Lect 2 History and scope - ENSC

Lecture Overview

  • Course Title: ENSC 201: Environmental Toxicology and Chemical Risks

  • Instructor: Louise M. Winn, Ph.D. (Email: winnl@queensu.ca)

Scope of Environmental Toxicology

Human vs. Ecosystem Protection

  • Classical Toxicology:

    • Focuses on protection of humans (1 species and surrogates)

    • Investigation limited to specific organisms (e.g., mice, rats)

  • Environmental Toxicology:

    • Aims to protect diverse species (about 35 million) and ecosystem structure and function

Experimental Approaches

  • Classical Toxicology:

    • Utilizes limited experimental options focused on human surrogates

  • Environmental Toxicology:

    • Can conduct experiments on organisms, model systems, and entire ecosystems

Nature of Concern

  • Classical Toxicology:

    • Treats the death of a single individual (e.g., human) as a tragedy

  • Environmental Toxicology:

    • May not always protect the most valued species; manages effects at population or ecosystem levels

Exposure Assessment

  • Classical Toxicology:

    • Measures chemical exposure directly via known routes and individual control

  • Environmental Toxicology:

    • Dose is often estimated indirectly through environmental concentrations (air, water, sediment)

Methodological Standards

  • Classical Toxicology:

    • Well-developed and standardized methods for exposure, toxicity, and risk assessment

  • Environmental Toxicology:

    • Methods are relatively new and must be adapted for each new species or ecosystem

Historical Context of Environmental Toxicology

Early Concerns

  • Historical environmental concerns trace back to Roman times.

  • Examples of early industrial pollution include:

    • 1600s: Air and water concerns in England

    • 1870s: Link between arsenic as a pesticide and wildlife deaths

    • 1924: Impact of trace metals from acid mine drainage on fish.

Industrial Timeline

  • 1750-1830: Emergence of coal tar and chemical factories

  • 1830-1890: Industrial revolution, rising pollution, and conservation awareness

  • 1890-1920: Growth of environmental reform with the formation of organizations like the Sierra Club

  • 1920-1940: Introduction of leaded gasoline, early pollution surveys, and the coining of "greenhouse effect"

  • 1940-1960: Issues from WWII, the rise of global warming awareness, and air pollution control initiatives

  • 1960-1970: Advancements due to "Silent Spring" and the establishment of environmental movements

  • 1970-1980: Formation of the EPA and addressing toxic chemicals

  • 1980-2000: Major environmental disasters raised awareness of widespread chemical concerns

  • 2000-present: Continues issues with climate change and toxic dumping in developing nations

Key Environmental Incidents (2010s)

  • 2010: Deepwater Horizon oil spill

  • 2011: Fukushima nuclear disaster

  • 2015: Flint, Michigan water crisis highlighting lead contamination issues

Case Study: The "Radium Girls"

  • Overview: Female factory workers painted watch dials with radium in the 1920s leading to serious health issues.

  • Events:

    • Initial suspicion of deaths

    • Consumer League investigation initiated

    • Legal actions led by victims like Grace Fryer

    • Highlighted radium's health impacts, including noted cases of severe health decline among workers and chemists

Impact of Pollution on Human Health

  • Great Smog of London (Dec. 1952):

    • A severe air quality event due to cold weather and coal burning

    • Estimated 4000 deaths and 100,000 illnesses

    • Resulted in legislative action leading to the Clean Air Act

The Modern Environmental Movement

Origin and Development

  • Starting Point: Marked by Rachel Carson’s 1962 publication of Silent Spring, which raised awareness about pesticides like DDT.

  • Increased public, scientific, and legislative awareness of chemical substances' environmental effects.

Notable Environmental Organizations

  • Foundations and Activism:

    • Sierra Club (1892)

    • World Wildlife Fund (WWF Canada, 1967)

    • Greenpeace (1971)

    • EarthFirst! (1991)

Regulatory Environment

  • Growth in mandatory testing and regulations from the 1960s to 1980s, largely influenced by rising pollution levels and industrial growth.

Environmental Technology Advances (1960s-1980s)

  • Technological Developments:

    • Gas chromatography advancements, improved pollutant monitoring

    • Mechanisms for understanding and regulating point source pollution emerged

    • Citizen science gained popularity through local initiatives.

Guiding Principles of Environment Canada

Canadian Environmental Protection Act (CEPA, 1999)

  • Core Principles Include:

    • Sustainable development and pollution prevention

    • Virtual elimination of hazardous substances

    • Ecosystem approach and precautionary principle

    • Emphasis on science-based decision-making

Implementation Goals

  • Focus on modernizing CEPA, ensuring every Canadian's right to a healthy environment, with regulatory safeguarding.