2-st- intro and history of environmental toxicology.ppt

7/22/2019 2-st- Intro and History of Environmental Toxicology.ppt

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Environmental Toxicology

Introduction and History


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Course Objectives Elucidate basic principles of

toxicology as they apply to bothecological and physiologicalsystems

Evaluate sources, effects, and fates

of toxins in individual componentsof ecosystems

Promote understanding of how toxic

effects are integrated withinecosystems and on a global scale

Increase knowledge of currentissues in environmental toxicology


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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 environmentaldegradation (either real or potential)the importance of a healthyenvironment in maintaining thequality of life


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Increased Presence of Humans


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Environmental degradation/improvement1970 1986 2002

World popn (109)

3.7 5.3 6.2World carbon emissions (109T) 3.9 5.2 6.6

Solid waste in U.S. /year (106t) 100 130 369

Land in urban develop. (106ac) 35 47 63

U.S. ac. treated w/herbicides (106) 158 362 194

Coal use (106t) 613 890 1065

Lead emissions (103 T) 204 21 6.2

Sulfur dioxide emissions (106T) 27 21 10.2

Fish kills in US by pollution (106) 22 10 10

Accidental oil spilled at sea (103 T) 84 6 116

DDT in human adipose tissue (ppm) 8 2 0.03


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Ecology vs Toxicology vsEnvironmental Toxicology

Definitions

Ecologythe study of the interactions among

organisms and between organisms and theenvironment

Toxicologystudy of biological effects of toxins

Environmental toxicology Truhart, 1969 - study of adverse effexcts of

chemicals and physical agents on living organisms

Duffus, 1980study of effects of toxic substances

in both natural and human-created environments Moriarity, 1985study of the fate and effects of

toxic compounds on ecosystems

Calow, 1993protection of ecological systems fromadverse effects by synthetic chemicals

Landis and Yu - ?


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Environmental toxicology: an interdisciplinary

science

Encompasses multiple disciplines Ecologists

Chemists

Molecular biologists

Geneticists

Pharmacologists

Mathematical modelers and statisticians

Happens because fundamental interaction oftoxicants is at the molecular level but effectsoccur across multiple biological and physicalscales (see Fig. 1.1)


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Difference between Toxicology and Environmental Toxicology

Single organisms Organisms-populations-communities-ecosystems

Only direct effects measured Both direct and indirecteffects measured

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

Homogeneous populationsunder controlled laboratoryconditions

Natural populations in avariable environment

Classical toxicology Environmental toxicology


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Variable Environments

1. Water (1)called

2. Air environmental

media

3. Soil


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t t t


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a n events oster ng c ange n pu c percept onand thus environmental regulationsSilent Spring

published

Cuyahoga Rivercatches fire

NEPA (NationalEnvironmental

Policy Act)

Establishment ofthe EPA


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Environmental Science is driven by protective legislation

A. Federal Food, Drug and Cosmetic Act

B. Toxic Substances Control Act (TOSCA)

C. Federal Insecticide, Fungicide and RodenticideAct (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 withdifferent standards Ex. EPA reg. for Hg in wildfish is 10X less than that allowed by FDA insupermarket fish


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Areas interacting within environmental toxicology

Scientific community (academia)

Governmental agencies

Industry

General Public


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Scientific community (academia)

Intellectual and industrial force drivingenvironmental research

Mostly financed by governmental grants

Dissemination of information by peer-reviewed publication, symposia andconferences, workshops

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


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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 $


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Industry Generally includes businesses that

mine, manufacture, transport, or usechemicals

Most environmental regulationsdesigned to control above

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

Often use environmental consultingfirms or in-house environmental staff

Fewer jobs but they can often pay

ridiculous amounts of $


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General Public Per Landis includes NGOs

Citizens groups

Rotary, Kiwanis

Unions

Environmental advocacy groups Sierra Club

Audubon Society

World Wildlife Fund

Defenders of the Environment

Etc

Primary avenues of action Informing laypersons

Lobbying legislators

?


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2-st- intro and history of environmental toxicology.ppt

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