hydrocarbons (PAHs), carbon monoxide (CO),
and formaldehyde (CH 2 O). The composition of
PM is highly variable and depends on its origin
and processing in the atmosphere. Some PM originates from engines burning liquid hydrocarbons.
This PM, commonly found in urban areas, contains a mixture of black soot, fuel residues, and
water. Indoor pollution also includes compounds
emitted from noncombustion sources, such as
building materials, paints, impregnated surfaces,
plastics, cleaning agents, batteries, plumbing,
etc. Increased attention to these pollutants has
led to decreased exposure in developed countries;
however, they are still an important class of pollutants in developing countries. Some specific
examples include formaldehyde, radon, asbestos,
lead, VOCs, moisture, and mold.
The concentrations of PM indoors are
influenced by indoor materials and activities, and
outdoor sources. A large source of indoor pollution is tobacco smoke [12]. A cigarette contains
up to 4000 different chemicals, and many deposit
onto particles and surfaces such as walls and furniture. Besides serious health problems, the accumulated pollution also causes discoloration and
aging. The deposition of environmental tobacco
smoke (ETS) onto indoor surfaces results in additional exposure beyond inhalation as deposited
ETS can be absorbed through the skin. Deposited
ETS is reemitted over the course of hours to
months, and is a significant source of airborne
particles in places where smoking is allowed.
The concentration of indoor ETS can be much
higher than outdoor concentrations [13].
Air Pollution in Industry and Public
Infrastructure
People working in industries such as foundries,
chemical and food processing, and waste management can be exposed to air pollution in excess of
levels typically found in residential air pollution.
For instance, workers in nuclear power plants
have a higher risk of exposure to radioactive
materials; in the same manner, a worker in vehicle
manufacture has a higher risk of contacting solvent vapors from glues or paint, or metal vapor
from welding. Most industrial countries have
implemented strict regulations in order to
maintain a safe working environment and minimize the potential of exposure to high levels of
polluted air in the workplace. However, there are
many countries where such regulations do not
exist or are not enforced, and many people are
unnecessarily exposed to hazardous levels of pollutants. Poor IAQ is linked to decreased productivity and personal satisfaction, while increasing
illness and workplace absence. Altogether,
improving IAQ provides short- and long-term
monetary benefits for companies [14].
Air Pollution in Offices
Office equipment is a well-known source of
indoor air pollution. However, “office” spans a
wide range of types of spaces, uses, and climatic
conditions around the world. Establishing a systematic guide to office pollution is quite challenging. Generally, office equipment like computers
and printers is a source of VOCs, SVOCs (“semivolatile organic compound,” which include brominated flame retardants and organophosphates),
dust (PM), and ozone. Printers and copiers emit,
on average, more VOCs than computers; these
emissions may include xylene, toluene, and
other alkylbenzenes. Ozone from printers easily
reacts with other indoor pollutants creating secondary pollutants and ultrafine aerosol particles
[15]. In this regard, the U.S. Environmental Protection Agency (EPA) gives a simple but effective
checklist on how to keep office air healthy. People
should be responsible for keeping airways clear
and unblocked, use dedicated smoking areas, taking care of plants, and managing food and waste
properly. Managers, in addition, are responsible
for maintaining a clean working environment by
integrating optimal HVAC systems, preventing or
avoiding polluting office supplies and equipment,
and developing other strategies to improve the
overall IAQ (US EPA, 2014) [16].
Biological, Physical, and Chemical
Sources of Pollution
Indoor air pollution is typically divided into that
stemming from occupancy and that from building
materials; the pollution may be of biological,
138
Indoor Air Quality: Status and Standards
and formaldehyde (CH 2 O). The composition of
PM is highly variable and depends on its origin
and processing in the atmosphere. Some PM originates from engines burning liquid hydrocarbons.
This PM, commonly found in urban areas, contains a mixture of black soot, fuel residues, and
water. Indoor pollution also includes compounds
emitted from noncombustion sources, such as
building materials, paints, impregnated surfaces,
plastics, cleaning agents, batteries, plumbing,
etc. Increased attention to these pollutants has
led to decreased exposure in developed countries;
however, they are still an important class of pollutants in developing countries. Some specific
examples include formaldehyde, radon, asbestos,
lead, VOCs, moisture, and mold.
The concentrations of PM indoors are
influenced by indoor materials and activities, and
outdoor sources. A large source of indoor pollution is tobacco smoke [12]. A cigarette contains
up to 4000 different chemicals, and many deposit
onto particles and surfaces such as walls and furniture. Besides serious health problems, the accumulated pollution also causes discoloration and
aging. The deposition of environmental tobacco
smoke (ETS) onto indoor surfaces results in additional exposure beyond inhalation as deposited
ETS can be absorbed through the skin. Deposited
ETS is reemitted over the course of hours to
months, and is a significant source of airborne
particles in places where smoking is allowed.
The concentration of indoor ETS can be much
higher than outdoor concentrations [13].
Air Pollution in Industry and Public
Infrastructure
People working in industries such as foundries,
chemical and food processing, and waste management can be exposed to air pollution in excess of
levels typically found in residential air pollution.
For instance, workers in nuclear power plants
have a higher risk of exposure to radioactive
materials; in the same manner, a worker in vehicle
manufacture has a higher risk of contacting solvent vapors from glues or paint, or metal vapor
from welding. Most industrial countries have
implemented strict regulations in order to
maintain a safe working environment and minimize the potential of exposure to high levels of
polluted air in the workplace. However, there are
many countries where such regulations do not
exist or are not enforced, and many people are
unnecessarily exposed to hazardous levels of pollutants. Poor IAQ is linked to decreased productivity and personal satisfaction, while increasing
illness and workplace absence. Altogether,
improving IAQ provides short- and long-term
monetary benefits for companies [14].
Air Pollution in Offices
Office equipment is a well-known source of
indoor air pollution. However, “office” spans a
wide range of types of spaces, uses, and climatic
conditions around the world. Establishing a systematic guide to office pollution is quite challenging. Generally, office equipment like computers
and printers is a source of VOCs, SVOCs (“semivolatile organic compound,” which include brominated flame retardants and organophosphates),
dust (PM), and ozone. Printers and copiers emit,
on average, more VOCs than computers; these
emissions may include xylene, toluene, and
other alkylbenzenes. Ozone from printers easily
reacts with other indoor pollutants creating secondary pollutants and ultrafine aerosol particles
[15]. In this regard, the U.S. Environmental Protection Agency (EPA) gives a simple but effective
checklist on how to keep office air healthy. People
should be responsible for keeping airways clear
and unblocked, use dedicated smoking areas, taking care of plants, and managing food and waste
properly. Managers, in addition, are responsible
for maintaining a clean working environment by
integrating optimal HVAC systems, preventing or
avoiding polluting office supplies and equipment,
and developing other strategies to improve the
overall IAQ (US EPA, 2014) [16].
Biological, Physical, and Chemical
Sources of Pollution
Indoor air pollution is typically divided into that
stemming from occupancy and that from building
materials; the pollution may be of biological,
138
Indoor Air Quality: Status and Standards