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CHAPTER 17 HUMAN HEALTH AND ENVIRONMENTAL RISKS CASE STUDY – CITIZEN SCIENTISTS – PG 463 FIGHT AGAINST MALARIA – PG 484 CHAPTER 17 PART 1 CASE STUDY – CITIZENS SCIENTISTS 1. Describe the location of this case study? 2. What were the diseases that led residents to be suspicious? 3. What was the primary goal of the Concerned Citizens of Norco? 4. What data did this group need to present their case and how did they do it? CITIZEN SCIENTISTS 5. What did the group find out about their data? 6. How long did it take the group to win fight against Shell Oil Company? 7. What did the community win? THREE CATEGORIES OF HUMAN HEALTH RISKS • Physical • Environmental factors Natural disasters - examples Natural phenomenon - examples • • • Biological • Disease • • Define Chemical • • Natural – example Synthetic – example LEADING CAUSES OF DEATH WORLDWIDE • Which cause leads to the most deaths? INFECTIOUS DISEASES • Infectious diseases • • • Define Causes – pathogens Top three • Non-infectious diseases • Two categories of all diseases (define) • Chronic • Acute LEADING HEALTH RISKS WORLDWIDE • WHO – World Health Organization Developing – risk factors associated with: Developed – risk factors associated with: TRANSITION OF RISKS How is the economic development of a country related to disease? TERMINOLOGY • Compare and Contrast • Similarities • Differences • Epidemic • Pandemic PATHWAYS OF TRANSMITTING PATHOGENS Cholera Tuberculosis AIDs Gastrointestinal diseases Mad Cow disease Plague HISTORICAL IMPORTANT INFECTIOUS DISEASES Name Plague Bubonic plague Black death Cause Bacterium Transmission Vector Fleas to rodents Fleas to humans Rodents to humans Symptoms Treatment Swollen glands Antibiotics Black spots on skin Extreme pain Killed ¼ of European population in 1300s MALARIA Predominately tropical areas Most affected is Africa Cause Protists – Plasmodium Transmission Vector Symptoms Treatment Mosquito to human Flu-like symptoms • Mosquito eradication program • DDT • Antimalarial drugs • Mosquito tents CASE STUDY GLOBAL FIGHT AGAINST MALARIA PG. 484 1. What is the modern history of malaria in terms of infection and death? 2. Where are most malaria cases? 3. Who is most likely to die from malaria? 4. How was malaria eradicated in the U.S.? 5. What were the unintended consequences of this eradication? 6. What is the problem with spraying to eliminate mosquitoes? 7. What are the multiple strategies now being used to eradicate the mosquitoes? 8. What did Bill Gates do differently to help in the eradication? 9. What are the challenges that remain? 10.What is new on the horizon? TUBERCULOSIS TB Cause Bacterium Transmission Vector Symptoms Treatment Person to person Weakness Taking antibiotics for through air Night sweats a year (coughing) Coughing up blood Often people stop taking the drug before all bacteria are killed. Leads to drug resistant strains of bacteria. DECLINE OF TUBERCULOSIS IN THE U.S. Due to: EMERGENT DISEASES • Emergent disease • Define: • Since 1970 in the world at least one emergent disease every year. • Since 1970 most of the emergent diseases are from pathogens that normally infect animal hosts but unexpectedly jumped to human hosts. • • • • • HIV/AIDS Ebola Mad Cow Disease Bird Flu West Nile Virus THE EMERGENCE OF NEW DISEASES ACQUIRED IMMUNE DEFICIENCY SYNDROME AIDS Cause Symptoms Human Originally from Immunodeficiency chimpanzees virus • butchering • eating the chimps. Transmission Symptoms Treatment Person to person Sexual contact Sharing needles Infected blood • Weight loss Antiviral • Recurring fever drugs • Profuse night sweats • Extreme tiredness • Swelling of the lymph glands in the armpits, groin, or neck • Sores of the mouth, anus, or genitals • Pneumonia • Red, brown, pink, or purplish blotches on or under the skin • Depression, neurologic disorders. EBOLA HEMORRHAGIC FEVER Cause Ebola virus Source Unknown Transmission Symptoms Treatment • Contact with • Fever, vomiting None virus • Internal and • Republic of external Congo bleeding • Near Ebola River • Death in 2 weeks MAD COW DISEASE Cause Source Transmission Prions – proteins in Cows Eating meat of cattle brains that infected cattle mutate into deadly Cow to cow – proteins that act like CAFOs (eating pathogens infected cows) Cow to person Symptoms Loss of coordination Death Treatment None Banning of export of cows from infected herds New rules prevent feeding animal remains to cows BIRD FLU Transmission primarily to people who handle birds. Cause H1N1 Virus Source Wild Birds Transmission Symptoms • Wild birds to • Fever, cough, sore domesticated throat, and muscle birds. aches. • Ducks, • Some people also chickens, have nausea, turkeys vomiting, diarrhea, • Birds to people eye infections. Treatment Vaccine WEST NILE VIRUS First human case in West Nile region of Uganda – 1937 First case in U. S. New York - 1999 West Nile Virus in U.S. Cause Virus Source Birds Transmission Bird to bird by mosquito Mosquitoes to horses and humans Symptoms Abdominal pain Diarrhea Fever Headache Muscle aches Nausea Rash Sore throat Swollen lymph nodes Vomiting Treatment Destroy the mosquitoes. Protect against mosquito bites TOXICOLOGY CHART RISK ASSESSMENT CHAPTER 17 PART 2 TOXICOLOGY • Study of chemical risks • 5 Types • • • • • Neurotoxins Carcinogens Teratogens Allergens Endocrine disrupters Type Effects Examples DECLINE IN LEAD IN CHILDREN What caused the decline? When was lead removed from gasoline and paint? CARCINOGENS Effects Examples CARCINOGENS IN TOBACCO Chemical Acetaldehyde Acrylonitrile 4-Aminobiphenyl o-Anisidine hydrochloride Arsenic Benzene Beryllium 1,3-Butadiene Cadmium 1,1-Dimethylhydrazine Ethylene oxide Formaldehyde Furan Heterocyclic amines Hydrazine Isoprene Lead 2-Naphthylamine N-Nitrosodi-n-butylamine N-Nitrosodiethanolamine N-Nitrosodiethylamine N-Nitrosodimethylamine N-Nitrosodi-npropylamine 4-(NNitrosomethylamino)-1(3-pyridyl)-1-butanone N-Nitrosonornicotine N-Nitrosopiperidine N-Nitrosopyrrolidine N-Nitrososarcosine Polonium-210 Polycyclic aromatic hydrocarbons o-Toluidine Vinyl chloride Teratogens Effects Examples Thalidomide – Prescribed to pregnant women to combat morning sickness between 1950 and 1960. – Taken off the market in 1961. – On the market now to treat leprosy, AIDS and some cancers. FETAL ALCOHOL SYNDROME • Small head • Facial abnormalities • Poor coordination • Poor socialization skills • Difficulty building and maintaining friendships • Lack of imagination or curiosity • Learning difficulties, including poor memory, inability to understand concepts such as time and money, poor language comprehension, poor problem-solving skills. • Behavioral problems, including hyperactivity, inability to concentrate, social withdrawal, stubbornness, impulsiveness, and anxiety. ALLERGENS Effects Examples http://www.youtube.com/watch?v=BQKBh5tB1Xs ENDOCRINE DISRUPTERS • • • • Male animals normally make estrogen then convert it to testosterone. With the site blocked the male has higher concentration of estrogen. Testes make sperm and eggs or only eggs Found in male reptiles, amphibians and fish. Effects Examples Dose-Response Studies • Exposure of animals or plants to different amounts of a chemical and then observe a variety of possible responses including mortality or changes in behavior or reproduction • Measured – Concentration – Dose – Dose studies • Acute studies – Threshold Dose Studies • Mortality response – S-shaped curve • Low dose • Threshold dose • Highest dose • LD50 • Measurement for comparing effects of different chemicals. • Whether a new chemical is more or less lethal in comparison to other chemicals. • ED50 – Sub-lethal effects • Dose that causes 50% of the population to display harmful but non-lethal effects. DOSE-RESPONSE STUDIES SAFE CONCENTRATIONS • For animals • LD50 divided by 10 • For humans • LD50 and ED50 from rats and mice • Divided by 1,000 • Tested on plants and animals. • LD50 5.5 • For animals • For humans .55 .0055 TESTING STANDARDS • Regulation – EPA • Toxic Substances Control Act of 1976 • Give the EPA the authority to regulate many chemicals. • Excludes food, cosmetics and pesticides. • Testing • • • • Cannot test every chemical on every organism. Test a few species – mammal, bird, fish, invertebrate. Don’t test amphibians. Why? Organism selected from each group is the one thought to be the most sensitive to a particular chemical. CHRONIC STUDIES • Studies conducted for longer periods of time • Determining the long-term effects of chemicals. Effects on behaviors and on reproduction. RETROSPECTIVE VERSUS PROSPECTIVE STUDIES Epidemiology Alternative studies to lethal dose studies for humans. • Retrospective studies • Study of people who have been exposed to a chemical at some time in the past compared to a second group who have not been exposed. • Prospective studies • Monitor people who might become exposed to harmful chemicals in the future. • Participants keep track of the food they eat, tobacco they use and the alcohol they drink for the next 40 years. • For researchers to determine if their habits of the participants have any association with future health problems. • Concern - Synergistic interactions FACTORS THAT DETERMINE CONCENTRATIONS OF CHEMICALS • Routes of Exposure • Knowing the exposure: • Determine the chemical solubility. • Potential for bioaccumulation. • Potential for biomagnification. • Bisphenol A • Chemical used in the manufacture of hard plastic toys, food containers and baby bottles. SOLUBILITY • How well a chemical can dissolve in a liquid. • Determines how a chemical moves through the environment. • Water-soluble chemicals • Chemical could be found in ground and surface water • Fat and Oil soluble chemicals • Chemical could be found in soil Bioaccumulation • Oil soluble chemicals are stored in the fat tissues of animals. • Continued exposure causes more of the chemical to be stored. • Bioaccumulation. • Depends on: Biomagnification • The increase in a chemical concentration in animal tissues as the chemical moves up the food chain. • Each tropic level is exposed to higher concentrations. PERSISTENCE • How long a chemical remains in the environment. • Depends on: RISK ANALYSIS • Risk Analysis • Risk Assessment • Risk Acceptance • Risk Management • Environmental hazard TYPES OF RISK ASSESSMENT Qualitative Quantitative • Categorize risks as being low, • Risk = medium or high. probability of being exposed to a hazard X • Make judgments based on our probability of being harmed if exposed perceptions but not based on actual probability Risk of dying in a plane crash. • Statistical likelihood of an • Probability of plane crash = Very low event causing harm. • Personal risk assessment often • Probability of dying if the plane crashes = 100% does not match the actual risk. • Choose to slow down on a wet highway because it is safer. • Choose a more expensive car because it is safer. Risk of dying of cancer from eating peanut butter which does have tiny amounts of carcinogens • Probability of eating peanut butter = 100% • Probability of getting cancer from peanut butter = very low Perceived Risk vs. Actual Risk Fundamental Rule of Risk Assessment: The risk of a rare event that has a high likelihood of causing harm can be equal to the risk of a common event that has a low likelihood of causing harm.. Risk Acceptance Risk Management • Level of risk that can be tolerated. • Balance the possible harm against other • According to EPA considerations. • 1 in a million risk is acceptable for • Economic considerations most environmental hazards. • Cultural or social or ethical considerations. • Example: • 1 in a million chance of death • Example: Regulation of arsenic in drinking from radiation leaks is small price water. to pay for electricity generated by • 50 mcl/L of arsenic causes cancer nuclear power. • EPA announced lowering to 10 mcl • Economic burden on mining companies/areas with high natural arsenic. • EPA caved to 50 mcl. • National Academy of Sciences said 5 mcl • Compromise to 10 mcl of arsenic/L WORLDWIDE STANDARDS OF RISK • 80,000 registered chemicals worldwide. • Not regulated the same way everywhere. • Types of regulation is used: STOCKHOLM CONVENTION • • • • In 2001, a group of 127 nations gathered in Stockholm, Sweden, to reach an agreement on restricting the global use of some chemicals. 12 chemicals were to be banned, phased out, or reduced • Dirty dozen POPs – Persistant Organic Pollutants These include DDT, PCBs, and certain chemicals that are by-products of manufacturing processes; all known to be endocrine disrupters. These countries continue to meet; in 2009 - 9 more chemicals have been added. LAWS • Occupational Safety and Health Act OSHA • Created to protect worker and health • Its main aim was to ensure that employers provide their workers with an environment free from dangers to their safety and health, such as exposure to toxic chemicals, excessive noise levels, mechanical dangers, heat or cold stress or unsanitary conditions • Consumer Product Safety Act • Purpose is to protect the public against unreasonable risks of injury associated with consumer products.