Environmental Science 102 Spring 1998
Lecture outlines I
I really don't need to tell you this, but these rough outlines are not meant to be complete nor are they meant to be a substitute for attending the lectures.

Wednesday, January 21, 1998
Fundamental units, examples
Prefixes for units
Derived units: area, volume 


Friday, January 23, 1998
Density, concentration units, examples
Emission rate
Connection between emission rate and environmental concentration
Chemical terms: element, atom, compound, molecule, mixture.
Pollution not self-defining.
Nature not pure.
Natural emissions versus human emissions


Monday, January 26, 1998
Synthetic organic chemicals: carbon, hydrogen, chlorine atoms
If detected in environment, means human emission
Toxic at elevated concentrations
Persistent: long half life; how bad, good
Biomagnification: long half life, fat solubility, how it works
Half life examples

Concentration/level, not presence, is important

Dose = concentration x amount, examples 


Wednesday, January 28, 1998
Definition of pollution
Examples of physical, chemical, biological agents
Emphasis of chemical contaminants
Concentration definition, examples
Concentration expressions: mass/mass, volume/volume, etc.
For common units, concentration as a ratio.
Concentration as a percent, as ppm, examples
Dose and dose rate
Dose rate = concentration x amount/time, example 3 ppm lead in potatoes x kilogram potatoes consumed/day
Dose- (adverse) response relationship
What is the adverse response being observed? Different severities.
Absorption factor (0-1) and fraction delivered to target organ (0-1)


Friday, January 30, 1998
Toxicology, definition
Paracelsus, dose makes the poison
Determining toxicity: animal, human data; acute, chronic data
Acute animal: LD50. Dose-response curve example
Acute human: volunteers, accidents
Chronic animal: rodents. Tumor-prone strains. Compare numbers of tumors.
Chronic human: epidemiology. Occupational groups.

Animals not humans. Species extrapolation.
Animal doses high. Dose extrapolation to humans.
Rodent mass v. human mass: Body size or surface area extrapolation.

Epidemiology. Need to wait (decades?) before results. Not a controlled experiment. Need adverse effects (body count) before knowing there's a problem. Many other exposures.

Mutagen screening. Ames test.
Mutagen link to carcinogen, not one-to-one. 


Monday, February 2, 1998
Dose routes: ingestion, inhalation, skin absorption
Response
Endpoint definition, how choice of endpoint changes response rate
Adaptive response. First, not adverese, examples
Physioligical adaptive responses.
Metabolic adaptive response.
Liver enzymes
Over metabolic change to less toxic; possible early activation to more toxic form
Metabolic change to increased water solubility, therefore excretion.
Dose rate can overwhelm adaptive response, examples.


Wednesday, February 4, 1998
Threshold dose
No observed adverse effect level
Examples of threshold dose-response curve, required nutrient D-R curve.
No threshold chemicals. Why certain chemicals are assumed to have no threshold.
Difficult of drawing a D-R for humans from animal tumor data.
No threshold chemicals assigned risk factors.
Using risk factors:
Dose (rate) = concentration x amount
Lifetime risk = dose x risk factor
Example of chemical with 2 x 10-6 risk per 1.0 mg/day, dose of 2 mg/day
Lifetime risk = 2 x 10-6 per 1.0 mg/day time 2 mg/day = 4 x 10-6, which means
a 4 in one million chance of a cancer from that chemical at that dose rate, given the risk factor.

Sensitive groups, factors determining:
Age, health status, nutritional status, genetic makeup, exposure to other chemicals

Genetic makeup connection to metabolism of chemicals by enzymes.


Friday, February 6, 1998
Setting an environmental standard.
Standard written in terms of allowable ambient concentration.
Steps in standard setting:
1. Define endpoint.
2. Determine threshold or NOAEL (will be in the susceptible group).
3. Set ambient concentration to avoid harmful dose.
Dose= concentration x amount, so figure concentration using chosen acceptable dose and assumed amount of the environmental medium.
Example of standard setting, using water pollutant.
If measurements of area air or water quality indicate concentrations over the standard, then area labeled as polluted. Interpretation of information that an area is pollutated involves measured concentrations, endpoints, susceptible groups, frequency of high readings.

Chemicals into the environment as
Emissions (from production or use)
Waste (industrial/municipal, nonhazardous/hazardous)
Products (accidental spills)

Usual concentrations of emissions, waste, product.


Monday, February 9, 1998
Chemical regulation, from preproduction to disposal of waste.

Regulations written by administrative agencies by authority of the various statutes. Administrative Procedure Act governs regulations drafting (called notice and comment rulemaking).
Federal Register, Code of Federal Regulations.


Wednesday, February 11, 1998
Legislative aspect of regulations writing: proposal, comments, response.
Causes of death, U.S., 1900 and 1997
Why shift in causes of death
Timelines for death rates for various diseases showing decline before treatment was available.
Average death rates do not equal age-specific or sex-specific death rates.
Top causes of death for U.S. do not equal top causes for various age groups.
Life expectancy, changes during 20th century in U.S.


Friday, February 13, 1998
Exam number one.


Beginning Monday, February 16, 1998 the class notes with be in a new file labeled Lecture notes outline II. This file will link from the course home page.


Instructor: Dr. Bruce Wyman 
Office: Frasch 236
Office hours: 8:00-9:00 a.m. MWF; 10:00-11:00 a.m. MWF; 8:30-9:25 a.m. 3:30-4:30 p.m. TTh

Campus e-mail: wyman@mail.mcneese.edu
Office telephone: 475-5669; office fax: 475-5677


Environmental Sciences Department Page
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www.faculty.mcneese.edu/wyman/es102notes.htm
Last modified: 2/11/98
Contact:  Dr. Bruce Wyman