Civil Engineering Reference
In-Depth Information
in Oxford 95 % of indoor data and 97 % of outdoor data (Lai et al.
2004
).
Otherwise, the BASE study reported that PCE was detected in all buildings sampled
(US EPA
2013a
).
2.8 Biological Pollutants: Dampness and Mould
Indoor biological pollution is particularly caused by a complex mixture of live and
dead microorganism, toxins, allergens, microbial VOCs and other chemicals
growing indoors when sufficient moisture is available. Biological pollutants can be
found in house dust, furniture surfaces, carpets and textiles among others (WHO
2009
). A summary of dampness-related pollutants is provided in Table
6
.
Main health effects associated with dampness and mould are adverse respiratory
symptoms, allergies and asthma, as well as perturbation of the immune system
(Mendell et al.
2011
). Behavioural problems such as depressive symptoms in adults
and poorer cognitive function in children (Casas et al.
2013
) were also reported to
be significantly associated with dampness and mould in dwellings and workplaces.
These effects cannot be quantitatively quantified and, hence, WHO guidelines do
not provide any threshold for biological pollutants. The general recommendation is
to prevent or minimise persistent dampness and microbial growth on indoor sur-
faces and building structures, such as wallpapers, furniture and textiles and, hence,
adequate building design, construction and maintenance are required (Schuchardt
and Strube
2012
). Building occupants are responsible for preventing and reducing
indoor moisture, by providing correct ventilation. Therefore, public authorities may
establish regulatory measures suitable housing and occupancy policies.
Table 6 Summary of dampness-related indoor pollutants (WHO
2009
)
Indoor pollutant
Type of organism and most common species
House dust mite
allergen
Small microscopic arachnids such as Dermatophagoides,
Pteronyssinus and Dermatophagoides farinae
Fungal allergen
Eukaryotic organisms such as Alternaria, Penicillium, Aspergillus,
and Cladosporium
Bacteria
Prokaryotic microorganisms such as Streptomycetes and mycobacteria
Endotoxins
Integral components of the bacteria cell, released after the destruction
of the bacteria
Fungal (1 ? 3)-b-D-
glucans
Non-allergenic and water insoluble components of the structural
cell-wall of most fungi, some bacteria, most higher plants and
many lower plants
Mycotoxins
Fungal toxins or biomolecules with relatively low-molecular mass
produced by fungi such as alcohols, aldehydes, ketones, terpenes,
esters, aromatic compounds, amines and sulphur-containing
compounds
Microbial and other
VOCs
Volatile metabolites produced by fungi
Viruses
Infectious agents that can cause respiratory diseases
