Envr 210 Tues. and Thurs- 3 credit hours: Room 1001 HookerSPH 11am to 12:15 pm snow days call me at 942 4880 or cell.
Download
Report
Transcript Envr 210 Tues. and Thurs- 3 credit hours: Room 1001 HookerSPH 11am to 12:15 pm snow days call me at 942 4880 or cell.
Envr 210
Tues. and Thurs- 3 credit hours: Room 1001 HookerSPH
11am to 12:15 pm
snow days call me at 942 4880 or
cell 919 614 4730
room 2304
http://www.unc.edu/courses/2006spring/envr/210/001/Env
r210.html
Rich Kamens; 966 5452
[email protected]
http://airsite.unc.edu/~kamens/
1
Introduction to Environmental
Physical Organic 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
2
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
organic and physical chemistry.
3
Class objectives:
Partitioning
is a thread that runs
through the course
Linear
free energy relationships
will be used to help quantify
equilibrium and kinetic processes
4
Thermodynamics
= uo1 +RT ln pi/p*iL
fi = i Xipi*pure liquid
ui
RT
ln fi hx /fiopure liq = RT lnfi H2O /fiopure liq
fi hx = fi H2O
ln
Kp = a 1/T+b
5
Vapor pressure
Tb
Tb
ln p *iL 19(1 ) 8.5(ln )]
T
T
How to calculate boiling points
ln piL*
ln p is
*
( S fus ) (Tm Tamb )
R
Tamb
6
Vapor pressure and Henry’s law
K
sat
iaw
P isat
C sat
iw
sat
iw
P iL* V iw
Solubility and activity
coefficients
Octanol-water partitioning
coefficients
7
Additional Principles
Organic
Acid-bases and LFERs
diffusion
chemical
Organic
Solid-
spills and mass transfer
reactions in the environment
liquid interactions
photochemistry
8
Homework, quizzes, exams
To insure that most of us stay reasonably
current with the lectures and readings, an
option is to have 6-8 unannounced
quizzes throughout the semester.
They will take ~10 minutes. The first quiz
will be on Chapter 2 since we will not cover
Chapter 2. Quizzes will count 10% of your
grade.
9
Another
option is a set of short
questions to be answered and handed
in before most lectures (5% of
grade)—your choice!
10
There will be a homework problem set
associated with each assigned chapter of
the book. It is due a week after the
completion of the book chapter.
These problem sets should take between 3
and 10 hrs.
Answers will graded and
returned to you as soon as possible. These
will count for 25% of your grade.
11
In
addition, you are expected to work
through the illustrative examples and
problems
which have answers in the test on your
own.
Some of these could appear on exams
There
will be three exams (70% of your
grade ), 25% homeworks, 5%???
12
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
13
Why the interest?
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
Some examples of
environmental chemicals
Polynuclear Aromatic HC (PAHs)
Dioxins
Ketones
PCBs
CFCs
DDT
O3, NO2, aerosols, SO2
PAHs
Formed
from small ethylene radicals “building
blocks” produced when carbon based fuels
are burned
Sources
in
are all types of burning
ChiangMai, Thailand:
a) 2-stroke motorcycle engines
b) cars- light diesels
c) open burning
d) barbecued meat??
Combustion Formation of PAH
Badger and Spotswood 1960
C
C
C
C
C
C
(II)
(I)
C
C
C
C
C
(IV)
(III)
C
Be nz o a Pyre ne
(VII)
(VI)
(V)
17
Some PAH structures
fluoranthene
naphthalene
anthracene
benz(a)anthracene
phenanthrene
benzo(a)pyrene [BaP]
18
PAHs
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 (AmesTA98+s9)
methyl PAHs are often more
biologically active than PAHs
Carcinogenic tests with 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??
Extraction
by soxhlet extraction starts
with solvent (MeCl2) in a flask
22
Hot
solvent fills this chamber and
bathes the filter
Heat
23
The
solvent in the filter chamber then
drains back into the heated flask with
chemicals
from the
particles
on the
filter
Heat
24
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
25
Professor Grimmer fractionated
the exhaust extracts
Total
HPLC
uv or
fluorescence
detector
Total
PAH 2
PAHs> Total
&3 rings 3 rings -PAHs
26
What did Grimmer see when
exposed rats and mice to the
different fractions?
skin
painted mice
implanted rat lungs
27
40
% cancers
30
20
10
0
Total
PAHs 2&3 rings
Total-PAHs
PAHs > 3 rings
rat lungs
Mouse-skin
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
29
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;
30
PFBHA O-(2,3,4,5,6-pentafluorobenzyl)
-hydroxylamine for carbonyl groups
PFBHA
acetone or ketone
F
F
O
C
F
CH2 O
NH2
R2
R1
F
F
F
F
R1
C
N
O
CH2
F
R2
H2O
31
F
F
Pentafluorobenzyl bromide (PFBBr)
derivatization for carboxylic and hydroxyl groups
PFBBr
H3C
O
HO
O
CH2
C
F
F
CH3
C
OH
F
CH2 Br
F
F
O
HO
H3 C
CH3
F
O
CH2 C
C
O
CH2
F
F
F
O CH3
CH2
F
F
HBr
F
F
F
F
F
O
C
CH3
F
O
CH2 C O
CH2
F
F
F
2 HBr
32
BSTFA for carbonyl, hydroxyl, and/or carboxylic
BSTFA
carboxylic acid
or alcohol
R
CF3
C
OH
(CH3)3Si
O
N
Si(CH3)3
H2N
O
C
(CH3)3Si
O
F3C
R
+
CF3
C
O
NH
Si(CH3)3
33
GC-EIMS for Oxygenated Terpenoids
Compound
Mw, g mol-1
a-Pinene oxide
Mw=152
m /z (EI) Compound
Mw, g mol-1
67 (100) Nopinone
109
Mw=138
83
152
79 (100) Menthone
71
Mw=154
41
152
Structure
O
b-Pinene oxide
Mw=152
O
Structure
m /z (EI)
83 (100)
55
95
109
83 (100)
56
112
140
O
O
C
Limonene-2-oxide
Mw=152
67 (100)
94
108
79
137(100)
68
93
79
136
O
H
d-Limonene
Mw=136
2-Hydroxy-3pinanone
Mw=168
Cineole
Mw=154
Myrtenal
Mw=150
OH
O
O
CHO
Camphore
Mw=152
O
CO H
Myrtenol
Mw=152
71 (100)
99
cis -Verbenol
168
Mw=152
84 (100)
71
108
154
139
79 (100)
107
135
150
trans -Pinane-1,10diol
Mw=170
trans -p-Menth-6-en2,8-diol
Mw=170
HO
C
95(100)
81
109
55
152
79 (100)
91
108
152
94 (100)
109
OH
81
137
OH 82 (100)
67
55
70
152
109
OH
(100)
59
OH
79
34
Thermal desorption particle beam
mass spectrometry (Paul Ziemann)
Particle generator or
smog chamber
35
Chlorinated dibenzo dioxins and
Furans
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
Combustion Formation of Dioxins from
Polychlorinated phenol
OH
Clx
OH .
Flame
Clx
OH
Polychlorinated
Phenol
+
.O
C ly
Clx
O
+ OH
O
OH
Cly
Clx
O
Cly
Chlorinated dibenzo dioxin
37
Shaub & Tsang, ES&T 1983.
They have the following general
structures
O
Cly
O
Clx
chlorinated dioxin
They have the following general
structures
O
Cly
O
O
Cly
Clx
chlorinated dioxin
Clx
chlorinated furan
More than 200 different
structures are possible
The
Cl
O
Cl
Cl
O
Cl
most toxic is either the 2,3,7,8
tetrachlorodibeno dioxin or furan
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)
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
43
US coal consumption vs chlorinated
aromatic production
800
600
500
600
Coal
400
400
300
chloroaromatics
200
200
100
0
1860
1880
1900
1920
1940
1960
10^6 lbs Cl-aromatics
US coal in 10^6 short-tons
700
0
1980
Year
44
1200
800
1000
600
800
600
chloroaromatics
400
chlorinated
dioxins and
furans
400
200
200
0
1900
1920
1940
1960
10^6 lbs Cl-aromatics
Total dioxins and furans in ppt
Chlorinated aromatic production vs dioxin
and furan conc. in lake core samples
0
1980
Year
45
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.
46
Polychlorinated biphenyls (PCBs)
Total
Jair
Flux = Jair + Jrain + Jparticles
= vw ( Cw-P/KH)
if resistance to mass transfer is in
the water phase
Jair
= va (Cw KH - P)/RT
if resistance is in the gas phase
In the late 1980s a fugacity model
was used to represent the
distribution of PCBs in different
environmental compartments
RT
ln fair /fiopure liquid = RT lnf H2O /fiopure
liquid
fair = f H2O
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.
49
Polychlorinated biphenyls (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
PCB structures
Cl x
Cl y
Environmentally,
they used to be
considered unreactive, but there is
evidence for some bio-degradation;
they can be transported long
distances
51
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
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 lifetime?
55
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.
56
New compounds are introduced into the
environment ... Toxicity? Where will it go?
CH 3 H3C
H3C
Si
CH 3
Si
Si
O
O
CH 3 H3C
H3C
OH.
O
OH
Si
O
O
O
CH 3
CH 3
Si
H3C
CH 3
O
H3C
D5
O
CH 3
Si
Si
Si
H3C
CH 3
CH 3
Si
Si
O
H3C
O
CH 3
CH 3
D4TOH
D4D'OH
57
Some examples of
environmental exposures
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.
Seveso, Italy Dioxin release
Over
the past eight years the birth ratio
has changed from 106 males: 100
females to 26:48
observed
decline
increases in cancers
in number of males born
59
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.
60
1. There is a general concern
that if we observe
abnormalities in wildlife,
similar kinds of mechanisms
may exist in humans.
61
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.
62
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.
63
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.
64
2. Toxic loads
Firstborns
from dolphins off the
coast of Florida usually die before
they separate from their mothers
65
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?
66
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
67
4. The end points may not only be
cancer, but compromised
immune systems and generally
poorer health.
68
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.
69
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
70
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.
71
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.
72
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.
73
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.
74
5. PCBs and lower intelligence
In 1979 in Taiwan, more than 2000
people were exposed to PCBcontaminated 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.
75
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.
76
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???
77
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.
78
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)
79
6. DDT and immune system damage
Aberdeen residents – those
between ages 18 and 40 – and people
who lived there before 1985 when the
plants were operating did show a twoto three-fold increased risk of herpes
zoster,
Younger
or
shingles, which indicates modest
suppression of the body’s immune
system
80
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.
81
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
82
from finding proof.
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 (hexachlorobenzenes) and cis nona chloridane
83
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
84
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:
85
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
86
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
87
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.
88
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.
89
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.
90
epididymus
91
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.
92