Biology 2485B Lecture Notes - Lecture 15: Environmental Toxicology, Nitrate, Methemoglobin

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orchidshark702

12 Apr 2019

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Lecture 15 pollutants and human health (and other organisms) Categories of environmental health hazards (hazards/risks related to the environment that affects human health: chemical hazard, chemicals that are present in the environment that can cause a hazard/risk to our health, physical hazard, not really a focus. Methemoglobinaemia caused by nitrate poisoning in ground water: nitrates lead to creation of methemoglobin. This is a form of haemoglobin in which the iron atoms of the heme group are ferric (fe3+) instead of ferrous (fe2+) This changes o2 binding affinity of the heme group: when there is >1% methemoglobin in red blood cells, the ability of those cells to release oxygen to tissues is impaired, may result in cyanosis (skin turns blue) Toxicology: the study of the effects of chemical hazards (poisonous substances) on humans and other organisms. Toxicant or toxin: any poisonous substance: can be of natural origin (e. g. snake venom) or synthetic toxins that we"ve produced.

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Can anyone help me with the following questions, it is due tonight and im having a hard time figuring most of these out and in-between a couple of answers. Thanks!

1. Which of the following is the PRIMARY goal of risk assessment?

A. maximize profit

B. balance risks and benefits

C. reduce liability

D. determine lethal doses

2. The probability of an adverse outcome based on the exposure and potency of a hazardous agent is known as the:

A. toxicity

B. risk

C. hazard

D. margin of safety

E. therapeutic index

3. Risk Assessment includes all the following, except:

A. risk characterization

B. exposure assessment

C. dose-response assessment

D. hazard identification

E. cost-benefit analysis

4. The process of making risk information understood by local officials, community groups and other stakeholders is known as:

A. risk management

B. risk characterization

C. risk communication

D. risk perception

E. risk estimation

5. The Hazard Identification step in the risk assessment paradigm may include which of the following:

A. in vitro testing

B. structure-activity relationships

C. animal bioassays

D. epidemiologic data

E. all of the above

6. A basic premise of carcinogen risk assessment is that:

A. surface area is proportional to body weight

B. chemicals that cause tumors in animals will cause tumors in humans

C. all dosing regimens are equivalent

D. all animal strains are relevant

7. The Point of Departure (POD) for a low-dose extrapolation could be which of the following:

A. NOAEL

B. LOAEL

C. BMDL

D. none of the above

E. all of the above

8. The benchmark dose (BMD) approach is preferred over the NOAEL/LOAEL approach for all the following reasons, except:

A. the full dose-response curve is considered

B. it includes a measure of variability

C. the same benchmark response be used across studies

D. it results in lower reference values

9. A biochemical change, functional impairment, or pathologic lesion affecting an organismâs performance, and reducing its ability to respond to environmental challenges is known in risk assessment as the

A. point of departure

B. benchmark dose

C. adverse effect

D. carcinogenic effect

10. When there is a cancer risk of 1 in 10,000, this is considered to be of

A. high concern

B. moderate concern

C. somewhat low concern

D. no concern at all

11. Which toxicant is commonly found in indoor air due to off-gassing of plywood and furniture?

A. arsenic

B. lead

C. methylene chloride

D. dioxin

E. formaldehyde

12. Which if the following was NOT an event in the United States that triggered widespread awareness of environmental issues in the 1960s?

A. Relocation of families from Love Canal in Niagara Falls, NY

B. Cuyahoga River catching on fire in Ohio

C. Publication of Silent Spring by Rachel Carson

D. Nationwide federal ban of smoking cigarettes in bars and restaurants

13. The study of the fate and effects of chemicals in the environment is the definition of: A. Environmental toxicology

B. Ecotoxicology

C. Environmental health toxicology

D. Risk assessment

14. An example of an area source of air emissions would be:

A. A volcano

B. A moving car

C. A gas station

D. A power plant

15. Which of the following is considered to be âgood up high and bad nearbyâ?

A. Ozone

B. Carbon monoxide

C. Carbon dioxide

D. Sulfur dioxide

16. Which of the following water disinfectants is safest from the perspective of not producing any known DBPs?

A. Chlorine

B. Chloramine

C. Ozone

D. UV

17. The most significant anthropogenic source of carbon monoxide would be classified as a:

A. Point source

B. Area source

C. Mobile source

D. Natural source

18. According to Genius (2006), what do some scientists believe is the most frequent cause of childhood cancer and leukemia?

A. Pharmaceuticals in drinking water

B. Exposure to diuretics in utero

C. Prenatal exposure to carbon monoxide and other industry emissions

D. Neonatal exposure to polyvinylchloride (PVC) plastic

19. In the Genius (2006) article, what did the scientists who published in the journal Science discover about the possible transgenerational impact of exposure to environmental toxicants in pregnancy?

A. Epigenetic mechanisms may permanently alter the germ-line and genetic traits of offspring of an exposed individual

B. Epigenetic changes die out after three successive generations of offspring

C. Epigenetic changes only occur when a toxicant is an endocrine disruptor

D. Epigenetic changes never take place when the toxicant is a pesticide or fungicide

20. According to the article by Chemnick and Climatewire (2013), âSoggy Vancouver Island in British Columbia has become an unlikely new home for Cryptococcus gattii, a tropical and subtropical yeast-based fungus.â What health effect does this yeast-based fungus have on humans when it is inhaled?

A. None

B. Triggers asthma attacks

C. Causes a kind of meningitis

D. Eventually leads to lung cancer

greykangaroo345

For this assignment, Part One of your course project, assume the role of Dr. Madness. Your rogue nation seeks global domination. With a bare bones laboratory and your exhaustive microbiological and epidemiological knowledge, you (Dr. Madness) decide that the best way to rule the world is to create and disseminate the perfect biological weapon.

For this part of the assignment, you will develop your weapon from the ground up. Discuss nearly all of the epidemiological criteria related to it, and justify and discuss why it is used and how effective it is. This agent could be a hybrid of other biological pathogens or an entirely new one. If the agent is newly created, there must be some basis and epidemiological support of a similar agent by which you can base your justification. In other words, it will be unrealistic to create an airborne virus that inoculates and kills within one hour. There must be a realistic exposure and incubation time and must be supported through current agent biology or biochemistry (for example, influenza exposure and incubation takes 1â4 days).

Name of Agent: Explain why you chose the name. If it is a biological agent, be sure to provide a taxonomic name

Etiology: This will talk about the genesis of your agent. Where was it discovered? How was it made? How long has it been around? Why was this agent created? What were the social and economic factors of your rogue nation that made Dr. Madness focus on this element of the agent? What are the environmental precursors to this agent? Discuss the interaction among agent, host, and environment.

Identification: This will describe the basics of the agent. Is it a bacteria, virus, toxin, parasite, hybrid, or something else? Discuss how your agent presents within the human population. What are the symptoms in humans? What are the (zoonotic) symptoms in animals? How does the disease progress? Are there stages? Discuss the various stages including length of infection, severity, and the like. What are the diagnostic indicators? How would a doctor be able to identify this agent in a clinic or emergency room?

Laboratory Analysis: How will the agent be identified? Can it be grown in media? What type of laboratory methods can be used to identify the agent (microscopy, chromatography, PCR, and so on)?

Occurrence: This is the epi: who, what, when, where, how, and why of the disease. Where does it happen? When can it be found? Who is most and least susceptible to the agent (risk factors). More exotic and hard to find agents are harder to prevent and control but are also more difficult to initiate an epidemic or pandemic, whereas more generalized and known agents may be easier to cure, but have a much wider swath of causing pandemics. How do socioeconomic factors foster or inhibit the spread of disease?

Reservoir: What is the natural reservoir of the agent? Are there other organisms where this agent can reside without causing disease? Increasing the reservoir can enhance transmission but can also allow for easier identification and treatment in response to it.

Mode of Transmission: Consider inhalation, absorption, digestion, contact, and so forth. If you use multiple modes, justify your selections.

Incubation Period: Provide the range with an average (median) day of disease onset. Does the period change in different socioeconomic status identifiers (sex, age, race, creed, and so on)? Why or why not?

Period of communicability: How long is a person with this agent contagious? Increasing this period also increases the opportunity for study and thus treatment and control.

Susceptibility: Is the agent susceptible to reinfection of the same person? Allowing for this increases morbidity but usually mortality wanes in subsequent infections.

Taking on the role of Dr. Madness, generate your superweapon and describe the weapon using the above mentioned criteria. Remember, the focus in on creating something that becomes difficult to identify, monitor, or treat with prophylaxis. You will write out the proposal as Dr. Madness submitting this to his lead researcher to develop. This proposal should be approximately 6â8 pages in length, but some submissions may be longer.

Submit your Bioweapons and Epidemiology Part One proposal in the assignment area.

Please be sure to review the Bioweapons and Epidemiology Part One Scoring Guide for information on how this assignment is graded.

Project Requirements

To achieve a successful project experience and outcome, you are expected to meet the following requirements.

Written communication: Written communication is free of errors that detract from the overall message.

APA formatting: Resources and citations should be formatted according to current APA style and formatting.

Resources: Include all literature cited in the project.

Length of paper: 6â8 typed, single-spaced pages, not including cover page and resource list.

Font and font size: Arial, 10 point.

Biology 2485B Lecture Notes - Lecture 15: Environmental Toxicology, Nitrate, Methemoglobin

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