Biology 6 Chapter 14

Biology 6 Chapter 14 - Biology 6 Chapter 14 Environmental...

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Biology 6 Chapter 14 Environmental Hazards and Human Health o Acquired immune deficiency syndrome caused by infection with human immunodeficiency virus is a serious and rapidly growing health threat o Virus itself is not deadly, but it cripples the immune system and leaves the body susceptible to infections such as tuberculosis and rare forms of cancer such as Kaposi’s sarcoma o Virus is transmitted from one person to another through unsafe sex, sharing of needles by drug users, infected mothers who pass the virus on to their offspring before or during birth, and exposure to infected blood. o Each year about 16,000 people died of AIDS-related diseases in United States. 3 million worldwide o Risk: probability of suffering harm from a hazard that can cause injury, disease, death, economic loss, or environmental damage o 4 types of Hazards: 1. Biological Hazards : more than 1,400 pathogens (bacteria, viruses, parasites, protozoa, and fungi) that can infect humans 2. Chemical Hazards : harmful chemicals in air, water, soil, and food 3. Physical Hazards : fire, earthquakes, volcanic eruptions, floods, and storms 4. Cultural Hazards : unsafe working conditions, unsafe highways, criminal assault, and poverty o Nontransmissible disease : caused by something other than living organisms and does not spread from one person to another; tend to develop slowly and have multiple causes ex. Most cancers, most cardiovascular disorders, asthma, emphysema, and malnutrition o Transmissible disease : an infectious disease caused by a pathogen and can be spread among people o Epidemic: large- scale outbreak of an infectious disease in an area or country o Pandemic: global epidemic o Problems with antibiotics : many disease carrying bacteria have developed genetic immunity to widely used antibiotics ; many disease transmitting species of insects such as mosquitoes have become immune to widely used pesticides that once helped control their populations; bacteria’s high reproductive rate allows organisms to become genetically resistant to an increasing number of antibiotics through natural selection; other factors that contribute to genetic resistance are human travel around globe, international trade; overuse of antibiotics by doctors; at least half of all antibiotics are prescribed unnecessarily; every major disease-causing bacterium now has strains that resist at least one
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o 3 most widespread and dangerous viruses: influenza(flu), human immunodeficiency virus (HIV), and hepatitis B virus (HBV) 1. Influenza – transmitted by the body fluids or airborne emissions of an infected person;
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This note was uploaded on 01/30/2010 for the course BIOL 6 taught by Professor Petersen during the Fall '08 term at Mt. SAC.

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Biology 6 Chapter 14 - Biology 6 Chapter 14 Environmental...

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