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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Enger & Smith Environmental Science A Study of Interrelationships.

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Presentation on theme: "Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Enger & Smith Environmental Science A Study of Interrelationships."— Presentation transcript:

1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Enger & Smith Environmental Science A Study of Interrelationships Twelfth Edition Chapter 18 Environmental Regulations: Hazardous Substances and Wastes

2 Environmental Regulations: Hazardous Substances and Wastes

3 Outline  Hazardous and Toxic Materials in Our Environment  Hazardous and Toxic Substances—Some Definitions  Defining Hazardous Waste  Determining Regulations  Environmental Problems Caused by Hazardous Wastes  Health Risks Associated with Hazardous Wastes  Hazardous-Waste Dumps—A Legacy of Abuse  Hazardous-Waste Management Choices  International Trade in Hazardous Wastes  Hazardous-Waste Management Program Evolution

4 Hazardous and Toxic Materials in Our Environment  Our modern technological society makes use of a large number of substances that are hazardous or toxic.  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 Hazardous and Toxic Materials in Our Environment The life cycle of toxic substances

6 Hazardous and Toxic Substances— Some Definitions  Hazardous substances or hazardous materials are those that can cause harm to humans or the environment.  The EPA defines hazardous materials as having one or more of the following characteristics: Ignitability (Fire hazard) Corrosiveness (Corrodes material) Reactivity (Explosiveness) Toxicity (May release toxins)  Some hazardous materials, such as gasoline, fall into several categories.

7 Hazardous and Toxic Substances— Some Definitions  Terms are incorrectly used interchangeably. Toxic commonly refers to a narrow group of substances that cause human injury or death. Hazardous is a broader term; it refers to all dangerous materials that create a human health or environmental problem.

8 Defining Hazardous Waste  Hazardous wastes are by-products of industrial, business, or household activities for which there is no immediate use. They must be disposed of in an appropriate manner. There are stringent regulations pertaining to production, storage, and disposal.

9 Defining Hazardous Waste  U.S. Resource Conservation and Recovery Act of 1976 (RCRA): This act created the “cradle-to-grave” concept of hazardous waste management by regulating generators, transporters, and Treatment Storage and Disposal Facilities (TSDF) as well as underground storage tanks (USTs) and petroleum products. This act also defined toxic and/or hazardous waste by using the terms listed and characteristic waste.

10 Defining Hazardous Waste  Under 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 improperly treated, stored, transported, disposed of, or otherwise managed.

11 Defining Hazardous Waste  Listing is the most common method for defining hazardous waste in many countries. There are numerous types of hazardous wastes, taking many forms: –Heavy metals (mercury, cadmium, lead) –Organic wastes –Liquid, sludge, incinerator ash  Improper handling and disposal can affect human health and the environment through contamination. Effects of exposure can be immediate or long-term concerns.

12 Defining Hazardous Waste  The United Nations Environment Programme estimates total annual international generation of hazardous wastes between million metric tons.  U.S. EPA indicates the U.S. generates about 36 million metric tons of hazardous waste annually.

13 Determining Regulations  The U.S. has attempted to deal with hazardous substances and wastes by using “command and control” methods of governmental regulations, beginning with the development of the EPA and OSHA in  Many states, as well as some countries, have tried to mirror these regulations by codifying their own statues specific to their needs.  State regulations can be equal or more stringent than federal regulations.

14 Determining Regulations  Most lists of toxic and hazardous substances include only known offenders, since many potentially harmful chemical compounds have yet to be tested adequately.  Governments and regulatory agencies must attempt to determine how to fairly enforce measures to successfully control exposures to humans and the environment. Sometimes the reason for the regulation is lost in the effort to enforce it.

15 Determining Regulations  Setting Exposure Limits Nearly all substances are toxic in sufficiently high doses. People can be exposed in three ways: –Inhalation –Consumption –Absorption

16 Determining Regulations  Typically the regulatory agency will determine the level of exposure at which none of the test animals is affected (threshold level) and then set the exposure level lower to allow for a safety margin.  Even when concentrations are set, they may vary considerably from country to country.

17 Determining Regulations  Acute vs. Chronic Toxicity Effects of massive doses at once (acute toxicity) and small doses over time (chronic toxicity) differ. –Chronic toxicity is much harder to detect as effects may not surface for long periods of time.  Synergism Assessing the effects of chemical mixtures is also problematic. –Most toxicity studies focus on a single compound. –Synergism is the potential of relatively harmless individual compounds to become highly toxic and do great damage when combined.

18 Determining Regulations  Persistent pollutants remain in the environment, essentially unchanged, for long periods. Most are human-made. Synthetic chemicals are part of our food, transportation, clothing, building materials, home appliances, medicine, recreational equipment, and many other items. –DDT is a persistent pollutant. –Polychlorinated biphenyls (PCBs) are also persistent.

19 Determining Regulations  Nonpersistent pollutants do not remain for a long period and are often biodegradable.  Many toxic organic materials can be destroyed by decomposer organisms. Organophosphates decompose in several weeks. They do not accumulate in food chain.

20 Environmental Problems Caused by Hazardous Wastes  Hazardous wastes enter the environment in many ways: Evaporation Fugitive emissions Improper disposal Improper labeling and record-keeping

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

22 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 were typically located convenient to the industry and were often in environmentally sensitive areas. –In North America alone, there are over 25,000 abandoned or uncontrolled sites.

23 Hazardous-Waste Dumps— A Legacy of Abuse  In the U.S., the federal government has become the principal participant in the cleanup of hazardous-waste sites.  The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was enacted in  This program deals with financing the cleanup of large, uncontrolled hazardous-waste sites and has become known as Superfund.

24 Hazardous-Waste Dumps— A Legacy of Abuse  CERCLA had several key objectives: Develop a comprehensive program to set priorities for cleaning up the worst existing sites. Make responsible parties pay for cleanup when possible. Set up a $1.6 billion Hazardous Waste Trust Fund (Superfund) to support the identification and cleanup of abandoned hazardous-waste sites. Advance scientific and technological capabilities in hazardous waste management, treatment, and disposal.

25 Hazardous-Waste Dumps— A Legacy of Abuse  A National Priorities List was drawn up for Superfund action.  Under CERCLA, over 44,000 sites were evaluated, and about 11,000 were considered serious enough to warrant further investigation. The number of sites on the National Priorities List fluctuates as new sites are added and old sites are deleted as they are cleaned up. Currently there are about 1,200 sites on the National Priorities List.

26 Hazardous-Waste Dumps— A Legacy of Abuse  Because any contributor to the site could be held responsible for entire cleanup costs, regardless of the degree to which they contributed to the problem, many companies found it cost-effective to hire lawyers to fight their inclusion in cleanup efforts.  About 900 sites have been cleaned up.  Most of the remaining sites are in the process of being cleaned up or are under study about the best way to proceed.  $27 billion in total expenditures

27 Hazardous-Waste Dumps— A Legacy of Abuse  In 1987, any industrial plant that released at least 23,000 kg of toxic pollutants into the environment was required to file a report.  These were primarily manufacturing industries.  The information collected allowed EPA to target specific industries for enforcement action.

28 Hazardous-Waste Dumps— A Legacy of Abuse  About 2.1 billion kg of toxic chemicals were reported released into the environment by industry in Primary industries involved are mining, power generation, chemical, and metal manufacturing.

29 Hazardous-Waste Dumps— A Legacy of Abuse Sources of toxic releases (2003)

30 Hazardous-Waste Management Choices  The amount of hazardous wastes released to the environment is about 23% of the total amount of hazardous waste produced.  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.

31 Hazardous-Waste Management Choices  The EPA promotes a pollution prevention hierarchy (P2): Reduce the 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.

32 Hazardous-Waste Management Choices Pollution-prevention hierarchy

33 Hazardous-Waste Management Choices  Pollution prevention (P2) encourages changes that prevent hazardous wastes from being produced.  Many of the actions are simple and cost little. U.S. army phasing out lead bullets.  Waste minimization involves manufacturing changes that can reduce waste. –Replace hazardous solvents.

34 Hazardous-Waste Management Choices  Recycling wastes involves using 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.

35 Hazardous-Waste Management Choices  Wastes can be treated in a way that their amount is reduced or their hazardous nature is modified. Neutralization Biodegradation Air stripping Carbon absorption Precipitation

36 Hazardous-Waste Management Choices  Currently, the two most common methods for disposing of hazardous wastes are incineration and land disposal. Incineration (thermal treatment) burns wastes at high temperatures. A well-designed, well-run incinerator can destroy % of hazardous materials. High costs and concerns about emissions have kept incineration from becoming a major method in North America.

37 Hazardous-Waste Management Choices  Land disposal is the primary method used when all other options have been exhausted. Deep-well injection Discharge of treated or untreated liquids into water sources Placement of liquid wastes into surface holding areas Storage of solid wastes in hazardous waste landfills

38 Hazardous-Waste Management Choices  Immobilizing a waste puts it into a solid form that is easier to handle, and is less likely to enter the surrounding area. Fixation Solidification

39 International Trade in Hazardous Wastes  There is particular concern about rich, industrialized countries exporting wastes to poorer, developing countries lacking administrative and technological resources to safely dispose of the waste.  Objectives of the Basel Convention (1989) are to minimize generation of hazardous wastes and control and reduce transboundary movements to protect human health and the environment.

40 Hazardous-Waste Management Program Evolution  The goal of a hazardous-waste management program is to change the behavior of those who generate hazardous wastes so that they routinely store, transport, treat, and dispose of them in an environmentally safe manner.  Major stages: Identify problem and enact legislation. Designate lead agency. Establish rules and regulations. Develop treatment and disposal capacity. Create a compliance and enforcement program.

41 Summary  Public awareness of the problems of hazardous substances and hazardous wastes is relatively recent.  Industrialized countries of Europe and North America began major regulation of hazardous materials within the past 30 years.  Many developing countries exercise little or no control over such substances.  There is no agreement as to what constitutes a hazardous waste.

42 Summary  Little is known about the amounts of hazardous waste generated throughout the world.  We have a limited understanding of the health effects of most hazardous wastes.  Large numbers of potentially hazardous chemicals are being developed faster than their health risks can be evaluated.  Industries need to be encouraged to generate less hazardous waste in their manufacturing processes.

43 Summary  Although toxic wastes cannot entirely be eliminated, technologies are available for minimizing, recycling, and treating wastes.  The final outcome rests with governmental and agency policy makers, as well as with an educated public.


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