Environmental Toxicology Introduction and History.

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Environmental Toxicology Introduction and History
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Transcript of Environmental Toxicology Introduction and History.

Environmental ToxicologyIntroduction and History

Course Objectives• Elucidate basic principles of

toxicology as they apply to both ecological and physiological systems

• Evaluate sources, effects, and fates of toxins in individual components of ecosystems

• Promote understanding of how toxic effects are integrated within ecosystems and on a global scale

• Increase knowledge of current issues in environmental toxicology

Why teach Environmental Toxicology?• A relatively new science that grew

out of two phenomena

1. Dramatic presence of human species on the landscape

2. Awareness of environmental degradation (either real or potential) the importance of a healthy environment in maintaining the quality of life

Increased Presence of Humans

Environmental degradation/improvement1970 1986 2002World pop’n (109) 3.7 5.3 6.2World carbon emissions (109 T) 3.9 5.2 6.6Solid waste in U.S. /year (106 t) 100 130 369Land in urban develop. (106 ac) 35 47 63U.S. ac. treated w/herbicides (106) 158 362 194Coal use (106 t) 613 890 1065Lead emissions (103 T) 204 21 6.2Sulfur dioxide emissions (106 T) 27 21 10.2Fish kills in US by pollution (106) 22 10 10Accidental oil spilled at sea (103 T) 84 6 116DDT in human adipose tissue (ppm) 8 2 0.03

Ecology vs Toxicology vs Environmental Toxicology• Definitions

Ecology – the study of the interactions among organisms and between organisms and the environment

Toxicology – study of biological effects of toxins

Environmental toxicology• Truhart, 1969 - study of adverse effexcts of

chemicals and physical agents on living organisms• Duffus, 1980 – study of effects of toxic substances in

both natural and human-created environments• Moriarity, 1985 – study of the fate and effects of toxic

compounds on ecosystems• Calow, 1993 – protection of ecological systems from

adverse effects by synthetic chemicals• Landis and Yu - ?

Environmental toxicology: an interdisciplinary science• Encompasses multiple disciplines

– Ecologists– Chemists– Molecular biologists– Geneticists– Pharmacologists– Mathematical modelers and statisticians

Happens because fundamental interaction of toxicants is at the molecular level but effects occur across multiple biological and physical scales (see Fig. 1.1)

Difference between Toxicology and Environmental Toxicology

Single organisms Organisms-populations-communities-ecosystems

Only direct effects measured Both direct and indirect effects measured

White rats/mice Daphnia (water flea), fathead minnow, midges, trout, Quail, Mallard duck, algae

Homogeneous populations under controlled laboratory conditions

Natural populations in a variable environment

Classical toxicology Environmental toxicology

Variable Environments

1. Water (1°)

called

2. Air environmental

media

3. Soil

History of Environmental Toxicology• A relatively new discipline

– 2006 = 30th annual symposium of the American Society for Testing Materials (ASTM) and 27th meeting of the Society of Environmental Toxicologists and Chemists (SETAC)

– Initial science directed at efficacy testing of pesticides in 1940’s moved thru cleanup of burning rivers, polluted lakes and wildlife kills of 1960’s environmental risk and life cycle assessments of recently developed compounds

Main events fostering change in public perception and thus environmental regulations•Silent Spring published

•Cuyahoga River catches fire

•NEPA (National Environmental Policy Act)

•Establishment of the EPA

Environmental Science is driven by protective legislationA. Federal Food, Drug and Cosmetic Act

B. Toxic Substances Control Act (TOSCA)

C. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)

D. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, Superfund)

E. Clean Water Act (CWA) 1974

F. Clean Air Act (CAA) – last amended in 1990

Note: can often have overlap of regulations with different standards Ex. EPA reg. for Hg in wild fish is 10X less than that allowed by FDA in supermarket fish

Areas interacting within environmental toxicology

• Scientific community (academia)

• Governmental agencies

• Industry

• General Public

Scientific community (academia)

– Intellectual and industrial force driving environmental research

– Mostly financed by governmental grants

– Dissemination of information by peer-reviewed publication, symposia and conferences, workshops

– Most work accomplished by graduate students (Thank you, graduate students!)

Governmental agencies• Includes federal, state, provincial

(Canada!) and municipal agencies• Mostly act as developers and

enforcers of policy• Prime examples - US EPA, AR DEQ,

AR G&F• Also includes

– FWS– ACE– NMFS– USCG

• Lots of jobs paying decent $

Industry• Generally includes businesses that

mine, manufacture, transport, or use chemicals

• Most environmental regulations designed to control above

• Industry has to test for toxicity, determine levels of chemicals, design treatment systems

• Often use environmental consulting firms or in-house environmental staff

• Fewer jobs but they can often pay ridiculous amounts of $

General Public• Per Landis includes NGOs

– Citizen’s groups– Rotary, Kiwanis– Unions– Environmental advocacy groups

• Sierra Club• Audubon Society• World Wildlife Fund• Defenders of the Environment• Etc

• Primary avenues of action– Informing layperson’s– Lobbying legislators– ?

Photo by R. Grippo

Midnight sunset over Alaskan fishing village