Environmental

• Environmental health


  Those aspects of human health and disease that are determined by factors in the environment. It also refers to the theory and practice of assessing and controlling factors in the environment that can potentially affect health
• Health is affected by the quality of the environment
• Globally, estimated 12.6 million deaths each year attributed to unhealthy environment
• That's a ¼ of all deaths every year
• Environmental risk factors, such as air, water and soil pollution, chemical exposures, climate change, and ultraviolet radiation, contribute to more than 100 diseases and injuries
• Maintaining environmental quality


  • Improve years of healthy living
  • Improve quality of life
  • Reduce global morbidity rates
  • Reduce global mortality rates
• Maintaining environmental quality is a pressing task for the 21st century
• Current Environmental Health Issues in the US

  • Outdoor air quality
  • Surface and ground water quality
  • Toxic substances and hazardous wastes
  • Homes and communities
  • Infrastructure and surveillance
  • Global environmental health
• Role of Government in Environmental Health

  • Environment is beyond the control of individuals
  • Local governments provide clean water and disposal of wastes
  • As population grew, environmental problems transcended local government
  • In the 1960s and 1970s, state and federal governments took more responsibility
  • Now, world population growth has led to global environmental problems
  • Depletion of the earth's ozone layer and accumulation of greenhouse gases are major concerns
• Environmental Hazards


  • Radiation
  • Mercury
  • Lead
  • Arsenic
  • Asbestos
  • Pesticides and industrial chemicals
• Federal government does research, sets standards for exposure limits, monitors, and enforces
• Environmental Protection Agency (EPA)

  Responsible for environmental hazards
• Radiation


  • Artificially produced radiation often worries people
  • Sun's ultraviolet light causes skin cancer and melanoma
  • Radon gas is produced by naturally radioactive decay of uranium
  • Present in soils and in rocks, even in our homes
  • Prolonged exposure to radon is potentially a cause of lung cancer
  • Early scandals with radium in patent medicines led to regulation
  • Chronic exposure to x-radiation used in medicine and dentistry cause cancer
  • Health effects of radiation were confirmed by long-term studies of survivors of atomic bombings in Japan
• Mercury


  • Mercury causes neurological damage in workers
  • Minamata Bay, Japan (1956) - mercury discharge from plastic factory caused 700+ deaths, and paralysis and brain injury in some 9000+ people
  • In the US, mercury enters the environment mainly through emissions from coal-burning power plants
  • They fall to the earth - pollute water and air, contaminate fishes
  • Nursing mothers and young children should not eat fish with high mercury content
  • Fever thermometers and school laboratory equipment are exposure concerns
  • EPA recommends that mercury containing products be removed from schools and homes
• Lead


  • Lead is harmful to brain and nervous systems, especially in children
  • It damages the red blood cells and kidneys
  • It has caused poisoning since the Roman Empire
  • Drinking water gets contaminated by lead pipes and lead solder used on copper pipes
  • Gasoline emitted lead air pollutant until the 1980s when banned
  • Lead paint was used until 1977 and is a threat in old houses' peeling paint and contaminated dust
  • Lead is the most important environment threat to children in the US
  • Children should be screened for lead levels in blood
• Arsenic


  • Arsenic is "the king of poisons"
  • Arsenic is naturally present at high levels in the groundwater of a number of countries
  • People who have private wells may be drinking water with 50–90 micrograms of arsenic per liter
  • Safe zone according to EPA is 15 micrograms/ liter
  • Contaminated water used for drinking, food preparation and irrigation of food crops poses the greatest threat to public health from arsenic
  • Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions. It has also been associated with developmental effects, cardiovascular disease, neurotoxicity and diabetes
• Asbestos


  • About 125 million people in the world are exposed to asbestos at the workplace
  • All forms of asbestos are carcinogenic to humans
  • Exposure to asbestos causes cancer of the lung, larynx, ovaries, and also mesothelioma
  • Valuable mineral for a variety of use due to its strength and fire resistance
  • Asbestos was used in insulation and still is used in roofing, gaskets, and brake linings
  • It was required in all school building between 1940 and 1973
  • We are all exposed to it due to old crumbling buildings in neighborhoods
  • World Trade Center clean-up and rescue workers were affected
• Pesticides and Industrial Chemicals

  • Rachel Carson's Silent Spring in 1962 launched an environmental movement
  • The book called attention to the harmful effects of DDT (dichloro-diphenyl-trichloroethane)
  • DDT was found in lakes, streams, plants, insects, etc.
  • When eaten by fishes, birds, and other animals, they accumulate in the flesh
  • DDT and some other pesticides are now banned since 1972 in the US
  • Endocrine disrupters affect reproduction, nervous system, and immune system, and may cause cancer
• Occupational Exposures


  • Workers are often the first to suffer effects of an exposure; they serve as guinea pigs
  • Carcinogens are recognized through occupational cancers
  • Neurotoxins also have been recognized through occupational illness
• Most chemicals have not been tested for health effects
• Federal government is empowered by various acts to set standards


  • Occupational Safety and Health Act
  • Toxic Substances Control Act
  • Federal Insecticide, Fungicide, and Rodenticide Act
  • Clean Air Act
• The process of standard setting is slow and always controversial
• The National Toxicology Program

  Responsible for setting standards
• Risk-Benefit Analysis


  • Absolute safety is impossible
  • Over-regulation can cause under-regulation
  • Risk must be balanced against other societal goals, including economic well-being
  • Political groups sometimes favor economic and business interests over environment and public health
• Air Pollution


  • Contamination of air by substances in great enough amounts to harm living organisms
  • Major sources in U.S. – transportation, electrical power plants fueled by oil and coal industry
• Weather inversion in London in 1952 caused more than 4,000 deaths
• Donora, Pennsylvania in 1948 had a similar weather inversion, killed 20, and sickened over 7,000 people
• Smog in Los Angeles in the 1950s and 1960s was severe
• Many air pollution events have occurred in cities across the US since the 60's
• Efforts by cities and states to regulate pollutant emissions prior to the 60's were not successful
• The federal government began attacking the air pollution problem in the mid 60's


  1. The first attempt setting emission standards for automobiles

  2. The first emission standards for automobiles were set in 1965, and took effect in 1968

  3. The first major attempt to control air pollution was the "Clean Air Act of 1970"

  4. Since then, improving air quality has been an almost constant political battle
• Criteria Air Pollutants


  • The "Clean Air Act" require monitoring and regulation of six common air pollutants, called Criteria Air Pollution
  • These six air pollutants are known to be harmful to health and the environment
  • All of these six pollutants enters the air as a result of combustion
• Particulate Matter


  • Particulate matter is the most visible air pollution form
  • Air pollutants can be products of combustion
  • First regulated total particulates
  • It reduces visibility, form layers of grime on buildings and streets
  • Six cities study found that death rates were higher in the most polluted cities
  • Residents in cities with higher particulates were more likely to suffer from respiratory symptoms and poorer lung function
  • Smaller particles penetrate deeper into lungs
• Early air pollution regulations focused on reducing particulate matter

  1. In 1987, the EPA set the standards for particulate matter at 10 micrometers (PM10)

  2. In 1997, 2006, and in 2012 the EPA set more stringent standards for PM2.5

  3. States had until the end of 2020 to meet this new standard
• Lung cancer, other lung diseases, and heart disease are proportional to PM2.5
• Every increase beyond PM2.5 is associated with high CVD's and lung diseases
• Sulfur Dioxide


  • Sulphur dioxide is an invisible gas, and has a nasty sharp smell
  • Produced by combustion of Sulphur-containing fuels
  • Main source include industrial activity that processes materials that contain sulfur, eg. the generation of electricity from coal, oil or gas that contains sulfur
  • When breathed in, Sulphur dioxide irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest
  • It reacts with vapor to form sulfuric acid - Acid rain
  • It sticks to fine particulates in the air
  • Potential for causing respiratory damage
• Carbon Monoxide


  • Is a poisonous, colorless, odorless, and tasteless gas
  • Carbon Monoxide is a highly toxic gas
  • Most is produced in motor vehicle exhaust
  • When breathed in, carbon monoxide Displaces oxygen in the blood
  • Deprives the heart, brain, and other vital organs of oxygen
  • Large amounts of CO can overcome you in minutes without warning—causing you to lose consciousness and suffocate to death
• PM2.5 levels


  Proportional to respiratory diseases and heart disease
• Sulfur Dioxide


  Invisible gas with a nasty sharp smell, produced by combustion of Sulphur-containing fuels