Environmental Health: Water, E-waste, and Risk Assessment

Week 8: Environmental Health (cont) - Objectives

• Environmental health involves studying pollutants, waste management, risk assessment, communication, and environmental justice
• February 24th focuses on water, e-waste, and solid waste pollutants, and risk assessment
• February 26th continues with risk assessment, including does-response assessment and risk determination, along with risk communication and environmental justice

Water Pollution

• Safe water access is fundamental for a healthy environment
• Roughly 80% of industrial and municipal wastewater globally discharges into the environment without any prior treatment
• Untreated wastewater leads to adverse effects on human health, as well as ecosystems
• The proportion of wastewater discharged without treatment is higher in least developed countries due to a lack of sanitation and wastewater treatment facilities

Sources and Impacts of Water Pollution

• Water pollution primarily stems from industrialization, agricultural practices, natural occurrences, and inadequate water and sewage infrastructure
• Natural factors contributing to water pollution include sedimentation, eutrophication, and thermal pollution which can indirectly affect human health
• Sedimentation involves the buildup of particles in water
• Eutrophication refers to the loading of nutrients into an aquatic ecosystem
• Thermal pollution consists of changes in water temperature caused by industrial processes
• Climate change impacts water pollution by increasing temperatures and altering flow regimes
• Developmental delays and learning difficulties can result from water pollution in children
• Prenatal exposure to water pollution can cause pre-term birth and low birthrate in babies
• Spread of communicable and gastrointestinal diseases are made possible primarily due to unsafe and contaminated water availability

Solid Waste and Microplastics

• Solid waste poses considerable risks to human health and is unsightly
• Food waste, packaging, and other solid wastes like asbestos comprise solid waste
• Exposure to toxins from solid waste occurs mainly through ingestion after toxins leach into the soil or water supply
• Microplastics are minute plastic particles and fibers, with toxic chemicals
• Plastics play an important role in society revolutionizing food storage, vehicle manufacture, and surgery
• Between 2010 and 2020, global plastic production rose from 270 to almost 370 million metric tons
• Larger plastic items on land and in water threaten wildlife
• Ingestion of microplastics and exposure to toxic chemicals in plastics pose threat to human health

Impact of Microplastics and EDCs

• Microplastics contaminate marine environments, affect aquatic life, and enter the food chain
• Inhalation of nanoplastics may result in lung disease
• Microplastics contain stabilizers, flame retardants, pigments, plasticizers, and carcinogens such as PET and PVC
• Bisphenol A (BPA), found in food and beverage can linings, is an additive in plastics of concern due to leaching
• BPA is an endocrine disruptor (EDC), with a group of chemicals mimicking hormones in the human endocrine system
• EDCs disrupt the endocrine system by mimicking or interfering with hormones and can affect metabolic processes
• Exposure to EDCs can occur through ingestion, inhalation, skin contact, and transplacentally or via breast milk
• EDCs increase cancer incidence in both sexes
• Mounting evidence suggests relationships between EDCs and fertility problems in males, breast cancer in females, as well as testicular cancer in males
• BPA is an EDC with potential endocrine-disrupting effects, but its threat is controversial
• The CDC has reported prevalent BPA exposure throughout the US, and humans have potential for exposure to BPA by ingestion from plastic bottles and food and beverage can coatings

E-Waste

• E-waste includes high-tech computer products and other discarded electrical equipment like refrigerators and televisions
• Electronics contain a complex mix of hundreds of substances, including mercury, lead, arsenic, cadmium, chromium, PCBs, and PBDEs, all of which present exposure risks
• E-waste accounts for a large proportion of heavy metals in landfills and is a fraction of solid waste globally
• Global volumes of e-waste are expected to rise due to increased electronic goods use in low-income countries
• Few countries have systems for labeling, handling, or disposing of e-waste properly
• Without recycling, precious elements such as gallium, indium, and tantalum, as include conflict elements like gold and tungsten, may be depleted within a century
• The reusing of these devices sends the task of disposing of them to other countries, raising environmental justice questions
• Unprotected exposure to e-waste is dangerous, with children being particularly vulnerable to its components

Risk Assessment Process

• Risk assessment assesses health risks from contaminants
• Risk management and communication involves taking actions to reduce risk and communicating with the public about environmental hazards
• Four major components in risk assessment include hazard identification, exposure assessment and monitoring, does-response assessment and risk determination

Hazard Identification

• Hazard identification clarifies the adverse health outcomes an environmental agent could have
• Types of hazards, symptoms, locations, affected populations, adverse effects, organs affected, and severity of harm are all hazard identification criteria

Exposure Assessment and the Study of Environmental Health

• Exposure assessments determine acceptable risk levels
• Considerations include how much money is available to protect health, and certainty needed on substance impacts prior to regulation
• Data collection leads to the public health field of risk analysis
• Most governments regulate substances to which populations are exposed
• Legislation often dictates safe disposal of materials and acceptable contamination levels in water/food
• Rational policy relies on understanding costs and benefits
• Health effects are a result of exposure, genetics, and behavior
• Objective techniques help address connections between exposure and disease
• Epidemiology studies distribution, patterns, and factors of health and disease conditions

Epidemiological Approaches and Exposure Components

• Positivist, quantitative epidemiology gathers information
• A positivist view relies on knowing based on observation and scientific experiments
• Statistics offer objective rules for quantitative data
• Exposure is any contact between individual and substance through a five-component pathway:
  • Contamination’s source
  • Environmental exposure media via water, soil, food, and air
  • Exposure point
  • Receptor population
  • Route of exposure via inhalation, ingestion, or dermal contact

Clinical Trials

• Rigorous experimental studies, known as "clinical trials", make up just one of the several testing methods
• Study participants are randomly assigned to two groups
• One group is administered the treatment or exposure for a certain period
• The other group, the control, experiences identical conditions except for treatment/exposure
• Outcomes of both groups are carefully measured and compared post-study
• A significant difference in health outcomes suggests the studied exposure has an effect

Limitations of Clinical Trials and Alternatives

• Ethical concerns hinder human exposure to potentially harmful agents in studies
• Clinical trials predominantly test drugs and therapies for health improvement
• To avoid harming living subjects, observational studies take advantage of people's exposure to toxins in their everyday lives rather than deliberately exposing them
• Observational studies assess proportions of exposed individuals within populations for hypothesized health threats
• Ethical considerations guide observational studies where researchers observe but do not alter participant behavior
• Observational investigations build the evidence for cause-effect, which can then be followed-up with additional research
• Methods exist for observing relationships via ecological, cohort, case-control, and cross-sectional studies

Study Designs: Cohort, Case-Control, and Cross-Sectional

• Cohort studies compare a group with a risk factor to a group without it
• Longitudinal cohort studies may require decades to link exposure to a health issue
• Medical records can assess changes to avoid long study timelines
• Running a cohort study involves significant spending and planning
• Case-control studies assign participants to groups based on disease cases and compare their exposure histories
• Smaller sample sizes and reduced follow-up make case-control studies cheaper than cohort studies
• Cross-sectional studies examine disease prevalence alongside individual level exposures at a specific time
• Populations for cross-sectional studies are chosen regardless of exposure or disease status
• Cross-sectional studies only support associations, not definitive cause-and-effect
• Current disease status related to current exposures without indicating the exposure that preceded the disease
• Cross-sectional studies are a low-cost method to evaluate health at the mass level

Ecological Studies and Confounding Factors

• Ecological studies uses aggregate data from geographic areas that usually have individual population
• These studies correlate health effects with district-level population data
• Ecological studies are cheap and utilize the existing data for secondary analysis
• Ecological fallacy involves assuming findings at an aggregate level apply at the individual level
• Confounding happens when a non-examined factor associates with the exposure and health result
• Confounding means may challenge outcomes through competing exposures of interest
• Factors are controlled using matching, restriction, statistical modelling, and randomization

Dose-Response Assessment and Key Concepts

• Dose-response relationship establishes likelihood and severity of adverse health responses according to exposure to an agent
• Dose-response applies to exposure concentration, calling it “concentration-response”
• Exposure-response term encompasses dose/concentration-response and specific conditions
• Measuring response increases as dose increases
• Response or adverse effects range among pollutants, persons, and routes of exposure
• Dose-response relies on agent, response type (tumor type, death), and experimental subject
• Adverse effect is how every type of toxicity and response occurs
• Mode of action entails a pattern of key events that start with an agent interaction, proceed during cell operations, then anatomy, and end with the result, like cancer
• Exposure data is used to see if adverse effects happen or that a measurable effect is found
• Daily intake calculates safe exposure when LOAEL or NOAEL are estimated

Threshold Estimates and Reference Values

• Threshold data helps determine reference dose or concentration
• RFD is estimated from daily human exposure likely without adverse effects, accounting for sensitivity, and is measured in mg/kg/day
• RFC assesses inhalation risks as micrograms by cubic meter of air
• "Threshold Compared to None-threshold Dose-Response Models"
• The amount of the response will have a threshold

Risk Determination Factors

• In risk determination, account for potential substance harm, the actual amount of exposure and the related response, the measure of uncertainty

Risk Communication and Form Types

• Risk communication encompasses messages and processes to people such as parents, children, representatives, regulators, scientists, farmers, industrialists, factory workers, and writers
• Target audience motivates for action with communication
• The risk communication aims to achieve objectives through
  • Care
  • Consensus
  • Crisis
• Risk is divided to categories according to safety, the environment and health issues

Communication Types: Care, Consensus, and Crisis

• Care communication conveys well-established, scientifically-accepted risks and ways to manage
• Agencies/units or governing authorities are often in charge since betterment of human lives is often the motivator
• Health and industrial healthcare make up two subsets
• Regular industrial hygiene reporting and personnel notifications make up for risk communication
• Consensus communication informs groups to establish managing risks
• The consensus aims to provide stakeholder participation in management in consensus building
• Crisis risk indicates extreme life-or-death concerns
• Communication includes prior assessment or the process and audience amount involved

Communicating Risk Effectively

• Start by learning the hazard with risk to physical health and stability
• An agency manages the hazard risk
• UOttawa keeps learning spaces secure and safe for its students
• Probabilistic risk assessment finds
  • Who is at risk with what ecosystem
  • Rate at harming
  • How to harm
• Involve a shareholder to communicate on risks with action that is required

Communication Strategies and Influences

• The stakeholder determines whether to manage risks with communications aiming to
• Evaluate a stakeholder’s perception of risk, how being managed, and process being reached
• Refrain persuasive techniques but negotiations with the agreed terms
• Weigh on all interests of the participants
• Aid come on an unanimous terms where everyone can agree on a resultions
• Take into account all feelings of shareholders in order for everyone to follow suit
• Assess and adjust to what communication with an issue may work and what may be ineffective
• Providing accurate details regarding the impact on an individual to make them want to be part of the community and promote a secure space to have an open conversation

Principles of Effective Risk Communication, Process, and Purpose

• Organizations should communicate trust to their audience
• Risk communication seeks to involve audience participation
• Principles help with planning and running communication
• Effectively state reason to speak with possible limits
• Set functions for audiences to know what is appropriate
• Disregarding concepts can encourage antagonism
• Analyze the individuals hearing or reading messages

Message and Perception

• Tailor messages to the people
• The communication should start early but with all the details
• Assessments should be a main piece rather than be an afterthought
• Real risks stem the process by which the decisions and information is analyzed

Presentation and Uncertainty

• Information requires more than one method
• Streamline communication without removing data
• Stay transparent rather than biased
• Use respect
• Show the information so all groups fully comprehend
• Be frank on confusion in what comes
• Examine information and communicate on care, deal with uncertainty, and create a general message to all

Comparing risks

• Present information correctly without changing the message
• Risks have to be the most acceptable for others

Environmental Justice

• The distribution of environmental toxin exposure is not equitable
• Disparities can be assessed to create equity through asking
• Which people face a disadvantage environment
• Is environmental help available based policies
• Should a different race and background change how environmental is given

10th February: Introduction to Environmental Health: Mercury Poisoning in Grassy Narrows, ON

• 1960s: A paper mill plant released about 10 tonnes of mercury into the river
• 1970: High mercury levels confirmed in Dryden Chemical plant downstream in fishes and water
• From 1978 to 1994: Infant cord tested shows report high mercury
• 1997 Canada issued a safe water advisory for the people there
• Recent studies show that 90 percent of Members of Grassy Narrow is suffering with mercury, along with current emissions that exacerbated to the amount of the river today

Environmental Health Today

• The question was for mercury level impact of water to affect how a new area of water, The Narrows
• An impact on environmental stability is in an uneven population and environment on the marginalized people

Environmental Health Hazards

• The complete of diseases and things happening effects the area that a person live and their well-being
• Not distributed in space that the health hazards is related to environments and human
• Environmental disparities with what happen to those effects in a area
• From any pollution: water, land, air, or ingestion
• The topic is to determine to prevent these environmental effects that adults in Canada is at risk for through group discussion

Concepts of Environmental Inequity and Historical Perspectives

• Inequalities are rooted in justice that may be a big problem in a society
• Geographic inequity is the result in what are race and social can cause that result in inequity that is related what they learn and function.
• How opportunities lack to influence on people
• Past problems could set precedent for future changes due to The First Environmental Crisis, The Second Environmental Crisis, and the Third Environmental Crisis

Environmental Exposures: Naturally-Occurring Geogens and Mitigation

• Changing of the planet that lead to death or diseases.
• Agents of disease are nonliving.
• Actions can determine the risk people take, also where a person is.
• Naturally they are dangerous.
• Heavy Metal and Toxic chemical effects the climate change that hurt many people .

Arsenic and Water

• Toxic exposure through air cause swelling, throat issues, irritation, ingesting would lead to other sickness, and skin would feel off
• People globally had consumed Arsenic through unclean water ways that had 140 over thousands people.
• The result of drinking Arsenic was a lot different. There’s was two instances
• Case Study 1 and Case Study 2

Arsenic Poisoning in Canada • It was found for being a very toxic place that had 2023 high cases of arsenic • Private tester to remove for the harmful province

Air Pollution, Its Impacts, and Control Measures

• Air pollution is a cause with environmental issue and will make heart and lung damage • Prevent pollution by not having to consume air in places for lung issues to not affect Major health issue can affect people and plants and animals To save water to have it tested and labeled if good to consume. Is harmful with different degrees how each action effects Arsenic may cause side effect like lung damaged an heart attack To clean or leave when the place is to dirty to live