1. Human health and toxicology

3. Major health issues May seem more important today than in the past
In part because of so many people
But are not new to the planet

4. Toxicity What is toxic? Chronic Acute Can rank toxicity
Some things are much more toxic than other, but . . .
Varies depending on individual
age
health
genes

5. Dose-response Some things are bad for you -
How much before harm is done?
Some things are good -
How much is too much?
Too much of a
good thing

6. Lab tests Expose animals to potential toxics
See how many die or get cancer or …
Depending on dosage
LD50 = lethal dose for half the population
Of course
Tough to translate to humans
And we can’t do human experiments
But, experiments confirm that very small amounts can be very bad

7. Top 10 most toxic substances (arguably) and estimated LD50 for 200 lb person based on lab experiments on various mammals
tetanus (bacteria) μg
botulinal neurotoxin (bacteria) μg
shigella (bacteria) μg
palytoxin (coral) μg
diphtheria (bacteria) μg
ricin (from castor beans) μg
aflatoxins (mold which grows on nuts, legumes, seeds) 0.1 μg
saxitoxin (shellfish) μg
tetrodotoxin (fugu pufferfish) μg
diphtheria (bacteria) μg
1 grain of salt is about 60 micrograms (μg)

8. Cancer and related problems
Carcinogens
Cause cancer
Malignant
melanoma

9. Cancer and related problems
Mutagens
Cause mutation

10. Cancer and related problems
Teratogens
Cause birth defects
Two-headed
kitten
Cancer, mutation, birth defects
caused by exposure to toxics
But often hard to tell which
Some, such as cigarettes,
are obvious

11. Endocrine disrupters Act like hormones in the endocrine system
Cause cancer, reduced sperm counts, immune problems . . .
Definitely affect animals – what about people?
Very difficult to determine dose-response for humans
Examples
DDT - pesticides
PCBs - transformers
Bisphenol A – epoxy, plastics
PDEs - solvents
Phthalates - plastics
Many others
Male sperm counts have decreased
all around the world during the past
15-20 years.
Cause is unknown.
But, at this rate there will be widespread
infertility within decades.
Many suspect endocrine disruptors are the cause.

12. What are the risks/costs/odds?
Risk-benefit
Hard to evaluate risk
And, how safe
do we want to be?
Cost-benefit
What is a human life worth?
And, what is the cost
of not doing something?
Precautionary principle
One major problem is that we know
there are synergies, and antagonistic
interactions -- but it is almost
impossible to evaluate them.

13. Started really being Concerned about Hazardous waste Because . . .
1977 Love Canal
Niagara Falls New York
Chemical company and school board
Really brought concerns to forefront
Dioxins
Next major issue
Form during chemical manufacturing involving chlorine-bearing compounds
Also comes from burning waste that contains chlorine in dumps or backyards
Also produced by paper mills, production of PVC plastic, and other industries
Times Beach MO 1970s
PCBs
PCBs are also chlorine-containing compounds
Once used as coolants, flame retardants, lubricants . . .
Now banned in US
Manufacturers knew PCBs causes health problems since the 1930s and 1940s
Many reports of serious health problems
Did not become real concern until 1970s
Chlorine is a key
component in many
toxics – plastics,
pesticides, etc.

14. Hazardous waste So, we have RCRA 1976 CERCLA and Superfund 1980
Requires cradle to grave tracking of toxics
CERCLA and Superfund 1980
Passed in response to Love Canal
And dioxin at Times Beach
And other such laws
Superfund sites in US
As of January 2013, there were 1,312 NPL sites in the U.S.
None in North Dakota any longer
Since 1980, <300 taken off the list

15. But, many things we encounter in our daily lives are toxic
Pesticides
Industrial chemicals
PVC, etc.
And more
And . . .
Even cautious use releases some stuff to the environment

16. Toxics are all around us: plastics
polystyrene
HDPE
PVC
PET
polypropylene
LDPE
When we use them, we absorb some although generally in small amounts.

17. Plastics in food FDA says all plastics put toxics in our food
Question is: how much, and how much is bad?
Manufacturers are required to “prove” safety
Which cannot be done

18. PVC
In toys, clear food and non-food packaging (e.g., cling wrap), some squeeze bottles, shampoo bottles, cooking oil and peanut butter jars, detergent and window cleaner bottles, shower curtains, medical tubing, and numerous construction products
PVC has been described as one of the most hazardous consumer products ever created. PVC leaches di(2-ethylhexyl) phthalate (DEHP) or butyl benzyl phthalate (BBzP), depending on which is used as the plasticizer or softener (usually DEHP). DEHP and BBzP are endocrine disruptors mimicking the female hormone estrogen. This type of plastic has been strongly linked to asthma and allergic symptoms in children; may cause certain types of cancer; is linked to negative effects on the liver, kidney, spleen, bone formation and body weight. In Europe, DEHP and BBzP and other dangerous pthalates have been banned from use in plastic toys for children under three since 1999.

19. PET
Soft drink, juice, water, beer, mouthwash, peanut butter, salad dressing, detergent and cleaner containers
Leaches antimony trioxide: workers exposed to antimony trioxide for long periods of time have exhibited respiratory and skin irritation; among female workers, increased incidence of menstrual problems and miscarriage. The longer a liquid is left in such a container, the greater the concentration of antimony is released into the liquid.

20. PS = polystyrene
In styrofoam containers, egg cartons, disposable cups and bowls, take-out food containers, plastic cutlery, and compact disc cases.
Polystyrene leaches styrene, which is an endocrine disruptor mimicking the female hormone estrogen, and thus has the potential to cause reproductive and developmental problems. Long-term exposure by workers has shown brain and nervous system effects. Polystyrene is also present in secondhand cigarette smoke, off-gassing of building materials, and car exhaust. Styrene migrates significantly from polystyrene containers into the container’s contents when oily foods are heated in such containers.

21. HDPE
In opaque milk, water, and juice containers, bleach, detergent and shampoo bottles, garbage bags, yogurt and margarine tubs, cereal box liners
Research on risks associated with this type of plastic is ongoing

22. LDPE
In grocery store, dry cleaning, bread and frozen food bags, most plastic wraps, squeezable bottles (honey, mustard)
Research on risks associated with this type of plastic is ongoing
Nalgene

23. PP = polypropylene
In ketchup bottles, yogurt and margarine tubs, medicine and syrup bottles, straws, opaque plastic storage containers, baby bottles, clothing
Research on risks associated with this type of plastic is ongoing.

24. PC = polycarbonate
In most plastic baby bottles, clear plastic “sippy” cups, hard “sports” water bottles, three and five gallon large water storage containers, metal food can liners, some juice and ketchup containers, compact discs, cell phones, computers
Polycarbonate leaches Bisphenol A (some effects described above), and numerous studies have indicated a wide array of possible adverse effects from low-level exposure to Bisphenol A including chromosome damage in female ovaries, decreased sperm production in males, early onset of puberty, various behavioral changes, altered immune function, and sex reversal in frogs.

25. Cancer rates Seem to be higher today Men Women Diet Life style
Environment
Men
Prostate
Lung – accounts for 75% of deaths
Colorectal
Women
Breast
Lung – accounts for 40% of deaths
Cancer clusters?

26. Cancer Worldwide – about 12% of deaths are due to cancer
US has highest cancer rates in the world
4 in 10 people in US get cancer today
Expected to increase in next decade
Due to continued smoking
Aging population
We have many products, including food, that contain toxics
And especially poor diet and unhealthy lifestyles
Brain cancer cells

27. Why Cancer clusters?
Prostate cancer

28. How should we handle toxics?
Ideally – use them safely
But, we don’t know what that is, and . . .
Routine use poses risk
Even if only a little escapes into the environment . . .
Small doses can be very bad
For many toxics we don’t know risk
Synergies and bioaccumulation not understood
Skeptics say we must prove risk
Before doing anything
Precautionary Principle says the opposite

29. Sadly, we mostly only act after catastrophe
e.g., Superfund after Love Canal and Times Beach

30. Pollution and human health
Are things getting better or worse?
Cancer has reached epidemic proportions
Billions of pounds of chemicals escape each year
Other new things causing alarm
Endometriosis
Emerging new problem affecting women’s uterus
ADD/ADHD
3% more victims each year
Asthma
Doubled between 1980 and 1996
Sperm counts
Falling rapidly

31. Pollution and human health
What is cause of increase in problems?
No certain answers but most experts say
1. exposure to toxics
2. lifestyles
For example food is routinely sprayed with pesticides whose safety is in question
Pesticide residues show up on all foods unless organic
Delaney clause says no carcinogens can be in food
But is not well enforced

32. Could problems be genetic, not environmental?
Study identical twins
Find that breast cancer rates do not match
Instead correlate with environmental factors
Study adopted children
Find that cancer rates do not correlate with biological parents
Instead with adopted parents and exposure to toxics

33. Why not do something? We do, sometimes: e.g., Delaney Clause
But delays caused by:
Scientific uncertainty
Economic cost
And, sadly:
Things may be worse than we think
If we delay, it could be too late
Even worse:
Politics: Government often will not do it even when it is clear that action is needed

34. And, what about (“natural”) diseases
Lyme disease

35. And, what about (“natural”) diseases
Novel infections seem more common these days
Not necessarily due to toxics but there could be a connection
In part probably due to
Better detection
People no longer die of unknown causes
People travel a lot more
Food and other things are shipped all over
Overuse of antibiotics means
Organisms are more virulent and resistant

36. New (“emerging”) and old diseases
Legionnaire’s disease 1976
Caused by bacteria living in air conditioners
Many people very ill
Half died

37. New (“emerging”) and old diseases
Legionnaire’s 1976
Aids
First recognized in 1981
30 million people infected worldwide
Most in Africa
Due to HIV virus
Many new drugs
Prolong life
but most victims still die

38. New (“emerging”) and old diseases
Legionnaire’s
Aids
Exotic diseases from Africa
Lhasa fever
Ebola virus
Marburg infection

39. New (“emerging”) and old diseases
Legionnaire’s
Aids
Lhasa fever
Ebola virus
Marburg infection
Lyme disease

40. New (“emerging”) and old diseases
Legionnaire’s
Aids
Lhasa fever
Ebola virus
Marburg infection
Lyme disease
Hanta virus
From Korea
Killed people in southwest US in 1993

41. New (“emerging”) and old diseases
Legionnaire’s
Aids
Lhasa fever
Ebola virus
Marburg infection
Lyme disease
Hanta virus
Some old diseases
seem to be coming back:
Malaria
Tuberculosis
In part because they are becoming resistant to antibiotics

42. Food poisoning

43. Food poisoning E coli Botulism Campylobacter Salmonella
Bovine spongiform
encephalitis (BSE)
bacteria
bacteria
bacteria
bacteria
protein

44. Food poisoning E coli Botulism Campylobacter Salmonella
Widespread organism
Many different types
Some very bad
Most associated with sewage
E coli
Botulism
Campylobacter
Salmonella
Mostly due to improper food handling
Found in raw poultry and meat,
Unpasteurized milk, untreated water
Most common identified form of food poisoning
Found in raw poultry, dairy and meat,
and unwashed vegetables,
In the gut and feces of animals and humans

45. Food poisoning E coli Botulism Campylobacter Salmonella
All of these got much worse because of:
Large centralized food production facilities
Intensive feed lots and agriculture
Overuse of antibiotics, etc
“Big box” food stores

46. mortality today In HDC countries Sanitation and drugs help
Disease and pathogens (mostly) under control
In U.S., leading causes of death: heart disease, cancer
Non-infectious, chronic, associated with lifestyle and aging
Not so In LDC countries
Malnutrition
Sanitation
Water supplies
Air pollution
 many infectious disease problems
Cholera occurrences

47. Should we be scared? Some people worry about pandemics
There are some warning signs

48. Should we be scared? Aids Out of Africa Most cases in Africa
Many in US
Many others in India, Asia, etc.
Not curable, but can be slowed

49. Should we be scared? BSE Bovine spongiform encephalopathy
a.k.a. mad cow disease
Disease in cattle
Especially in UK
May be transmitted to people
Leads to Creutzfeldt-Jakob disease
Causes brain degeneration in people
Contributing cause is that cattle are fed meat and bone meal, causing disease to spread
Not necessary because cattle are herbivores
But cattle operators make more profits if fattened with animal based feed

50. Should we be scared?
BSE
Led to slaughter of entire British dairy industry in late 1980s
But spread to Canada
So, temporary bans put on importing Canadian beef
So, how bad is it?

51. Should we be scared? Swine flu a.k.a. pig flu or pig influenza
Common in pigs
Especially pigs in feed lots
So, operators give lots of antibiotics to pigs
Which are the same antibiotics humans use
So, super strains of flu and other pathogens develop that are antibiotic resistant
Pigs die
And humans catch disease that originated in pigs
CDC has warned for years that we need to stop giving antibiotics to livestock
But intensive livestock operations need it
So pig/cattle operators make more profits
So, how bad is it?

52. But, so far, these disease risks are small compare with risks from . . .
Cancer
Second leading cause of death in US (following heart disease)
Many different kinds (>200)
Can start in any type of body tissue
Not a pandemic
Many factors contribute
Most important
Tobacco
Diet/weight/physical activity
Ultraviolet radiation
Carcinogens

53. So . . .
Don’t smoke
(There are lots of reasons not to smoke besides cancer . . .)
Eat healthy foods and get exercise

54. Cosmetics and other beauty products

55. Avoid carcinogens? Carcinogens include Antiperspirants Talcum powder
Hair dyes, cosmetics, and almost everything else in a beauty salon
Dry cleaning fluid
Insect spray
Food ingredients: aspartame, bovine growth hormone, artificial colors and flavors
And many more common product ingredients

56. Everything causes cancer . . . ?
They say:
A cop out
Excuse not to think about a very complex problem
Some things are known to be carcinogens (or possibly to be carcinogens)
Others are not
Which do you want in your life?

57. So, should you be worried?
Only if you haven’t thought about these issues . . .
And don’t plan to think about them now.