1 enst 110: may 15 – june 17, 2006 mon-fri, room 9:45am-11:15am location: murphey room 204 call...
TRANSCRIPT
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Enst 110: May 15 – June 17, 2006
Mon-Fri, room 9:45AM-11:15AM
Location: Murphey room 204
Call number 33409, Section 001
http://www.unc.edu/courses/2006ss1/enst/110/001/
Rich Kamens; 966 5452 [email protected] http://airsite.unc.edu/~kamens/
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Textbook "Environmental Chemistry by
Colin Beard and Michael Cann, ISBN 0-7167-4877-0, publishers W.H. Freeman and Company, New York, 652 pages, 2005
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Who is Richard Kamens Professor of Atmospheric chemistry
and teach graduate classes in Environmental chemistry
Direct a smog chamber research gorup Focus on aerosol formation in the
atmosphere Direct a student exchange program
between UNC and Thai Universities
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UNC outdoor chamber
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New UNC Aerosol Smog Chamber
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Link gas and particle phases
C=OO
cis-pinonaldhyde
particleC=OO
Gas phase reactions
TSPC
CK
gasi
parti
p
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Particle phase
model TSP
mg
/m3
Particle phase
model TSP
mg
/m3
Measured particle mass vs. model
data
Time in hours EST
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The Thai-CEP Undergraduate/Graduate Exchange Program
• Pollution does not understand boarders.
• We must begin to address these problems from both inside and outside ones culture.
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General Approach Since 2001, UNC-CEP undergraduates
participated in a 6+ month experience in Thailand that begins at the end of May 2001
Small groups of UNC students come together with Thai students to study and work on a research project at various Thai universities.
Thai students will go back with UNC students for a semester at UNC.
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Feasibility of Ethanol Use and an Energy Analysis and Environmental Impact of Ethanol in Thailand:KMUTT 2001- 2002
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The Feasibility of Bio-diesel Production as Petroleum Substitute in Thailand : KMUTT 2004
Energy balance
Used vegetable oil
Production from Jatropha
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Introduction to Environmental Chemistry
Environmental chemistry may be defined as "the study of sources, reactions, transport, effects, and fates of chemical species in water, soil, and air environments, and the effects of technology thereon.” Manahan, 1994
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Class objectives:
Highlight some important areas in environmental chemistry
present some of the common techniques that environmental chemists use to quantify process that occur in the environment
It is assumed that everyone has courses in calculus and general chemistry.
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Class objectives:
We will cover general topics: Global warming, Strat. O3, aerosols, photochemical smog, acid rain, etc.
Develop relationships will be used to help quantify equilibrium and kinetic processes
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Thermodynamics
ui = uo1 +RT ln pi/p*
iL
fi = i Xipi*pure liquid
RT ln fi hx /fio
pure liq = RT lnfi H2O /fi
opure liq
fi hx = fi H2O
ln Kp = a 1/T+b
18amb
ambmfusiL T
TT
R
Spp is
)()(lnln **
Vapor pressure
)]()( ln.*lnT
T
T
Tp bbiL 58119
How to calculate boiling points
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Vapor pressure and Henry’s law
KPC
P Viawi
iwiw
satsat
satsat
iL*
iw
Solubility and activity coefficients
Octanol-water partitioning coefficients
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Additional Principles
Organic Acid-bases and LFERs
diffusion
chemical spills and mass transfer
Organic reactions in the environment
Solid- liquid interactions
photochemistry
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Homework, quizzes, exams To insure that most of us stay
reasonably current with the lectures and readings, an option is to have 8-10 unannounced quizzes throughout the semester.
They will take ~10 minutes. Quizzes will count 10% of your grade.
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Another option is a set of short questions to be answered and handed in before most lectures (20% of your grade)—your choice!
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There will be a homework problem set associated with each assigned chapter of the book.
These problem sets should take between 1 and 3 hrs.
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Some of these could appear on exams
There will be two exams
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Important Environmental Issues
Global warming and stratospheric ozone depletion
Concentration of environmental pollutants at the poles; pesticides in foods, etc.
Buildup of environmental chemicals in the oceans; contamination of soil and ground water
Particle exposure, photochemical oxidant exposure, acid deposition
Energy shortages
There are more than 70,000 synthetic chemicals that are in daily use:– solvents– components of detergents– dyes and varnishes– additives in plastics and textiles– chemicals used for construction– antifouling agents– herbicides, insecticides,fungicides
Why the interest?
Polynuclear Aromatic HC (PAHs) Dioxins Ketones PCBs CFCs DDT O3, NO2, aerosols, SO2
Some examples of environmental chemicals
Formed from small ethylene radicals “building blocks” produced when carbon based fuels are burned
Sources are all types of burning
in ChiangMai, Thailand: a) 2-stroke motorcycle
engines b) cars- light diesels c) open burning d) barbecued meat??
PAHs
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Combustion Formation of PAH
Badger and Spotswood 1960
(I) (II) (III) (IV)
C
C
C
C
C
C
CC
CC
CC
(VII) (VI) (V)
Benzo a Pyrene
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Some PAH structures
anthracene
phenanthrene
fluoranthenenaphthalene
benz(a)anthracene
benzo(a)pyrene [BaP]
Naphthalene, phenanthrene and anthracene are found in the gas phase
pyrene and fluoranthene are in both the gas and particle phase
BaA and BaP are mostly on the particles, Why???
PAHs
Metabolized to epoxides which are carcinogenic; O PAH
are indirect acting mutagens in bacterial mutagenicity tests (Ames-TA98+s9)
methyl PAHs are often more biologically active than PAHs
PAHs
Professor Gernot Grimmer extracted different types of smoke particles
He then took the extract and applied it to mouse skin
and implanted it into rat lungs
How did he obtain extracts? How did he fractionate his extracts??
Carcinogenic tests with PAHs
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Extraction by soxhlet extraction starts with solvent (MeCl2) in a flask
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Hot solvent fills this chamber and bathes the filter
Heat
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The solvent in the filter chamber then drains back into the heated flask withchemicalsfrom the particleson the filter
Heat
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The organic liquid in the soxhlet flask can be concentrated by evaporation by a dry nitrogen stream or rotary evaporation
the extract can then be fractionated into different polarity compound groups
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Professor Grimmer fractionated the exhaust extracts
HPLC
PAH 2&3 rings
Total
PAHs>3 rings
Total
Total-PAHs
uv orfluorescencedetector
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skin painted mice implanted rat lungs
What did Grimmer see when exposed rats and mice to the different fractions?
0
10
20
30
40 %
can
cers
TotalTotal-PAHs
PAHs 2&3 ringsPAHs > 3 rings
rat lungs Mouse-skin
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Analysis of reaction products
soxhlet extraction for 3 hours– blow up with dry gentle flow of nitrogen to
about 0.5 to 1 ml evaporation to about 0.5 to 1 ml 1 to 2 ul injected directly to GC-MS (EI and CI) The remainder solution: derivatization
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In environmental samples why don’t we see some large highly oxygenated compounds that form in the atmophere??
Reverse reactions to the original aldehyde parent structures can occur during sample work up/solvent extraction procedures;
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PFBHA O-(2,3,4,5,6-pentafluorobenzyl) -hydroxylamine for carbonyl groups
FF
F
F F
CH2 O NH2
H2O
PFBHA
R1
C
O
R2
CH2
F F
F
FF
ONC
R1
R2
acetone or ketone
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Pentafluorobenzyl bromide (PFBBr) derivatization for carboxylic and hydroxyl groups
CH2 C
O
OH
H3C CH3
C
O
H O
FF
F
F F
CH2Br
C CH2
O
HO C O CH2
F F
F
FF
OH3C CH3
HBr
PFBBr
C CH2
O
O C O CH2
F F
F
FF
OCH3 CH3
CH2
FF
F
F F
2 HBr
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BSTFA for carbonyl, hydroxyl, and/or carboxylic
BSTFA
R OH
carboxylic acid or alcohol
C N
Si(CH3)3
CF3
O(CH3)3Si
C O
H2N
F3CR
O(CH3)3Si
C NH
Si(CH3)3
CF3
O
+
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Compound
Mw, g mol-1Structure m /z (EI) Compound
Mw, g mol-1Structure m /z (EI)
-Pinene oxideMw=152
67 (100)10983152
NopinoneMw=138
83 (100)5595109
-Pinene oxideMw=152
79 (100)7141152
MenthoneMw=154
83 (100)56112140
Limonene-2-oxideMw=152
67 (100)9410879137
CamphoreMw=152
95(100)8110955152
d-LimoneneMw=136
68 (100)9379136
MyrtenolMw=152
79 (100)91108152
2-Hydroxy-3-pinanoneMw=168
71 (100)99168
cis -VerbenolMw=152
94 (100)10981137
CineoleMw=154
84 (100)71108154139
trans -Pinane-1,10-diolMw=170
82 (100)675570152
MyrtenalMw=150
79 (100)107135150
trans -p-Menth-6-en-2,8-diolMw=170
109 (100)59 79
O
C O H
O
O
O
H
OHO
O
C
C H O
OH
O
O
O H
C O H
HOOH
GC-EIMS for Oxygenated Terpenoids
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Thermal desorption particle beam mass spectrometry (Paul Ziemann)
Particle generator or smog chamber
These are some of the most toxic organics in the environment - LD50
Created by burning organics which have chlorine; incineration is a big source of atmospheric dioxins and furans
bleaching in making paper is another source
Chlorinated dibenzo dioxins and Furans
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Combustion Formation of Dioxins from Polychlorinated phenol
O H
PolychlorinatedPhenol
Flame
OH .
.OO H
C ly
+
O
O H
+ OH
Chlorinated dibenzo dioxin
ClxO
O
Shaub & Tsang, ES&T 1983.
Cly
Clx
ClxCly
Clx
They have the following general structures
O
O Clx
Cly chlorinated dioxin
They have the following general structures
O
O Clx
Cly chlorinated dioxin
O Clx
Cly chlorinated furan
The most toxic is either the 2,3,7,8 tetrachlorodibeno dioxin or furan
More than 200 different structures are possible
O
O
Cl
Cl
Cl
Cl
These types of compounds produce toxic enzymes: arylhydrocarbon hydroxylase and 7-ethoxyresorufin deethylase
At low concentrations they may behave as environmental estrogens
Environmentally, they are unreactive and can be transported long distances
They did not start to show up in the environment until the 1920s when there was a big increase in the production of chloro-organics (Professor Ron Hites, and students)
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Environmental Fate of Chlorinated Dioxins and Furans
(Czuczwa and Hites, 1984)
Collected core sediment samples from southern Lake Huron in the USA
Based on sedimentation rates they established age vs. concentration profiles for chlorinated dioxins and furans
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US coal consumption vs chlorinated aromatic production
0
100
200
300
400
500
600
700 U
S c
oal
in 1
0^6
shor
t-to
ns
0
200
400
600
800
10^6
lbs
Cl-a
rom
atic
s
1860 1880 1900 1920 1940 1960 1980
Year
Coal
chloro-aromatics
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Chlorinated aromatic production vs dioxinand furan conc. in lake core samples
0
200
400
600
800
1000
1200 To
tal d
ioxi
ns a
nd fu
rans
in p
pt
0
200
400
600
800
10^6
lbs
Cl-a
rom
atic
s
1900 1920 1940 1960 1980
Year
chlorinateddioxins andfurans
chloro-aromatics
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PCBs in the U.S. Great Lakes
PCBs were banned in the early 1970s
In 1980 Eisenreich and co-workers estimated that still 85% of the PCBs in the US great lakes came from atmospheric sources.
Total Flux = Jair + Jrain + Jparticles
Jair = vw ( Cw-P/KH)
if resistance to mass transfer is in the water phase
Jair = va (Cw KH - P)/RTif resistance is in the gas phase
Polychlorinated biphenyls (PCBs)
RT ln fair /fio
pure liquid = RT lnf H2O /fi
opure liquid
fair = f H2O
In the late 1980s a fugacity model was used to represent the distribution of PCBs in different environmental compartments
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In 1990 Eisenreich and co-workers reported that ambient measurements over the great lakes were generally constant for the past 10 years.
For the past 15 years sources to the lakes had declined because of the PCB ban.
Based on mass transfer calculations it was proposed that during the summer months the lakes were actually a source of atmospheric PCBs.
used as coolants - insulation fluids in transformers, capacitors , plastercisers, additives to epoxy paints
are thermally stable and biologically stable
can exist in the gas and particle phases
Polychlorinated biphenyls (PCBs)
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Cl y
Cl x
PCB structures
Environmentally, they used to be considered unreactive, but there is evidence for some bio-degradation; they can be transported long distances
Up until the 1970s there was a lot of dumping of industrial wastes in the USA
In one example, from 1950 to 1975 there were two capacitor manufacturing plants on the Hudson river in New York State, which discharged into the river.
Levels in the river sediments downstream from the plants exhibited concentrations of 10 ppm which was a factor of two higher than commonly found.
Dredging was considered financially impossible
it was also believed that is very difficult to bio-degrade PCBs with multiple chlorine atoms
Investigations in the 1980s revealed that PCBs in sediments were being slowly converted to the mono and dichloro forms via very slow anaerobic processes.
{CH2O} + H2O + 2Cl-PCB---> CO2 +2H++ 2Cl-- +2H-PCB
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What do we do now, when new compounds are introduced into the environment...??
toxicity?? low concentration health effects? damage to the ecosystem ? where will it show up in the
environment? how is it transported in the
environment and what is its life-time?
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An example is a new compound called D5. It is a silicon-oxygen compound
It is used to make silicone plastics.
It is possible that it could be used to replace toxic solvents like toluene and dichloro-methane.
Before it can be put into use in the US, we need to know its toxicity, chemical reactivity , environmental half-life, etc.
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New compounds are introduced into the environment ... Toxicity? Where will it go?
Si
O
Si
O
Si
O
O
Si
O
Si
CH3
CH3CH3H3CCH3
H3C
CH3 CH3H3C H3C
Si
O
Si
O
Si
O
O
Si
O
Si
CH3
CH3CH3H3CCH3
H3C
CH3 OHH3C H3C
D5 D4D'OHD4TOH
OH.
In 1976 there was a significant industrial explosion in the town of Seveso, Italy that spewed out chlorinated dioxins.
735 people were evacuated from the immediate vicinity.
Now excess cancers are showing up.
Some examples of environmental exposures
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Seveso, Italy Dioxin release
Over the past eight years the birth ratio has changed from 106 males: 100 females to 26:48
observed increases in cancers
decline in number of males born
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A similar observation has been made in the bird population
In the Great Lake region of the USA during the 1980’s, hatchlings of crested cormorants with a crossed bill deformity were almost always female
Male birds did not show the deformity
Scientist speculate that the chemicals causing the deformity were also killing the males before they hatched.
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1. There is a general concern that if we observe abnormalities in wildlife, similar kinds of mechanisms may exist in humans.
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Mercury poisoning off the coast of Minamata, Japan is an example
Fishermen in the 1950s noticed sea birds were dying and feral cats that scavenged fish from the docks were “stiff legged”
Cerebral palsy and mental retardation started showing up in children.
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2. Toxic loads
Scientists have hypothesized that the fetus is sharing the mother’s toxic load, and may actually provide some protection to the mother by reducing her internal exposure.
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2. Toxic loads
Children get 12% of their lifetime exposure to dioxins during the 1st year.
Their exposure is 50 times greater than an adult during a very critical developmental period.
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2. Toxic loads
Firstborns from dolphins off the coast of Florida usually die before they separate from their mothers
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2. Toxic loads It is speculated that mother dolphins
unload 80% of their accumulated pollutants into their calves, probably during nursing.
The greatest exposures occurs with the 1st born
Does this have any implications for humans?
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3. Pesticide exposures
Children of farm families in the western Minnesota area of the US have significantly higher rates of birth defects than the general population.
The highest rates are among children conceived in the spring when spraying of pesticides is most intense; male babies had far more birth defects than females
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4. The end points may not only be cancer, but compromised immune systems and generally poorer health.
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4. Immune systems & Mother’s milk
In the Netherlands researchers have found that children with higher levels of dioxins and PCBs in their bodies have more health problems (immune system and hormonal changes) than children with lower levels.
This was linked to levels of PCBs in Mother’s milk.
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4. Mother’s milk
Overall, however, it was concluded that nursing was still of greater benefit than bottle feeding babies, but that even mild exposures may weaken immunity
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4. Mother’s milk
Mother’s milk from Inuit Indians in the Canadian Arctic has 7 times the PCBs as mother’s milk from women in the urban industrialized areas of southern Quebec.
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4. Mother’s milk
During the first year, Inuit babies suffer through 20 times more colds than babies in southern Quebec.
Acute ear infections are rampant.
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4. Mother’s milk
Babies nursed by mothers with the highest contamination levels in their milk are afflicted with more acute ear infections than bottle fed Inuit babies.
Many of these children don’t seem to produce enough antibodies for childhood vaccinations to take.
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5. PCBs and lower intelligence
There is evidence of lower intelligence in babies exposed to PCBs.
In adults, a blood-brain barrier insulates the brain from many potentially harmful chemicals circulating through the body
In a human child this barrier is not fully developed until 6 months after birth.
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5. PCBs and lower intelligence
In 1979 in Taiwan, more than 2000 people were exposed to PCB-contaminated cooking oil.
In the 1st 3 months many babies died outright. As the surviving children grew up, many were slower intellectually than other kids their age, were hyperactive and had behavioral problems.
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5. PCBs and lower intelligence
Similar observations were made in "high-PCB kids" in the Lake Michigan area.
This was associated with mothers eating salmon and trout from the Lake during the years before their children were born.
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5. PCBs and lower intelligence
At age 4 the high exposure group had poor short term memories. At age 11 the 30 most highly exposed kids had average IQ scores that were 6 points lower than the lowest-exposed group.
biomarker-metabolites???
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6. DDT and immune system damage
In a recent study (1998), residents whose homes are within a mile of Aberdeen, Texas pesticide sites show elevated DDE levels in their blood.
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6. DDT and immune system damage
DDE is a byproduct of the body’s attempt to break down the pesticide DDT, which has been banned in the USA since 1972.
“Levels of plasma DDE in the study population overall were low (6ppb) compared to nationwide levels between 1976 and 1980, just after the DDT ban,” (UNC, Prof. Vine)
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6. DDT and immune system damage
Younger Aberdeen residents – those between ages 18 and 40 – and people who lived there before 1985 when the plants were operating did show a two- to three-fold increased risk of herpes zoster,
or shingles, which indicates modest suppression of the body’s immune system
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7. Sexual impairment
There is evidence for sexual impairment in both animals and humans from high PCB exposures and other environmental chemicals.
Male beluga whales in the very polluted St. Lawrence River have exhibited female organs.
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7. Sexual impairment
Highly exposed humans, alligators and panthers exhibit smaller male sex organs and low sperm counts.
Testicular cancers have nearly doubled among older teenagers in the US between 1973 and 1992.
In previous lectures I have said these have been linked to toxic exposures....long way from finding proof.
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7a. Sexual impairment
In a new study (Hardwell et al, Environ Presp, 2003) woman who’ve had substantial exposure to certain environmental pollutants are more likely to bear sons who develop testicular cancers (men ~ 30 years of age)
From 1973-1999 testicular cancers up 67%
Men with test-cancers had high cis nona chloridane, not PCBs, etc
Mothers, however, had high PCBs, HCB (hexa-chlorobenzenes) and cis nona chloridane
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7b. Sexual impairment
These same mothers probably had high exposures when environmental contaminets peaked in Scandinavia in the 1970s
Richard Sharpe of Edinburogh and Niels Skakkebek (Denmark) propose that exposure to endocrine disruptors before birth can alter testicular-cell development and some of these cells may be cancerous after puberty.
This may also may explain rising rates of male infertility, and other sexual deformities
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8. Endocrine disrupters
These studies have led to the notion of environmental "endocrine disrupters".
In the lock and key relationship between hormone and receptor molecules, these "hormone impostors" can:
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8. Endocrine disrupters
bind with receptors and trigger biological processes
or bind with receptors and tie up an active hormone site
Some of these have been called environmental estrogens
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9. Other chemicals
From a historical perspective, everyone is now carrying at last 250 measurable chemicals that were not part of human chemistry before the 1920s (Peter Myers, 1996)
The most basic toxicity testing results cannot be found in the public record for nearly 75% of the top volume chemicals in commercial use in the USA
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9. Other chemicals
In other words, the public cannot tell whether a large majority of the highest-use chemicals in the United States pose health hazards or not (Amicus Journal, p23, Spring 1998).
An example are phthalates that go into many types of plastics which have been shown to reduce the sperm counts in mice.
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9. Other chemicals
Bisphenol-A (BPA) is an additive in polycarbonate plastics used in food liners, dental sealants, and dental fillings.
BPA causes increased prostate size in mice exposed to tiny doses while in the womb. These doses were 25,000 times smaller than the EPA threshold.
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9. Phthalates
Exposure of female rates to 200 to 1000 mg/kg body weight results in much lower testosterone in male offspring( L. Earl Gray. Jr. EPA, RTP, J. Tox and Ind. Health, Mar, 1999).
Exposures to the herbicide linuron made the epididymis (sperm-storing organ in rats) much smaller in male rats.
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epididymus
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Recommendations During the insecticide spraying season,
farmers should not try to have children. Limit exposures to pesticides around the home. When possible, buy foods that were grown
without pesticides. Governments must try to limit PCB introduction
into the environment. If incineration is used, chlorinated plastics
should be removed, along with modern technology.