addressed. Basically, the che mical could most likely be attached to soil
particles within the soil substrata. Low Koc t
shouldn’t travel very far down gradient unless the groundwater flow is fast enough.
7
Acrylonitrile: due to the fact that
this chemical is highly volatile and soluble in water, this chemical will
easily and quickly travel as a vapor in the air and in the groundwater
flow. If there is enough distance
between the farmer and the chemical release, the chemical may be diluted enough
before it comes in contact with the farmer and cause serious health
problems. The chemical may quickly flow
through the groundwater table and highly and quickly affect the groundwater
quality. 8
Benzene: Because this chemical is
heavier than air, it could flow down hill toward the farm without being diluted
very much. No As going by the picture, vegetation may stop
the continued movement of the chemical toward the farmhouse. Most if not all vegetation will be affected
in some way if not killed. Because the
chemical is somewhat soluble in water, there will be small amounts of the
chemical found in the groundwater.
Other traces will be found in the soil and at the top of the groundwater
table.5
Aroclor 1242: Because the chemical
is mostly benzene, acrylonitrile and tetrachloroethylene, aroclor 1242 will act
a little like all three chemicals.5
3. (50) For each of the four substances from Question 2, consult IRIS and an MSDS sheet and then describe the acute toxicity for cleanup workers and the chronic toxicity for the farmer. These responses should parallel your answers from 2. above, but in all cases assume for this question that there is enough exposure to warrant an analysis of the toxicity data. Try to explain what the data is based upon [epidemiology, laboratory] [You'll be using some numbers here, but be sure to explain, what the numbers mean. You may need to spend some more time explaining the first time the word comes up, less the second time it comes up.]
Because a Frank Effect (death of an
infant) was noted at the lowest dose tested in a sensitive animal species, oral
ingestion of aroclor 1248 is not suggested at any dosage at any time. Aroclor 1248 was chosen because it is the
closest chemical to aroclor 1242.
Therefore, acute toxicity by drinking groundwater is quite possibly
death. That is a little severe. Always
remember Parclesus. In fact the adverse
effects of PCB at relevant doses is not a sure thing.
Acrylonitrile
Critical Effect Exposures* UF
MF RfC
-------------------- --------------------------- -----
--- ---------
Degeneration and NOAEL: None 1000
1 2E-3
inflammation of nasal mg/cu.m
respiratory epithelium; LOAEL: 43
mg/cu.m (20 ppm)
hyperplasia of mucous LOAEL(ADJ): 7.7 mg/cu.m
secreting cells LOAEL(HEC): 1.9 mg/cu.m
Rat 2-Year Inhalation Study
Chronic and acute toxicity levels
are considered to be similar because of the lack of data on human health.
Need to explain these and relate
to farmer or worker.
Benzene: do to the lack of data on chronic oral and
inhalation exposure there is a strong opinion that benzene is a carcinogenetic
to humans. Benzene is definitely a human
carcinogen.
Tetrachloroethylene:
Chronic oral exposure
Critical Effect Experimental Doses* UF MF RfD
-------------------- ----------------------- -----
--- ---------
Hepatotoxicity in NOAEL: 20 mg/kg/day 1000 1 1E-2
mice, weight gain (converted to mg/kg/day
in rats 14 mg/kg/day)
6-Week Mouse Gavage LOAEL: 100 mg/kg/day
Study (converted to
71 mg/kg/day)
There is no data on inhalation
exposure. For humans, there should not
be any acute sickness. Chronic toxicity
would most likely affect the farmer.
4. New situation. You are an environmental scientist/engineer working for the North End Refinery. About 20 years ago the refinery has a massive leak in its main carbon tetrachloride (CCl4) tank, and several million gallons of this chemical were released to the groundwater. The refinery put in wells and removed most of the chemical. Groundwater movement is slow and the CCl4 mixed into the groundwater. And it now appears that the residents of the subdivision nearby, where many of the residents are refinery workers, will be exposed to 0.04 mg/L of CCl4 in their water supply wells for a long time (Assume that is the same as 0.04 ppm). The expert consultants the refinery hired have determined the following risk.
You can get the RISC prj file from Blackboard, Course Information, Final Exam folder, but you should not need it.
Your boss has asked you to help on this issue and advise the "external affairs" person the refinery uses to talk to the public. Your consultants have advised that each home in the subdivision should have a charcoal filter put into the water supply lines from their wells. The filers have been advertised to reduce CCl4 from 0.04 mg/L to 0.004 mg/L. Here is the associated risk based on 0.004 mg/L:
The filters cost $750, which the refinery will pay for, plus a $1250 one-time fee to compensate the residence for maintenance of the filters. That is, each home will get a check for $2000. Your consultant tells you that the filters need to be changed every three months and cost $25. Also the consultant admits he has never used the filters, and had based his opinion on the manufacture's literature. He also tells you that filters sometimes need changing more often if there is iron in the water (and you know there is a lot of iron in the water at this location) and that the filters have never been tested in cold water.
[Look at this EPA site about CCl4
http://www.epa.gov/OGWDW/dwh/t-voc/carbonte.html]
You see two problems: First, refinery workers who live in the subdivision will not notice the CCl4, because they smell it at much higher concentrations all day. You are concerned they will use the money to change the sparkplugs in their airboats and not bother installing the filters. Second, the non-refinery workers, who have hired a lawyer and their own consultant, a former high-school science teacher, want the refinery to remove "all" the CCl4, or pipe them water from the town, 20 miles away. Both of which the refinery, state, and federal environmental agencies believe are infeasible. The $2000 offer has been in the paper, so everyone knows a little about it. The lawyer has asked you to address an informal meeting of the residents.
4.A. (30) Write a brief (two or three paragraph) memo to the refinery workers who live in the subdivision. Describe the risks and hazards if they do not install the filters. You may use some numbers for reference and in order to be technically correct, but assume the workers do not understand the numbers and you must communicate with them via your text description.
According to the EPA, the current contaminate level of
CC14 is above the recommended level of the chemical in drinking water. Under the current water quality conditions,
liver damage or even liver cancer for long-term exposure. By placing a water filter, the level of the
chemical CC14 is lowered to a level that is much less likely to cause any
health problems in your families, even over a long period of time. Buying a water filter and properly keeping
the filters clean by changing them regularly could be and quite possibly a
matter of life and death
to either yourself and/or your family. A little too
strong at the end but otherwise quite good.
4.B (30) Prepare a set of notes that you will give to the external affairs person that you expect he will have written up for a press release and will use for notes at the public meeting. You will go to the meeting also. He already has a draft of the memo to the workers. Describe the chemical and it toxicity. Prepare some information about the risk that remains after the water is filtered. Explain why you think the residents will be "safe." Explain the residual is below the MCL. What will you say, if asked, about the MCLG. (See bottom of http://www.epa.gov/safewater/mcl.html#1 for explanation). As you did for the workers, you must use some numbers, but the explanation must be clear to people who are not facile with numbers.
Because of the properties of the chemical, it does not stick to soil particles where it could continue to pollute the groundwater table. Rather, it stays with the water and since the company pumped out and filtered the groundwater table, most of the chemical was recovered from the groundwater table. Since the chemical does not entirely stay in water and a little does stick to soil particles, there is some of the chemical left in the ground. The amount left in the groundwater table is higher than what the federal government says to be safe for long periods of time when drinking the water regularly over a long period of time. But with the addition of water filters that the company is wanting to buy for the residents, the amount of chemical in the water that comes out of the water filter is less than the recommended amount by the federal government for drinking the water for long periods of time on a regular bases. Now, there are still some risks associated with drinking the water by certain residents. Small children and the elderly should be very careful about the amount of water that is drunk regularly, as a precautionary measure since not everyone is the same and can handle the chemical the same.
The down-side and possible problem with using and relying on the water filters is that the filters have not been proven to work properly in cold climates such as ours and that iron in the groundwater is known to shorten the life of the water filter, thereby requiring the filter to be changed more often than noted. So, instead of changing the filter every 3 months or so, the filters may have to be changed every month or sooner. It is really unknown. The cost of having a water filter system drastically rose by these two factors. The $2000 pay-off is extremely low because the over-all cost of having a water filter system for the rest of the resident’s life is very large. If the filter is changed once a month at $25 per filter, the cost of a filter each year is $300. If the house is there for 50 years, that is $15,000 for filters alone. Additional cost for repairs and replacements would then have to be added into the over-all cost of the water filter system.
4.C (20) Consider the Sandman site on outrage. Write out 3 or 4 reasons the non-refinery subdivision residents might be outraged.
They do not receive any benefits from the refinery being
where it is, which is close to their residency. They know even less about the chemical because they are not
routinely around the chemical as refinery workers are. If the refinery was not located in the
present location, their lives would be better in the present and in the
future. If the refinery was not there,
then they probably would not have to use water filters and would not have a
chance that someone in their family could get liver problems or cancer.Need to review Sandman.
4.D (30) Your memo to external affairs included information about the iron in the water and the lack of cold water experience with the filters. At the public meeting the external affairs did not bring this up, neither did you or the subdivision people. You were happy that you did have to deal with this. Now it is 2 o'clock Sunday morning, you are lying wide-awake, and berating yourself and the refinery for not mentioning the iron in the water and the lack of cold water testing. Here are two sets of principles:
Fundamental Canons from the National Society of Professional Engineers (NSPE)
http://www.nspe.org/ethics/eh1-code.asp
or
Canons of Ethical Conduct from
the American Board of Industrial Hygiene (ABIH).
http://www.abih.org/Docs/Code-of-Ethics.htm
Both have similar information, six basic principles in the front and more detailed explanation further back. Select one or the other (they are similar, so tell me which you are using). Pick two or three of the fundamental principles (canons) and write two or three paragraphs (total) about applying them to your situation. Several of the principles might conflict; you should describe at least one of these conflicts.
Counsel affected parties factually regarding potential health risks and precautions necessary to avoid adverse health effects. As a scientist, you are to analyze the scientific facts and present the facts in an unbiased manner to the public or in this case the employer. The job of the scientist was not to be a PR but rather a scientist, a professional that is capable of understanding the complexity of nature, the chemical and human health risks. By presenting the data in an unbiased format to the employer and/or the public, then the job was done correctly.
Perform services only in the areas of their competence. In this case, the person was a scientist not an economist. There are many scientist that are capable and do high levels of calculus but are not capable and do not balance their check books. Do what you are hired to do and do it well and try not to do other’s jobs.
What is the definition of “well-being of people” in this context? Does it include economics? Does the scientist have an obligation to step outside the company/employer and telling his/her opinion of the matter in its entirety? By doing so, is he/she helping or hurting the community? What if by telling everyone, everything, the refinery has to close down and leave town? Then, the community does not have a steady income and is not able to pay for water filters or worse, the company was not able to buy the water filter systems before it went bankrupt and so the community is stuck with buy the water filter system as well as filters.