Environmental Engineering Reference
In-Depth Information
mold infestation problems; and a favorable indoor climate for development
of large dust mite populations, with their associated antigen production and
exposure risks.
Other site characteristics also contribute to moisture and IE concerns.
Heavily shaded sites tend to retard drying of exterior building surfaces as well
as the site itself. Well-drained sites with sandy or gravelly soils reduce risks
associated with moisture-requiring biological contaminants. On the other
hand, high soil permeability may be associated with elevated radon levels.
G. Occupants and occupant behavior
Once a dwelling is occupied, it is subject to a number of contaminant-
generating activities. These include: production of bioeffluents by occupants
as well as odors associated with food preparation and use; emissions from
personal care and clothing/home cleaning products; smoking of tobacco
products (and possibly other weeds); emissions/by-products of hobbies,
crafts and in-home enterprises; fragrant emissions from candles, potpourri
and decorative items, as well as combustion by-products from the frequent
use of candles; pet odors and danders; production of organic debris that
serves as food for antigen-producing dust mites, cockroaches, mice, etc.; both
proper and improper use of pesticides to control common household pests;
building interior renovation activities; improper/ inadequate care and main-
tenance of building combustion, plumbing and other systems; introduction
of furniture and other materials which may be a significant source of con-
taminants; and introduction of particulate-phase contaminants on shoes and
clothing from the building site (e.g., lead-based paint dusts and pesticides)
as well as work environment (e.g., industrial dusts, starch and talc from hair
care establishments, etc.).
H. Exposure concerns
Occupants of dwellings are exposed to indoor air and other environmental
contaminants in ways that are different from other nonindustrial buildings.
As indicated previously, occupants of residences can be exposed to poten-
tially toxic indoor contaminants 12 to 24 hours/day. Exposed populations
include infants/children, healthy adults, the aged, and the infirm.
Contaminant exposure concerns that are unique in residences include:
radon; HCHO; environmental tobacco smoke (ETS); pesticides; unvented
combustion appliances; biocontaminants such as dust mite and cockroach
antigens, mold, and animal danders; lead-based paint-contaminated dust;
emissions from personal and home-care products, and arts and crafts activ-
ities; and contagious disease.
Exposure concerns in residences are increased due to limited dilu-
tion/ventilation potential when windows are closed during heating and
cooling seasons. Residences, unlike other nonindustrial buildings, are not,
in most cases, mechanically ventilated.
