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Chapter 15 & 16 Lecture Risks and Pests Hazard vs. Risk • Hazard • Anything that causes: 1. Injury, disease, or death to humans 2. Damage to property 3. Destruction of the environment • Cultural hazard - a risk that a person chooses to engage in • Risk The probability of suffering (1, 2, or 3) as a result of a hazard • Perception What people think the risks are Cost-Benefit Analysis Risk Analysis • Public policy is generated more by the perceived risks of the public than through logic cost benefit analysis. • A cost-benefit analysis is a requirement for every regulatory action for EPA • Also is a means of deciding whether or not to proceed with a given project. • Common indoor air pollutants like: cigarette smoking, asbestos, radon, and formaldehyde require risk analysis Cigarette Smoking • Leading cause of cancer in U.S. • Can cause cancer, lung disease, a bigger risk of death in addition with other types of air pollution. • Highest health risk in U.S. Cancer • Proving that a chemical is a cause of cancer is hard because a long time may elapse between exposure and development of the cancer • If cancer risk from exposure to a chemical is less than 1/1,000,000 then no EPA regulation is needed. • 25% of cancers can be traced to environmental causes Pesticides • Integrated Pest Management (IPM) includes: – – – – – – adjusting environmental conditions providing protection against pest damage chemical pesticides disease resistant varieties crop rotation biological controls • Insecticides kill plants (* - not supposed to), mammals (*), fish (*), & birds (*) • A broad spectrum pesticide is effective towards many types of pests (and us) DDT • DDT was not used for handling weeds but has saved millions of lives by controlling disease-causing pests • The 1948 Nobel prize was awarded to Paul Muller for discovering DDT • DDT is a cheap, persistent, synthetic, organic, compound & is subject to biomagnifications in food chains Determine toxicity for a chemical by using a Dose-Response Curve If the response is expected to be death, what kind of organism should be tested? Lethal dose at 50% = LD50 • The LD50 is a standardized measure for comparing the toxicity of chemicals. • The LD50 is the dose that kills half (50%) of the animals tested in an experiment. • LD50 tests result in the deaths of many laboratory animals and the data are often controversial. • Oral LD50 in rats for DDT is 87 mg/kg. So what does that mean for humans? • Threshold level of toxicity = The dose below which no lethal effects are observed and/or above which the lethal effects are apparent. • Epidemiology is the study of the presence, distribution and control of a diseases in a population • Morbidity is the incidence of disease in a population • Mortality is the incidence of death in a population Diseases • Lyme disease can be transferred to humans through a bite from an infected tick (vector) • Mosquitoes are the vector for Malaria – The protozoan of the genus Plasmodium is the causative agent of malaria – DDT is great at killing mosquitoes… should we use it? • Lack of access to safe drinking water is a major cause of disease transmission in developing countries. Acts • The Federal Food, Drug, and Cosmetic Act (FFDCA) is a piece of legislation that controls the safe amounts of pesticide residues left on food eaten in the US • Federal Insecticide Fungicide Rodenticide Act (FIFRA) is a law that protects human and environmental health from misuse of pesticides • Food Quality Protection Act (FQPA) page 421 & 433