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Geography 361a Environment and Health. Introduction: Key Concepts (Moeller Chapter 1). Discussion: Is the world more dangerous? Historical Context Concepts/Definitions. Context: Discussion. Is the world more dangerous now than it was 20 years ago?
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Geography 361aEnvironment and Health Introduction: Key Concepts(Moeller Chapter 1) • Discussion: Is the world more dangerous? • Historical Context • Concepts/Definitions Geog 361b
Context:Discussion • Is the world more dangerous now than it was 20 years ago? • What are some useful ways to qualify/refine the question above? • Break into groups of 4 and discuss. Geog 361b
Context • healthier than ever • highest life expectancy ever • awareness of hazards and risk high • e.g., 46,962 articles on “hazards” in major Canadian dailies 1985 to present. • (reference: “free trade” – 76,531) • population “at risk” increasing Geog 361b
Life Expectancy http://www.undp.org/hdr2003/indicator/indic_1_2_1.html http://www.cia.gov/cia/publications/factbook/rankorder/2102rank.html Geog 361b
Life ExpectancyTime-trends USA For Geog 361b
Life ExpectancyTime-trends Canada For Geog 361b
Causes of Death Canada For Geog 361b For
Causes of Death Geog 361b Source: Thomas and Hrudey (1997) Risk of Death in Canada
World Population Growth world population clock Source: http://www.prb.org/ Geog 361b
Concepts/Definition Environmental Health • “That segment of public health that is concerned with assessing, understanding, and controlling the impacts of people on their environment and the impacts of the environment on them." (Moeller 1997, 1) Human Health • emphasis of this course is the latter half of this definition • former half is an “undercurrent” of the course Geog 361b
Concepts/Definitions Contamination • when substance exceeds capacity of “environment” to eliminate it • aggregate output of substance exceeds some sensory or predetermined limit • e.g., wood fires “allowed” in rural vs urban areas. Geog 361b
Selective Historical ContextEarly Writings Hippocrates (460 BC) • On Airs, Waters and Places • winds, seasons and sources of water important for physician diagnosis • occupational diseases – e.g. “lead colic” in miners • explanation for decline of Rome? • water delivery lead pipes/aqueducts • lead-lined vessels – aristocracy Geog 361b
Selective Historical ContextOccupational Health • Georgius Agricola (1556) • De Re Metallica (12 books!) • occupational diseases among miners – joints, lungs (e.g. silicosis, tuberculosis, lung cancer), eyes Geog 361b
Selective Historical ContextOccupation and Cancer • Percival Pott (1775) • First detailed writing about occupationally-induced cancer • scrotal cancer in chimney sweeps • soot + tar + infrequent washing Geog 361b
Selective Historical Context • John Snow (1855) • On the Mode of Communication of Cholera • well intake near sewage outfall “graph on map to mark cholera deaths” Broad Street pump linked to cholera Geog 361b
Selective Historical Context • water sanitation dramatically decreased several water borne diseases Geog 361b
Contamination Natural Contamination • e.g., sulfur, radionuclides, radon Anthropogenic Contamination • e.g., CO, pesticides • focus of most attention (not always deservedly so) Geog 361b
Scope Some Problems Studied • toxic chemicals • waste (e.g., toxic, municipal, radioactive) • workplace stress • built environment • overpopulation • food supplies • acid deposition • global warming • resource depletion • … Geog 361b
Practitioners Some Disciplines (Multidisciplinary) • toxicologists • epidemiologists • economists • geographers (health, hazards) • sociologists • lawyers • planners • engineers • managers • … Geog 361b
Defining “Environment” Inner vs Outer Environment • protective barriers between inner and outer: • skin • GI tract • lungs • which barrier makes humans most vulnerable? Why • problems with this categorization of “environment”? Geog 361b
Defining “Environment” Personal vs Ambient Environment • personal = individual control • ambient = outside individual control • problems with this categorization of environment? Geog 361b
Cancer Caused by Environmental Exposures categorize each above as “personal” or “ambient” Geog 361b
Defining “Environment” • gaseous, liquid and solid • each linked with particular routes of exposure to humans • problems? Geog 361b
Defining “Environment” Chemical, Biological, Physical, Socioeconomic • Chemical - contaminants • Biological – disease organisms • Physical – e.g., noise, temperature, radiation • Socioeconomic – e.g., SES, environmental justice • problems with this categorization? Geog 361b
Exercise:Defining “Health” Define “health”. Geog 361b
Defining “Health” WHO (1948) • “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” • physical • mental • social well-being Geog 361b
Disease Classification infectious vs non-infectious • infectious • e.g., malaria, cholera, diarrhea • pathogenic organisms • major killer in the past • not typically considered an “environment and health” issue (e.g., Nadakavukaren, 2000) – but Walkerton! • historically mono-causal • non-infectious • e.g. cancer, heart disease, asthma • major killer now • multi-causal model • typical environment and health concern these outcomes Geog 361b
Disease Classification endemic vs epidemic • endemic • pathogen carried by many people • typically not considered an environmental illness issue • e.g., ? • epidemic • pathogen carried by many people • sudden and severe outbreak of a disease in a population • e.g., ? Geog 361b
Disease Classification acute vs chronic • acute • severe short term disease • or disease/symptoms due to short term high dose exposure to environmental substance • QOL: if survive, no long-term effects • e.g., ? • chronic • long term disease/condition • or disease/condition due to long term low dose exposure to environmental substance • QOL: long-term effects often duration of life • e.g., ? Geog 361b
Systems Approach • controlling one form of environment and health problem can lead to other problems • e.g., chlorination, fluoridation of water • e.g., pesticides • risk analysis and cost/benefit analysis helpful • not strictly a technical problem Geog 361b
Components of Assessing Environment and Health Problems • determine the source of contamination/stress • determine how contamination/stress contacts humans • measure the resulting effects • assess the seriousness of the effects • apply controls as necessary How “social” is this process? Geog 361b
Models of Environmentand Health Geog 361b
Models of Environmentand Health: Multicausality source: Jones and Moon (1987) Health Disease and Society source: Jones and Moon (1987) Health Disease and Society Geog 361b