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Environmental Health

Environmental Health. How safe are you? How do you know? Risk Assessment What should you do to be safe? Risk Management Who do you rely on to protect you? Risk Assessment and Management Entities. Any Surprises?. Environmental Toxins. https://www.youtube.com/watch?v=V5q_I9O6ItE 2 min.

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Environmental Health

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  1. Environmental Health • How safe are you? How do you know? • Risk Assessment • What should you do to be safe? • Risk Management • Who do you rely on to protect you? • Risk Assessment and Management Entities

  2. Any Surprises?

  3. Environmental Toxins • https://www.youtube.com/watch?v=V5q_I9O6ItE 2 min https://www.youtube.com/watch?v=6RSlByht8Us What is a safe level? 2min https://www.youtube.com/watch?v=oq2K1IvRf8M Stop at 6:20 (can go 1:37:23)

  4. Environmental health hazards Toxicants in the environment Hazards and their effects Risk assessment and risk management Philosophical approaches to risk Policy and regulation in the U.S. and internationally This lecture will help you understand:

  5. Central Case: Lake Apopka alligators Alligators in Lake Apopka, Florida, had reproductive problems Louis Guillette The lake had high levels of agricultural runoff Chemical contaminants were disrupting the endocrine systems of alligators during egg development Because alligators and humans share the same hormones, chemicals can affect people, too

  6. There are many types of environmental hazards Environmental health = assesses environmental factors that influence human health and quality of life Natural and human-caused factors are both considered Three Main Types of Hazards: Physical Hazards Biological Hazards Chemical Hazards

  7. Physical hazards • Threats to our health that is due to physical trauma • Falls • Projectiles • Burns • Electrical Shock • Drowning • Can occur naturally in our environment • Sunburns, earthquakes, volcanoes, fires, floods, droughts • We can’t prevent them, but we can prepare for them • We increase our vulnerability by deforesting slopes (landslides), channelizing rivers (flooding), etc. • We can reduce risk by better environmental choices

  8. Chemical and biological environmental hazards Chemical = synthetic chemicals such as pesticides, disinfectants, pharmaceuticals Harmful natural chemicalsalso exist Biological = result from ecological interactions Viruses, bacteria, and other pathogens Infectious (communicable, or transmissible) disease = other species parasitize humans, fulfilling their ecological roles We can’t avoid risk, but we can reduce the likelihood of infection

  9. Cultural environmental hazards • Cultural = result from the place we live, our socioeconomic status, our occupation, our behavioral choices • Smoking, drug use, diet and nutrition, crime, mode of transportation

  10. Four types of environmental hazards

  11. Biological Hazards • West Nile Virus • Flu • Ebola • Zika • Malaria • Dengue fever • Chukugaya • AIDS

  12. Disease is a major focus of environmental health Despite our technology, disease kills most of us Disease has a genetic and environmental basis Cancer, heart disease, respiratory disorders Poverty and poor hygiene can foster illnesses

  13. Infectious diseases kill millions • Infectious diseases kill 15 million people per year • Half of all deaths in developing countries • Developed countries have better hygiene, access to medicine, and money • Vector = an organism that transfers pathogens to a host

  14. Many diseases are increasing • Tuberculosis, acquired immunodeficiency syndrome (AIDS), and the West Nile virus • Our mobility spreads diseases • Diseases are evolving resistance to antibiotics • Climate change will expand the range of diseases • To predict and prevent diseases, experts deal with complicated interrelationships

  15. Infectious disease accounts for ________% of deaths globally. 26

  16. Chemical Hazards • BPA • Phthalates • PFOA • PBDE • PCE- • Dry Cleaning • Glyphosate • Tryclosan • Atrazine • PCB • DDT • Lead • Mercury • Asbestos • Thalidamide • Organochlorides • Organophosphates

  17. Toxicology is the study of poisonous substances Toxicology = the study of the effects of poisonous substances on humans and other organisms Toxicity = the degree of harm a toxicant can cause “The dose makes the poison” = toxicity depends on the combined effect of the chemical and its quantity Analogous to pathogenicity or virulence = the degree of harm of biological hazards that spread disease Toxicant = any toxic agent

  18. Paracelsus “All substances are poisons: there is none which is not a poison. The right dose differentiates a poison and a remedy.” • Paracelsus (1493-1541) • Swiss German Renaissance physician, botanist, alchemist, astrologer, and general occultist. He founded the discipline of Toxicology.

  19. Environmental toxicology Deals with toxic substances that come from or are discharged into the environment Studies the health effects on humans, other animals, and ecosystems Focus mainly on humans, using other animals as test subjects Can serve as indicators of health threats Don’t forget, chemicals have given us our high standard of living

  20. Toxic agents in the environment The environment contains countless natural chemicals that may pose health risks But, synthetic chemicals are also in our environment Every human carries traces of industrial chemicals 80% of U.S. streams contain at least trace amounts of 83 wastewater contaminants

  21. Types of toxicants Carcinogens = cause cancer Mutagens = cause DNA mutations Can lead to severe problems, including cancer Teratogens = cause birth defects https://www.youtube.com/watch?v=AGL-FQ8nH9U 5min Allergens = overactivate the immune system Neurotoxins = assault the nervous system Endocrine disruptors = interfere with the endocrine (hormone) systemhttps://www.youtube.com/watch?v=ibfAF66JzFE 2 min

  22. Heavy Metals

  23. The Heavy Metals • Mercury/Methylmercury • Lead • Cadmium • Arsenic • Copper • Zinc

  24. Heavy Metals Minamata Disease 3:12 http://www.youtube.com/watch?v=ihFkyPv1jtU&feature=fvwrel

  25. FDA Advisory for Pregnant women • The U.S. Food and Drug Administration (FDA), in conjunction with the EPA, have issued an advisory on mercury in fish and shellfish for women who may become pregnant, pregnant women, nursing mothers, and young children.  The recommendations are as follows: • Avoid fish that contain high levels of methylmercury • Shark • Swordfish • King mackerel • Tilefish • Consume no more than 12 ounces (2 average meals) a week of fish with lower methylmercury content: • Shrimp • Canned tuna • Salmon • Pollock • Catfish • Albacore tuna has more mercury content than canned tuna, so only 6 ounces are recommended per week • When catching fish for food, local advisories should be consulted to ask about mercury content of local bodies of water. If no advice is available, only 6 ounces of fish and shellfish per week should be consumed.

  26. Endocrine disruptors

  27. A recently recognized hazard • Polybrominated diphenyl ethers (PBDEs) = has fire-retardent properties • Used in computers, televisions, plastics, and furniture • Persist and accumulate in living tissue • Endocrine disruptors = compounds that mimic hormones and interfere with the functioning of animals’ endocrine (hormone) systems https://www.youtube.com/watch?v=ibfAF66JzFE 2 min • Affect brain and nervous system development, and may cause cancer

  28. What was the significance of the book Our Stolen Future? It focused on the impacts of endocrine-disrupting chemicals on humans. It was first published in 1994.

  29. Endocrine disruption may be widespread Theo Colburn wrote Our Stolen Future in 1996 Synthetic chemicals may be altering the hormones of animals This book integrated scientific work from various fields Shocked many readers and brought criticism from the chemical industry http://www.youtube.com/watch?v=jNz8yASPXoI&feature=related Our stolen future 14 min Look back 15 years ago http://www.youtube.com/watch?v=GtagXfTPMgk

  30. Male sperm counts are dropping • Scientists attribute the shocking drop in men’s sperm counts to endocrine disruptors • The number and motility of sperm has dropped 50% since 1938 • Testicular cancer, undescended testicles, and genital birth defects are also increasing

  31. Why are aquatic animals such as fish and frogs especially good indicators of pollution? Most chemicals are water soluble so they enter these organisms through drinking or skin absorption

  32. Evidence for hormone disruption • Frogs also have gonadal abnormalities • Male frogs became feminized from atrazine concentrations well below EPA guidelines • PCB-contaminated human babies were born weighing less, with smaller heads • Tyrone Hayes Developmental Exposure in Children is different (17:48) http://www.mnn.com/family/babies-pregnancy/blogs/watch-a-mom-and-a-scientist-talk-toxins-and-babies

  33. What has the European Union's experience with PBDE's shown? If the toxin is removed from the environment, concentrations in human tissues fall

  34. What caused penis abnormalities in Taiwanese boys whose mothers used contaminated cooking oil ? PCB’s

  35. Endocrine disruption research is controversial • Research results are uncertain, which is inherent in any young field • Negative findings pose economic threats to chemical manufacturers • Banning a top-selling chemical could cost a company millions of dollars • Bisphenol-A, found in plastics, can cause birth defects, but the plastics industry protests that the chemical is safe • Studies reporting harm are publicly funded, but those reporting no harm are industry funded

  36. Environmental Health • How safe are you? How do you know? • Risk Assessment • What should you do to be safe? • Risk Management • Who do you rely on to protect you? • Risk Assessment and Management Entities

  37. Risk Assessment • Probability of harms (Death, headache, asthma, etc.) • Studies- Case Studies, Epidemiological, Controlled Expt • LD 50 • Perceived vs Actual Risk • Risk Considerations

  38. 2015 Hazzard Risk and Risk Management 5 min https://www.youtube.com/watch?v=PZmNZi8bon8 Example of misperceived risk flying 1:30 https://www.youtube.com/watch?v=2RQKEiiz-hg

  39. Risk Assessment Considerations • Types of Hazards – Physical Biological Chemical • Exposure Pathways-Ingestion, Inhalation, Skin, Blood • Type of Exposure- Chronic, Acute • Persistence- Long, Short • Bioaccumulation • Bio magnification • Synergies • Breakdown Products • Sensitivity- Age, Development, Health, Genetics

  40. Problems with Risk Assessment • Few chemicals are actually tested • Few of those are tested for age, synergies, breakdown products, endocrine disruption, chronic dosing, bioaccumulation, biomagnification • Expensive and usually conducted by manufacturers and distributers who have a financial interest in sales rather than safety. • Difficult to assess endocrine disrupters that operate in small doses and are difficult to test with lab animals.

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