US Health final - A Clean Environment: The Basis of Public Health: Chapter 20 Flashcards
Introduction
The basic needs of life are:
Air
Water
Food
Environmental health functions ensure
A clean water supply
Safe disposal of wastes
Definition
Environmental health and protection are:
the art and science of protecting against environmental factors that may adversely impact human health or adversely impact the ecological balances essential to long-term human health and environmental quality
Factors include: air, food, water contaminates, radiation, toxic chemicals, waste, disease vectors, & safety hazards
Role of Government in Environmental Health
Local governments provide clean water and disposal of wastes
As population grew, environmental problems transcended local government
In 1960’s and 1970’s, state and federal governments took more responsibility
Now, world population growth has led to global environment problems
Depletion of earth’s ozone layer and accumulation of greenhouse gases are major concerns
Identification of Hazards
A major role of government is to identify hazards in the environment and to set safety standards
Standards must be met by:
Industry
State and local governments
Concerns about climate changes
Depletion of the ozone layer
Allows harmful ultraviolet (UV) rays to enter the Earth’s atmosphere. UV rays of the sun are associated with health-related and environmental issues.
The production and emission of chlorofluorocarbons (CFCs) is the leading cause of ozone depletion. Accounts for 80% of the total depletion of the ozone
Concerns about climate changes
Accumulation of “greenhouse gases”
Greenhouse gases trap heat and make the planet warmer.
Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years.
The largest source of greenhouse gas emissions the United States is from burning fossil fuels for electricity, heat, and transportation
Environmental Hazards
Environmental hazards include:
Radiation
Mercury
Lead
Arsenic
Asbestos
Pesticides and industrial chemical
Federal government does research, set standards for exposure limits, monitors and enforces.
Environmental Protection Agency (EPA)
Radiation
Sun’s ultraviolet light causes skin cancer and melanoma
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 bombing in Japan
Radon is produced by the natural radioactive decay of uranium, present in many homes across the country
Prolonged exposure is a potential cause of lung cancer
Radium
“Radium Girls”
Workers developed radiation poisoning from painting watch dials with glow in the dark paint
Developed anemia, bone fractures and necrosis of the jaw
Constant exposure to low-dose radiation has been linked to leukemia and other cancers
Mercury
Toxicity can cause many neurological problems
“Mad as a hatter”
In the U.S. mercury can enter the environment from coal-burning power plants that pollute water and contaminate fish
Nursing mothers and young children should not eat fish with high mercury content
EPA recommends removal of mercury containing products from the home
Lead
Harms the brain and nervous system-especially in children
May lead to behavioral and learning delays
Drinking water contaminated by lead pipes and lead solder used on copper pipes
Common in exterior and interior paint especially in older homes—banned in 1977
Lead was also present in gasoline—phased out in 1980’s
Has been reported present in toys recently from China
Children should be screening for lead levels in blood
Arsenic
Private wells- may consume 50-90 mcg of arsenic per liter
Bangladesh wells-WHO dug wells to provide clean water but unfortunately they had a high concentration of arsenic in the wells
Challenge- develop effective strategies to mitigate effects of arsenic poisoning
Long term low dose exposure has been liked to diabetes and cancer
Asbestos
Wide spread use was for strength and fire resistance
Used for insulation, still used in roof, gaskets, and brake linings
Was a requirement for schools built between 1940 and 1973 for fire safety
Hazards were first recognized in an occupational setting
Fibrous dust causes scarring of lungs and cancer (lung cancer and mesothelioma)
Asbestos
The Asbestos Hazard Emergency Act of 1986 requires
All primary and secondary schools to be inspected
If loose asbestos found-must remove, enclose or encapsulate the asbestos
Asbestos
9/11 attacks—-the World Trade Center was built during a time of asbestos use
When it collapsed asbestos was released into the air
Many first responders and workers have reported respiratory issues
Pesticides and Industrial Chemicals
Dichlorodiphenyltrichloroethane (DDT)-Organochloride pesticide
Banned in 1972
Similar chemicals
Aldrin
Mirex
Kepone
These agents are soluble in fatty tissues
Persist in the environment for a long time
Pesticides and Industrial Chemicals
Polychlorinated biphenyls (PCBs)
Used in sealed systems such as transformers
They enter the environment through industrial waste
Contaminated the Hudson River
Worldwide contaminate
Chloracne-severe skin rash and discoloration associated with exposure
Possible carcinogen
Pesticides and Industrial Chemicals
These chemicals are classified as endocrine disruptors
Affect the reproduction, nervous and immunize system and may cause cancer
PCB production halted in the US by 1977- “Coca-Cola babies”
Dioxins and Furans
By products of industrial process
Stable in fatty tissues of fish, animals and humans indefinitely
Stockholm Convention on Persistent Organic Pollutants (POPs)
Agreed to reduce/eliminate production of 12 POPs
Biphenol A (BPA) and Phthalates
Common in plastic containers
BPA is found in hard plastics (water bottles, baby bottles, CDs)
Phthalates (diethyl phthalates are plasticizers) are found in soft and flexible materials (vinyl shower curtains)
Considered a possible endocrine disruptor
Can interfere with the endocrine system in humans.
May cause cancerous tumors, birth defects, and other developmental disorders.
Both leach into liquids and are found at low levels in humans
Occupational Exposures
Due to their high level of exposure-workers tend to suffer ill effects before those not exposed to such high levels
Occupational risks
Dye factory workers——–bladder cancer
Radiologists——-various cancers
Neurotoxins
Signs and symptoms can be similar to those of aging (muscle weakness, memory issues)
Hexane—-shoemakers
Trichloroethylene —–dry cleaners
Pesticide applicators——landscapers
New sources of pollution
Factory farming
Produce tons of manure each year
Gases emitted from lagoons that can be toxic to humane are:
Ammonia
Hydrogen Sulfide
Methane
People living near these lagoons have complained of medical issues
Overflow of manure can flow into lakes, streams etc.
Regulation has proven to be difficult
Setting standards
How safe is it????
Many compounds have been developed since WWII
Many of these compounds have not been tested for their harmful effects in humans or on the environment
Setting Standards
Most chemical have not been tested for health effects
Federal government is empowered by various acts to set standards:
Occupational Safety and Heath Act
Toxic Substances Control Act
Federal Insecticide, Fungicide, and Rodenticide Act
Clean Air Act
Process of standard setting is low and always controversial
The National Toxicology Program
Legislation
Occupational Safety and Health Act (1970)- standards for workers exposure to toxic substances
Toxic Substances Control Act (1976)- requires testing before on the market and ban if necessary
Federal Insecticide, Fungicide & Rodenticide Act-approval of product before use
Federal Agencies
Environmental Protection Agency (EPA)
Food and Drug Administration (FDA)
Dept. of Agriculture
Dept. of Transportation
Nuclear Regulatory Commission
Consumer Product Safety Commission
Occupational Safety & Health Administration
Risk Vs. Benefit
Absolute safety is impossible
Risk must be balanced against other societal goals, including economic well-being
Mission of these agencies should be to deliver services in a manner to protect the health of the public and the quality of the environment
The goal is to provide optimal health, safety, ecological well-being and quality of life
