|Health hazards in housing are often interrelated
in both cause and solution. For example, moisture is a major cause of paint
deterioration, which can expose children to lead dust and paint chips. Moisture
problems also encourage the growth of mold, mildew, dust mites, pests, and
microbes, which contribute to asthma and other respiratory diseases. Inadequate
ventilation increases the concentration of other indoor air pollutants and
exacerbates moisture and humidity problems.
Homes and buildings are very similar to ecosystems. Just
as we have learned that one change to an ecosystem (e.g. the
introduction of a new plant or insect) causes ripple effects
to all the species in that system, changes to one aspect of
a building (e.g. plumbing) has implications for the way the
whole house operates to support or interfere with good health.
Understanding a building as a system is critical to avoiding inadvertent
health hazards and to fixing hazards. While exhaust fans to remove excess
humidity and vent cooking exhaust can promote indoor air quality, they
can sometimes draw so much air out of the house that they cause backdrafting
in the furnace flue, drawing unhealthy air (containing carbon monoxide
and other combustion by-products) into the home. Thus, the size and placement
of exhaust fans need to take into account the patterns of air flow and
pressure throughout the structure.
Similarly, taking a holistic approach can yield multiple health benefits
and reduce overall costs. Efforts to improve the energy efficiency of
a home or multi-unit building can incorporate some simple, low-cost actions
that improve the health of residents and the durability of the building.
For example, when installing new windows to reduce air leakage, it is
easy and cheap to add pan flashing—simple materials that force water
to drain outside the building. When sealing holes to reduce energy waste,
it is a simple matter to use methods and materials that will also prevent
access to rodents and other pests.
Addressing housing-related health hazards individually—by separate
teams of specialists trained only in a single hazard—is inherently
inefficient. Past policies have individually and serially abated asbestos,
mitigated radon, and controlled lead-based paint hazards. Ensuring healthy
housing conditions requires policies and practices that acknowledge and
address the interconnections. This type of comprehensive and house-as-a-system
approach is also flexible. As new housing-based health conditions emerge,
the infrastructure will be in place to address such hazards.