1. Environmental Science A Study of Interrelationships
Tenth Edition
Enger • Smith
Chapter 19
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2. Regulating Hazardous Materials
Chapter 19

3. Outline
Hazardous and Toxic Materials in Our Env.
Hazardous and Toxic - Some Definitions
Defining Hazardous Waste
Issues Involved in Setting Regulations
Environmental Problems
Health Risks Associated with Wastes
Hazardous-Waste Dumps
Hazardous-Waste Management Choices
International Trade in Hazardous Wastes

4. Hazardous and Toxic Materials in Our Environment
At sites around the world, accidental or purposeful releases of hazardous and toxic chemicals are contaminating the land, air and water.
Increasingly, governments and international agencies are attempting to control the growing problem.

5. Life Cycle of Toxic Substances

6. Hazardous and Toxic - Some Definitions
Hazardous - EPA defines hazardous materials as having one or more of the following characteristics:
Ignitability (Fire hazard)
Corrosiveness (Corrodes material)
Reactivity (Unstable)
Toxicity (May release toxins)
Some hazardous materials fall into several categories.

7. Hazardous and Toxic - Some Definitions
Terms are incorrectly used interchangeably.
Toxic - Commonly refers to a narrow group of substances that cause human injury or death.
Hazardous - Broader term; refers to all dangerous materials that create a human health, or environmental problem.

8. Hazardous and Toxic - Some Definitions
Hazardous Wastes: By-products of industrial, business, or household activities for which there is no immediate use.
Must be disposed of in an appropriate manner.
Stringent regulation pertaining to production, storage, and disposal.

9. Defining Hazardous Waste
U.S. Resource Conservation and Recovery Act (RCRA) 1976:
Yields one of the most common definitions of hazardous:

10. RCRA
Substances are considered toxic or hazardous if they:
Cause or significantly contribute to an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness; or pose a substantial present or potential hazard to human health or the environment when properly treated, stored, transported, disposed of, or otherwise managed.

11. Hazardous and Toxic - Some Definitions
Numerous Types:
Heavy metals; Organic wastes
Many Forms:
Liquid, Sludge, Ash
Improper handling and disposal can affect human health and the environment through contamination.
Immediate or long-term concerns.

12. Hazardous versus Toxic
United Nations Environment Program estimates total annual international generation of hazardous wastes between million tons.
U.S. EPA indicates U.S. generates about 40 million tons of hazardous waste annually.

13. Issues Involved in Setting Regulations
Identification of Hazardous & Toxic Materials
List often limited to current offenders and substances already linked to adverse effects.
Asbestos
DDT

14. Issues Involved in Setting Regulations
Setting Exposure Limits
Nearly all substances are toxic in sufficient quantities.
People can be exposed in three ways:
Inhalation
Consumption
Absorption

15. Setting Exposure Limits
Typically the regulatory agency will determine the level of exposure at which test animals are affected (threshold level) and then set the exposure level longer to allow for a safety margin.
Must account for species-specific thresholds.

16. Issues Involved in Setting Regulations
Acute vs. Chronic Toxicity
Effects of massive doses at once (acute toxicity) and small doses over time (chronic toxicity) differ.
Chronic much harder to detect as effects may not surface for long periods of time.
Synergism
Assessing effects of chemical mixtures.
Most toxicity studies done on a single compound.

17. Issues Involved in Setting Regulations
Persistent and Non-Persistent Pollutants
Persistent toxins remain in the environment, essentially unchanged, for long periods, and build-up leads to chronic problems.
Most are man-made.
Polychlorinated Biphenyls PCB’s

18. Persistent and Non-Persistent Pollutants
Non-Persistent toxins do not remain for a long period, are often biodegradable, and usually responsible for acute problems.
Many toxic organic materials can be destroyed by decomposer organisms.
Organophosphates
Do not accumulate in food chain.

19. Environmental Problems Caused by Hazardous Wastes
Hazardous wastes enter the environment in many ways:
Evaporation
Fugitive Emissions
Improper Disposal
Improper Labeling and Record-Keeping

20. Health Risks Associated with Hazardous Wastes
Each year, roughly 1,000 new chemicals are produced and distributed.
70,000 already in daily use.
Industrial chemical products and by-products often handled and disposed of improperly.
May pose human health hazard.
Problem of linking a particular chemical to specific diseases is compounded by lack of toxicity data.

21. Hazardous Waste Dumps: A Legacy of Abuse
Prior to RCRA in 1976, hazardous waste was essentially unregulated.
Hazardous wastes were simply buried or dumped.
Sites typically located convenient to the industry and were often in environmentally sensitive areas.
In North America alone, currently over 25,000 abandoned or uncontrolled sites.

22. Comprehensive Environmental Response, Compensation and Liability Act
CERCLA or “SUPERFUND” (1980)
Develop comprehensive program to set priority list.
Make responsible parties pay for clean-up when possible.
Set up $1.6 billion Hazardous Waste Trust Fund.
Advance scientific and technological capabilities in hazardous waste management, treatment, and disposal.

23. CERCLA
National Priority List
Under CERCLA, over 44,000 sites were evaluated, and about 11,000 were considered serious enough to warrant further investigation.
About 1,200 of those sites were placed on National Priority List.

24. CERCLA
Because any contributor to the site can be held responsible for entire clean-up costs, many companies find it cost-effective to hire lawyers and fight their inclusion into clean-up costs.
But by 2004, there were about 1,200 sites on the National Priorities list.
About 900 cleaned up.
Most of remaining sites in progress.
$27 billion in total expenditures.

25. Toxic Chemical Releases
In 1987, any industrial plant that released at least 23,000 kg of toxic pollutants into the environment was required to file a report.
Primarily manufacturing industries.
Allowed EPA to target specific industries for enforcement action.

26. Toxic Chemical Releases
About 2.8 billion kg of toxic chemicals reported released into the environment by industry in 2001.
Primary industries involved are mining, power generation, chemical, and metal manufacturing.

27. Sources of Toxic Releases

28. Hazardous Waste Management Choices
In the past, management of hazardous waste was always added on to the end of the industrial process.
In recent years, EPA and other regulatory agencies have emphasized pollution prevention and waste minimization.

29. Hazardous Waste Management Choices
EPA Pollution Prevention Hierarchy
Reduce amount of pollution at the source.
Recycle wastes whenever possible.
Treat wastes to reduce hazard and / or volume.
Dispose of wastes on land or incinerate them as last resort.

30. Pollution-Prevention Hierarchy

31. Reducing Waste at the Source
Pollution Prevention
Encourage changes that prevent hazardous wastes from being produced.
U.S. army phasing out lead bullets.
Waste Minimization
Manufacturing changes to reduce waste.
Replace hazardous solvents.
Allow water to evaporate from waste to reduce volume.

32. Recycling Wastes
Use wastes for another purpose, thus eliminating them as “waste.”
Burn waste oils and solvents as fuel.
Incorporate ash or other solid wastes into concrete or other building materials.

33. Treating Wastes
Reduce amounts of waste or modify hazardous nature.
Neutralization
Biodegradation
Air Stripping
Carbon Absorption
Precipitation

34. Disposal Methods
Currently, the two most common methods for disposing of hazardous wastes are incineration and land disposal.
Incineration (Thermal Treatment)
Burn wastes at high temperature. Can destroy % of hazardous materials
High costs and concerns about emissions have kept incineration from becoming a major method in North America.

35. Disposal Methods
Land Disposal is the primary method used when all other options have been exhausted.
Deep-Well Injection
Discharge or Liquids Into Water Sources
Placement of Liquid Wastes into Surface Holding Areas
Storage of Solid Wastes in Hazardous Waste Landfills

36. Disposal Methods
Immobilization puts waste into a solid form that is easier handle, and is less likely to enter the surrounding area.
Fixation
Solidification

37. International Trade in Hazardous Wastes
Concern of industrialized countries exporting wastes to poorer, developing countries lacking administrative and technical resources to safely dispose of the waste.
Basel Convention (1989)
Minimize generation of hazardous wastes and control and reduce transboundary movements to protect human health and the environment.

38. Hazardous-Waste Management Program Evolution
Major Stages
Identify problem and enact legislation.
Designate lead agency.
Establish rules and regulations.
Develop treatment and disposal capacity.
Create compliance and enforcement program.

39. Review
Hazardous and Toxic Materials in Our Env.
Hazardous and Toxic - Some Definitions
Defining Hazardous Waste
Issues Involved in Setting Regulations
Environmental Problems
Health Risks Associated with Wastes
Hazardous-Waste Dumps
Hazardous-Waste Management Choices
International Trade in Hazardous Wastes