Ethics, Toxicity, Ecotoxicity, Persistence,
Bioaccumulation and Green Chemistry
Terry Collins
Central Catholic High School,
September 21, 2005, Pittsburgh PA
Western Civilization is
not sustainable as it is
currently constituted
— flawed technologies are an
important component of the
sustainability dilemma
“Altered Nature of Human Action”
“All previous ethics…[have been based upon the
premises]…that the human condition, determined by
the nature of man and the nature of things,was given
once for all; that the human good on that basis was
readily determinable; and that the range of human
action and therefore responsibility was narrowly
circumscribed. … [But] with certain development of
our powers the nature of human action has changed,
and … [given rise to] … a whole new dimension of
ethical relevance for which there is no precedent in
the standards and canons of traditional ethics.”
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
The altered, always enlarged nature of human
action, with the magnitude and novelty of its
works and their impact on man’s global future,
raises more issues for which past ethics, geared to
the direct dealings of man with his fellow men
within narrow horizons of space and time, has
left us unprepared.
A new reflection on ethical principles—including
such that, for lack of application, could hitherto
remain silent—is required for coping with those
issues.
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
The lengthened reach of our deeds moves
responsibility, with no less than man’s fate for its
object, into the center of the ethical stage.
Accordingly, a theory of responsibility, lacking so
far, is set forth for both the private and the public
sphere.
Its axiom is that responsibility is a correlate of
power and must be commensurate with the
latter’s scope and that of its exercise.
For its discharge today, therefore, we need
lengthened foresight, that is, scientific futurology.
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
Even at its best, however, such an extrapolation
from presently available data will always, in
certainty of prediction, fall short of the causal
pregnancy of our technological deeds.
Consequently, an imaginative “heuristics of fear”
replacing the former projections of hope, must tell
us what is possibly at stake and what we must
beware of.
The magnitude of those stakes, taken together with
the insufficiency of our predictive knowledge, leads
to the pragmatic rule to give the prophecy of doom
priority over the prophecy of bliss.
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
What we must avoid at all cost, is determined by what we must
preserve at all cost, and this in turn is predicated on the “image
of man” we entertain. Formerly, this image was enshrined in the
teachings of revealed religions. With their eclipse today, secular
reason must base the normative concept of man on a cogent, at
least persuasive, doctrine of general being: metaphysics [the
branch of philosophy that examines the nature of reality] must
underpin ethics. Hence, a speculative attempt is made at such
underpinning of man’s duty to himself, his distant posterity, and
the plenitude of terrestrial life under his dominion.
That attempt must brave the veto of reigning analytical theory
against all attempts of this kind and indeed cannot hope for
more than a tentative result. But dare it we must. A philosophy
of nature is to bridge the alleged chasm between scientifically
ascertainable “is” and morally binding “ought”.
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
The thus-gained conception of objective imperatives for man
in the scheme of things enables us to discriminate between
legitimate and illegitimate goal-settings to our Promethian
[boldly creative or defiantly original in behavior or actions]
power (a distinction encompassing but surpassing that
between realistic and unrealistic goals). This discrimination
is elaborated in assessing the potentials of “progress” up to
the most ambitious idea of it— contemporary utopianism as
represented by the Marxian alliance with technology.
Against the immodesty of its goals, which maximize the
inherent dangers of overstraining nature, the more modest
and fitting goal is set to save the survival and humanity of
man from the excesses of his own power.
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
“A whole new dimension of ethical relevance”
The Imperative of Responsibility: Finding an Ethics for the Technological Age, Hans Jonas, U. Chic. Press, 1984
• Today, because of science and technology, individual power projects
into both time and space much further than ever before.
• Ethics is about the forces that guide human action. Science, especially
chemistry, has become completely intertwined with human action.
Accurate analysis of any human action in the developed world is
impossible absent an examination the influence of chemistry on that
action, from the way we communicate, educate ourselves, feed
ourselves, protect our health, and even to the way we procreate.
• Ethical principles need to be reinterpreted to recognize the reality of
the vast power we now have over life and the environment because
of science and technology.
• Thus, chemistry is inextricably intertwined with ethics! A healthy
education in chemistry should contain a significant analysis of
sustainability ethics.
The idea that our civilization is not sustainable, now
broadly accepted in a growing consensus, implies that
someone is responsible for fixing things. If unsustainable
technologies are part of the problem, the technical
leadership is clearly responsible for fixing this part.
• The leadership must first ask, for each identified
problem, if solutions are conceivable.
• If the answer is affirmative, the responsibility of the
leadership translates into a duty to engage
energetically in finding the solutions.
• If the answer is negative, their responsibility translates
into a duty to alert the civilization to move away from
the dependence that is undermining it.
The Fundamental
Green Chemistry
Concept
Risk = f1(exposure)  f2(hazard)
Paul Anastas and John Warner
To teach green chemistry
properly, green chemists must
develop an adequate
understanding of toxicity and
ecotoxicity [of f2(hazard)] and
incorporate this into the basic
course material of chemistry.
T, J. Collins, The Importance of Sustainability Ethics, Toxicity
and Ecotoxicity in Chemical Education and Research, Green
Chemistry, 2003 (August), G51-G52
Safe
Energy
New chemistry for
solar-to-electrical
or solar-tochemical energy
conversions
Renewable
Feedstocks
The
Chemical
Goals for
Sustainability
Pollution
Reduction
Economical
feedstocks for
chemical and
polymer
industries from
plants
Move the elemental composition of
technology closer to biochemistry to
eliminate persistent environmentally
mobile pollutants
Solar Stirling Engines
Solar Stirling Engines
Solar Stirling Engines
The stakes of
failing to address
toxicity and
ecotoxicity are
incredibly high.
• Decrease in anogenital distance among male infants
with prenatal phthalate exposure, Shanna Swan et al.,
Environmental Health Perspectives on-line May 27, 2005
• Exposure to methoxychlor and vinclozolin produces
male reproductive problems down 4 generations, Michael
Skinner et al., Science 2005, 308, 1391-1392
• Perinatal exposure to low levels of the environmental
anti-androgen vinclozolin alters sex-differentiated
social play and sexual behaviors in the rat, Vincent
Markowski, et al., Environmental Health Perspectives, 2005, 113, 700-707
• Use of di(2-diethylhexyl)phthalate-containing medical
products and urinary levels of mono(2diethylhexylphthalate) in neonatal intensive care units,
Howard Hu et al., Environmental Health Perspectives, on-line, June 10, 2005.
Exposure to anti-androgen, Flutamide
Percentage of
offspring affected
100
Males with areolae
75
Hypospadias
50
25
16
Courtesy of
J. Peterson Myers
Small prostate
Abnormal
bladder
Abnormal
seminal
vesicles
17
18
19
Day of exposure after conception
Paul Foster and Martha Harris, Toxicol Sci, 2005, 1591
How might chemists learn how to avoid known
toxicity/ecotoxicity in the design of new products
and processes?
• Historical analyses building from the anecdotal,
to the epidemiology, to the molecular level
understanding — importance.
• Toxicity testing as an integral component of
chemical research — guidance.
• More interdisciplinary research involving
chemists and toxicologists — synergy.
• An outright rejection of “spin” — obligation.
Discovery of Lead Toxicity
“Sweet Poison”
Josef Eisinger
Natural History, 7/96
Goslar
The Bastion of Ulm
Hemisperic Lead Pollution: Greenland Ice Evidence
Evidence belies the idea that Pb is part of the natural human intake!
4
10
10
10
10
10
10
10
7
6
5
4
3
2
1
0
10
7
Industrial
6
revolution
Exhaustion
of Roman
lead mines
10
10
10
5
Spanish
3
of2 silver in
2000
Silver
production
in Germany
1
0
2000
2
Discovery
of
cupellation
10
New World
10
3
Use of
coinage
4
10
production
10
Rise and
fall of
Athens
1000 1000
Years
Roman republic
and empir e
0 0
time / sec
years
1
Lead concentration pg/g
Lead production (tons/yr)
10
0
-1000
-1000
-2000
Boutron et al. Science, 1994, 265, 1841–1843
Selective History of Lead Toxicity
German tribes
ban Roman
wines, rightly
associating them
with illness
David Stewart (USA)
reports in Medical News
that 9 family members
poisoned by eating
PbCrO44 dyed bread
Louis Tanquerel des
First countries
Planches (France)
ban/restrict white
notes children placing
Pb for interior
lead-painted toys in
painting: France,
mouths develop colic
Belguim, Austria
Ε0AD 1848
1690s
Eberhard Gockel in
Ulm identifies wine
correcting with PbO
as cause of colic
Deceit and Denial: The
Deadly Politics of
Industrial Pollution,
Gerald Markowitz &
David Rosner, Univ. CA
Press, Berkeley, 2002
1887 1909
1890s-1920s
Literature
accumulates in
Australia, USA
and England on
Pb poisoning of
children,
especially by
Pb paint
Pres. Nixon signs Lead-Based
In 5-day period, Paint Poisoning Prevention Act
(LBPPPA) prohibiting paints
5 workers die,
40 of 49 severely with >1% Pb in any house built
with federal assistance; 1973
poisoned in
>0.5%, 1975 >0.06%Ρ1977
Standard OilΥs
Consumer Products Safety
Bayway PbEt 44
labs, Elizabeth, NJ Commission bans >0.06% Pb
paints from interstate commerce
1924
1922
PbEt44 developed
by Thomas
Midgeley Jr. and
chemistry
professor William
Mansfield Clark
immediately warns
menace to the
public healthΣ
1964
224,000
tons of
lead used
in gasoline
in USA,
ca. 1/5
total
1971
1976-96
CDC claims that as Pb
in gasoline was lowered
between 1976 and 1996
(when Pb was
completely phased out),
90% reduction in the
average BLL of US
children.
Lead Poisoning May
Have Doomed Beethoven
A house painter affected by chronic
lead poisoning. Wasted muscles
and wrist-drop are tell-tale
symptoms of lead poisoning.
Lead Industry
Advertises
through Children
The cover of the National
Lead Company’s trade
magazine conveys the
message that children can
be encouraged to use lead
paint safely on toys.
(Dutch Boy Painter,
December 1928)
“Deceit and Denial”,
Markowitz and Rosner
Lead Industry
Advertises
through Children
Even after WWII, lead was
promoted as a boon to
children. Here, National
Lead tells parents that lead
solder is not a problem,
even in canning evaporated
milk meant for babies.
(Saturday Evening Post,
February 23, 1946)
“Deceit and Denial”,
Markowitz and Rosner
Some People of Lead
“Deceit and Denial”,
History Markowitz and Rosner
• Felix Wormser, General Secretary Lead Industries Association
(LIA) from 1928 to 1947, led the industry’s battle against negative
publicity.
• Joseph Aub, Harvard University Lead Researcher supported by
LIA, regularly underplayed lead paint toxicity.
• Robert Kehoe, University of Cincinnati Kettering Labs
physiologist who helped formulate the lead industries position on
toxicity of PbEt4—Aub and Kehoe dominated lead toxicity
research for three decades from the 1920s.
• Herbert Needleman, academic pediatrician at Children’s
Hospital in Philadelphia, later psychiatrist at Harvard and then
University of Pittsburgh, leader in showing toxic effects of low
level lead in children.
Metabolism of Lead in Humans
Environmental Toxicology: Biological and Health Effects of
Pollutants, 2nd Edn. Ming-Ho Yu, CRC Press, Boca Raton 2005
Lead ingested
(20-400 mg/day)
Skeleton (90%)
t1/2 ≈ 25 years
(Estimate:
20–400 mg/day)
GI tract
Lead inhaled
(≈8% adult,
≈25% children,
perhaps 50%)
Blood
(≈92% adult,
≈75% children)
Lungs
Soft tissues
(liver, brain, pancreas,
kidneys, bone marrow)
t1/2 ≈ 40 days
Kidney
Feces
Urine
Lead is a systemic poison
National BLLs
BLL above 10 mg/dL (% children)
Casarett and Doull’s Toxicology: the basic science of poisons, 6th Edn. Curtis D. Klassen,
McGraw-Hill, New York, 2001
30
African
American
Children
25
Low Income
Children
20
All children
15
10
5
0
Pre'48
'48-73
'74Present
Age of residence (year built)
Nearly a million US
children are at risk from
lead poisoning (BLLs >
10 mg.dL-1) and specific
groups of children are at
greatest risk.
Biological Effects of Lead
Environmental Toxicology: Biological and Health Effects of Pollutants, 2nd
Edn. Ming-Ho Yu, CRC Press, Boca Raton 2005
• in plants, Pb inhibits electron transport in corn mitochondria, depresses respiratory rate in
germinating seeds, and inhibits various enzyme systems.
• Pb has a high affinity for the sulfhydryl group (–SH). Enzymes with function dependent
upon the –SH group may be inhibited by mercaptide formation leading to inactivation.
2RSH + Pb2+ RS–Pb–SR + 2H+
eg’s: adenyl cyclase: catalyzes conversion of ATP to cyclic AMP needed in brain
neurotransmission, aminotransferase involved in transamination, important in protein
metabolism
• in mammals, Pb2+ can compete with Ca2+ for entry at the presynaptic receptor — because
Ca2+ evokes release of acetylcholine (ACh) across the synapse, inhibition induces a
decreased end-plate potential. The miniature end-plate potential release of sub-threshold
levels of ACh is increased.
• adverse effects on nucleic acids leading to decreased or increased protein synthesis.
• Pb decreases aminoacid acceptance by tRNA and the ability of tRNA to bind to the
ribosome
• Pb causes dissociation of ribosomes
• Pb inhibits ALAD and ferrochelatase — both involved in heme biosynthesis —
ferrochelatase catalyzes the incorporation of Fe2+ into protophyrin IX
Scheme of Heme Biosynthesis Showing Sites
Where Pb Has an Effect
Casarett and Doull’s Toxicology: the basic science of poisons,
6th Edn. Curtis D. Klassen, McGraw-Hill, New York, 2001
Cytoplasm
Mitochondrion
Cytochrome C
Pb
Heme
+
Fe2+
Pb
Succinyl CoA
+ glycine
Fe2+
ALA synthetase
ALA-S
Protoporphyrin IX
Ferrochelatase
+
d-aminolevulinic
acid (ALA)
Pb
Pb
Heme
Oxidase
microsomal
Bilirubin
+
Fe
Copro III
Coproporphyrinogen
oxidase
Coproporphyrinogen III
Uroporphyrinogen III
Uroporphyrinogen I
ALA
dehydratase
ALA-D
Porphobilinogen
(PBG)
Pb
Site of Pb
inhibition
Reproductive Toxicology of Lead
Principles of Toxicology. Karen F. Stine & Thomas M. Brown, CRC Press, Boca Raton 1996
MALE
• Pb2+ (also Cd2+) are well known reproductive toxicants — exposure has been associated
with infertility and chromosomal damage in sperm.
• Cd2+ can cause testicular necrosis, probably by decreasing blood flow to the testes.
• Other male reproductive toxicants include:
– ethanol, which causes delay in testicular development and may effect supporting
cells
– the pesticides, kepone and DDT, the solvent, CS2, and tobacco smoke (smokers
have a higher % of abnormal sperm cells than non-smokers).
FEMALE
• Pb poisoning associated with reduced fertility, miscarriages and stillbirth since antiquity
• cytotoxic substances such as antineoplastic agents, heavy metals, polycyclic aromatic
hydrocarbons (PAHs), or radiation may damage oocytes, particularly in adult women .
• some cytotoxic substances, e.g., PAHs, must be metabolized to produce toxicity — the
activation can take place via cytochrome P450 in the ovaries (epoxide formation). Toxic
PAH metabolites destroy primary oocytes, providing one explanation for the observation
that smoking may lead to early menopause.
• other toxicants include pesticides, chlorinated hydrocarbons, and aromatic solvents
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Peroxidase Mimics
first effective peroxideusing enzyme mimics
Mechanism
detailed understanding
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High Oxidation state Chemistry
synthesis and characterization of
rare or unprecedented species
Water Cleaning
chlorinated pollutants,
antibiotics, phenols destruction
Oxygen Chemistry
direct reaction of
oxygen with ferric ion
Biological Warfare
Rapid destruction of
anthrax-like spores
Pesticides Decon
major class (thiophosphates)
rapidly-completely destroyed
Laundry
dye transfer inhibition,
stain removal
Textiles
dye bleaching,
effluent decolorization
Pulp and Paper
pulp bleaching, effluent smell,
organochlorine and color removal
Pharmaceuticals Decon
trace pharmaceuticals removed
from water supply
Drinking Water Disinfection
safer drinking water free of
chlorinated disinfection byproducts
Agricultural
animal husbandry,
renewable feedstocks
Chemical Warfare
rapid destruction of
chemical warfare agents
Petroleum Refining
removal of sulfur
contaminants in diesel & gasoline
Others
metal refining, carpet
recycling, hospital disinfection