EHSC7060 T2

  1. Common factors in historic air pollution episodes
    • Persistent thermal inversion
    • Significant industrial and domestic pollutant emissions
    • Resulted in high ground-level concentrations that caused acute illness and death
  2. Criteria air pollutants - Primary and Secondary
    • Primary - sulfur dioxide, carbon monoxide, nitrogen oxides, lead
    • Secondary - ozone, some particulate matter
  3. Hazardous air pollutants
    • volatile organic compounds (VOCs)
    • metals
    • aldehydes
    • semivolatile organic compounds (SVOCs)
    • diesel exhaust
    • 188 total
  4. Ozone
    • Can irritate lung airways and cause inflammation
    • Symptoms - wheezing, coughing, painful breathing/breathing difficulties
    • Repeated exposure may lead to permanent lung damage
    • Anyone who spends time outdoors during the summer is at risk
  5. Particulate matter
    • ER visits for people with heart and lung disease
    • Leads to: aggravated asthma, increases in respiratory symptoms like coughing and difficulty breathing/painful breathing, chronic bronchitis, decreased lung function, and premature death
    • Settles on soil and water and changes the nutrient and chemical balance
    • Causes: erosion and staining of structures
  6. Direct Formation vs. Indirect Formation of Particles
    • Direct - cars, tractors, fire --> direct release of particles
    • Indirect - sun, aerosols, products of pure combustion, water vapor, solvents --> reaction --> indirect formation of particles
  7. Carbon Monoxide & Sources
    • poisonous to all people at high levels
    • can affect people with heart disease, and the central nervous system
    • Sources: industrial process, fuel combustion, misc., nonroad vehicles & engines, onroad vehicles
  8. Sulfur Oxides & Sources
    • can cause temporary breathing difficulty for people with asthma
    • can aggravate existing heart disease
    • reacts with other chemicals in the air to form sulfate particles which can increase respiratory symptoms and siease, difficulty in breathing and premature death
    • Major cause of reduced visibility in the US
    • SO2 and nitrogen oxides react with other substances to form acids
    • Sources: metal processing, nonroad engines & vehicles, all other, fuel combustion - industrial & other, fuel combustion - electrical utilities
  9. Nitrogen Oxides & Sources
    • Involved in the formation of ground-level ozone, which can trigger serious respiratory problems
    • Reacts to form nitrate particles, acid aerosols, as well as NO2 which can cause respiratory problems also
    • Contribute to the formation of acid rain
    • Contribute to atmospheric particles that cause visibility impairment
    • Contribute to global warming
    • Sources: all other, industrial/commercial/residential, motor vehicles
  10. Lead & Sources
    • Cause damages to the kidneys, liver, brain & nerves, and may lead to osteoporosis & reproductive disorders
    • Can cause seizures, mental retardation, behavioral disorders, memory problems, and mood changes
    • Causes high blood pressure & heart disease, and leads to anemia
    • Sources: other, nonroad, fuel combustion, waste disposal, metal processing
  11. Woodsmoke Components
    • similar to cigarette smoke
    • polycyclic aromatic hydrocarbons
    • benzenes
    • aldehydes
    • respirable particulate matter
    • carbon monoxide
  12. Pollutants from solid fuel combustion are known to cause:
    • acute respiratory infections
    • chronic obstructive pulmonary disease
    • asthma
    • low birth weight
    • nasopharyngeal and laryngeal cancers
    • tuberculosis
    • diseases of the eye
  13. PM2.5
    • Particulate matter with aerodynamic diameter less than 2.5 micrometers
    • Penetrate deep into the lungs and may reach the alveolar region, potentially interfering with gas exchange
  14. Improved Stoves - reduce indoor air pollution by means of:
    • better combustion
    • improvements in ventilation
    • lower emissions levels
    • potentially shorter cooking time
  15. Benefits from improved stoves
    • less smoke
    • less wood use
    • reduced cough
    • lower blood pressure
    • less eye irritation
    • fewer headaches
    • less lower back pain
  16. Biomarker sampling
    • Exhales CO & %COHb - measures effects of smoke exposure
    • Exhaled NO - pulmonary inflammation, immune system function
    • Total hemoglobin - oxygen transport efficiency
    • Blood lead - possibly released in wood smoke, development effects
  17. Limitations of Indoor Air Study
    • small study populations
    • short term study
    • between-home variation
  18. Food Safety Definition
    "safe food, if handled properly at all steps of production through consumption, is reliable unlikely to cause illness or injury"
  19. 3 Criteria of Food Safety
    • 1. to provide necessary nutrients for growth, health, and survival
    • 2. no toxic or adverse health effects
    • 3. should not be contaminated by known food safety hazards
  20. Food Safety Hazards definition
    biological, chemical, or physical agents that are reasonably likely to cause human illness or injury in the absence of their control
  21. Biological Food Safety Hazards
    • microbial pathogens
    • - infections - growth of disease-causing microorganism
    • - intoxications - toxins produced by a microorganism
  22. Chemical Food Safety Hazards
    • food additives
    • agricultural components
    • - pesticides, antibiotics, and growth hormones
    • industrial chemicals
    • - cleaners and sanitizers
    • - equipment related - oils, gasolines, lubricants
    • natural and environmental contaminants
    • - mycotoxins
    • - heavy metals Pb, Hg
  23. Physical Food Safety Hazards
    glass, wood, plastic, stones, metals, bones
  24. Foodborne Diesases
    • foodborne intoxications & infections
    • illnesses acquired by consumption of contaminated food (not food poisoning)
    • acute and chronic
  25. Foodborne Outbreaks
    the occurrence of a similar illness among 2 or more people which an investigation linked to a consumption of a common meal or food item in a defined time period, except for botulism
  26. Foodborne Illness
    • A major cause of morbidity (& mortality)
    • Affects 76 million in the US a year
    • Causes 9000 deaths annually with an economic cost of $5 billion
    • Causes adverse birth outcomes, chronic illnesses & disabilities
  27. Etiology of Foodborne Disease Outbreaks
    • bacterial
    • chemical
    • parasitic
    • viral
    • unknown
  28. Salmonellosis
    • About 40,000 cases and nearly 600 deaths each year in the US
    • Food contaminated with salmonella typhi or salmonella saintpaul
    • Since Apr 2008, 1442 persons infected in 43 states, DC & Canada, at least 286 persons hospitalized, possibly 2 died
    • Jalapeno and Serrano peppers from Mexico and Tomatoes are major sources of contamination
    • Peanut butter & products
  29. Escherichia coli O157:H7
    • 73000 cases and nearly 60 deaths in the US each year
    • Beef, milk, juice & vegetables (lettuce & spinach) contaminated
    • Waterborne transmission
    • Fresh spinach produced in Salinas, CA
    • Shredded iceberg lettuce from Taco Bell
  30. Listeriosis
    • food contaminated with listeria monocytogenes
    • about 2500 persons become seriously ill each year, 500 die
    • 1/3 cases happen in pregnant women
    • newborns suffer the serious effects
    • vulnerable - persons with weakened immune systems (patients, the elderly)
    • uncooked meats and vegetables and some processed food were sources of contamination
  31. Other foodborne disease
    • botulism - foodborne intoxication caused by clostridium botulinum
    • staphylococcus aureus intoxication - exotoxin
    • shigellosis - shigella bacteria
    • hepatitis A
    • norovirus
    • prions
    • parasitic foodborne illnesses
  32. Hazardous Food Components
    • food-derived naturally occurring toxicants and carcinogens (biotoxins, plants, animals)
    • toxic additives
    • toxicants generated during food processing & cooking
    • food allergens
    • unavoidable food contaminants
  33. Naturally occurring mycotoxins
    toxic agents mainly produced by fungi genera
  34. Mycotoxins with carcinogenic effects
    • aflatoxins - liver, lung, colorectal
    • fumonisms - liver, kidney, esophageal
    • ocharatoxins - kidney, urinary tract
    • zearalenon - esophageal, breast
    • sterigmatocystin - liver
  35. Food Additives
    • intentionally added ingredients
    • up to 32 categories based on their functions
    • natural products or synthetic chemicals
  36. Toxically important food additives
    • colors & coloring agents - aromatic amines or aromatic azo
    • preservatives - antimicrobial agents, antioxidants
    • sweeteners - saccharin
    • flavors & flavor enhancers - monosodium glutamate
  37. Safety evaluation of Food Additives & Four Factors considered
    • determination of exposure levels
    • 1. the foods to which the substance is added
    • 2. the level of use in such food
    • 3. the purpose for which the substance is used
    • 4. the population expected to consume the substance
  38. Calculation of EDI
    Estimated daily intake = the concentration of the substance in that food x the daily intake

    Assignment of concern level based on structure activity (I to III)
  39. Toxicity Testing Levels I - III
    • I - short term tests (toxicity & mutagenicity)
    • II - subchronic feeding study (rodent & nonrodent), short term carcinogenic potential, multigenerational reproductive study (teratogenic study)
    • III - longterm feeding study (rodent & nonrodent), short term carcinogenic potential, carcinogenicity study in 2 rodents, multigenerational reproductive study (teratogenic study)
  40. Other chemical toxins & hazards
    • marine toxins
    • mushroom toxins
    • heavy metals
    • pesticides
    • antibiotics
    • growth hormones
  41. US National Food Safety Programs
    • US FDA
    • USDA
    • US Dept of Homeland Security
    • US EPA
    • CDC
    • US Customs and Board Protection
  42. US FDA
    • Center for Food Safety & Applied Nutrition
    • - office of food safety
    • - food protection plan
    • Center for Veterinary Medicine
    • Food Defense and Terrorism Program
  43. USDA
    • food safety and inspection service
    • animal and plant health inspection service
    • agricultural research service
    • food and nutrition information center
  44. US Dept. of Homeland Security
    Centers for Food Safety & Security
  45. US EPA
    • food safety unit
    • office of pesticide programs
    • office of water
  46. CDC
    • food safety office
    • foodborne outbreak response and surveillance unit
    • national center for infectious diseases
    • - emerging infectious diseases
  47. Microbial Pathogens
    most common biological hazard in US food

    salmonella, escherichia coli O157:H7, listeria monocytogenes
  48. Imported Food & Ingredients
    • Almost $2 trillion of imported products enter US & will triple by 2015
    • About 15% of these imported products are food and ingredients for human and animal consumption
    • FDA regulates $417 billion worth of domestic foods, and $49 billion worth of imported food each year
    • USDA regulates imported meat, poultry, and some egg products
    • Mexico & Canada are 2 major food exporters
    • China is growing - major supplier of seafood, canned vegetables, fruit juices, honey, etc.
  49. Problems in Imported Food Safety
    • unintentional contamination
    • unavoidable contaminants
    • heavy metals, chlorinated hydrocarbons,
    • nitrosamines & N-nitroso substances
    • foodborne molds & mycotoxins, microbial
    • avoidable contaminants
    • pesticide residues, hormones & drugs in animals
    • deliberate adulteration - illegal use of chemicals or drugs
  50. Dietary Supplements
    • a product taken by mouth that contains a "diet ingredient" intended to supplement the diet
    • include vitamins, minerals, herbs/other botanicals, amino acids, enzymes, organ tissues, glandulars, metabolites
    • can be extracts or concentrates in many forms
  51. Safety Problems for Dietary Supplements
    • untruthful labeling and advertising
    • misleading claims
    • -health claims
    • -structure/function claims
    • -nutrient content claims
    • fake products
    • potential toxicity and toxicosis
    • -contamination
    • -adulteration with illegal drugs
  52. USDA Food Protection Plan
    • prevention - develop scientific and analytical tools to better identify and understand risks and the effectiveness of control measures
    • intervention - using targeted risk-based inspections and testing to monitor preventive measures through use of modern detection technology system for targeting and conducting inspection and surveillance
    • response - responding rapidly when problems are identified to inform consumers and to limit economic hardship to the affected industries
  53. Draft of the Food Safety Enhancement Act of 2009
    • 1. creates and up to date registry of all food facilities serving American customers
    • 2. generates resources to support FDA oversight of food safety
    • 3. prevents food safety problems before they occur
    • 4. requires safety plans for fresh produce
    • 5. increases inspections of food facilities
    • 6. improves traceability of food
    • 7. enhances safety of imported food
    • 8. expands lab testing capacity
    • 9. provides strong, flexible enforcement tools
    • 10. creates fast-track import process for food meeting security standards
    • 11. enhances the safety of infant formula
    • 12. advances the science of food safety
    • 13. enhances FDA's ability to block unsafe food from entering the food supply
    • 14. directs FDA to assess the use of carbon monoxide in certain foods
    • 15. enhances transparency of GRAS program
    • 16. requires country-of-origin labeling and disclosure
  54. Safety Considerations of Genetic Modified Foods
    • Toxicants known to be characteristic of the host and donor species
    • the potential that food allergens will be transferred from one food source to another
    • the concentration and bioavailability of important nutrients for which a food crop is ordinarily consumed
    • the safety and nutritional value of newly introduced proteins
    • the identity, composition and nutritional value of modified carbohydrates or fats & oils
  55. Summary for Food Safety
    • food is more complex and variable in composition than all other environmental substances
    • food safety is different due to the nature and chemical complexity of food
    • different issues in food safety around the world due to social, economical, and political systems
    • traditional food safety (microbial and toxicological) methods and protocols challenged by new problems and technology
  56. Point Source vs. Non Point Source Pollution
    • PS - discrete, identifiable source
    • can be regulated - discharge limits, effluent receiving water testing
    • ex. industrial discharge, WWTP discharge, CAFOs, holding ponds

    • NPS - diffuse pollution - multiple and/or nondiscrete sources
    • difficult to monitor, regulate and control
  57. Control of Surface Water Quality
    • 1948 - Water Pollution Control Act
    • 1972 - Clean Water Act
  58. Designated Uses for Water Quality Standards
    • drinking water
    • human contact
    • aquatic life - warm/cold water species, habitat
    • agricultural water supply
    • industrial water supply
    • multiple uses
  59. Water Quality Criteria
    • relate to - protection of designated use, portion/characteristics of aquatic organisms, FW or marine?
    • Numeric criteria consists of - concentration, exposure duration, recurrence interval, specific environmental conditions
  60. National Pollutant Discharge System
    • effluent standards
    • industry requirements for permitting - pretreatment and self-monitoring
    • enforced by EPA
  61. Total Maximum Daily Load
    • calculation of the max amount of a single pollutant that a surface water can receive and still meet water quality standards
    • includes PS & NPS pollution
  62. Control of Drinking Water Quality
    • 1914 - US Public Health Service
    • 1974 - Safe Drinking Water Act
  63. Sedimentation & Causes
    • #1 NPS pollution problem in US
    • causes - construction, erosion from agricultural fields, deforestation
  64. Impacts of Development
    • decreased infiltration
    • decreased groundwater flow to stream
    • stream bank erosion
    • increased runoff
  65. Consequences of Sedimentation
    • effects on resident organisms
    • - smother benthic organisms
    • - irritate/clog gills
    • - reduce visibility
    • effects on surface waters
    • - silt deposition, clogged transportation channels
    • - transport associated metals, nutrients, bacteria to water
    • human health ramifications
    • - contaminated DW supplies
    • - increased cost of water purification
  66. Phosphorus Sources
    • industry
    • agriculture
    • animal waste
    • detergents & soap
  67. Nitrogen Sources
    • urban - WWTP effluents
    • stormwater
    • sewer overflows
    • light industry
    • untreated sewage
    • industrial waste

    • rural - animal wastes (CAFOs)
    • fertilizer runoff
    • woodlots
  68. Effects of Nutrient (N,P) Enrichment
    • cultural eutrophication
    • primary effects - algal blooms, low DO, shift to anaerobic decomposition
    • secondary effects - population shifs
  69. Effects of Low DO
    • changes the type of biota that can survive
    • - loss of low DO intolerant organisms
    • - increases in low DO tolerant organisms
    • decreases rate of aerobic decomposition
    • increases anaerobic decomposition
  70. Burden of Diarrheal Disease
    • 4 million cases worldwide
    • 2.2 million deaths per year
    • - 90% are children < 5
    • - 80% are children < 2
    • 1 in 200 children die from diarrhea worldwide
    • 88% of diarrheal disease due to unsafe water, inadequate sanitation, and hygiene
  71. Water Quality Legislation
    • Safe Drinking Water Act - regulated pathogens
    • Federal Water Pollution Control Act
    • - Clean Water Act
    • - BEACH Act
  72. Microbiological contaminants
    • bacteria
    • eukaryotes
    • viruses
  73. Bacteria - Microbiological Contaminants
    • aeromonas hydrophilia
    • cyanobacteria
    • helicobacter pylori
    • mycobacterium avium intracellulare
  74. Eukaryotes - Microbiological contaminants
    • acanthamoeba
    • microsporidia (enterocytozoon & septata)
  75. Viruses - Microbiological Contaminants
    • adenoviruses
    • caliciviruses
    • coxsackieviruses
    • echoviruses
  76. Clean Water Act - Goals & Attainment
    • Goals:
    • 1. eliminate discharge of pollutants
    • 2. achieve WQ levels that are fishable and swimmable
    • Attainment:
    • 1. nationwide use of secondary treatment
    • 2. development of national permit system
    • Priorities for discharge
    • - reducing BOD (biological oxygen demand)
    • - suspended solid
    • - toxic contaminants
  77. BEACT Act 2000
    added pathogen indicators for all coastal (recreational) waters
  78. The Ideal Indicator for Water Quality
    • 1. occurs simultaneously with pathogens
    • 2. cannot grow in the environment
    • 3. more resistant to disinfection and treatment than are pathogens
    • 4. easy to isolate and count
    • 5. can isolate from all types of water
    • 6. not subject to antimicrobial action in the environment
    • 7. only found in sewage (human feces)
    • 8. found in higher numbers than pathogens
    • 9. the density of the indicator should relate to the degree of contamination
    • 10. the density of the indicator should relate to a specific health hazard or type of pollution
  79. New Criteria for Water Quality
    • 1st major shift in regulation policy for pathogens since CWA
    • Evaluating WHO & EU approaces
    • New rapid detection assays
    • Predictive Modeling
  80. Combined Sewer Overflows
    • common in older cities
    • stormwater and sewer lines are the same - if it rains, then treatment plants can't handle the volume and release untreated sewage
    • overflow events vary by season - every rain event, threshold events
    • reduce events by building holding tanks
  81. Water Quality and Waterborne Disease Trends
    • increase in malnutrition
    • increase in number of people who die or contract a disease or illness from extreme weather conditions
    • increase in the frequency of cardiorespiratory diseases from changes in air quality
    • change in the range of infectious disease vectors
    • reduction of cold related deaths
    • increase in the burden of diarrheal diseases
  82. Much of the world continues to inappropriately dispose of refuse which...
    • 1. invites the proliferation of rodents and insects
    • 2. becomes a source of contamination to ground water
    • 3. pollutes ambient air when combusted
    • 4. facilitates the spread of debris around the dumping site
    • 5. lowers property values about the site
    • 6. encourages the spread of disease from microorganisms and toxic chemicals
  83. The Resource Conservation and Recovery Act (RCRA)
    • forbade open dumping and introduced the concept of the sanitary landfill
    • the definition of hazardous waste in RCRA includes any discarded material that may pose a substantial threat or potential danger to human health or the environment when improperly handled
  84. USEPA endorsed several different practices to reduce MSW that include:
    • source reduction (including reuse of products and backyard composting of yard trimmings)
    • recycling of materials (including composting)
    • waste combustion (preferably with energy recovery) and landfilling
  85. Definition of Municipal Solid Waste
    • materials in MSW include paper and paperboard, yard trimmings, food wastes, plastics, glass, metal, and food wastes
    • excludes municipal sludge, industrial non-hazardous waste, construction and demolition waste, agricultural waste, oil and gas waste, and mining wastes (everything that is landfilled in Subtitle D landfills)
  86. Components of US solid waste
    • US produces 11 billion tons of solid waste each year
    • Agricultural Waste - 50%
    • Residues produced by mining and primary metal processing - 30%
    • industrial waste - 400 million metric tons/year (3.6%)
    • municipal waste - 200 million metric tons/year (1.8%) or 2 kg/person/day
  87. Collection and Disposal of Solid Waste
    • removal of solid waste is the responsibility of the government
    • must develop and enforce regulations that protect the public health by proper collection and disposal
  88. Collection of MSW
    • Collection vehicles often include manually loaded compacting bodies which increases the capacity of the load that can be carried, and facilitates emptying at the disposal site
    • A transfer station is a site where solid waste is concentrated before taken to a processing facility or a sanitary landfill
    • Most often involves compaction by placing the waste into a metal channel where a ram compresses the waste into a roll-off collection container
  89. Fate of MSW
    • Landfill - 55.5%
    • Recovery for recycling (including composting) - 27.3%
    • Combustion - 17.2%
  90. Landfill Design
    • Image Upload 2
    • the bottom liners may be composed of one or more layers of clay or a synthetic flexible membrane (or some combination of both)
  91. Landfill caps are meant to be impermeable but can be disturbed by:
    • burrowing and soil-dwelling animals, roots of vegetation
    • precipitation, freeze-thaw cycles, wind
    • uneven settling, migration of chemicals of objects
    • exposure to sunlight
  92. % of Landfills by Region
    • Southeast - 35.9%
    • West - 34.8%
    • Midwest - 20.5%
    • Northeast - 8.7%
  93. Source Reduction of Hazardous Waste
    • Activities that reduce the amount of the toxicity of wastes prior to entering the waste stream
    • - products package reuse
    • - package or product redesign that reduces material or toxicity
    • - reducing use by modifying practices
  94. Recovery for Recycling
    the act of removing materials from MSW for a productive use

    • Materials recycling facilities (MRFs) prepare recyclables for marketing
    • a magnet removes steel objects, and recyclables are sorted manually
    • glass bottles are separated into clear, brown, and green glass, and ground into small smooth pellets called cutlets
  95. Recycling is perceived to:
    • 1. conserve resources by reducing the need for virgin and nonrenewable materials
    • 2. reduce the amount of pollution by using secondary materials that require less energy to process
    • 3. save energy by using recycled materials, since less is required for processing
  96. Trends in Resource Recovery
    • most of the recovery appears to be in paper and paperboard, accounting for nearly 57% of the material recovered
    • this is followed by yard trimmings and food wastes which are composted (19.7%) and metals at 11.1%
  97. Composting
    • a controlled process of degrading organic matter by microorganisms into a humus-like material
    • the composting material is often low in plant nutrients but is useful for conditioning soil by improving soil porosity and aeration and increasing water retention
  98. Compost
    • being used for wetlands mitigation, land reclamation, storm filtrates, soil amendments, mulches, and low-grade fertilizers
    • the market penetration of compost is likely to increase when combined with education on the benefits of compost use
  99. Combustion
    • combustion with the production of energy is called waste-to-energy (WTE)
    • combustion of MSW without energy recovery is called incineration

    • WTE plants are generally mass burn, although many incorporate recycling activities that remove noncombustible items such as metals and glass prior to burning
    • the facility is designed in stages to minimize emissions
    • Combustion --> Energy Recovery --> Pollution Control
  100. Hazardous Wastes
    • discarded solids or liquids with substances that are fatal in low concentrations, toxic, carcinogenic, mutagenic, or teratogenic - includes corrosive, explosive, reactive, and flammable materials
    • US industries generate about 265 million metric tons of officially classified toxic wastes each year
    • chemical and petroleum industries are the biggest sources of toxins
  101. "Cradle-to-Grave" system of RCRA protects public health by:
    • 1. defining what wastes are hazardous
    • 2. tracking wastes to the point of disposal
    • 3. assuring that treatment, storage, and disposal (TSD) facilities meet minimum national standards
    • 4. making certain TSDs are properly maintained after closure and that facility operators are financially responsible for hazardous waste releases that occur
  102. Hazardous and Solid Waste Amendments (HSWA)
    amendments made to RCRA in 1984 that significantly expanded its regulatory powers
  103. 3 Major Options for managing hazardous waste
    • 1. reducing the production of waste by reducing the amount generated or recycling/reusing the hazardous material after its generation
    • 2. reducing the volume and/or hazard of the waste
    • 3. long-term storage or disposal
  104. The generation of hazardous waste can be minimized by
    • 1. eliminating or substituting raw materials for less hazardous ones
    • 2. changing the manufacturing process to reduce or eliminate hazardous waste
    • 3. separating or segregating waste at the source to prevent the contamination of non-hazardous waste
  105. Hazardous Waste Disposal
    • landfills
    • deep-well injection
    • surface impoundments
  106. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
    • "superfund"
    • authorized the federal government to spend $1.6 billion over a 5 yr period for emergency clean-up activities
    • US EPA identifies potentially responsible parties (PRPs)
    • liability rules applied include - retroactive liability, joint and several liability, and strict liability
  107. Superfund
    • the USEPA established a hazard-ranking system (HRS) based on the estimated hazard potential of the hazardous waste site
    • the factors used to make this estimate include the waste characteristics, the distance to the local population, surface water, groundwater, and drinking water supplies
    • environmental groups and concerned citizens say RCRA was not being vigorously enforced
    • Superfund Amendments and Reauthorization Act of 1986 (SARA) - increased the program's funding and provided new and stricter standards
    • nearly 3,000 hazardous waste sites that have come under Superfund authority
    • More than 1300 of these sites are on the USEPA's National Priority List (NPL)
  108. Occupational Health Definition
    multidisciplinary approach to the recognition, diagnosis, treatment, and prevention and control of work-related diseases, injuries and other conditions
  109. Relationship between Environmental Health and Occupational Health
    EH - encompasses a wide array of determinants that can affect a person's health, including OH
  110. Components of Occupational Health
    • Industrial hygiene
    • Occupational toxicology
    • Occupational epidemiology
    • Occupational medicine
    • Regulatory Science
  111. Components of OH - Industrial Hygiene
    handle occupational hazards - anticipation, recognition, evaluation, and control
  112. Components of OH - Occupational Toxicology
    use the principles and methodology of toxicology to study adverse health effects and mechanisms of occupational hazards encountered at workplace
  113. Components of OH - occupational epidemiology
    statistical analysis on frequency and occurrence of occupational disease, including biomonitoring and surveillance
  114. Components of OH - occupational medicine
    diagnose and treat occupational illnesses or injuries
  115. Components of OH - Regulatory Science
    laws and regulations
  116. Workforce Characteristics in the US Occupations
    • Over 40% of US workers are women, not accounting for full-time homemakers
    • Approx 14% of American workers belong to unions
    • Most US workers are employed by small or moderate-sized firms that do not employ physicians or other health professionals to provide health & safety
    • Approx 2400 US physicians have been certified in Occupational Medicine by the American Board of Preventive Medicine
  117. Magnitude of Occupational Problems
    • An estimate 10 million work-related injuries and 430,000 new work-related illnesses occur each year in the US
    • There may be 100,000 or more work-related deaths in the US each year
    • 5,400 traumatic occupational fatalities occur in the US each year
    • Highest rate are in mining, construction, and agriculture
    • Each day in the US - avg of 9000 workers sustain disabling injuries on the job, 16 workers die from workplace injury, and 137 die from work-related diseases
    • The number of occupational disease injuries reported is much lower
  118. Economic Costs of OH
    • Costs of occupational injuries were $145 billion/year
    • Costs of occupational illnesses were $26 billion/year
    • Total of $171 billion
    • $33 billion for HIV
    • $57 billion for Alzheimer's disease
    • $164 billion for circulatory diseases
    • $171 billion for cancer
  119. Iceberg of Occupational Disease
    • 1. Recognized as being related to work
    • 2. Medical attention received, but relationship of illness to work not recognized
    • 3. Symptoms, but no medial attention sought
    • 4. Affected, but no symptoms
  120. Issues of Occupational Health
    • Government role
    • - Federal Coal Mine Safety and Health Act
    • - Occupational Safety and Health Act (establishment of NIOSH)
    • Occupational safety and health education
    • Social and ethical questions
    • Advances in technology
    • The environmental movement
    • Globalization of the economy
  121. Workforce Characteristics in the Developing World
    • Most people who are employed work in the informal sector of the economy - mainly in agriculture or in small-scale industries
    • High rates of unemployment, often 25%+
    • Workers are at greater risk of occupational hazards b/c
    • - lower rates of education and literacy
    • - unfamiliarity with work processes and exposure
    • - high prevalence of endemic disease and malnutrition
    • - inadequate infrastructure and human resources to recognize,
    • diagnose, treat, and prevent and control work-related illnesses
    • and injuries
    • Wages are low - annual per capita income is $500 or less
    • Vulnerable populations - women, children, migrants (floating populations)
  122. Occupational Hazards
    • Also called occupational disease causing agents
    • Industrial hazards - chemicals
    • Degreasing solvents
    • Acids, bases, other corrosive substances
    • Metals
    • Fumes & vapors
    • Poison gases
    • Chemical manufacture
  123. OH - construction, painting, maintenance, mechanical
    • acids, bases, other corrosive substances
    • cleaning/degreasing solvents
    • tar/asphalt
    • paint, varnish, paint remover fumes
    • particulates
    • used oil
    • exhaust fumes
  124. OH - mining
    • metals
    • particulates
    • radiation
  125. OH - agriculture & laboratory
    • A - pesticides (neurotoxicants, carcinogens, thyroid toxins)
    • ammonia - irritant, nerve toxin
    • nitrite - methemoglobin

  126. Evaluationg of Occupational Hazards
    • 1. establishing causality - difficult
    • 2. occupational risk-assessment process
    • In vitro assays
    • Animal toxicology studies - identifying adverse effects, providing mechanistic data, establishing dose response relationships, and aiding the process of establishing standards
    • Human challenge studies - verifying findings from animal studies, establishing biomarkers of exposure
    • Case report
    • Epidemiology studies - cross-sectional, cohort, case-control
  127. Problems with Establishing Causality in OH
    • occupational vs. non-occupational exposures - are you on/off the job?
    • latency periods - diseases from chemical exposure may be manifested many years after acute exposure or require many years of chronic exposure
    • multifaceted etiology - there are many things which can cause a disease, figuring out which one is not easy
  128. Common occupational diseases
    • cancer
    • cardiovascular disorders
    • eye disorders
    • hearing impairment
    • hematologic disorders
    • hepatic disorders
    • musculoskeletal disorders - low back pains, neck and upper extremity symptoms
    • neuropsychiatric disorders
    • renal and urinary tract disorders
    • reproductive disorders
    • respiratory disorders - fibrosis (silicosis, asbestosis, and pneumoconiosis), occupational asthma, pulmonary edema
    • skin disorders - contact dermatitis
  129. Screening for Occupational Disease
    • The main goal of screening is early detection and treatment of disease
    • Other goals include evaluation of the adequacy of exposure control and other means of primary prevention, detection of previously unrecognized health effects suspected on the basis of toxicologic and other studies, and suitable job placement
    • Screening methods include questionnaires, physical examinations, and lab tests
    • Should be simple, noninvasive, safe, rapid, and relatively inexpensive
  130. Diagnosis of Symptomatic Workers
    • Use of lab for biomonitoring and clinical testing
    • Proper workplace exposure assessment
    • Concerns with ethical, legal, and socioeconomic factors
    • The occupational history
    • - description of all jobs held, both past and present
    • - a review or work exposures in these jobs
    • - information on the timing of symptoms in relation to work
    • - epidemiology of symptoms or illnesses among coworkers
    • - info on nonwork factors
  131. Guidelines of Occupational Health
    • controlling risks at the source
    • identifying new risks at the earliest possible time
    • delivering the best level of theurapeutic care and rehabilitation for workers who are ill or injured
    • preventing recurrence of disease and injury in other workers who are exposed to similar risks
    • ensuring that affected workers receive economic compensation legally due them
    • discovering new relationships between work exposure and disease
  132. Occupational Surveillance
    • the systematic and ongoing collection, analysis, and dissemination of information on disease, injury, or hazard for the prevention of morbidity and mortality
    • different from "medical surveillance" which is focused on the interview and examination of the individual
    • Two kinds:
    • case-based
    • rate-based
  133. Goals of Occupational Surveillance
    • to identify illnesses, injuring, and hazards that represent new opportunities for prevention
    • to define the magnitude and distribution of the problem in the workplace
    • to track trends in the magnitude of the problem as a rudimentary method of assessing the effectiveness of prevention efforts
    • to target (identify) categories of occupations, industries, and specific worksites that require attention in the form of consultations, educational efforts, or inspections of compliance with established regulations
    • to publicly disseminated information so that wise personal and societal decisions can be made
  134. Primary Prevention of Occupational Diseases
    • designed to deter or avoid the occurrence of occupational disease or injury
    • a carefully designed occupational surveillance program, using both case- and rate-based approaches
  135. Secondary Prevention of Occupational Diseases
    • designed to identify and adequately treat a disease or injury process as soon as possible
    • the selection and use of screening and monitoring tests that are appropriate to identify workplace risks
  136. Tertiary Prevention of Occupational Diseases
    • designed to treat a disorder when it has advanced beyond its early stages so as to avoid complication and limit disability
    • the correct diagnosis and approach to treatment of a worker with an occupational illness or injury is essential to maximize opportunities for protection
  137. Controlling Exposure - Levels of PPE
    • Personal protective equipment (PPE)
    • Level A - self-contained breathing appartus with oxygen tank, thick rubber seamless suit - for highly toxic substances that may be present as gases or vapors and readily penetrate skin
    • Level B - thin but chemical-impervious suit with or without hood, rubber gloves, boots, full face respirator (high performance filter but not air supply)
    • Level C - label coats, overalls, face shield, eye protection, gloves, apron, may or may not require full/half-face respirator, surgical or dusk mask, shoe covers
    • Level C - no special PPE other than uniform
  138. Engineering Controls for Exposure in OH
    • ventilation
    • fume hoods
    • shileding
    • glove boxes
    • dosimeters and mointors
    • warning sirens
    • mechanized/robotic handling of materials for highly toxic or radioactive materials
  139. Administrative Controls for Exposure in OH
    • limitations on duration and frequency that a person is allowed to work with a chemical or physical hazard or in a hazardous area, or limitations on distance from hazard
    • monitoring - environmental, biological
    • training and hazard communication
  140. Pesticides definition
    • any substance or mixture of substances intended for preventing, destroying, repelling or mitigating pests
    • specific chemical or biological agents deliberately added to the environment for the purpose of killing or injuring some form of life
    • Pests can be insects, rodents, weeds, a host of other unwanted organisms
  141. Classification of Pesticides
    • relies on the target species they act on
    • insecticides
    • herbicides
    • fungicides
    • rodenticides
    • acaricides/miticides
    • molluscides
    • larvicides
    • pediculocides - lice
    • plant growth regulators
    • reppellents
    • attractants
  142. Benefit of Pesticides to Economics
    • In developing world, excessive loss of food crops to insects or other pests may contribute to starvation, and use of pesticides have a favorable cost-benefit relationship
    • in the developed world, use of pesticides makes production of abundant, inexpensive, and attractive fruits and vegetables, as well as grain
    • pesticides are widely used in forestry, during reforestation, as well as the clearing of roadways, train tracks, and utilities surroundings
    • in the urban settings, pesticides are used in the home and garden area to control insects, weeds, and other pests
  143. Benefits of Pesticides to Public Health
    • play a major role in the control of vector-borne diseases
    • help to control various common diseases - malaria, yellow fever, etc
    • balance between benefits and risks is still a challenge for the use and ban of certain pesticides (ex. DDT)
  144. Pesticides Exposure
    • via oral or dermal routes, or by inhalation
    • oral exposure - suicidal or accidental, due to improper storage
    • dermal and respiratory acute exposure for works involved in the production, transportation, mixing and loading, and application of pesticides
    • chronic low dose exposure occurred as consumption of pesticide residues in food or as contaminants in drinking water
  145. Human Poisoning due to Pesticides
    3 million poisonings and 220,000 deaths each year worldwide
  146. Other Human Health Effects of Pesticides
    • cancer risks -occupational, general population risks
    • susceptible populations, especially for children
    • endocrine disruptors for reproductive and developmental toxic effects
  147. Regulation of Pesticides
    • awareness that the misuse of pesticides may pose potential health hazards
    • Federal Insecticide, Fungicide and Rodenticide Act
    • Federal Food, Drug, and Cosmetic Act - establishes max allowable levels of pesticide residues in food and animal feed
    • Food Quality and Protection Act - continuing the expedite review for pesticides that may provide reduced risk for human health, nontarget species and the environment; exclude pesticide residues from the definition of food additives; assess special risks of pesticides to infant and children
  148. Current and Future Pest Control Measures
    • physical and mechanical interventions - use of techniques or materials
    • biological control agents - use, manipulation and conservation of living organisms, usually natural enemies
    • transgenic species
    • chemical pesticide application - least harmful to the environment and human health
  149. Arguments against DDT usage
    • DDT belongs to persistent organic pollutants (POPs), accumulates in ecosystems for years, and bioconcentrates as it moves up the food chain
    • Has been shown to cause reproductive failure and other adverse outcomes in other species beyond target insect species
    • May disrupt reproductive and endocrine functions and neurological development
    • Potentially carcinogenic
    • Continued use will result in insect resistance
    • Alternatives are available
  150. Arguments for Continued DDT Usage
    • has very low acute toxicity for humans and evidence for human carcinogenicity and other adverse effects is weak, in contrast the burden of mortality and morbidity from malaria is enormous
    • relatively inexpensive compared to alternatives
    • easy to mix and apply, thereby eliminating the need for training and supervision - practical for widespread use
    • malaria and other vector-borne disease have surged in many areas following the phaseout of DDT
    • now used for house spraying, a selective approach that requires much less volume than the previous agricultural and area spraying, which results in a much lower environmental load
  151. Toxic Substances
    • "pollutants"
    • Toxins - substances that poison or harm a living organism
    • Carcinogen - a substance known to cause cancer
    • Endocrine disrupter - an agent that binds with hormones, blocking their normal function
    • Teratogen - an agent causing malformation of a fetus through the mother
  152. Chemical Interaction Possibilities
    • Additive - linear relationship (2+3=5)
    • Synergistic - effect is way bigger than either one alone (3+3=30)
    • Potentiation - no effect unless in the presence of the other (0+4=12)
    • Antagonism - decrease toxicity by adding one to another (2+7=4)
  153. Bioaccumulation vs. Biomagnification
    • bioaccumulation - when an organism is exposed to a substance over a period of time, accumulating higher levels of the substance in the body
    • biomagnification - when organisms low on the food chain (prey) are consumed by organisms higher on the food chain (predators), increasing the levels of toxic agent in the predator
  154. Environmental Toxins
    • naturally occurring
    • by-products of industry, transportation, and other human activities
  155. Essential Metals
    • Arsenic
    • Chromium
    • Cobalt
    • Copper
    • Iron
    • Magnesium
    • Manganese
    • Molybdenum
    • Nickel
    • Selenium
    • Tin
    • Vanadium
    • Zinc
  156. Non-Essential Metals
    • Aluminum
    • Beryllium
    • Cadmium
    • Lead
    • Mercury
    • Nickel
    • Plutonium
    • Silver
    • Thallium
    • Titanium
    • Uranium
  157. Speciation of Heavy Metals
    • In solution, metals give up electrons to be net positive in charge
    • as pH decreases, mobility and bioavailability increases
    • ionization is influenced by environmental factors and differences amount metals, making generalities difficult
    • biotransformation - speciation and conversion of metals by organisms
    • microorganisms (& plants) can be used to transform metals into less toxic forms
  158. Pharmacokinetics of Heavy Metals
    • inhalation is a primary route for occupational exposure
    • oral ingestion is another significant route, esp in children
    • Drinking water is a primary source of metals
    • blood flow largely determines rate and distribution of metals
    • non-enzymatic proteins bind and inactivate metals, and are later excreted
    • chelation therapy - agents given to organisms to bind metals
  159. Toxicity of Heavy Metals
    • many metals bind to sulfhydryl (-SH) groups
    • metals inhibit enzyme activity by displacing essential metals & disrupt cell membrane integrity
    • chronic exposure can lead to carcinogenicity
    • several metals attack the CNS
    • each metal has a unique mechanism of action to induce carcinogenicity
  160. Biomarkers for Heavy Metals
    • biomarkers can be induced proteins, RNAs, or even the metals
    • blood shows current/recent exposure
    • hair & fingernails show longer-term exposure
Card Set
EHSC7060 T2
Test 2 Information