Environmental Health exam 2
exposure assessment
Procedure that "identifies populations exposed to the toxicant, describes their composition and size, and examines the roots, magnitudes, frequencies, and durations of such exposures" One of the weakest aspects of risk assessment
Environmental Impact Assessment (EIA)
Process that reviews the potential impact of anthropogenic activities with respect to their general environmental consequences
Role of Policy and Environmental Challenges
Protection from environmentally associated health hazards Regarded as a fundamental human right
Toxic Substances Control Act (TSCA) of 1976
Provides EPA with authority to require reporting, record-keeping, and testing requirements, and restrictions relating to chemical substances and/or mixtures Various sections of TSCA provide authority to maintain the TSCA Inventory, under Section 8, which contains more than 83,000 chemicals
risk assessment and risk management are interrelated
Some decisions are based on scientific judgment; others are policy decisions informed by science. How separated should risk assessment and risk management be? Most current frameworks recommend an iterative process. Transparency is key: "Conducting a risk assessment in such a manner that all of the scientific analyses, uncertainties, assumptions, and science policies which underlie the decisions made throughout the risk assessment are clearly stated"
risk
A measure of the probability that damage to life, health, property, and/or the environment will occur as a result of a given hazard
case studies of environmental health policies
EPA strategic plan (2009-2014) Water policy reform in South Africa Environmental policies in economies in transition Control of pollution across international boundaries
Safe Drinking Water Act of 1974
Established to protect the quality of drinking water in the US Authorizes EPA to establish minimum standards to protect tap water Requires all owners or operators of public water systems to comply with these primary (health-related) standards
environmental toxicology
Examines how environmental exposures to chemical pollutants may present risks to biological organisms Animals Birds Fish
Ways of describing a dose
Exposure dose Absorbed dose Administered dose Total dose External dose Internal dose Effective dose
subacute
Exposure for 1 month or less
subchronic
Exposure for 1 to 3 months
chronic
Exposure for more than 3 months
toxic plants
Some mushrooms (e.g., Amanita phalloides, "death cap") Poison hemlock Foxglove Poison oak/poison ivy Rhubarb, especially the leaves, which have high levels of oxalates Some houseplants, such as dieffenbachia
precautionary principle
States that "preventive, anticipatory measures . . . [should] be taken when an activity raises threats of harm to the environment, wildlife, or human health, even if some cause-and-effect relationships are not fully established"
subjects used for testing toxicity of chemicals
Volunteers who have had normal or accidental exposures Animals exposed purposively (in vivo experiments) Cells derived from human, animal, or plant sources (in vitro experiments)
future exposures
What is the estimate of future exposures?
magnitude frequency duration
components of an exposure assessment include
environmental policy
"A statement by an organization [either public, such as government, or private] of its intentions and principles in relation to its overall environmental performance. Environmental policy provides a framework for action and for the setting of its environmental objectives and target" Example: United States: the National Environmental Policy Act of 1969
Basic Assumption of Toxicology
"All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy."
hazard identification
"Examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgment about the strength of that evidence"
hazard
"Inherent capability of a natural or human-made agent or process to adversely affect human life, health, property, or activity, with the potential to cause a DISEASE, EPIDEMIC, ACCIDENT, or DISASTER."
Health Impact Assessment (HIA)
"Method for describing and estimating the effects that a proposed project or policy may have on the health of a population"
polluter-pays principle
"Polluter should bear the expenses of carrying out the pollution prevention and control measures . . . to ensure that the environment is in an acceptable state"
antagonism
"Two chemicals administered together interfere with each other's actions or one interferes with the action of the other"
dose
"amount of a substance administered at one time" The amount of a substance available for interactions with metabolic processes or biologically significant receptors after crossing the outer boundary of an organism
poison
"any agent capable of producing a deleterious response in a biological system"
toxicity
"degree to which something is poisonous" Related to a material's physical and chemical properties
toxicology
"study of the adverse effects of chemicals on living organisms"
environmental sustainability
Adheres to the philosophical viewpoint "that a strong, just, and wealthy society can be consistent with a clean environment, healthy ecosystems, and a beautiful planet"
internal dose
Amount absorbed and available for interaction (μg / kg)
quantifying exposures
Assessing exposures using monitoring devices in the community Placing exposure measuring devices on the body of the exposed individual
Mathieu Orfila
Authored a number of significant works in 1800s, among them Trait des poisons (1813). Described various types of poisons and their bodily effects Contributed to the foundations of forensic toxicology
carcinogen
Chemical (or substance) that causes or is suspected of causing cancer, a disease associated with unregulated proliferation of cells in the body
target organ effects
Chemical effects confined to specific organs
additive
Combination of two chemicals produces an effect equal to their individual effects added together
synergism
Combined effect of exposures to two or more chemicals is greater than the sum of their individual effects
3. After listening to the podcast on an offshore wind energy project in New England, how can the federal government assess the potential environmental impacts of this wind farm? Describe this process.
Commercial fisherman are concerned with the impact the windfarms will have on their fishing grounds. The company who is planning on constructing the wind farm, Vineyard Wind, plans on constructing the farm to leave the smallest geographical footprint on the fishing grounds. In order for the federal government to assess the environmental impacts this wind farm would have, they would have to utilize the Health impact assessment (HIA). This method will enable the government to describe and estimate the effects this proposed project may have on the health of a population. Major construction projects can have a damaging effect upon the health of human populations, and accordingly, should require an HIA. Because the wind farm has the potential to effect commercial fishing, it would affect the humans who rely on these fisheries to earn their incomes.
Clean Air Act of 1970
Comprehensive federal law Regulates air emissions from stationary and mobile sources Authorizes EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and public welfare and to regulate emissions of hazardous air pollutants
local effects
Damage where chemical first contacts body
environmental justice
Denotes the equal treatment of all people in society irrespective of their racial background, country of origin, and socioeconomic status
risk characterization
Develops "estimates of the number of excess unwarranted health events expected at different time intervals at each level of exposure" The last phase of the risk assessment process that estimates the potential for adverse health or ecological effects to occur from exposure to a stressor and evaluates the uncertainty involved. The integration of information on hazard, exposure, and dose-response to provide an estimate of the likelihood that any of the identified adverse effects will occur in exposed people.
Resource Conservation and Recovery Act (RCRA) of 1976
EPA controls hazardous waste from the "cradle-to-grave." Includes the generation, transportation, treatment, storage, and disposal of hazardous waste Enabled EPA to address environmental problems that could result from underground storage tanks Focuses on waste minimization and phasing out land disposal of hazardous waste as well as corrective action for releases
National Institute for Occupational Safety and Health (NIOSH)
Federal agency Responsible for conducting research and making recommendations for the prevention of work-related injury and illness Created in the Occupational Safety and Health Act of 1970 along with the Occupational Safety and Health Administration (OSHA)
Frequent Sites of Exposure to Environmental Chemicals
Gastrointestinal tract Respiratory system Skin
systemic effects
Generalized distribution throughout body by the bloodstream to internal organs
process of risk assessment
Hazard identification Dose-response assessment Exposure assessment Risk characterization
exposure routes
How does the agent gain access to the body?
exposure pathways
How does the agent move from its source to the individual?
magnitude
How large is the exposure?
frequency
How often does an exposure take place?
potential dose
Ingested, inhaled, applied to skin
Routes of Exposure
Ingestion (e.g., consumption of contaminated food or drink) Injections into the bloodstream Contact with the surface of the skin (topical mode) Inhalation
risk management
Involves the adoption of steps to eliminate identified risks or lower them to acceptable levels Often determined by a government agency that has taken into account input from the public
Lethal Dose 50 (LD50)
Is "the dosage (mg/kg body weight) causing death in 50 percent of exposed animals" Used to compare the toxicities of different chemicals
Examples of projects that may affect health:
Large dams, mines, power plants, airports Development corridors, urban redevelopment
examples of risk management
Licensing laws Standard-setting laws Control-oriented measures Monitoring
World Health Organization (WHO)
Major international agency Responsible for environmental health at the global level Provides leadership in minimizing adverse environmental health outcomes associated with pollution, industrial development, and related issues
dose-response can be expressed as
Measured or observed incidence or change in level of response Percent response in a group of subjects (or populations) Probability of occurrence or change in level of response within a population.
dose-response assessment
Measures "the relationship between the amount of exposure and the occurrence of the unwanted health effects" Evaluating the quantitative relationship between dose and toxicological responses. A determination of the relationship between the magnitude of an administered, applied, or internal dose and a specific biological response.
US Environmental Protection Agency (EPA)
Mission: protect human health and the environment Established by the White House and Congress in July of 1970 in response to the growing public demand for cleaner water, air, and land
potentiation
One chemical that is not toxic causes another chemical to become more toxic
two types of dose-response curves
One for the responses of an individual to a chemical One for a population
National Environmental Policy Act of 1969
One of the first laws ever written that establishes the broad national framework for protecting our environment NEPA's basic policy is to ensure that all branches of government give proper consideration to the environment before undertaking major federal action that significantly affects the environment.
Paracelsus
One of the founders of modern toxicology Active during the time of da Vinci and Copernicus (early 16th century) Contributed to the concept of the dose-response relationship and notion of target organ specificity of chemicals
risk management
Oriented toward specific actions "taken to control exposures to toxic chemicals in the environment." "Exposure standards, requirements for premarket testing, recalls of toxic products, and outright banning of very hazardous materials are among the actions that are used by governmental agencies to manage risk."
duration
Over what time period has the exposure occurred?
Principle of environmental policy development
Precautionary principle Environmental justice Environmental sustainability The polluter-pays principle
applied dose
Present in exposure medium (μg / m3)
Endangered Species Act of 1973
Provides a program for the conservation of threatened and endangered plants and animals and the habitats in which they are found The US Fish and Wildlife Service (FWS) maintains a worldwide list of endangered species Birds, insects, fish, reptiles, mammals, crustaceans, flowers, grasses, and trees
risk assessment
Provides a qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences
CERCLA 1980 (Comprehensive Environmental Response, Compensation, and Liability Act)
Provides federal "Superfund" to clean up waste Uncontrolled or abandoned hazardous waste sites Accidents, spills, and other emergency releases of pollutants and contaminants into the environment EPA was given power to seek out those parties responsible for any release and ensure their cooperation in the cleanup.
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) of 1996
Provides for federal regulation of pesticide distribution, sale, and use All pesticides distributed or sold in the US must be registered (licensed) by EPA. Before EPA registers a pesticide under FIFRA, the applicant must show that using the pesticide according to specifications "will not generally cause unreasonable adverse effects on the environment."
exposure
Quantified as the amount of an agent available at the exchange boundaries of the organism (e.g., skin, lungs, gut).
threshold
Refers to the lowest dose at which a particular response may occur
fields within toxicology
Regulatory Forensic Clinical Environmental Reproductive Developmental
Relationship of Risk Assessment to Policy Process
Risk assessment is closely aligned with the policy process through the balancing of economic and other costs with health and societal benefits that may accrue through specific policy alternatives.
Factors That Affect the Concentration and Toxicity of a Chemical
Route of entry into the body Received dose of the chemical Duration of exposure Interactions that transpire among multiple chemicals Individual sensitivity
toxicologist
Scientist who has received extensive training in order to investigate in living organisms "the adverse effects of chemicals . . . (including their cellular, biochemical, and molecular mechanisms of action) and assess the probability of their occurrence"
4. Identify any two major environmental health law in the US and suggest how they might protect vulnerable groups (e.g. children, elderly, poor, etc.)
The Clean Air Act was established in 1970 in which the federal government regulates air emissions from stationary and mobile sources. This is important in reducing the environmental risks children are exposed to. They typically spend more time outdoors than other groups of the population, and their immune systems and lungs are still developing at this point in their life, so ensuring cleaner air can prevent health complications especially among children. Another law established by the government includes Clean Water Act of 1977. This law established the basic structure for regulating pollutant dischargers into the waters of the U.S. This act can greatly improve the health of individuals that are particularly impoverished. The quality of the water affects poorer populations because they typically acquire water from these sources that could have possibly been exposed to contaminants. By prohibiting the discharge of waste into water sources, it can improve the health of poorer populations who rely on these water sources for their needs.
Clean Water Act
The Federal Water Pollution Control Act of 1948 First major US law to address water pollution Amended in 1972 and 1977 to become the Clean Water Act (CWA) Established basic structure for regulating pollutants discharged into the US waters
1. Identify one global and one national environmental agency and describe their role, and involvement in the implementation and enforcement of environmental policies?
The World Health Organization (WHO) is an example of a global organization that provides leadership in minimizing adverse environmental health outcomes associated with pollution, industrial development, and related issues. A national organization includes the U.S. EPA, the environmental protection agency is responsible for protecting human health and safeguarding the natural environment, including air, land, and water. They are also responsible for developing and enforcing environmental regulations, which bring about cleaner air and purer water as well as protect the land.
inherent toxicity
The _________ _________ of a compound. Hazard identification of a given substance is an informed judgment based on verifiable toxicity data from animal models or human studies.
5. Distinguish between the terms environmental laws and environmental regulations Identify at any emerging environmental risk that is not addressed in the current list of environmental laws https://www.epa.gov/laws-regulations
The difference between laws and regulations is that laws are written by Congress and they provide the authority for the Environmental Protection Agency to write regulations. Regulations explain the technical, operational, and legal details necessary to implement laws.
2. List and define the stages of the policy cycle. Explain how the lack of environmental research might affect the policy process.
The first step in the policy cycle is the policy definition/formulation/reformulation process. This process of defining the problem for which the policy actors believe that policies are necessary. This step is regarded as the most crucial phase of the policy development process. The second step is known as agenda setting. This refers to setting priorities, deciding at what time to deal with the environmental problem, and determining who will deal with the problem. The third step, policy establishment, involves the formal adoption of policies, programs, and procedures that are designed to protect the public from environmental hazards. The fourth step, policy implementation, is the phase of the policy cycle that focuses on achieving the objectives set forth in the policy decision. This phase is neglected in favor of the earlier phases of policy development. The fifth and final step of the policy cycle is known as policy assessment. Assessment/evaluation, refers to assessment of the effectiveness of the policy. In order to facilitate assessment, environmental policies may incorporate environmental objectives, which are statements of policy intended to be assessed using information from a monitoring program.
latency
Time period between initial exposure and a measurable response Can range from a few seconds (in the case of acutely toxic agents) to several decades for agents that may be carcinogenic
toxicants
Toxic substances that are human-made or result from human (anthropogenic) activity
dose-response relationship
Type of correlative relationship between "the characteristics of exposure to a chemical and the spectrum of effects caused by the chemical"
dose-response curve
Type of graph Used to describe the effect of exposure to a chemical or toxic substance upon an organism such as an experimental animal
acute
Usually a single exposure for less than 24 hours
toxin
Usually refers to a toxic substance made by living organisms Reptiles Insects Plants Microorganisms
exposure assessment takes into account:
Where the exposure occurs How much exposure occurs How a toxic substance is absorbed by the body