Download Atmosphere E

Atmosphere E
Indoor Air Quality
 Indoor air quality refers
to the properties of
indoor air that affect
the health and wellbeing of those in it.
 There have been as
many as 900
contaminants identified
as present in indoor air
at ppb or higher.
Types of contaminates
 VOCs are volatile organic
compounds such as
formaldehyde (H2CO),
benzene (C6H6), toluene
(C7H8), chloroform
(CHCl3), acetone (C2H6O)
and styrene (C8H8). These
come from cleaning
products, plastics,
perfumes, hair sprays,
paints, carpet, furnishings,
dry-cleaned clothes,
plywood and other
products.
Biological Contaminants
 Molds, fungi, bacteria,
viruses, pollen, and
insects. In order to
lessen biological
contaminants, indoor
humidity should not
exceed 50%.
Combustion Products
 Carbon monoxide,
nitrogen dioxide, sulfur
dioxide, tobacco
smoke components,
and polyaromatic
hydrocarbons such as
benzo [a] pyrene.
 Contaminants generated
by office equipment and
supplies such as ozone
from computer terminals
and photocopiers, ethanol
and methanol from
duplicating machines, and
acetone from typewriter
correction fluid.
 Environmental tobacco
smoke (ETS)
 It is estimated that
470,000 tons of
tobacco are burned
indoors each year
generating both
mainstream and
sidestream smoke.
 The concentration of
pollutants include:
 1. air exchange rate
 2. the rate at which
pollutants are
generated indoors.
 3. reaction rates
among indoor air
components.
RADON
 Radon is a radioactive,
colorless, odorless and
tasteless gas formed by the
nuclear decay of U-238 in
ground under and around
buildings.
 When inhaled it can cause lung
cancer.
 It is measured in picocuries per
liter.
 A picocurie is equal to about 4
nuclear disintegrations per
minute or about 16 nuclear
disintegrations per minute in a
liter of air.
FORMALDEHYDE
 Formaldehyde, H2CO is a
pungent-smelling gas found
both indoors and outdoors.
 It comes from carpets, cabinets,
cigarettes, and insulation.
 Phenol-formaldehyde and ureaformaldehyde resins are found
in plywood and foam insulation
(UFFI).
 UFFI was banned in 1982 but a
court action reinstated its use in
1983.
 Formaldehyde irritates tissue
and is a possible carcinogenic
(cancer causing) chemical.