Environmental Health Risk Assessment and Intervention

Chapter 6

Federal Agencies That Monitor Health Risks for Citizens

• Consumer Product Safety Commission (CPSC)• Environmental Protection Agency (EPA)• Food and Drug Administration (FDA)• National Institute of Environmental Health

Sciences (NIEHS)• National Institute for Occupational Safety and

Health (NIOSH)• Occupational Safety and Health Administration

(OSHA)

Why Public Laws Are Necessary

• To mandate responsibility for each of the agencies.

• To create regulations and standards, based on laws, for regulating businesses and industries, in the interest of public health.

• Local and Federal laws are often necessary so the regulations can be enforced routinely.

Terms

• Code—laws easily referenced for a nation or city.

• Regulation—a rule or ordinance that must be enforced.

• Standard—a measure or criterion used to establish that which is acceptable, optimal, or ideal.

• Guideline—a suggestion used to improve a practice.

• Policy—a rule or precedent often used when judging appropriateness of an action.

Public Health Laws and the Environment

• Environmental laws have three purposes:

1. To protect people and their property

2. To protect health

3. To conserve ecology

• Laws translate into codes and statutes that guide the establishment of regulations.

Risk

• A health risk is a deviation from normal body functioning due to exposure.

– Some are unavoidable.

• Risk assessment considers the risk of a particular exposure and estimates the impact to human health.

– It is applied to populations; estimating the probability and magnitude of an event (such as in the case of an accident or violation).

Risk Assessment Methods

• Historical data

• Knowledge of comparative risks

• Epidemiological studies

• Longitudinal studies

• Laboratory studies

Four Components of Risk Analysis

1. Hazard identification

2. Exposure assessment

3. Dose-response assessment

4. Risk characterization

Hazard Identification

• Determination of risk from chemical, physical, and biological agents

• Often use blood samples to determine toxicity

– Descriptive studies

– Case studies

– Cohort studies

Exposure

• Intensity and duration of contact with a substance

• Dosimeters are used to determine exposure to radiation

• Mode of exposure:

– Inhalation

– Ingestion

– Absorption

– Injection

Dose-Response Relationship

• The absorbed dose is determined according to

– The type of substance

– Concentration or intensity of the agent

– The amount

– The route

– The duration of exposure

Calculating or Estimating Risk

Three mathematical models:

1. Tolerance distribution model

Individuals vary in their tolerance and

threshold levels.

2. Mechanistic model

Estimates cell growth from a single cell to a tumor.

3. Time-to-tumor model

Determines the time it took to develop a tumor after the individual was exposed.

Biological Effect

• Determined according to

– The substance’s chemistry or physical agent’s type

– The dose

– The persons’ susceptibility to disease (some are more vulnerable than others)

The Acceptance of Risk• Not every person exposed will have an adverse

response.• The magnitude of an adverse response depends on

the type of exposure and threshold of the individual.• Individuals have different responses to the same

dose of a hazardous agent due to age, gender, prior exposure, concurrent exposure with other substances, and level of detoxifying enzymes in the body.

• The data used to assess risk in humans is inadequate or absent.

• For risk assessment professionals, a certain amount of risk is acceptable, particularly if it is voluntary, if the risk is outweighed by convenience, or if compensation can be received for the damages.

Risk Equations

Disease rate =

Number of cases of illness in a population at risk

Number of persons in the population at risk

Risk ratio =

Rate of illness in a population with the risk factor

Rate of disease in a population without the risk factor

Acceptable Risk

• In cases where the risk is unavoidable or there are economic disadvantages, acceptable daily limits are established.

Acceptable daily intake (ADI) =

No observed adverse effect level (NOAEL) or Lowest adverse effect level (LOAEL)

Uncertainty factors (UF)

General Rule Regarding Risk

• The less that is known, the higher the uncertainty factor.

Risk Monitoring

• Ambient air quality

• Emissions levels

• Water sampling

• Food and meat inspections

• Restaurant inspections

• Animal control

• Pesticide regulation

• Radiation protection

• Epidemiological surveillance for new cases

The Use of Geographic Information Systems

• GIS is now used to monitor water supplies, emissions, pollutant levels, and land uses.

The Precautionary Principle

• It is based on ethical principles and is also called “foresight planning.”

• Precautionary measures are applied to anticipate and avoid damage.

• The idea is to protect the public health and environment

– when threats of significant harm are evident,

– even in the face of scientific uncertainty.

Environmental Impact Assessments

• Government officials and developers share the burden in determining how destruction or a change in the environment will affect the quality of life for residents.

• Can only be educated guesses.

• Costs and risks are weighed in regard to economic development as well as human health.

• There can be “trade-offs” when land disputes occur.

Models to Assess Environmental Risks

Epidemiologic Model(Epidemiologic Triad)

• Susceptible host• Infective or toxic agent• Environment that

supports growth, exposure, or circumstances increasing the possibility of harm

Exposure-Disease Model

• Exposure to the substance

• Dosage absorbed• Biological effects from

the absorbed dose• Clinical illness or

disease

Risk Management

• The management of risk integrates risk assessment– with cost-benefit analysis – for the purpose of developing strategies to regulate and control risk

• Margins of safety are also determined.• Regulations and standards are set according to

the laws (and are enforceable).• Guidelines are established (not enforced by law).• Policies are developed within an organization to

state exactly how a problem is to be managed (reviewed if problems arise or are anticipated).

Control Strategies

• Primary prevention

– Control at the source, along the path or at the level of the person

• Secondary prevention

– Early detection

– Special procedures

– Mock trainings to handle environmental disasters

• Tertiary prevention

– Occupational and environmental medicine

Risk Management Strategies

• Develop policies

• Establish priorities

• Enact statutes

• Process regulations and standards

• Surveillance

• Inspection

• Issue permits

• Conduct epidemiological evaluations

• Hold public hearings• Foster community

support• Issue administrative

orders• Implement embargoes• Issue court orders or

mandates• Charge offenders with

citations• Impose court or

administrative penalties

Possible Ways Information Can Be Acted On

• Deny there is a problem so the media will not exaggerate it.

• Suppress the information because it is too difficult to consider.

• Redefine the problem so positive effects are told to diminish the negative impact on citizens.

• State information in a way that is acceptable because nothing can be done about it.

• Amplify concerns because of stressors and other factors to make the problem bigger than it is.

Public Health Approaches

• Microbial (“germ theory” of public health)– Epidemiological model

• Behavioral• Ecological

Department of Health and Human Services

• Formerly part of the Department of Health, Education, and Welfare (HEW)

• It is the largest grant-making agency in the federal government

• The U.S. Public Health Service is a part of DHHS and is led by the Surgeon General

• The Centers for Disease Control and Prevention (CDC) is a part of DHHS

Centers for Disease Control and Prevention

• The CDC Division of Environmental Hazards and Health Effects initiated the National Environmental Public Health Tracking Program in 2002 in all 50 states to– Focus on better environmental health care– Promote legislation and enforcement– Provide public awareness

The Future Promises

• Green architecture

• Green energy and transportation

• Wilderness preservation

• Sustainable development

Green Architecture

• The design of buildings and homes that cost less to build, own, and maintain

• Energy efficient with solar or alternative types of heating/cooling

• Use recycled materials• Nonpolluting paint• Heat-efficient windows• Low-flow toilets• A reservoir for rainwater

Green Energy and Green Transportation

• New machines with alternative fuel sources, such as biomass

Wilderness Preservation

• National forests, parks, and refuges

• Preservation of wetlands

• Establishment of “green areas” or “greenways” for biking, hiking, and recreation

Sustainable Growth

• Approaches to integrate urban design, public transportation, energy conservation, waste treatment, and urban forestry

• Includes:

– Affordable housing

– Electric shuttles instead of buses

– Garden projects

– Downtown redevelopment

– Recycling centers

– Vertical farms

Successes and Failures

• We have a history of degrading our own environment

• We also have a history of providing guidelines and laws for those who continue the practice of degrading the environment and risking harm to human health

• As citizens we have a responsibility to honor those laws and monitor the activities of others

• We can make a difference by taking personal measures to preserve and improve environmental health