10. VOCs AND HEALTH EFFECTS
VOC Hazard summary
Acrolein Extremely toxic to humans in inhalation and dermal exposure. Acute (short-term)
inhalation exposure may result in upper respiratory tract
irritation and congestion.
Acrylonitrile Acute (short-term) exposure of workers to acrylonitrile has been observed to
cause mucous membrane irritation, headaches, dizziness, and nausea.
Benzene Acute (short-term) inhalation exposure of humans to benzene may cause
drowsiness, dizziness, headaches, as well as eye, skin, and respiratory
tract irritation, and, at high levels, unconsciousness. Chronic (long-term)
inhalation exposure has caused various disorders in the blood,
including reduced numbers of red blood cells and a plastic anemia, in
occupational settings.
Chlorobenzene The major effect from acute (short-term) inhalation exposure to chloroform
is central nervous system depression. Chronic (long-term) exposure to
chloroform by inhalation in humans has resulted in effects on the liver,
including hepatitis and jaundice, and central nervous system effects,
such as depression and irritability.
Ethylidene Dichloride
(1,1-Dichloroethane)
Acute (short-term) inhalation exposure to high levels of ethylating dichloride
in humans results in central nervous system (CNS) depression and a
cardio-stimulating effect resulting in cardiac arrhythmias
Formaldehyde Acute (short-term) and chronic (long-term) inhalation exposure to
formaldehyde in humans can result in respiratory symptoms, and eye,
nose, and throat irritation.
11. CCoonntt……....
Hexane Acute (short-term) inhalation exposure of humans to high levels of hexane
causes mild central nervous system (CNS) effects. Chronic (long-term)
exposure to hexane in air is associated with polyneuropathy in humans,
with numbness in the extremities, muscular weakness, blurred vision,
headache, and fatigue observed
Styrene Acute (short-term) exposure to styrene in humans results in mucous membrane
and eye irritation, and gastrointestinal effects. Chronic (long-term)
exposure to styrene in humans results in effects on the central nervous
system (CNS), and peripheral neuropathy.
Tetrachloroeth—ylene
(Perchloroet-hylene)
The main effects of tetrachloroethylene in humans are neurological, liver, and
kidney effects following acute (short-term) and chronic (long-term)
inhalation exposure.
Xylenes
(Mixed Isomers)
Acute (short-term) inhalation exposure to mixed xylenes in humans results in
irritation of the eyes, nose, and throat, gastrointestinal effects, eye
irritation, and neurological effects. Chronic (long-term) inhalation
exposure of humans to mixed xylenes results primarily in central nervous
system (CNS) effects, respiratory, cardiovascular, and kidney effects
Polycyclic organic
matter (POM)*
Cancer is the major concern from exposure to POM. Epidemiologic studies
have reported an increase in lung cancer in humans exposed to coke oven
emissions, roofing tar emissions, and cigarette smoke; all of these mixtures
contain POM compounds.
* The term polycyclic organic matter (POM) defines a broad class of compounds that includes the
polycyclic aromatic hydrocarbon compounds (PAHs), of which benzo[a]pyrene is a member. POM
compounds are formed primarily from combustion and are present in the atmosphere in particulate
form
12. effe Harmful effeccttss ooff ssoommee ccoommmmoonn VVOOCCss
►BBeennzzeennee can enter our body through our lungs, gastrointestinal tract,
and across our skin when we are exposed to high levels. In the bloodstream,
benzene travels throughout the body and can be temporarily stored in the bone
marrow and fat.
►It is converted to products, called metabolites, in the liver and bone marrow.
People who breathe benzene for long periods may experience harmful effects
in the tissues that form blood cells, especially the bone marrow. These effects
can disrupt normal blood production and cause a decrease in important blood
components.
►TToolluueennee in the air combines with oxygen and form benzaldehyde and cresol,
which are harmful to humans. A serious health concern is that it may have an
effect on our brain. Toluene can cause headaches, confusion, and memory
loss.
►Low-to-moderate, day-after-day exposure in our workplace can cause
tiredness, confusion, weakness, drunken-type actions, memory loss, nausea,
and loss of appetite
13. CCoonnttiinnuuee……
►XXyylleennee can also cause a number of effects on the nervous system, such as
headaches, lack of muscle coordination, dizziness, confusion, and changes in
one's sense of balance.
►Short-term exposure of people to high levels of xylene can cause irritation of
the skin, eyes, nose, throat; difficulty in breathing; impaired function of the
lungs; delayed response to a visual stimulus; impaired memory; stomach
discomfort; and changes in the liver and kidneys.
►PPhheennooll in Short-term causes respiratory irritation, headaches, and burning
eyes. Chronic effects of high exposures include weakness, muscle pain,
anorexia, weight loss, and fatigue; effects of long-term low-level exposures
include increase in respiratory cancer, heart disease, and effects on the
immune system.
►Exposure to high concentrations for several weeks results in paralysis &
severe injury to the heart, kidneys, liver, and lungs, followed by death in some
cases. Effects reported in humans following dermal exposure include liver
damage, diarrhea, dark urine, and RBC destruction.
14. CCoonnttiinnuuee……
► PPyyrriiddiinnee: Most important health concern for humans exposed to it is damage
to the liver. Other health concerns for humans may be neurological effects, renal
effects, and irritation of the skin and eye. Effect of pyridine as cancer or birth
defect is not known
►CChhlloorrooffoorrmm affects the central nervous system (brain), liver, and kidneys after
a person breathe air or drinks liquids that contain large amounts of chloroform.
Breathing about 900 ppm or 900,000 ppb for a short time causes fatigue,
dizziness, and headache. Elevated levels of chloroform, over a long period may
damage liver and kidneys.
►MMeetthhyyll EEtthhyyll KKeettoonnee concentrations above the TLV may cause headache,
dizziness, nausea, shortness of breath, and vomiting. Higher concentrations may
cause central nervous system depression and unconsciousness.
►It may produce abdominal pain, nausea. Aspiration into lungs can produce
severe lung damage.
38. CCoonnttiinnuuee
……
In general the microbes used for biological treatment are
organisms that are naturally occurring. These microbial
populations may be dominated by one particular microbial species
or may interact with numerous species to attack a particular type
of contaminant.
The particular contaminants of interest must be biodegradable
and non toxic for biological treatment to be successful. The most
successful removal in bioreactors occur for low molecular weight
and highly soluble organic compounds with simple bond
structures.
Biodegradation was the major mechanism for the removal of
nonchlorinated VOCs including toluene, benzene, ethylbenzene
and methylene chloride. Some compounds that show moderate to
slow degradation include phenols, chlorinated hydrocarbons,
polyaromatic hydrocarbons and highly halogenated hydrocarbons.
Inorganic compounds such as hydrogen sulfide and ammonia
are also biodegraded well.
41. Waste Air
SScchheemmaattiicc ddiiaaggrraamm ooff aa bbiiooffiilltteerr
Particulate,
Temp and Load
Control
Discontinuous Water Addition
Humidifier
Biofilter
Reactor
Clean Air
Leachate
Blower
Nutrient, Buffer
(Discontinuous)
Water Influent
43. Schematic ddiiaaggrraamm ooff aa bbiioottrriicckklliinngg ffiilltteerr
Waste Air Blower
Particulate,
Temp and
Load Control
Biotrickling
Filter
Clean Air
Wastewater Purge
Recycled Water
Water
Nutrient
Buffer
Water Influent
Pump