17-1: What Major Health Hazards Do We Face?
Risk: probability of suffering harmPossibility vs. ProbabilityRisk assessment: how much harm a
particular hazard can cause to human health or environment
Risk management: whether or how to reduce risk to certain level and at what cost
17-1
Five major types of hazards: Biological hazards (pathogen) Chemical hazards Physical hazards Cultural hazards Lifestyle choices
17-2 What Types of Biological Hazards Do We Face?
Nontransmissible DiseaseInfectious Disease
Transmissible Disease
Epidemic vs. Pandemic Global threat from Tuberculosis
Strikes 9.2 million per year, kills 1.7 million per year
3 Most Widespread and Dangerous Viruses
Influenza, or flu virus Transmitted by the body fluids or airborne emissions of infected person
HIV (human immuno-deficiency virus) Infects about 2.5 million people each year Results in AIDS
Hepatitis B virus (HBV) Damages liver & kills about a million peopleper year
Growing Global Threat from Tuberculosis
Kills 1.7 million people per year 84% of them in developing countries
Too few TB screening programs, most strains have developed genetic resistance 1) Reproductive rate of bacteria 2) spread of bacteria
around the globe- allow for increased genetic resistance
Multi-drug resistant TB
Malaria- Case Study
About one of every five people in the world at risk from malaria
Bites of certain mosquito speciesKills 1-2 million each yearPeople with HIV more vulnerable to malariaNew antimalarial drugs
Artemisinins Too little funding
Helping to Prevent Infectious Diseases
Reduce poverty
Decrease malnutrition
Improve drinking water quality
Reduce unnecessary use of antibiotics
Educate people to take all of an antibiotic
Careful hand washing
Immunize children
Oral rehydration therapy
17-3: What Types of Chemical Hazards Do We Face?
Toxic chemical: can cause temporary or permanent harm or death to humans & animals
3 major types of potentially toxic agents: Carcinogens: arsenic, benzene, chloroform Mutagens: chemicals & forms of radiation Teratogens: angel dust, benzene, cadmium
17-3
• Immune system• Neurotoxins can harm nervous system– Ex. PCBs, methyl mercury, arsenic
• Endocrine system• Hormonally active agents (HAAs)• Estrogen mimics• Hormone blockers• Gender benders• Thyroid disrupters
• Phthalates
17-4 How Can We Evaluate and Deal with Chemical Hazards?
Factors determining effects of a chemical: Toxicology: study of poisons Toxicity: measure of how harmful a substance is Dose: amount of harmful chemical ingested, inhaled,
etc. Response: damage to health
Acute vs. Chronic
Case reports0Epidemiological Studies
17-4
Laboratory animals and nonanimal tests to estimate toxicity 2-5 years Dose-response curve
Nonthreshold dose-response model Threshold dose-response model
17- 4: Precautionary Principle
Pollution preventionTwo major changes:
New chemicals would be assumed harmful until studies prove otherwise
Existing chemicals that have change of causing harm removed from market until safety is established
European Union 2000ban of 12 most notorious persistent organic
pollutants 2006required registration of 30,000 untested
chemicals
17-5: How Do We Perceive Risks and How Can We Avoid the Worst of Them?
Risk analysis Risk assessment Comparative risk analysis Risk management Risk communication
Greatest risk: Poverty malnutrition, increased susceptibility to normally
nonfatal infectious diseases, unsafe drinking water
Ways to reduce risk of premature death: Avoid smoking, exercise regularly, avoid excess
sunlight
17-5
• Reliability• System reliability (%) = Technological
reliability x Human reliability• Evaluating risks (fear, degree of control,
catastrophic or chronic, optimism bias, instant gratification, unfair distribution of risks)
• Guidelines for evaluating and reducing risk– Compare risks, determine how much risk willing to
accept, determine actual risk involved, concentrate on evaluating and carefully making important lifestyle choices
Smoking
EU (European Union) Commission trying to ban smoking in public places in 2011
Health experts urging for $3-5 federal tax for each pack of cigarettes in the U.S. to make up for health, economic, and social costs associated with smoking
Media coverage of harmful health effects of smoking attributed to decline in smoking http://www.youtube.com/
watch?v=SfAxUpeVhCg&feature=related
Cholera Outbreak in Haiti
October, 2010 Spread through ingestion of contaminated food or drinking
water Large scale exposure to contaminated food or water Unclear how cholera was introduced to Haiti
Not related to earthquake in January 2010 Acute, diarrheal illness Infection of intestine by vibrio cholerae In November, 1,344 dead
Carcinogens Found in Baby Toiletries
March 2009 Products like Johnson &
Johnson Baby Shampoo and Baby Magic lotion tested positive for 1,4-dioxane or formaldehyde
Byproducts of the manufacturing process
Campaign for Safe Cosmetics claims that the contamination is unnecessary, while Johnson & Johnson claims that the FDA considers the trace levels of contaminates safe
Works Cited
http://www.nacsonline.com/NACS/News/Daily/Pages/ND1013104.aspx
http://articles.cnn.com/2010-11-22/world/haiti.cholera.alert_1_cholera-outbreak-cholera-epidemic-rehydration-salts?_s=PM:WORLD
http://www.saidaonline.com/en/newsgfx/Cholera%20Haiti-saidaonline.jpg
http://www.washingtonpost.com/wp-dyn/content/article/2009/03/12/AR2009031202940.html