Transcript The powerpoints from the Living with Chemicals Everywhere talk

Living With Chemicals Everywhere
Hardin Valley Academy, 18 Jan 2011
Prof. John E. Bartmess
Dept. of Chemistry
University of Tennessee
Knoxville TN 37996-1600
<[email protected]>
http://web.utk.edu/~bartmess/livechem.ppt
Informed Citizens in
a Technological Society
Chemistry Focus here
- Science and Society / Science vs. Society
- Risk/Benefit Analysis
- Specific problems
- Information Resources to aid evaluation
- The nature of scientific judgment-making and expertise:
which "expert" do you believe?
How accurate are the media?
- Life cycle analysis and recycling of specific chemicals.
- Hazards in everyday life as a basis for making judgments.
Science and Society
What can and can't science do for society?
- What are scientists 99% sure of?
- What don't scientists know, but can probably determine
(and how much is it worth to you to know?)
- What can't scientists determine, to the best of
current knowledge?
- How much uncertainty (accuracy versus precision) is
there in what scientists "know"?
Science Issues in Policy-making:
- Human versus ecological health
- Short term versus long term effects
- Harm versus death
- Politics
- Economics: true monetary cost versus up-front costs
- Ideals and ethics
- The desire for absolute, simple answers:
Scientist: "On the one hand, this is good;
on the other hand, this is bad"
Politician: "We need one-handed scientists!"
People Problems
People who want something to be true,
because it's convenient (or profitable)
People who want something to be false,
because it's inconvenient (or costly)
Risk versus Benefits
Automobile: ca. 40,000 deaths/year in
300 million population =
1/7500 chance per year, or 1%/lifetime.
Control mechanisms:
alcohol education
seat belts, air bags
auto design
costs: $, personal freedom
Perception of Risk:
Bears in US: <5 deaths/year;
Bees in US: ~100 deaths/year.
Lightning: 30 deaths/year (1 in 10 million chance)
EPA action level on chemicals: 1 in a million chance.
Loss of life expectancy of more than 3 years:
1. Being unmarried
2. Smoking
3. Obesity
4. Heart disease
5. Certain professions (timber cutter, coal miner,
commercial fisher, structural metal worker…)
“Correlation is not Causation.”
Man-Made Chemicals in Our Environment
Approaches:
Risk Assessment
Life Cycle Analysis
- Toxicity
acute: one dose
chronic: multiple low doses over time
hydrogen sulfide (“rotten egg”)
versus hydrogen cyanide
- Exposure ("the dose makes the poison")
- Persistence ("the problem will go away")
Specific Acute Topics
Tobacco: nicotine LD50 4 mg/kg
Socialization of dosage
Medicine:
aspirin: Reyes syndrome,
phenacetin: kidneys.
Age and toxicity.
Cleaning Supplies: detergent 1 tsp/lb,
bleach + ammonia
Paint: latex or oil base, turpentine or mineral spirits
Glue and Hobby supplies
Pesticides/Herbicides/Fungicides
e.g. malathion converts to toxic form more slowly
in humans than insects
others block enzymes to make certain amino acids
Fertilizer
Batteries: (all, but especially rechargeable)
Plants: Dieffenbachia,
tobacco,
Poinsettia,
sweet pea (bone growth),
lupines (teratogen),
brachen fern (carcinogen),
comfrey (liver - pyrrolizidine alkaloids,
esp. during pregnancy)
Food:
Lima beans (cyanide),
chick peas (oxalic acid),
rhubarb (oxalic acid),
tomato (leaves - nightshade),
potato (green: solanine alkaloid);
castor beans: ricin (peptide) MLD: ng
-natural defense mechanisms against predators
-“It’s all natural!”
Salt
2.5g/kg Minimum Lethal Dose
= 6 oz/ typical person
Lecithin
Vitamins, esp. A,D,E,K (fat soluble)
Vitamin D in milk - joint calcification
at 1 gal/day
Specific Chronic Topics: Air
Natural gas (NOx pollutants)
Auto Exhaust - Carbon monoxide, lead,
carcinogens (gardens)
Formaldehyde from old urea-formaldehyde insulation
(esp. mobile homes)
Floor wax.
Sealed (energy-efficient) houses.
Radon
Water:
Organics, especially halogenated ones from
water chlorination
activated carbon filter (vs. bacteria)
Ozonation/trace chlorination
boiling - need to reduce x2, then in air.
"Heavy metals": lead (soldered pipes),
mercury, cadmium
Septic field above garden.
Fluoridation.
Food:
- pesticide and hormone residues vs. natural toxins
- sodium nitrite in cured meat (botulism vs. weak carcinogen):
ascorbate or erythorbate fix.
- artificial flavors, colors.
- polychlorinated dibenzodioxins(TCDD)
- polychlorinated biphenyls(PCBs).
- Place in the food chain.
Radon
Element, radioactive gas
All Radiation Exposure:
50%=ground & water emission,
30%=cosmic rays,
5%=medical
2%=fallout
Breathe in, decays in lungs: cancer
Increasing problem with air-tight, energyefficient homes
Considerably increased risk if smoker
EPA recommended action level 4 picoCuries/L;
Easy to test a home
Alar
Anti-ripening agent for apples
Converts to carcinogenic UDMH (Me2NNH2) if heated.
Apple juice, apple sauce are pasteurized by heating.
Alar is used mainly on eating apples
… which aren’t heated.
1/50 million of cancer if 5 yrs of 10 oz/day apple juice.
Recognizing the Situation:
Examples:
- Perfect lawn
- Cleaning up waste
Solve the problem, not just the symptoms!
Generally Reliable Sources of Information:
Consumer Reports, Consumer's Union
Science, Nature, Scientific American:
Journals (many public, all University Libraries)
Chemical and Engineering News: (American Chemical
Society weekly news magazine)
Merck Index(not the Merck Manual)
Physician's Desk Reference (PDR)
Hazardous Properties of Industrial Materials, V. Sax.
Material Safety Data Sheet (MSDS)
The Net? Lack of peer review
Human Resources:
- Reference Desk of Library.
- Local College/University Chemistry Department.
- me: John E. Bartmess,
Professor, Organic Chemistry
Dept. of Chemistry, University of Tennessee,
Knoxville TN 37996-1600
(W) 865-974-6578 <[email protected]>
Household Waste:
City of Knoxville Solid Waste Management
1033 Elm St. (off Baxter Ave. at I-275)
215-2921 option #6
20 gal or 100 lb/vehicle/day limit