Bellringer

1. Brainstorm all the possible pollutants that might affect human health. Don’t forget natural pollutants. What are the sources of the pollutants you stated? Bellringer

2. FYI: The chemical symbol for lead is Pb, not Ld…why? Lead has been used in plumbing for centuries, so the element lead is represented by Pb, which is short for plumbum…that Latin word for “plumbing”. Romans used lead pipes to distribute water within their cities. As poisonous lead leached in to the water, Romans experienced and increase in dementia!

3. Environmental Effects on Health • Pollution causes illness in 2 main ways: • Directly by poisoning us, such as lead poisoning • Indirectly because many infectious diseases spread in polluted environments

4. World Health Organization (WHO) • Collects data on how the environment affects human health. • Fig. 1 in your book on pg. 511 shows the WHO’s estimate of poor health by world region. • Who do you think suffers more from poor health? Developed or developing nations?

5. Pollutant Types and Effects • Pesticides: used in agriculture and landscaping nerve damage, birth defects, and cancer • Lead: lead paint and gasoline brain damage and learning problems • Particulate matter: vehicle exhaust, burning waste, fires, and tobacco smoke respiratory damage (asthma, bronchitis, cancer) • Coal dust: coal mining black lung disease • Bacteria in food: poor sanitation and poor food handling gastrointestinal infections

6. 2 studies associated with pollutants Toxicology Epidemiology Study of the spread of diseases Epidemiologists try to trace a disease to its origin and figure out how to prevent it from spreading Scientists and health officials work together on risk assessments (an estimate of the risk posed by an action or substance) for pollutants. • Study of harmful effects of substances on organisms • How harmful something is depends on what it is and dose of the substance • Dose: amount of a harmful chemical to which a person is exposed. • Toxicity of a chemical can be shown on a Dose-response curve. Refer to pg. 512.

7. Types of Pollution Pollution from Natural Sources Pollution from human activities Most pollution comes from human activities Recently regulation have helped reduce our exposure to pollutants Types of Human pollution will be shared on next slide • Not all pollution is from humans, some pollutants occur naturally in environment, Ex: Radon gas • Most common natural pollutant: Particulate (particles in air that are small enough to breath into the lungs and cause irritation) • Heavy metals are another important type of pollution from natural resources, Ex: mercury, lead • Most heavy metals cause nerve damage when ingested in large quantities

8. Types of pollution from humans • Pesticides • Chemicals designed to kill unwanted organisms (insects, fungi, or weeds). • Are helpful, but can become harmful to humans in large doses. • Industrial chemicals • Often are not known to be toxic until used for many years • We are exposed to industrial chemicals in low doses every day. • Toxic chemicals make carpets, cleaning fluids, and furniture) • Waste disposal • Much of the pollution in our environment is a byproduct of inadequate waste disposal. • We have made strides in improving waste disposal, but there are still issues such as old landfills leading, sewage treatment plants that release raw sewage into a river or ocean, and laws regulating waste disposal are not always enforced. • Burning fuels • continues to be one of our weakest areas…we burn fuel to run our cars, warm homes, in power plants and this causes air pollution which is a major health problem

9. Section 2, Chapter 20 Biological Hazards • Damage caused to human health in which the environment plays a role is not always caused by toxic chemicals, but sometimes by organisms that carry disease! • Examples: West Nile virus, mad cow disease, malaria, hookworm, and yellow fever

10. The Environment’s Role in Disease • Infectious diseases are caused by pathogens • Pathogens: organisms that cause disease • Some diseases are transported through the air or are spread by drinking water that contains the pathogen • Other diseases are transmitted by a secondary host, such as a mosquito • A host is an organism in which a pathogen lives all or part of its life

11. Waterborne Disease • Almost 3/4s of infectious diseases are transmitted through water. • Often in developing countries, water can be very polluted because the drinking water is also used for washing and sewage disposal • Pathogens breed in water and transfer diseases directly to humans through water or organisms carry the pathogens to transfer the disease to humans (Ex: mosquitoes). • These organisms are called vectors.

12. Waterborne Disease • The deadliest waterborne diseases come from drinking water polluted by human feces. • Pathogens, such as those that cause cholera, enter the water in human feces. • Another waterborne disease called malaria was once the world’s leading cause of death. • Malaria is caused by parasitic protists and is transmitted by a bite from females of mosquitoes.

13. Environmental Change & Disease • Oftentimes, we change the environment to make it more suitable for pathogens to live and reproduce. • Antibiotic resistance: pathogens evolve to resist antibiotics that are used to kill them • Do you think we should continue to use antibacterial soaps and gels?

14. Cross Species Transfers • Pathogens move from one species to another • Examples: West Nile and HIV lived for centuries in wild animals and have done little damage until the pathogens invaded humans and caused serious disease. • Some ecologists think that the ways in which we are altering the environment and destroying habitats ensure that diseases like these will become more common in the future.