unit 9 – public health environmental issues in public health: part ii chapter 22 – solid and...
TRANSCRIPT
Unit 9 – Public HealthEnvironmental Issues in Public
Health: Part II
Chapter 22 – Solid and Hazardous Wastes: What To Do With the Garbage?
Before 1970sOpen dumps
Outlawed by Resource Conservation and Recovery Act (RCRA), 1976
Burned in incinerators or in the openOutlawed by Clean Air Act, 1970
Poured into rivers, lakes, or oceansOutlawed by Clean Water Act (1972) and
Marine Protection, Research, and Sanctuaries Act (1972)
Sanitary LandfillsSite should be dry, impervious clay soilLined with plasticDrains for liquidsVents to control explosive gasesTipping fee
Cost of disposing of one ton of municipal wasteHighest cost is in northeast
New York City – Fresh Kills, Staten Island
Alternatives to LandfillsThree R’s: Reduce, Reuse, RecycleReduce: buy only what’s needed; avoid
excessive packagingReuse: Use reusable items rather than
disposableRecycle
Encouraged by deposits on bottles and cansYard salesComposting
Waste to energy incineration Special incinerators -- still concern about pollution
Hazardous Wastes Love Canal, New York – 1978Times Beach, Missouri – 1972-1976Resource Conservation and Recovery Act,
(RCRA), 1976, 1984All hazardous wastes accounted for “from
cradle to grave”Wastes from petroleum refining, pesticide
manufacturing, some pharmaceuticalsIgnitable, corrosive, reactive, toxic wastes
SuperfundComprehensive Environmental Response,
Compensation, and Liability Act – 1980Emergency cleanup of old waste sites, paid
for by a tax on industryMired in controversy; much effort focused on
determining who is liableTax not reauthorized in 1995
Unit 9 – Public HealthEnvironmental Issues in Public
Health: Part II
Chapter 23 – Safe Foods and Drugs: An Ongoing Regulatory Battle
Causes of Food-Borne IllnessBacteria
Salmonella -- eggs, poultry, meatE. coli O157:H7 – ground beef, alfalfa sprouts,
unpasteurized apple juice, raw milk, lettuce Viruses
Hepatitis A – green onions from Mexico, shellfish
Norwalk virus -- shellfishParasites
Cyclospora – raspberries from GuatemalaParasites in sushi, sashimi, ceviche
Government Food Safety ActivitiesResponsibility is divided among many
agenciesDepartment of Agriculture (USDA) – meat,
poultry, processed eggsFood and Drug Administration (FDA) – all
other foodsStates regulate shellfishState and local governments regulate
stores, restaurants, institutions (schools, nursing homes)
Irrationality of SystemUSDA has bigger budget, more authority
Regulates 20% of foodDetailed laws on regulation of meat
FDA has smaller budget, less authorityRegulates 80% of foodInspects only 1% proportion of imported food
55% of seafood is imported 12% of vegetables 30% of fruit
Safety MeasuresHazard Analysis Critical Control Point
(HACCP)Focuses on procedures; reduces need for
inspectionsIrradiation – kills bacteria, parasites, pestsCDC surveillance for food-borne disease
FoodNetPulsenet – DNA fingerprinting of bacteria
Additives and ContaminantsFDA sets tolerance levels for pesticide
residuesHormones
Estrogen banned in chickensBovine growth hormone allowed for cows (does
not get into milk)Antibiotics – causes antibiotic resistanceOrganic foods – USDA set standards in 2004Additives
To prevent deficiency diseasesPreservatives or to improve color, flavor or textureMust be approved by FDA, or GRAS
Drugs FDA must approve after studies by
pharmaceutical companyNew Drug Application Three phases of trial
I. Small number of subjects, measure absorption, distribution, metabolism, excretion; look for side effects and toxicities
II. Signs of effectivenessIII. Clinical trial
Post-marketing surveillance
Food and Drug Labeling and AdvertisingFDA regulates labeling of foods with
information on specified nutrients, recommended daily intakes
FDA regulates labeling of drugsLabeling of over-the-counter drugs is by
Federal Trade Commission
Dietary SupplementsDietary Supplement Health and Education
Act – 1994Forbids FDA from regulating herbs and food
supplementsCan remove substance from market only if
proven harmfulEphedra removed only after many deaths
Politics of the FDAFDA subject to intense political pressuresComplaints it is too slow in approving drugsDrug companies pay a fee to speed up review
processNow complaints that the FDA is too cozy with
industry
Politics of the FDA, ctd.Too many drugs found to be unsafe only
after approved for marketingFen-phenVioxxAntidepressants for children
Problems with the way clinical trials are reported
Calls for a database of all clinical trials, to be registered at the beginning of the trial, with all results to be reported
Unit 9 – Public HealthEnvironmental Issues in Public
Health: Part II
Chapter 24 – Population: The Ultimate Environmental Health Issue
Population BiologyPatterns of population growth: S curve and J curveCarrying capacity – number of organisms that can be
supported without degrading environmentThomas Malthus predicted in about 1800 that
population growth would outgrow food supplyPaul Ehrlich – The Population Bomb, 1968Population growth has slowed, but many negative
effects of overpopulation are occurring
Public Health and Population GrowthPublic health has contributed to population growth by
reducing death rates, especially among children, in developing countries
Birth rates tend to fall as a result of falling death rates – demographic transition
Excess population settles in cities – homelessness, shantytowns – poor sanitation
HIV/AIDS shortening life expectancies in Africa
Depletion of Global ResourcesFresh water
Drinking, cooking, washingAgricultureUnevenly distributed
FuelDeforestation – leads to degradation of land
Arable landAmount of land under cultivation is declining
Food from the seaDecline of harvests of fish and shellfish
Climate ChangeGreenhouse effect from burning fossil fuelsRise of 1 degree during 20th centuryPredict 3 to 8 degree rise during 21st centuryU.S. has 5% of world’s population, contributes 21% of
greenhouse gasesKyoto Protocol – Bush administration has rejected
Prospects for Population ControlU.N. conference in Cairo, 1994
Opposition to contraception by Catholics and MuslimsRich and poor countries blame each other
20 year Programme of Action Education for women Empowering women to choose fewer children
Population stabilization comes with modernization and economic viability