Deck 14: Environmental Hazards and Human Health

Question 1

Describe the global threat from tuberculosis. Describe the threat from flu. Summarize the story of health threats from the global HIV/AIDS pandemic and list six ways to reduce these threats. Describe and compare the threats from the hepatitis B and West Nile viruses.

Answer 1

Tuberculosis, HIV/AIDS, hepatitis B, West Nile viruses, SARS viruses, and malaria are biological hazards that threaten the world's population. Among these biological hazards, the emergent diseases are caused by the West Nile virus , severe acute respiratory syndrome ( SARS ) virus , human immunodeficiency virus ( HIV ), and Plasmodium. Emergent diseases are diseases that are previously unknown to humans. Emergent diseases pose a threat to people.
Tuberculosis or TB is a contagious disease. Bacteria cause TB and infect the lungs. Many people with TB do not appear sick. The bacteria may be dormant and not active. TB could be cured by antibiotic. However, the problem is many strains of bacteria are becoming resistant to existing antibiotics.
Multidrug-resistant TB is a form of TB that are resistant to most currently available antibiotics. The number of people who are infected with multidrug-resistant TB is increasing. These infected people are isolated from the rest of the population to prevent infections.
Acquired immunodeficiency syndrome or AIDS is caused by a virus called human immunodeficiency virus (HIV). This virus evolves very quickly. Antiviral drugs used to treat AIDS are not developed quick enough to combat the constantly changing virus. HIV is transmitted through blood.
People with AIDS have a compromised immune system. Their immune system cannot fight against common infections. Hence, a cold or flu could kill people with AIDS. Their bodies are not armed with defense mechanisms to fight off the infections.
Hepatitis B is caused by the hepatitis B virus (HBV). HBV is transmitted through contaminated blood. HBV causes damages to the livers. Many people have died from hepatitis B each year.
The emergent diseases are new diseases that are known recently. The emergent diseases are caused by the West Nile virus , severe acute respiratory syndrome virus , and Plasmodium. Little information about the emergent diseases is known compared to other infectious diseases.
Mosquitoes transmit the West Nile virus through their bites. The severe acute respiratory syndrome ( SARS ) virus can be spread from one person to another person. Plasmodium is a parasite that causes malaria. Mosquitoes are carriers of Plasmodium. Hence, people who get mosquitoes are at high risk of getting malaria.
There are several ways to prevent infectious diseases. First, increase research on diseases and vaccines would provide more effective drugs to cure the diseases. Second, reducing poverty would enable people to have better living conditions that reduce the risks of getting infectious diseases.
Improve drinking water quality is another way to prevent infectious diseases. Many harmful bacteria and parasites live in the water. People who drink unclean water are at very high risk of getting the infectious diseases.
Reduce taking antibiotics unnecessarily would reduce the rate of bacteria evolve to more resistant strains. This method would give scientists time to develop other types of antibiotics that are more effective. Taking antibiotics indiscriminately would make the antibiotics less effective at killing the more resistant strains bacteria.
Other ways that would prevent the spread of infectious diseases include immunizing children against viral diseases, hand washing by all medical personnel, decreasing malnutrition to adults and children, and educating people about ways to protect themselves, their families, and their communities.

Question 2

Explain why you agree or disagree with the proposals for reducing the death toll and other harmful effects of smoking listed in the Case Study on p. 367. Do you believe there should be a ban on smoking indoors in all public places Explain.

Answer 2

According to the case study the person who leaves smoking before the age of 30 or 40 years can maintain his healthy life later on. Putting ban on cigarettes helps to put some stop on the smokers.
Nicotine in cigarette is very addictive and it is not easy to quit smoking, but some factors such as high price or ban can make some justice. It is also important that death due to passive smoking is also very dangerous. Therefore, one's habit can take the life of the others. Therefore, there must be ban on cigarette on public places.

Question 3

Describe the threat from malaria for about 47% of the world's people and how we can reduce this threat. Explain how deforestation can increase the spread of malaria. List five major ways to reduce the global threat from infectious diseases.

Answer 3

Malaria is caused by mosquito. Malarial parasites destroy the red blood cells in the body. This can cause intense fever, sweats, abdominal pain, headache and vomiting. Almost half of the world population is suffering from this disease and it is the major global killer.
Modern vaccines are developed to reduce the effects of the malaria. Education and better medical facilities are required for the developing countries to reduce the effects of the malaria. Funding to the developing countries also helps to develop the better life style for the people.
Studies show that the chances of being beaten by the malaria mosquito are higher in deforested area. This is because of the fact that clearing the forest provides more sites for breeding and also water absorbing capacity of the land decrease with deforestation.
There are many ways to reduce the infectious disease and these include:
• Reducing the poverty
• Providing better food and water
• Reducing the unnecessary use of the antibiotics
• Education
• Better medical facilities and technologies
• Better social life and clean place
• Provide knowledge for the global diseases

Question 4

What are the three major risks you face from (a) your lifestyle, (b) where you live, and (c) what you do for a living Which of these risks are voluntary and which are involuntary List three steps you could take to reduce these risks. Which of these steps do you already take or plan to take

Question 5

What is the key concept for this section What is a toxic chemical Distinguish among carcinogens, mutagens, and teratogens, and give an example of each. Describe the human immune, nervous, and endocrine systems and give an example of a chemical that can threaten each of these systems. Describe the toxic effects of the various forms of mercury and ways to reduce these threats. What are hormonally active agents, what risks do they pose, and how can we reduce these risks Summarize concerns about exposure to bisphenol A (BPA) and the controversy over what to do about exposure to this chemical ( Core Case Study ). Summarize concerns over exposure to phthalates.

Question 6

Should we ban the use of hormone mimics such us bisphenol A (Core Case Study) in products used By children younger than age 5 Should we ban them for use in all products Explain.

Question 7

In deciding what to do about risks from chemicals in the area where you live, would you support legislation requiring the use of pollution prevention based on the precautionary principle Explain.

Question 8

The graph below shows the effects of AIDS on life expectancy at birth in Botswana, 19502000, and projects these effects to 2050. Answer the questions below.

a. By what percentage did life expectancy in Botswana increase between 1950 and 1995
b. By what percentage was life expectancy in Botswana projected to decrease between 1995 and 2015

Question 9

What are the two key concepts for this section Define toxicology, toxicity, dose, and response. Give three reasons why children are more vulnerable to harm from toxic chemicals than are adults. Explain how the toxicity of a substance can be estimated by testing laboratory animals, and discuss the limitations of this approach. What is a dose-response curve Explain how toxicities are estimated through use of case reports and epidemiological studies, and discuss the limitations of these approaches. Why do we know so little about the harmful effects of chemicals Discuss the use of the precautionary principle and pollution prevention in dealing with health threats from chemicals.

Question 10

Pick a potentially harmful chemical not discussed in detail in this chapter and use the library or Internet to evaluate (a) what it is used for and how widely it is used, (b) its potential harm, (c) the scientific evidence for such claims, and (d) solutions for dealing with this threat. Pick a study area, such as your dorm or apartment building, your block, or your city. In this area. try to determine the level of presence of the chemical you are studying You could do this by finding 4 or 5 examples of items or locations containing the chemical and then estimating the total amount based on your sample.

Question 11

Congratulations! You are in charge of the world. List the three most important features of your program to reduce the risks from exposure to (a) infectious disease organisms and (b) toxic and hazardous chemicals.

Question 12

Search for bisphenol A ( BPA ) and research the latest developments in studies of the potentially harmful health effects of BPA (Core Case Study) , List the names of three or four countries that have restricted its use. Pick one of these countries and try to find some details on how that country is regulating; the use of BPA. Write a short report summarizing your findings. Have any countries completely banned the use of BPA What are they Try to find reports of two studies that, give opposing conclusions about how BPA should be regulated. Summarize the arguments for these conclusions on both sides. Based on what you have found, do you believe the use of BPA should be regulated more strictly in the state or country where you live Should it be banned altogether Explain your reasoning.

Question 13

What is the key concept for this section What is risk analysis In terms of premature deaths, what are the three greatest threats that people face Describe the health threats from smoking and how we can reduce these threats.

Question 14

Describe the potential risks from exposure to trace amounts of hormone mimics such as bisphenol A (Core Case Study).

Question 15

How can we reduce the threats resulting from the use of various technologies What are five factors that can cause people to misjudge risks List four guidelines for evaluating and reducing risk.

Question 16

what are three actions you would take to reduce the global threats to human health and life from (a) tuberculosis, (b) HIV/AIDS, and (c) malaria

Question 17

What are this chapter's three big ideas Discuss how we can lessen the threats of harm from chemicals such as hormone mimics by applying the three principles of sustainability.

Question 18

The graph below shows the effects of AIDS on life expectancy at birth in Botswana, 19502000, and projects these effects to 2050. Answer the questions below.

a. By what percentage is life expectancy in Botswana projected to increase between 2015 and 2050
b. By what percentage was life expectancy in Botswana projected to decrease between 1995 and 2050

Question 19

What is the key concept for this section Distinguish among risk, risk assessment, and risk management. Distinguish between possibility and probability. Give an example of a risk from each of the following: biological hazards, chemical hazards, physical hazards, cultural hazards, and lifestyle choices. What is a pathogen

Question 20

Evaluate the following statements:
a. We should not worry much about exposure to toxic chemicals because almost any chemical, at a large enough dosage, can cause some harm.
b. We should not worry much about exposure to toxic chemicals because, through genetic adaptation, we can develop immunities to such chemicals.
c. We should not worry much about exposure to toxic chemicals because we can use genetic engineering to reduce our susceptibility to their effects.
d. We should not worry about exposure to a chemical such, is bisphenol A (BPA) because it has not been absolutely proven scientifically that BPA hits killed anyone.

Question 21

What is the key concept for this section Distinguish between bacteria and viruses, and how the diseases they can cause are usually treated. Distinguish among infectious disease, transmissible disease, and nontransmissible disease, and give an example of each. List four ways in which infectious organisms can enter the body. In terms of death rates, what are the world's four most serious infectious diseases Distinguish between an epidemic and a pandemic of an infectious disease. List the causes and possible solutions for the increasing genetic resistance to commonly used antibiotics. What is MRSA and why is it so threatening

Question 22

Workers in a number of industries are exposed to higher levels of various toxic substances than is the general public. Should we reduce workplace levels allowed for such chemicals What economic effects might this have