Embedded Files
CHAPTER 20-1: POLLUTION AND HUMAN HEALTH
Pollution causes illness in 2 ways:1. direct – poisoning us (lead poisoning, cancer)2. indirect – spread of disease (cholera, typhoid) The World Health Organization (WHO)- collects data on how the environment affects our health- Poor health is measured by the estimated number of days of healthy life lost to death and disease. - Less developed countries suffer more. The 5 Pollutant types and their effects:1. Pesticides – from agriculture and landscaping – can lead to nerve damage, birth defects, cancer2. lead – lead paint and gasoline – brain damage, learning problems3. particulates – from vehicle exhaust, burning waste, fires, tobacco smoke – can lead to respiratory damage like asthma, bronchitis, and cancer b/c particulates get trapped in the air sacs of the lungs4. coal dust – from mining – black lung disease5. bacteria in food – poor sanitation and food handling – gastrointestinal infections Toxicology = study of the harmful effects of substances on organisms- Almost any chemical is dangerous if taken into the body. We need to know how much is dangerous and how much is in the environment.- dose = the amount of harmful chemical a person is exposed to- response = the damage that results. It depends on how much the person is exposed, size of the person, and how well the body breaks it down.- persistent chemicals – break down slowly (DDT)- dose-response curves help show the relative effect of various doses of chemicals on an organism- threshold dose = below it there are no adverse affects. Above is harmful. epidemiology = study of the spread of disease- scientists use it to find the origin of disease, how it spreads, and how to keep it from spreading further.- they do risk assessment of different pollutants to safeguard the public – they estimate the probability of negative effects from an action/substance. Pollution from natural sources:Natural things can become hazardous when they are above normal levelsRadon from granite, dust from dust storms, soot from volcanoes, and other particulates (small enough to breath in and get trapped in the lungs), heavy metals Pollution from human activities:burning fuels (puts carbon monoxide and particulates in the air), pesticides, industrial chemicals (can be poisonous, hormone mimics, etc.)A lot of the pollution is a byproduct of inadequate waste disposal (like releasing raw sewage into rivers and oceans).CHAPTER 20-2: BIOLOGICAL HAZARDS
75% of infectious disease is spread through waterIn developing countries where there’s not enough water, it is used for drinking, washing, and sewage disposal – it gets polluted and becomes a breeding ground for pathogens.- humans can catch pathogens directly from water or through vectors (vector = organism that transmits diseases to people, like mosquitoes)- construction of dams and irrigation canals has increased the habitat for vectors- cholera and dysentery – from water polluted by poop – results in diarrhea and vomiting- malaria – mosquitoes transmit protests that cause it – see above- hookworm – from contaminated soil Things we do to the environment that promote disease:- soil erosion – pollutants that were in the soil are blown and washed away and can contaminate other areas- over-use of antibiotics (in us and livestock) – leads to pathogens evolving resistance- habitat destruction – puts humans in greater contact with wild animals Emerging virus = virus that was unknown in the recent past but now threatens humans. Examples include AIDS, ebola, west nile, etc. There an increasing number of pathogens that can make a cross-species transfer.- Because of the way we alter the environment.- Examples include HIV, west nile, haunta, fluGoogle Sites
Report abuse