Environmental Engineering Reference
In-Depth Information
outside air; uniquely they have interior pressures comparable to an altitude
of 8000 feet. Despite the fact that ventilation standards for aircraft have been
revised to increase outside air, aircraft designs limit outside air delivery
capacities to environmental control systems. In a filled-to-capacity airplane,
the amount of outside air provided to passengers and crew is half that
recommended for office buildings.
Commercial aircraft personnel and passengers are subject to a variety
of contaminant exposures. These include human bioeffluents, VOC emis-
sions from seats and other interior materials, entrained fuel combustion by-
products, ETS on smoking-permitted flights [respirable suspended particu-
late (RSP) levels are approximately 20 times those on nonsmoking flights],
and elevated ozone when flying at high altitudes (circa 30,000 to 40,000 feet).
Passengers and crew are often subject to low relative humidity (5 to 25%)
as well.
C. Trains
Trains are used for both surface and underground transportation. Tens of
millions of individuals, in North America and other parts of the world, use
train transportation daily. Such use is particularly heavy in large cities.
Underground transportation includes two indoor environments, the train
and underground tunnels and platforms. Underground systems require ven-
tilation that occurs passively or by mechanical means.
Contaminant exposures in train compartments may include human bio-
effluents, emissions from interior materials, entrainment from combustion-
driven systems, entrainment of contaminants from underground sources, etc.
D. Ships
A ship can be likened to a hotel. It contains sleeping/living quarters, dining
areas, food-handling areas, lounges, theaters, etc. It also includes an on-
board, combustion-driven propulsion system, and waste handling and stor-
age systems.
Many modern passenger ships are mechanically ventilated and air con-
ditioned. Like land-based nonresidential buildings, such systems vary in the
degree of thermal comfort provided, as well as ventilation adequacy.
Exposure concerns on ships may include human bioeffluents, emissions
from ship materials, ETS in smoking-permitted areas, entrainment from
combustion systems, and cross-contamination from high source areas. Of
special concern have been the transmission of contagious diseases, such as
influenza, and outbreaks of Legionnaires' disease.
E.
Submarines and space capsules
Submarines and space capsules represent truly unique indoor environments
and exposure concerns. In both cases, ventilation is not possible. Air/oxygen,
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