1. PCBs and PAHs:
Measurement and Effects
Presented by:
SURAYYA MUHD LAMIDO
20122555
ENVS 509
ADVANCED AIR POLLUTION

2. THE DOSE MAKES THE POISON
All Substances are poisonous
There is none which is Not a poison
The Right dose differentiate a poison
and a Remedy.
Paracelsus (1493-1541)

3. POLYCHLORINATED
BIPHENYLs (PCBs)
A mixture of compounds
containing the biphenyl structure
with varying numbers (i.e., one to
ten) and arrangements of
chlorine atom attached.

4. Fully-Chlorinated PCB Molecule

5. STRUCTURE OF PCBs

6.  Polychlorinated biphenyls (PCBs) were
widely used as dielectric and coolant
fluids, for example in transformers,
capacitors, and electric motors. Due to
PCBs' environmental toxicity and
classification as a persistent organic
pollutant, PCB production was banned by
the United States Congress in 1979 and
by the Stockholm Convention on
Persistent Organic Pollutants in 2001

7. Why Were PCBs Banned?
• Persistent in the environment
• Bioaccumulation & bioconcentration
effects
• Found in virtually all human fat tissue
􀂃 Humans 2300 ng/g
􀂃 Human Breast Milk 1200 ng/g

8. PHYSICAL AND CHEMICAL
PROPERTIES OF PCBs
PHYSICAL
•Odorless
• Colorless
•Low vapor pressure
•Viscous liquid or solid
CHEMICAL
Flame Retardant
• Lipophilic (mix easily with oil or fat)
• Very Stable
•Low electrical conductivity

9. EFFEETS OF PCBs
ACCUTE EFFECTS:
No reports of effects in humans following
acute (short-term) exposure to PCBs are
available.
Animal studies have reported acute effects
on the liver, kidney, and central nervous
system from oral exposure to PCBs.
Acute animal tests in rats have shown
PCBs to have moderate acute toxicity from
oral exposure.

10. CHRONIC EFFECTS
(No cancer):
 EPA has not established a Reference
Concentration for all PCB mixtures.
 Chronic inhalation exposure of workers to PCBs
has been reported to result in respiratory tract
symptoms, such as cough and tightness of the
chest, gastrointestinal effects including anorexia,
weight loss, nausea, vomiting, and abdominal
pain, mild liver effects, and effects on the skin
and eyes, such as skin rashes, and eye
irritation.

11. SIGNS

12. Reproductive/Developmental
Effects:
 Human studies are not conclusive on the
reproductive effects of PCBs. One study of
men who were occupationally exposed to
PCBs showed no fertility abnormalities,
while another study of men with low sperm
counts found elevated levels of PCBs in
the blood and an association between
certain PCB compounds in semen and
decreased sperm motility.

13. CANCER RISK:
 Human studies provide inconclusive, yet
suggestive evidence of an association
between PCBs' exposure and liver
cancer. Several studies have reported an
increase in liver cancer among persons
occupationally exposed to some PCB
formulations. However, the studies are
inconclusive due to confounding
exposures and lack of exposure
quantification.

14. CONT…
 No animal inhalation studies are available
on the health effects of PCBs. PCBs are
absorbed through inhalation though,
indicating that there may be concern for
this route of exposure.
 EPA has classified PCBs as a Group B2,
probable human carcinogen.

15. POLYCYCLIC AROMATIC
HYDROCARBONs
(PAHs)
 Polycyclic Aromatic Hydrocarbons (PAHs)
are a group of chemicals that are formed
during the burning of coal, oil, gas, garbage,
tobacco or charbroiled meat.
 PAHs occur naturally or can be man-made.

16. Common PAHs





Anthracene
Benzo(a)pyrene
Chrysene
Fluorene
Pyrene

17. STRUCTURE OF PAHs

18. Properties of PAHs
 Colorless, white, or pale
yellow-green solid
 Evaporate quickly into
the air when heated
 Attach strongly to soil
and other particles
 Break down slowly
 Do not dissolve easily in
water
 Do not burn easily

19. How do PAHs get in the
Environment?
PAHs are released to the environment
through natural and man made processes.
Man-made sources contribute far more
PAHs to the environment than natural
sources.

20. Man-made Sources







Burning of wood
Vehicle exhaust
Grilled/smoked foods
Cigarette smoke
Asphalt roads/Parking lots
Roofing/coal tar products
Agricultural burning

22. Natural Sources
• Forest fire
• Volcanoes

23. PAHs in the Environment
 PAHs stick tightly to soil particles.
 Some PAHs evaporate into the air from soil or
surface waters.
 PAHs in air settle to the ground where they are
deposited on soil, plants, or in lakes and
streams.
 PAHs stay very close to the surface of the
ground or move to lakes and streams by a
process called erosion.
 PAHs that enter lakes or streams settle to the
bottom and are buried in sediments.

24. How can PAHs enter and leave
your body? PAHs can
One of the most common ways
enter the body is through breathing
contaminated air. PAHs get into your
lungs when you breathe them. If you live
near a hazardous waste site where PAHs
are disposed, you are likely to breathe
PAHs. If you eat or drink food and water
contaminated with PAHs, you could be
exposed.

25. Exposure to PAHs can also occur if your
skin contacts PAH-contaminated soil or
products like heavy oils, coal tar, roofing
tar, or creosote. Creosote is an oily liquid
found in coal tar and is used to preserve
wood. Once in your body, PAHs can
spread and target fat tissues. Target
organs include the kidneys and liver.
However, PAHs will leave your body
through urine and feces in a matter of
days.

26. EFFECTS ON LABORATORY
ANIMALS
 Tumors occur in some
animals exposed for
long periods of time.
 PAHs have been shown
to have an effect on the
immune system of some
animals.
 EPA considers PAHs to
be probable human
carcinogens (cancercausing substances).

27. CLASSIFICATION OF TOXIC
ORGANIC COMPOUNDS

28. MEASUREMENTS IN AMBIENT AIR
Sample and Analysis Approach
PCBs
Ambient air is drawn through a glass fiber filter and a
polyurethane foam (PUF) adsorbent cartridge by
means of a high volume sampler. The filter and PUF
cartridge are returned to the laboratory and extracted
using toluene. The extract is concentrated using the
Kuderna-Danish technique, diluted with hexane, and
cleaned up using column chromatography. The
cleaned extract is then analyzed by high resolution
gas chromatography/high resolution mass
spectrometry.
DETECTION LIMIT: 0.25-5000pg/m3

29. PAHs
Ambient air is drawn through a glass fiber filter
and polyurethane foam (PUF) or XAD-2
adsorbent cartridge by means of a high volume
sampler. The filter and PUF cartridge are
extracted using 10% diethyl ether. The extract is
concentrated using Kuderna-Danish technique,
diluted, and cleaned up using column
chromatography. The cleaned extract is then
analyzed by gas chromatography/mass
spectrometry.
DETECTION LIMIT: 0.5-500ng/m3

30. For more information
Contact your state health or environmental
department, or: Agency for Toxic Substances
and Disease Registry Division of Toxicology
1600 Clifton Road, N.E., E-29 Atlanta,
Georgia 30333