❤️‍🩹Intro to Public Health Unit 6 – Environmental Health & Safety in Public Health

Key Concepts in Environmental Health

• Environmental health focuses on the relationships between human health and the natural and built environments
• Encompasses the assessment and control of environmental factors that can potentially affect health
• Aims to prevent disease and create health-supportive environments
• Considers both the direct pathological effects of chemicals, radiation, and some biological agents, as well as the effects on health of the broad physical, psychological, social, and aesthetic environment
• Addresses all the physical, chemical, and biological factors external to a person, and all the related factors impacting behaviors
• Incorporates the assessment and control of those environmental factors that can potentially affect health
• Includes both the direct pathological effects of chemicals, radiation, and some biological agents, as well as the effects (often indirect) on health and well-being of the broad physical, psychological, social, and cultural environment

Environmental Hazards and Their Sources

• Environmental hazards are agents or factors in the environment that have the potential to cause harm or adverse health effects
• Can be classified into physical, chemical, biological, and psychosocial hazards
  • Physical hazards include noise, vibration, radiation, extreme temperatures, and ergonomic hazards
  • Chemical hazards encompass toxic substances, pollutants, metals, pesticides, and endocrine disruptors
  • Biological hazards comprise pathogenic microorganisms, allergens, and toxins produced by living organisms
  • Psychosocial hazards relate to stress, violence, and other factors that impact mental health
• Sources of environmental hazards can be natural or anthropogenic (human-made)
• Natural sources include geological events (earthquakes, volcanic eruptions), weather-related phenomena (hurricanes, floods), and biological agents (mold, pollen)
• Anthropogenic sources encompass industrial activities, transportation, agricultural practices, waste disposal, and the built environment
• Exposure to environmental hazards can occur through various routes, such as inhalation, ingestion, dermal contact, or injection

Health Effects of Environmental Exposures

• Environmental exposures can lead to a wide range of health effects, depending on the type of hazard, the level and duration of exposure, and individual susceptibility
• Acute effects occur immediately or shortly after exposure and are often reversible (eye irritation, nausea, headache)
• Chronic effects develop over a longer period and may be irreversible (cancer, respiratory diseases, neurological disorders)
• Some environmental exposures can have specific effects on vulnerable populations, such as children, pregnant women, the elderly, and individuals with pre-existing health conditions
• Exposure to air pollutants can cause respiratory and cardiovascular diseases, aggravate asthma, and increase the risk of lung cancer
• Water contamination can lead to waterborne illnesses (cholera, typhoid fever), developmental issues (lead poisoning), and chronic diseases (arsenic exposure)
• Soil pollution can result in the uptake of contaminants by plants, leading to food chain contamination and potential health risks
• Noise pollution can cause hearing loss, sleep disturbance, and cardiovascular effects

Risk Assessment and Management

• Risk assessment is the process of identifying, evaluating, and quantifying the potential adverse health effects associated with exposure to environmental hazards
• Involves four main steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization
  • Hazard identification determines whether exposure to an agent can cause an increase in the incidence of a health condition
  • Dose-response assessment examines the relationship between the amount of exposure (dose) and the severity or frequency of the health effect
  • Exposure assessment estimates the intensity, frequency, and duration of human exposures to an environmental agent
  • Risk characterization combines the information from the previous steps to estimate the probability and severity of potential adverse health effects in a given population
• Risk management is the process of evaluating, selecting, and implementing actions to reduce or eliminate identified risks
• Involves considering technological feasibility, economic costs, social acceptance, and political considerations when making decisions
• Utilizes a variety of strategies, such as setting exposure limits, implementing engineering controls, promoting safe work practices, and providing personal protective equipment

Environmental Health Policy and Regulations

• Environmental health policies and regulations aim to protect human health and the environment by setting standards, guidelines, and laws that control or prevent exposure to environmental hazards
• Policies can be developed at the local, national, or international level and may involve various stakeholders (government agencies, industry, non-governmental organizations, and the public)
• Examples of environmental health regulations include the Clean Air Act, the Safe Drinking Water Act, and the Toxic Substances Control Act in the United States
• The World Health Organization (WHO) sets international guidelines for air and water quality, as well as for the management of hazardous substances
• The precautionary principle is often applied in environmental health policy, which states that when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically
• Environmental impact assessments (EIAs) are used to identify and evaluate the potential environmental and health consequences of proposed projects or policies before they are implemented
• Public participation and stakeholder engagement are essential components of environmental health policy development to ensure transparency, accountability, and the incorporation of diverse perspectives

Monitoring and Surveillance Techniques

• Environmental monitoring involves the systematic collection, analysis, and interpretation of data on environmental factors to assess exposure levels and potential health risks
• Can include monitoring of air quality (particulate matter, ozone, nitrogen oxides), water quality (microbiological and chemical contaminants), and soil quality (heavy metals, pesticides)
• Utilizes various sampling techniques (grab sampling, continuous monitoring) and analytical methods (chromatography, spectroscopy, microscopy)
• Biomonitoring assesses human exposure to environmental contaminants by measuring the contaminants or their metabolites in biological specimens (blood, urine, hair)
• Surveillance systems track and analyze environmental health data over time to identify trends, detect outbreaks, and evaluate the effectiveness of interventions
• Geographic information systems (GIS) are used to map and analyze spatial patterns of environmental hazards and health outcomes
• Remote sensing techniques, such as satellite imagery and aerial photography, can provide data on land use, vegetation cover, and other environmental variables

Interventions and Prevention Strategies

• Environmental health interventions aim to reduce or eliminate exposure to environmental hazards and prevent adverse health effects
• Primary prevention focuses on preventing exposure before it occurs through measures such as source reduction, substitution of safer alternatives, and engineering controls (ventilation systems, noise barriers)
• Secondary prevention aims to detect and control exposure early to minimize health impacts, using strategies like regular environmental monitoring, health screenings, and education programs
• Tertiary prevention seeks to manage and treat the health effects of environmental exposures and prevent further complications (medical treatment, rehabilitation)
• Risk communication is an essential component of prevention, involving the effective exchange of information about environmental risks and protective measures between experts, decision-makers, and the public
• Community-based participatory research (CBPR) engages community members as equal partners in the research process to identify environmental health concerns, develop interventions, and promote environmental justice
• Health impact assessments (HIAs) evaluate the potential health effects of a policy, program, or project before it is implemented, allowing for the integration of health considerations into decision-making processes

Global Environmental Health Challenges

• Climate change poses significant risks to human health, including heat-related illnesses, respiratory diseases, vector-borne diseases, and mental health impacts
• Air pollution is a major global health threat, contributing to millions of premature deaths annually and increasing the burden of respiratory and cardiovascular diseases
• Water scarcity and contamination affect billions of people worldwide, leading to waterborne diseases, malnutrition, and economic impacts
• Exposure to hazardous chemicals, such as pesticides, heavy metals, and persistent organic pollutants (POPs), can cause acute poisoning, chronic diseases, and developmental disorders
• Electronic waste (e-waste) poses growing environmental and health challenges, as the improper disposal of electronic devices releases toxic substances into the environment
• Urbanization and the built environment can influence health through factors such as air quality, access to green spaces, and the promotion of active transportation
• Food safety and security are impacted by environmental factors, such as soil degradation, water pollution, and climate change, affecting the availability and quality of food
• Environmental injustice refers to the disproportionate exposure of disadvantaged communities to environmental hazards and the unequal distribution of environmental benefits, requiring attention to social determinants of health and equity in environmental health policies and interventions