Science and the Environment

Transcription

1 Activity 1 You are a female named Jenny Smith, and you live in Common Town. On Main Street, you can see your house, the Doctor's Office, Town Hall, and down the street, the Town Factory. You are sitting at home and have just been diagnosed with colon cancer. You know that you do not have a family history of cancer, so you review your medical record to identify possible environmental factors. Question 1: Choose the items on your medical record that are possible environmental factors in causing cancer. A. 55 years old B. Lived in Common Town entire life C. Works at town's power plant D. Has garden and grows own vegetables E. Eats burgers, chicken, and cheese F. Father died of a heart attack when he was 50 Answer: The correct answers are letters B, C, and D: Lived in Common Town entire life, works at town's power plant; and has garden and grows own vegetables. There may be some environmental concerns within Common Town, at the power plant, and possibly from your garden. Question 2: Write an analysis of your environmental risk factors. Elaborate on each of them and why they might be harmful. Model Answer: I have lived in Common Town all my life, so anything that has affected Common Town's ecosystem, including air and water, may affect me. I also work at the power plant in town, which may have produced some harmful chemicals. I regularly eat from my garden, which could be contaminated if the water or soil are contaminated with anything. In addition, you realize there may be environmental factors inside your home that contribute to cancer. Kitchen: Household drinking water has been treated with chlorine for years to kill bacteria that cause diseases. The chlorine in drinking water has also been found to contribute to colorectal cancers. Also, 1

2 well-done or charred meats pose the highest risk. When meats are cooked at very high temperatures, heterocyclic amines (Has) are formed, which are linked to cancer. Bathroom: Methylene chloride, the propellant used in many aerosol products, is carcinogenic. Open windows when using these products. In addition, certain cleansers and many brands of cat litter contain the carcinogen crystalline silica. Bedrooms: Lead is a toxic metal used for many in products found in our homes. Lead can cause behavioral problems, learning disabilities, seizures, and death. Attic: Asbestos can be inhaled and cause lung cancer. Family room: Indoor air pollution is a pressing concern. Toxic chemicals have been identified in humans. Question 3: Which one of the carcinogens found in your house is an environmental concern that is directly connected to the Common Town ecosystem and affects your neighbors as well? Model Answer: Excessive chlorine in the drinking water. Drinking water flows throughout the entire water system throughout Common Town and affects its ecosystem. Question 4: Is chlorine in drinking water a natural or human disturbance to the ecosystem? A. Natural disturbance B. Human disturbance Answer: The correct answer is letter B: Human disturbance. Chlorine has been added to drinking water by humans; thus, it is a human disturbance, not a natural one. Activity 2 Now that you have your diagnosis and your medical record, and you have searched your environment for cancer risk factors, you want to dig a little deeper with some Internet research. You do three online searches to learn more about colon cancer causes, environmental causes, and cancer prevention. 2

3 Your first search is for Colon Cancer Causes and you find this Web page, which provides some of the following information (American Cancer Society, 2014b): Age: Your chance of having colorectal cancer goes up after age 50. More than 9 out of 10 people found to have colorectal cancer are older than 50. Ethnicity: Some studies have found that the Jewish people of Eastern European descent (Ashkenazi Jews) have the highest colorectal cancer risk of any ethnic group in the world. Several kinds of gene changes (mutations) account for some, but not all, of this increased risk. Race: African-Americans have the highest number of colorectal cancer cases and the highest death rates from colorectal cancer of all racial groups in the United States. The reason for this still unknown. Diet: A diet high in fat, especially fat from animal sources, can increase the risk of colorectal cancer. Over time, eating a lot of red meats and processed meats can increase colorectal cancer risk. Lack of exercise: People who are not active have a higher risk of colorectal cancer. Smoking: Most people know that smoking causes lung cancer, but recent studies show that smokers are 30% to 40% more likely than nonsmokers to die of colorectal cancer. Smoking increases the risk of many other cancers as well. Your second search is for Colon Cancer Prevention, and you find this Web page, which provides some of the following information (American Cancer Society, 2014a): Although the exact cause of colon cancer is not known, it is sometimes possible to prevent. Screening: Regular colorectal cancer screening or testing is important because it usually takes 10 to 15 years to develop. Even people with no risk factors should begin regular screening at age 50. Diet and exercise: Lower your risk by controlling the things you can control, such as your diet and physical activity. Eat whole grain foods, fruits, and vegetables and limit your intake of high-fat foods. In addition, everyone should get minutes of physical activity 5 or more days of the week. Vitamins, calcium, magnesium: Studies have suggested the following can help reduce risk: o Taking a daily multivitamin 3

4 o o o Increasing calcium intake Getting enough vitamin D from the sun or in a pill Eating a diet high in magnesium (for women) Your third search is for the Environmental Causes of Cancer and you find this Web page, which explains that cancer is caused by many factors, as follows (Cancer Research UK, 2014): Carcinogens: A carcinogen is something that can help to cause cancer. Tobacco smoke is a powerful carcinogen, but not everyone who smokes gets lung cancer, so there must be other factors at work. Age: Most types of cancer become more common as people get older. This is because the changes that cause a cell to become cancerous in the first place take a long time to develop. Genetic makeup: There must be a number of genetic mutations within a cell before it becomes cancerous. Sometimes, people are already born with one of these mutations. This does not mean they will get cancer, but with one mutation from the outset, it makes it more likely statistically that they will. The immune system: People who have problems with their immune systems are more likely to get some forms of cancer. Diet: Cancer experts estimate that changes to one's diet could prevent about one in three cancer deaths in the UK. In the Western world, many people eat too many animal fats and not enough fresh fruits and vegetables. The sun: Most skin cancers are largely caused by overexposing your skin to ultraviolet radiation from the sun. Workplace hazards: Some individuals risk being exposed to a carcinogen because of the work that they do. For example, workers in the chemical dye industry have been found to have a higher incidence than normal of bladder cancer. There are strict regulations covering exposure to known carcinogens at work. Asbestos: This is included in its own right because it is such a wellknown cause of cancer. Question 5: According to your research, what lifestyle changes can you make immediately to help prevent more cancer or prevent your cancer from growing? Also, what questions could you ask your doctor? 4

5 Model Answer: I can change some daily habits immediately to help decrease my risk of more cancer. I should eat less red meat, processed meat, and high-fat cheeses. I should eat more fruits and vegetables. Although I don't smoke, I am exposed to secondhand smoke at the bar where I drink, so maybe I should spend less time there. I should also increase the amount of time I exercise every week and take some vitamin supplements. I will ask my doctor to do some genetic tests. Do I have any genetic mutations that would have caused this cancer? Do I have any problems with my immune system? Do I have any signs of any other types of cancer, such as skin cancer because I spend time in my garden? Have you seen cancer in other people who work at the factory in town? Do you think there may be some environmental causes? Question 6: In addition to changing your daily habits and asking your doctor a few questions, what other research could you do to find out the possible causes of your cancer? Model Answer: I should have my house and tap water inspected for asbestos, chlorine, air pollution, and lead paint. I should look up the Environmental Protection Agency regulations about various pollutants and then go to the Town Hall and look up Common Town records to see if the town and businesses are in compliance. Good work. Although you have cancer, you are on the right track to figuring out the possible biological, chemical, and environmental causes and starting to implement your own treatment plan based on your research. References American Cancer Society. (2014a). Can colorectal cancer be prevented? Retrieved from lorectal-cancer-prevention American Cancer Society. (2014b). What are the risk factors for colorectal cancer? Retrieved from lorectal-cancer-risk-factors 5

6 Cancer Research UK. (2014). What causes cancer? Retrieved from 6