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TOXIC ORGANIC
CHEMICALS
Environmental Chemistry

Submitted by: Jerrypol C
...
Flora Dayag
5/21/2015

INTRODUCTION
The word “toxicity” describes the degree to which a substance is poisonous
or can cause injury
...
This term relates to poisonous or deadly effects on the body by
inhalation (breathing), ingestion (eating), or absorption, or by direct contact with
a chemical
...

There is increasing demand to evaluate the potential health risk of these
substances under the conditions in which they are used
...

Now there is a need for their complete replacement or at least some
modifications are essential in their structures or compositions so that their harmful
effects may be minimized
...
VOCs include a variety of chemicals, some of which may have shortand long-term adverse health effects
...

VOCs are emitted by a wide array of products numbering in the thousands
...


ii

Organic chemicals are widely used as ingredients in household products
...
Fuels are made up of
organic chemicals
...

EPA's Office of Research and Development's "Total Exposure Assessment
Methodology (TEAM) Study" (Volumes I through IV, completed in 1985) found
levels of about a dozen common organic pollutants to be 2 to 5 times higher inside
homes than outside, regardless of whether the homes were located in rural or
highly industrial areas
...

On this reasearch paper, we will be dealing with the sources, effects, and
treatments of toxic organic chemicals found in the environment
...


ii

56

1

W
...
Mullins © 1974

Gregg Patterson

ii

Results of NAWQA studies show that pesticides are widespread in streams and ground
water sampled within agricultural and urban areas of the Nation
...

The frequency of pesticide contamination, however, is greater than expected
...
Moreover, individual pesticides seldom were found alone— almost every water and fish
sample
from streams and about one-half of samples from wells with a detected pesticide contained two
or more
pesticides
...
Average concentrations in streams
and wells rarely exceeded standards and guidelines established to protect human health
...

Important questions remain unanswered about potential risks of pesticide contamination
to humans and the environment
...
Long-term exposure to low-level mixtures of pesticide compounds,
punctuated with seasonal pulses of higher concentrations, is the most common pattern of
exposure, but the effects of this pattern are not yet well understood
...

Pesticides have numerous beneficial effects
...

1

For example pesticides may be used in the prevention of malaria, which kills up to 1
million children per year, and for preventing other vector-borne diseases such as dengue,
leishmaniasis and Japanese encephalitis
...

Their mode of action is by targeting systems or enzymes in the pests which may be
identical or very similar to systems or enzymes in human beings and therefore, they pose risks
to human health and the environment
...
There is growing
concern about children's exposure to pesticides and their special susceptibility
...


The pie chart shows the global use of pesticides
and the different types
...


2

•It is important to consider the
presentation, concentration and formulation
of the products, as the toxic effects depend
on the physical state of the product and also
on the characteristics of the solvent or other
substances contained in the formulation
...
(See
US EPA website
...

There is a large variety of pesticides designed to kill specific pests – those most widely

used
are listed below
...
This category also includes
insect repellents such as diethyltoluamide
(DEET)
and citronella (of natural origin)
...
g
...

•Fungicides (to kill mould or fungi): when
applied to wood, they are called wood

preservatives
...

•Fumigants are pesticides that exist as a gas
or a vapour at room temperature and may be
used as insecticides, fungicides or
rodenticides, especially in closed storage
places – as they kill every living organism
...


Some domestic, agricultural or veterinary products may contain more than one chemical
belonging to the sameor a different chemical group
...
For example exposure can occur in children
during:
- agricultural use (spraying fields) or seed treatment;
- use in cattle dips and in animal husbandry;
- use as household insecticide (indoor), or in gardens;
- sanitary indoor use in schools, offices, hospitals and other institutions;
- public health use (outdoor or indoor): in parks and urban areas and for vector control (e
...

malaria, Chagas
disease, dengue and onchocercasis); - medical human use: to treat head lice or scabies; and veterinary products for pets (e
...
to treat infestations with fleas or ticks)
...

This should be addressed to
gain an understanding of
how acute and chronic
exposure may occur because
air, water and soil are the
media of exposure
...

When a pesticide is applied directly to a target pest (plant or animal) the whole site is affected
including crop

plants, soil organisms and, potentially, humans and wildlife in the immediate area
...
Once on the target
4

site, the pesticide may "drain" (6) into surface waters or volatilize (7) into the air
...
From the animals or plants where it
was applied the pesticide may leak (5) into groundwater
...
The persistence of the pesticide depends on its
physical and chemical properties (partition coefficients,degradation rates, deposition rates) and
the characteristics of the environment
...

Studies in the Arctic have shown that insecticides and herbicides persist 3 to 8 times longer in
cold climates than in temperate ones
...
A recent survey found that 90% of

streams and 50% of wells tested were
positive for at least one pesticide
...
The word pesticide may refer to
insecticides, herbicides, fungicides, or other pest control formu- lations
...
1
Organochlorine pesticides are a large class of multipurpose chlorinated
hydrocarbon chemicals
...
Thus, they stay in
the environment and food web long after the being applied
...

Many organochlorine pesticides are endocrine disrupting chemicals, meaning
they have subtle toxic effects on the body’s hormonal systems
...


Organochlorine Pesticides in Our Bodies
Organochlorine pesticides are ubiquitous environmental con- taminants because
they break down very slowly
...
4 Many organochlorine pesticides are persistent organic pollutants (POPs), a
class of chemicals known to break down very slowly and bio- accumulate in lipid rich
tissue such as body fat
...
5 Chemicals in a
maternal body bur- den may be transferred to fetuses in utero via the placenta and
to children though breast feeding
...
6

6

How Are We Exposed?
Because of the multiple types and uses of organochlorine pes- ticides, there
are many ways people can be exposed to these chemicals
...
7,8 Using pesticides in your home or on your land
may increase your exposure to these chemicals, and living or working close to where
pesticides are used is also a risk factor
Organochlorine pesticides are not often used in personal prod- ucts because
of their toxicity, but some products, such as lice shampoos, may be a source of
exposure
...


Organochlorine pesticides are carried long distances via atmospheric and oceanic
currents from where they are manu- factured and used, and build up in the fatty
tissues of animals
...
Fetuses and chil- dren may be exposed to pesticides in utero as well as
through breast milk
...
It is important
to note that both the dosage and the timing of exposure have significant effect on
any potential health outcome
...

The health effects of organochlorine pesticide exposure depend on the
specific pesticide, the level of exposure, the timing of exposure and the
individual
...

Cancer
Numerous studies have linked organochlorine pesticide exposures with
cancers and other health effects
...
Exposure to DDT early in life is associated with
an increased breast cancer risk later in life
...
A
study of women from an agricultural area in India showed that women with breast
cancer had much higher total organochlorine pesticide concentra- tions in their
blood
...


Neurodevelopmental Outcomes

There is clear evidence that exposure to organochlorine pesti- cides disrupts
normal development
...
Prenatal exposure to the
organochlorine pesticide chlordane has been linked to reduction of testosterone in
adult female rats and behavioral changes in both sexes
...


Organochlorine pesticide exposure is associated with neuro- developmental
health effects in humans
...
Children born in agricultural areas where pesticides
8

were applied were found to have lower performance on numerous neurobehavioral
assessments when compared to children not born in an agricultural region
...


Reproductive Effects

In humans, maternal concentrations of DDE (a metabolite of DDT) above 10
ppb (µg/L) are associated with preterm birth and babies’ size
...
Maternal ex- posure to beta-HCH, a byproduct of lindane manufacture, is
associated with preterm births
...
83 ppb (ng/mL) in their blood
...
Women with
hexachlorobenzene concentrations that ranged from 7
...
0 ppb (ng/mL) had
altered thyroid hormone levels
...
Women with decreased thyroid hormone had
average dieldrin concentrations of 5380 ppb (ng/mL)
...
3Thyroid hormones are critical for normal
growth and development in fetuses, infants, and small children
...
Additionally, there is specu- lation that thyroid disrupting chemicals may
play a role in the development of autism
...


Lindane and Endosulfan are both current use organochlorine pesticides
...


Lindane

Lindane is a pesticide used both as an agricultural insecticide and as a
treatment for scabies and lice
...

In a study of women giving birth, high levels of lindane in maternal blood
were found to be associated with intra-uterine growth retardation in fetuses
...
Women with recurrent
miscar- riages had average lindane concentrations of 6
...

Lindane also disrupts natural levels of estrogens, androgens and thyroid
hormones in rodents
...
This is significant
because it suggests that lindane may have the greatest effect during development
...
Dopamine is an
important neurotransmitter with effects on mood and behavior
...


10

Exposure to lindane decreased both thyroid hormones and progesterone in
developing lambs

Endosulfan

Endosulfan is an organochlorine pesticide used primarily in agriculture
...

Endosulfan has been shown to compete with estradiol for binding with an
estrogen receptor—if estradiol cannot bind to the receptor site, then it cannot
influence the cell’s growth and development
...
44 Endosulfan has been shown to act like estrogen and
reduce the levels of testosterone and other hor- mones in rats
...
47 ppb
...

Chronic exposure to endosulfan has been associated with abnormal behavior
in rats
...
Researchers found that exposure to endosulfan during
growth and development is likely to cause permanent neurobehavioral impairment
...


Regulation of Organochlorine Pesticides

In the U
...
, pesticides are regulated by the Environmental Pro- tection Agency
(EPA) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)
...
The UN and World Health Organization (WHO) may also influence use
of pesticides through treaties and declarations
...
The European Union (EU) recently proposed that
endosulfan be included under provisions of the Stockholm Convention as well
...
S
...


Dichlorodiphenyltrichloroethane (DDT)

Dichlorodiphenyltrichloroethane (DDT) is an insecticide used in agriculture
...
DDT has also been used in the past for the treatment of lice
...
DDT and its related
chemicals persist for a long time in the environment and in animal tissues
...
DDT can be absorbed by eating, breathing, or touching products
contaminated with DDT
...
DDT and DDE are stored in the body’s fatty tissues
...
Both chemicals are found in breast milk,
resulting in exposure to nursing infants
...

Following exposure to high doses, human symptoms can include vomiting, tremors
or shakiness, and seizures
...


DDT is considered a possible human carcinogen
...
Prior survey periods of 1999–2000 and 2001–2002 are also included in the
Fourth Report
...

le DDT
...
DDE stays in the body longer than DDT, and DDE is
an indicator of past exposure
...

Finding measurable amounts of DDT and DDE in serum does not mean that
the levels of these chemicals cause an adverse health effect
...

Biomonitoring data can also help scientists plan and conduct research on exposure
and health effects
...
The structural formulas of several chlorinated hydrocarbon insecticides
are shown in Figure 7
...
It can be seen that the structural formulas of many of these
insecticides are very similar; dieldrin and endrin are stereoisomers
...
They are
discussed briefly here, largely because of their historical interest, and because
their residues in soils and sediments still contribute to water pollution
...

It has a low acute toxicity to mammals, although there is some evidence that it
might be carcinogenic
...
It has been banned in the U
...
since 1972
...
Structurally similar chlordane,
aldrin, dieldrin/endrin, and heptachlor, all now banned for application in the U
...
,
share common characteristics of high persistence and suspicions of potential
carcinogenicity
...

This compound had the widest use of any agricultural insecticide, particularly
on cotton
...
A mixture of five isomers, 1,2,3,4,5,6hexachlorocyclohexane has been widely produced for insecticidal use
...
A formulation of the

14

essentially pure gamma isomer has been marketed as the insecticide called lindane
...
Structurally similar chlordane,
aldrin, dieldrin/endrin, and heptachlor, all now banned for application in the U
...
,
share common characteristics of high persistence and suspicions of potential
carcinogenicity
...

This compound had the widest use of any agricultural insecticide, particularly
on cotton
...
A mixture of five isomers, 1,2,3,4,5,6hexachlorocyclohexane has been widely produced for insecticidal use
...
A formulation of the
essentially pure gamma isomer has been marketed as the insecticide called lindane
...

Organophosphates (OPs) are a class of insecticides, several of which are
highly toxic
...
Thirty-six of them are presently registered for use in the
United States, and all can potentially cause acute and subacute toxicity
...

All share a common mechanism of cholinesterase inhibition and can cause
similar symptoms, although there are some differences within the class
...
It is impor- tant to understand, however, that there is a wide range of
toxicity in these agents and wide variation in dermal absorption, making specific
identification of the agent and individualized management quite important
...
The result is a loss of available AChE so that the
effector organ becomes overstimulated by the excess acetylcholine (ACh, the
impulse-transmitting substance) in the nerve ending
...

Once a critical proportion of the tissue enzyme mass is inactivated by
phosphorylation, symp- toms and signs of cholinergic poisoning become manifest
...

At cholinergic nerve junctions with smooth muscle and secretory cells, high
ACh concen- tration causes muscle contraction and secretion, respectively
...

Impairment of the diaphragm and thoracic skeletal muscles can cause respiratory
paralysis
...

Increased pulmonary secretions coupled with respiratory failure are the usual causes
of death from organophosphate poisoning
...

Rarely, certain organophosphates have caused a different kind of
neurotoxicity consisting of damage to the afferent fibers of peripheral and central
nerves and associ- ated with inhibition of “neuropathy target esterase” (NTE)
...
This delayed syndrome has been termed organophosphateinduced delayed neuropathy (OPIDN) and is manifested chiefly by weakness or
paralysis and paresthesia of the extremities
...

Only a few of the many organophosphates used as pesticides have been implicated
as causes of delayed neuropathy in humans
...

In addition to acute poisoning episodes and OPIDN, an intermediate syndrome
has been described
...
It is characterized by acute respiratory paresis and muscular weakness, primarily in the facial, neck and proximal limb
muscles
...


17

Like OPIDN, this syndrome lacks muscarinic symptoms and appears to result
from a combined pre- and post-synaptic dysfunction of neuromuscular transmission
...
The most common compounds involved in this
syndrome are methyl parathion, fenthion and dimethoate, although one case with
ethyl-parathion was also observed
...
Exposure by
inhalation results in the fastest appearance of toxic symptoms, followed by the oral
route and finally the dermal route
...
6 The critical
symptoms in initial management are the respiratory symptoms
...
Bronchospasm and bronchorrhea can occur,
producing chest tightness, wheezing, productive cough and pulmonary edema
...
A life-threatening
severity of poisoning is signified by loss of consciousness, incontinence, seizures and
respiratory depres- sion
...

There usually is a secondary cardiovascular component to the respiratory
symp- toms
...
However, this may be superseded by tachycardia and hypertension
from nico- tinic (sympathetic ganglia) stimulation
...
28
Some of the most commonly reported early symptoms include headache,
nausea, dizziness and hypersecretion, the latter of which is manifested by sweating,
saliva- tion, lacrimation and rhinorrhea
...


18

Treatment of Organophosphate Toxicosis
CAUTION: Persons attending the victim should avoid direct contact with
heavily contaminated clothing and vomitus
...

Wear rubber gloves while washing pesticide from skin and hair
...


Ensure that a clear airway exists
...
Administer oxygen by
mechanically assisted pulmonary ventilation if respiration is depressed and keep
patient on a high FiO
...

2
...
Remember that atropine can be administered
through an endotracheal tube if initial IV access is difficult to obtain
...


Carbamates
Pesticidal organic derivatives of carbamic acid, for which the formula is shown
in Figure , are known collectively as carbamates
...
Carbaryl has been widely used as an insecticide on
lawns or gardens
...
Carbofuran has a high water
solubility and acts as a plant systemic insecticide
...

Pirimicarb has been widely used in agriculture as a systemic aphicide
...
The
toxic effects of carbamates to animals are due to the fact that these compounds
inhibit acetylcholinesterase
...

Their inhibition of acetylcholinesterase is relatively reversible
...


Herbicides
Herbicides are applied over millions of acres of farmland worldwide and
are widespread water pollutants as a result of this intensive use
...
S
...

The herbicides named were atrazine, simazine, cyanazine, metolachlor,
and alachlor, of which the first three are the most widely used
...


20

Paraquat, which was registered for use in
1965, has been one of the most used of
the bipyridilium herbicides
...
”
Exposure to fatal or dangerous levels of
paraquat can occur by all pathways, including
inhalation of spray, skin contact, ingestion, and
even suicidal hypodermic injections
...
Because of its
widespread use as a herbicide, the possibility exists of substantial paraquat
contamination of food
...

Herbicidal Heterocyclic Nitrogen Compounds
A number of important herbicides contain three heterocyclic nitrogen
atoms in
ring structures and are therefore called triazines
...
Selectivity is gained by the inability of target plants to
metabolize
and detoxify the herbicide
...
Another
member of this class is metribuzin, which is widely used on soybeans, sugarcane, and
wheat
...
At one time the latter
was of particular concern because of contaminant TCDD (see below) present as a
manufacturing byproduct
...
Prominent among
these are propanil,
applied to control
weeds in rice fields,
and alachlor,
marketed as Lasso
and widely applied to
fields to kill
germinating grass and
broad-leaved weed
seedlings:

22

PCB
What are PCBs?
Polychlorinated biphenyls (PCBs) were developed in the 1940's and were used
extensively in the manufacture of transformers, capacitors, and other heat transfer
devices through the late 1970's
...
Because of this, they were used
extensively as heat transfer fluids in transformers and capacitors
...
Today they
are classified as probable human carcinogens and are listed in the top 10% of EPA’s
most toxic chemicals
...
Many of these transformers are at or close to
the end of their useful life and proper disposal of them is required to prevent the
unnecessary (and unlawful) release of PCBs into the environment
...
PCBs do not
easily break down, and can bioaccumulate in the fatty tissues of fish and mammals
...
People who eat sport-caught fish consumed 2-3 times more fish than
the overall U
...
population
...
People who live near hazardous waste sites may be exposed to PCBs by
consuming PCB- contaminated sportfish and game animals, by breathing PCBs in air,
or by drinking PCB- contaminated well water
...
Many older transformers and capacitors may still contain PCBs, and
this equipmen can be used for 30 years or more
...
When these electric devices get hot during operation, small amounts
of PCBs may get into the air and raise the level of PCBs in indoor air
...

Workplace exposure to PCBs can occur during the repair and maintenance of
PCB transformers, accidents, fires, or spills involving PCB transformers and older
computers and instruments, and disposal of PCB materials
...

Contact with PCBs at hazardous waste sites can happen when workers breathe air and
touch soil containing PCBs
...

How can PCBs enter and leave my body?
If you breathe air that contains PCBs, they can enter your body through your
lungs and pass into the bloodstream
...
A common way for PCBs to enter your
body is by eating meat or fish products or other foods that contain PCBs
...
It is also possible that PCBs can enter your
body by breathing indoor air or by skin contact in buildings that have the kinds of old
electrical devices that contain and can leak PCBs
...

Once PCBs are in your body, some may be changed by your body into other related
chemicals called metabolites
...

Some of the metabolites may leave your body in the feces in a few days, but
others may remain in your body fat for months
...
PCBs collect in milk fat and can enter the bodies of
infants through breast-feeding
...
Some of these
studies investigated people exposed in the workplace, and others have examined
members of the general population
...
These effects on the skin are well
documented, but are not likely to result from exposures in the general population
...
Some studies in workers suggest that exposure to PCBs may also cause
irritation of the nose and lungs, gastrointestinal discomfort, changes in the blood and
liver, and depression and fatigue
...
Most of the studies of health
effects of PCBs in the general population examined children of mothers who were
exposed to PCBs
...

Now, all people in industrial countries have some PCBs in their bodies
...
These are not
regular or routine clinical tests, such as the one for cholesterol, but could be ordered
by a doctor to detect PCBs in people exposed to them in the environment and at work
...
However, these measurements cannot determine
the exact amount or type of PCBs that you have been exposed to, or how long you
have been exposed
...
Blood tests are the easiest, safest, and probably the
best method for detecting recent exposures to large amounts of PCBs
...
Nearly everyone has
been exposed to PCBs because they are found throughout the environment, and
people are likely to have detectable amounts of PCBs in their blood, fat, and breast
milk
...

What levels of exposure have resulted in harmful health effects?
Human health studies indicate that: 1) reproductive function may be disrupted
by high levels of exposure to PCBs; 2) neurobehavioral and developmental deficits
occur in newborns and continue through school-aged children who had in-utero
exposure to PCBs; 3) other systemic effects (e
...
, self-reported liver disease and
diabetes, and effects on the thyroid and immune systems) are associated with
elevated serum levels of PCBs; and 4) increased cancer risks, e
...
, non-Hodgkin's
lymphoma, are associated with PCB exposures
...
The federal
government develops regulations and recommendations to protect public health
...
Federal agencies that develop regulations for
toxic substances include the Environmental Protection Agency (EPA), the Occupational
Safety and Health Administration (OSHA), and the Food and Drug Administration
(FDA)
...
Federal organizations that develop recommendations for
toxic substances include the Agency for Toxic Substances and Disease Registry
(ATSDR) and the National Institute for Occupational Safety and Health (NIOSH)
...
Sometimes these not-to- exceed levels differ
among federal organizations because of different exposure times (an 8-hour workday
or a 24-hour day), the use of different animal studies, or other factors
...
For the most current information, check with the federal agency or
organization that provides it
...
5 parts of PCBs per billion parts
(ppb) of water
...
17 parts of PCBs per trillion parts (ppt) of water
...
FDA required limits include 0
...
3 ppm in eggs, 1
...

OSHA regulates that workers not be exposed by inhalation over a period of 8
hours for 5 days per week to more than 1 milligram per cubic meter of air (mg/m³) for
42% chlorine PCBs, or to 0
...

NIOSH recommends that workers not breathe air containing 42 or 54% chlorine
PCB levels higher than 1 microgram per cubic meter of air (µg/m³) for a 10-hour
workday, 40-hour workweek
...
EPA also
limits the amount of PCBs put into publicly owned waste water treatment plants
...


HEALTH EFFECTS OF PCBs
Cancer:
PCBs are likely to cause cancer and are classified as a “probable carcinogen” by
the federal Environmental Protection Agency and the International Agency for Research
on Cancer
...


Immune System:
PCBs suppress the immune system and thyroid function
...
More specifically, children have an increased risk of asthma and other
infectious respiratory diseases when exposed to persistent organic pollutants, including
PCBs
...

The existing evidence suggests that qualitative differences in the toxicokinetic
disposition of PCBs exist among humans and the numerous animals species studied
and also among animal species (Lutz and Dedrick 1987; Safe 1989a; Sipes and
Schnellmann 1987)
...

Further pharmacokinetic modeling studies with additional groups of PCB
congeners would be valuable to determine the validity of extrapolating data
...
In general, all species absorb PCBs
efficiently and accumulate PCBs in tissues rich in fat
...
Identification of
metabolites in humans and animals suggests that all species examined share some
common biochemical reactions
...
1984; Klasson-Wehler et al
...
Analysis
of the excreta of humans exposed in the workplace and near hazardous waste sites
would provide information regarding biotransformation and elimination kinetics in
humans
...

Monkeys and minks are the most sensitive species tested regarding dioxin-like
effects, but pharmacokinetic data in minks are scant
...
1988a; Fischbein et al
...

This and other effects seen in monkeys, not observed in populations
occupationally or environmentally exposed to PCBs, have led some to suggest that
monkeys may not represent a suitable animal model (James et al
...
However, the clinicopathologic picture in monkeys is more like humans than
any other species
...


Polycyclic Aromatic Hydrocarbons (PAHs)
Short for polycyclic aromatic hydrocarbons, PAHs describe chemicals that are
often found together in groups of two or more
...
In their purest form, PAHs are solid and
range in appearance from colorless to white or pale yellow- green
...
Although PAHs can exist in over 100 different
combinations, the National Waste Minimization Program defines this group using the
Toxic Release Inventory reporting category for polycyclic aromatic compounds
...
Benzo(a)anthracene, 56-55-3
2
...
Benzo(a)pyrene, 50-32-8
4
...
Benzo(j)fluoranthene, 205-82-3

28

6
...
Benzo(j,k)fluorene (fluoranthene), 206-44-0
8
...
Dibenz(a,h)acridine, 226-36-8
10
...
Dibenzo(a,h)anthracene, 53-70-3
12
...
Dibenzo(a,e)pyrene, 192-65-4
14
...
Dibenzo(a,l)pyrene, 191-30-0
16
...
7,12-Dimethylbenz(a)anthracene, 57-97-6
18
...
3-Methylcholanthrene, 56-49-5
20
...
Because they do not burn very
easily, they can stay in the environment for long periods of time
...
Some can turn into a vapor in the air very easily
...

How can PAHs enter and leave your body?
One of the most common ways PAHs can enter the body is through breathing
contaminated air
...
If you live near a
hazardous waste site where PAHs are disposed, you are likely to breathe PAHs
...

Exposure to PAHs can also occur if your skin contacts PAH-contaminated soil or
products like heavy oils, coal tar, roofing tar, or creosote
...
Once in your body, PAHs can spread
and target fat tissues
...
However, PAHs will
leave your body through urine and feces in amatter of days
...
Because PAHs exist naturally in the environment and are man-made, you
can be exposed in a number of ways
...

You could be exposed to PAHs by breathing cigarette and tobacco smoke, eating
foods grown in contaminated soil, or by eating meat or other food that you grilled
...
If you
work in a plant that makes coal tar, asphalt and aluminum, or that burns trash, you
can be exposed to PAHs
...


How can PAHs affect your health?
A number of PAHs have caused tumors inlaboratory animals that were exposed
to PAHs through their food, from breathing contaminated air, and when it was applied
to their skin
...

In addition, the offspring of the pregnant mice showed birth defects and a
decrease in their body weight
...
However, these effects have not been seen in humans
...
This test can
only tell you if you have been exposed; but it can’t reveal how harmful the effects of
the exposure will be
...

Another test currently being developed will be able to measure PAHs in your
body tissue and blood
...

30

Many large cities and towns will provide municipal trash pickup
...

Non-certified parties may be disposing of waste through processes such as
incineration or landfill, which can be harmful to public health and the environment if
not carefully controlled and approved by third parties
...


proper regulatory and
is ultimately disposed of

If a company is located in a rural area without a certified provider, it can
identify the nearest town with a municipal or certified provider
...


Methods for Storage and Disposal: Hazardous Waste
If a company uses hazardous materials, proper precautions must be taken in
the storage and disposal of these materials
...
If such materials are
not stored and disposed of properly, they could create health risks for employees,
the community or the public at large
...
By mandate of the World Health Organization’s InterOrganization Programme for the Sound Management of Chemicals (IOMC), all
manufacturers of hazardous materials are required to provide a MSDS so that end
users can treat the materials properly
...
These sheets should be made readily available to all employees who come
into contact with hazardous materials
...
A manual for the storage and disposal of wastes should be available in the
local language
...
They should be
monitored once a week to ensure no spillage or damage to the container
...
The records
should be reviewed periodically to identify trends in the use of hazardous materials
on site and potential ways to reduce the level of such materials
...
Contact
the local government or search through private sources for information on pickup or
drop-off
...
They are so diverse that it is difficult to classify them neatly
...
The primary pollutants are those that are emitted directly from
the sources
...

The secondary pollutants are those that are formed in the atmosphere by
chemical interactions among the primary pollutants and normal atmospheric
constituents
...
An example of this category in the formation of
photochemical smog due to the interaction between terpene hydrocarbons from
conifer trees and nitrogen oxides from automobiles
...
Pests can
be insects, mice and other animals, weeds, fungi, or microorganisms such as bacteria
and viruses
...
Pesticides also are used to kill
organisms that can cause diseases
...
For this reason the Office of Pesticide Programs of the
Environmental Protection Agency regulates pesticides in the United States to protect
public health and the environment
...


Did you know that these common products are considered pesticides?
•

Cleaners used to disinfect the kitchen floor
...


•

Household plant sprays
...

33

•

Some swimming pool chemicals
...
The most frequent application of herbicides occurs in row-crop farming,
where they are applied before or during planting to maximize crop productivity by
minimizing other vegetation
...
Herbicides are used in forest management to prepare logged areas for
replanting; the total applied volume and area covered is greater but the frequency of
application is much less than for farming (Shepard et al
...
In suburban and
urban areas, herbicides are applied to lawns, parks, golf courses and other areas
...

1979)
Non-water soluble chlorinated hydrocarbon in use since Second World War
(1939-1945) as an insecticide for the control of lice (that spread typhus) and
mosquitoes (that spread malaria and yellow fever)
...
Being
non-biodegradable it persists in nature and climbs up the food chain by accumulating
in body fat (in which it is soluble), causing widespread poisoning of birds and other
small animals and plants
...
01 part per million)
retard photosynthesis in plankton by 20 percent, and one part per billion (ppb) has
been known to kill 39 percent of the sea water shrimp in three weeks
...
The latter are by far the major contributors
...

Polychlorinated biphenyls are a group of organic chemicals which can be
odorless or mildly aromatic solids or oily liquids
...


34

REFERENCES:
 Schreiber, Lukas, and Jörg Schönherr, “Uptake of Organic Chemicals in Conifer
Needles: Surface Adsorption and Permeability of Cuticles,” Environmental
Science and Technology 26, 153-159 (1992)
...
, Andrew J
...
Prest, Eiliv Steinnes, and
Kevin C
...

 Graedel, T
...
, Chemical Compounds in the Atmosphere, Academic Press, San
Diego, 1978
...
C
...
Tuazon, Roger Atkinson, and Janet
Arey, “Products of the Gas-Phase Reactions of Linalool with OH Radicals, NO
Radicals, and O ,” Environmental Science and Technology, 31, 896-904 (1997)
...

 Yu, Jianzhen, Richard C
...
Seinfeld, “Identification of Products
Containing –COOH, –OH, and –C=O in Atmospheric Oxidation of Hydrocarbons,”
Environmental Science and Technology 32, 2357–2370 (1998)
...
R
...
P
...
Jungkamp, Richard C
...
Seinfeld, “The
Atmospheric Aerosol-Forming Potential of Whole Gasoline Vapor,” Science,276,
96-99 (1997)
...
B
...

 Butler, James H
...
Montzka, Andrew D
...
Lobert, and
James W
...

 Molina, Mario
...
and F
...

 Madronich, S
...
L
...
O
...
M
...

 “ICI to Boost Capacity of Hydrofluorocarbon,” Chemical and Engineering News,
June 21, 1999, p
...

 Zurer, Pamela, “Perfluorocarbons Use, Emissions May Face Restriction,”
Chemical and Engineering News, August 9, 1993, p
...

 Manahan, Stanley E
...
, Lewis Publishers/CRC
Press, Boca Raton, FL, 1992
...
, “The Study of Xenobiotic-Metabolizing Enzymes and their
Role in Toxicity In Vivo Using Targeted Gene Disruption,” Toxicology Letters,
102, 161-166 (1998)
...
, “The Fate of Xenobiotics in Mammals: Biochemical Processes,”
Progress in Pesticide Biochemistry and Toxicology, 8, 1-86 (1995)
...
, Cytochromes P450: Metabolic and Toxicological
 Aspects, CRC Press, Boca Raton, FL, 1996
...
, Biological Reactive Intermediates V: Basic Mechanistic
Research in Toxicology and Human Risk Assessment, Plenum Press, New York,
1996
...
, Mary F
...
, Chemical Induction of
Factors Which Influence Carcinogenesis, Birkhauser, Boston, 1995


Hemminki, K
...
, DNA Adducts: Identification and Biological Significance,
Oxford University Press, New York, 1994

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