Living With Chemicals Everywhere Hardin Valley Academy, 18 Jan 2011Prof. John E. BartmessDept. of ChemistryUniversity of TennesseeKnoxville TN 37996-1600

<bartmess@utk.edu>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 SocietyWhat 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:

5. Certain professions (timber cutter, coal miner, commercial fisher, structural metal worker…)

2. Smoking 3. Obesity 4. Heart disease

1. Being unmarried

“Correlation is not Causation.”

Man-Made Chemicals in Our EnvironmentApproaches: 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 TopicsTobacco: nicotine LD50 4 mg/kg Socialization of dosageMedicine: aspirin: Reyes syndrome, phenacetin: kidneys. Age and toxicity.Cleaning Supplies: detergent 1 tsp/lb, bleach + ammoniaPaint: latex or oil base, turpentine or mineral spiritsGlue 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.

RadonElement, radioactive gasAll Radiation Exposure: 50%=ground & water emission, 30%=cosmic rays, 5%=medical 2%=falloutBreathe in, decays in lungs: cancerIncreasing problem with air-tight, energy- efficient homesConsiderably increased risk if smoker

EPA recommended action level 4 picoCuries/L; Easy to test a home

Alar

Anti-ripening agent for applesConverts 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 <bartmess@utk.edu>

Household Waste:

City of Knoxville Solid Waste Management1033 Elm St. (off Baxter Ave. at I-275)215-2921 option #620 gal or 100 lb/vehicle/day limit