|
  Many
chemical polluting agents may be present as mixture in the indoor air. Some
of them originate almost exclusively indoors, whereas others may
penetrate with the outdoor air, especially if the environmental pollution
is high.
The main chemical polluting agents include:
Combustion gases(NO2, SO2,CO)
The most important and plentiful compound in indoor pollution is
represented by NO2.
SO2 is a combustion gas originating from combustible materials
containing sulphur, such as combustible oil and some natural gases.
CO originates from passive smoking and from combustion sources lacking
appropriate aspiration; it may also come from outdoors if the room
overlooks roads with heavy traffic.
Tobacco smoking
Tobacco smoking is a mixture containing gases, particles, organic
compounds and products originated from the incomplete combustion of
tobacco and paper. More than 200 elementary compounds have been
identified, some of which of certain toxic and irritating power for
biological tissues.
Organic compounds
Volatile organic compounds (VOC) include substances whose boiling poit
ranges from 50°C to 100°C. This class includes numerous compounds such as
(aliphatic) and aromatic hydrocarbons, chlorate hydrocarbons, aldehydes,
terpenes, alcohols, esters and ketones. The main sources of VOC are
people and their activities (combustion sources, cigarette smoking,
photocopyng process, laser printers), fittings (furnishings, moquette,
linings), cleaning materials and, sometimes, the outdoor environment.
Particulates
Inhaled particulates is produced by cigarette smoking and combustion
sources.
Exposure to small concentrations of NO2 (1-2,5 ppm) is
responsible for decreased respiratory function in children and, probably,
also in adults. Furthermore some epidemiological studies seem to suggest
an interaction of this gas with other polluting agents, leading to
immunodepressive effects.
Experimental exposure for less than 1 minute to SO2
concentrations of 0,75 ppm is responsible for a decrease in pulmonary
function in suckling and in elderly people. Furthermore in the exposed
subjects there is an important increase in airways resistance. CO is
responsible for a variety of effects depending on the concentration
(asthenia, decrease of the working ability, headache, sensory
obnubilation, loss of consciousness, death). Furthermore chronic
cardiovascular effects related to chronic exposure to small doses of CO
have been postulated.
Passive tobacco smoking has been suspected of being the cause or
concomitant cause of cardiovascular disease, respiratory disease and lung
cancer. Epidemiological studies on subjects exposed to passive smoking
have not shown clear results regarding the first issue, whereas they seem
to suggest an increased carcinogenic risk for the lung.
The impact of VOC on man can be responsible for a big variety of effects
that range from sensorial discomfort to serious alterations of health,
including genotoxic effects. Recently it has been postulated that indoor
pollution by VOC may represent a significative carcinogenic risk for the
subjects that spend a long time in confined spaces. Furthermore studies
that have been carried out suggest a causal relation between exposure to
VOC and irritating disorders to the upper airways and the eyes and alterations
of comfort.
Cancer is the most serious effect associated to exposure to combustion
particulate. Soot has carcinogenic properties and a number of aromatic
polycyclic hydrocarbons (VEDERE), some of which carcinogenic, are
adsorbed on the particulate fine that, once inhaled, penetrates deeply
into the lung. The particles may play an additive or synergic role in the
carcinogenesis produced by the compounds adsorbed onto them.
For additional information
|
![[collegamenti]](ico/collEfdr.gif){kind=small}
