ENV100: Hazardous Waste and the Environment Comprehensive Notes
Section 1: General Introduction
- Subject: ENV100 - Hazardous Waste and the Environment
- Instructor: Damian Maddalena, University of Toronto Mississauga
- Semesters: Fall-Winter 2024-2025
Section 2: Hazardous Waste
Key Topics:
- Definition of hazardous waste
- Role of households in hazardous waste generation and management
- Emerging types of hazardous waste (e-waste, medical waste)
- Hazardous waste disposal methods
- Contaminated sites and brownfields
Definition and Types of Hazardous Waste:
- Hazardous Waste: A solid or liquid waste that is toxic, chemically reactive, infectious, flammable, corrosive, or radioactive.
- Impacts: Can threaten human health and the environment when not managed properly.
- Characteristics:
- Ignitability
- Reactivity
- Corrosivity
- Toxicity
- Radioactivity
- Infectivity
- Phytotoxicity
- Mutagenicity
- Cytotoxicity
- Teratogenicity
Historical Context of Hazardous Waste Management:
- Earlier practices involved uncontrolled disposal of hazardous waste with limited regulation.
- Events prompting regulation:
- Minamata Disaster (1958): Methyl mercury contamination led to severe health impacts.
- Bhopal Disaster (1984): Gas leak resulted in thousands of deaths and injuries.
- Koko Incident (1988): Transport of hazardous waste from Italy to Nigeria highlighted the need for better management.
Household Hazardous Waste (HHW):
- Examples: Paints, garden pesticides, pharmaceuticals, batteries, electronics.
- Impact: HHW is a significant source of unregulated hazardous waste, with cities attempting to manage through designated sites and collection days.
- Statistics: Canadians improperly dispose of 27,000 tonnes of HHW annually.
E-Waste:
- Definition: Discarded electronics that are no longer functional.
- Issues: Often landfilled or incinerated without recycling; contains hazardous components that can cause pollution.
- Global Context: Significant illegal e-waste exports from developed to developing countries without proper recycling.
Section 3: Environmental Health and Hazards
Key Topics:
- Case studies in environmental health
- Types of environmental hazards
- Risk vs. hazard in the context of health
Environmental Health Overview:
- Definition: Branch of public health focused on natural and built environments affecting health.
- Connection to ecosystems: Concern for healthy ecosystems as integrally linked to human health.
Environmental Hazards:
- Types:
- Physical Hazards: Natural disasters (earthquakes, floods).
- Cultural Hazards: Lifestyle choices affecting health (diet, smoking).
- Biological Hazards: Pathogens and invasive species.
- Chemical Hazards: Toxic substances from industrial and household chemicals.
Important Case Studies:
- Flint Water Crisis: Lead contamination from water source change exposed thousands of children to health risks, leading to long-term legal and health consequences.
- Cancer Clusters: Observed increase in cancers in specific communities connected to environmental contaminants.
Section 4: Basics of Environmental Toxicology
Definition and Role of Toxicology:
- Toxicology: The study of harmful substances or toxins; emphasizes the need for scientific knowledge for safety assessments.
- Toxicity Factors: Depends on chemical type, dose, route of exposure, and context (i.e., individual susceptibility).
Toxicity Pathways:
- Various routes of exposure include oral, respiratory, and transdermal pathways.
- Different exposure types can influence health outcomes (acute vs. chronic).
Key Points:
- Anything can be toxic depending on dose and exposure conditions.
- Modern Techniques: Advanced technologies are critical in analyzing and managing toxic substances at low concentrations.
Take-Home Messages:
- Hazardous waste management is crucial for public and environmental health.
- Emerging concerns in waste management require updated regulations and public awareness.
- The relationship between environment and health is complex and necessitates ongoing research and policy development.