On August 26, 1999, the Milwaukee Department of Neighborhood Revitalization,
Milwaukee Health Department, Wisconsin Energy Bureau, and DOE's Partnership
of Affordable Housing conducted a test to discover whether lead contaminated
dust is drawn into living spaces when a blower door is operated. It was
found that no significant amounts of lead dust were pulled from behind walls
or window openings.
The test was organized in response to a concern raised regarding the use
of blower doors to test rehabbed homes involved in an energy efficiency
component of Milwaukee's neighborhood revitalization program. The Milwaukee
program rehabs between 800 and 1000 housing units each year, most of which
are single family homes or two-flat wood frame residential structures. These
homes are located in older neighborhoods where lead-based paint is a major
public health concern.
Milwaukee Health Department having extensive experience in testing for the
presence of lead-based paint was asked to participate in the test. Also
participating was a staff member of a local weatherization agency. The Health
Dept. chose the apartment for the test. The apartment
was the upstairs unit of a wood frame two-flat, similar to many in Milwaukee's
revitalization program.
The participants chose 5 sites around the apartment: two window sills, two
painted horizontal surfaces next to windows, and one foot square floor surface
next to an exterior wall. There was air movement around and near each test
site when the blower door was operated.
The 5 sites were tested with dustwipes at the start of the test. Mary Smith of the Bureau of Public Health conducted the tests.
All windows were then closed. The sites were cleaned by Ms. Smith and retested.
Hector Ruiz then operated the blower door at 50 Pascals
for 10 minutes. We checked the apartment to see if air was moving in
through perimeter walls. We found air moving through outlets, around windows,
and in other normal sites. Mr. Ruiz agreed with the characterization that
the apartment was not tight and could benefit from air sealing measures.
After turning off the blower door, Ms. Smith again tested the 5 sites with
dustwipes. The dustwipes for each of the 3 tests at each of the 5 sites
were sent to the Bureau of Public Health Laboratory and tested. All sites
showed lead dust levels below EPA clearance levels (as given in "Guidelines
for the Evaluation and Control of Lead-Based Paint Hazards in Housing",
p. 15-10). Sharon Pendleton, the project coordinator at the Health Department,
characterized the test results as showing "very little lead dust impact"
in the dustwipe that showed the highest reading on the final test. She said
further that she believes "that this is not likely to be a fluke since
the suction/draft created during such tests are not likely to disturb dust
that much."
The test results (micrograms/sq.ft.) are as follows:
| Location |
Pretest |
Cleaned |
Post Blower
Door |
Clearance |
| Kitchen Sill |
83 |
6 |
22 |
500 |
| Kitchen Radiator Cover |
38 |
3 |
0 |
500 |
| Kitchen Floor |
8 |
3 |
2 |
100 |
| Parlor Sill |
325 |
33 |
39 |
500 |
| Parlor Radiator Cover |
31 |
9 |
21 |
500 |
Though this is but one test, it does offer support for the safety of
using a blower door in older rehab projects. Moreover, it should be remembered
that a blower door simulates the pressure on a building's envelope that
one would find with a 20 to 25 mile per hour wind, an occurrence that is
experienced commonly during storms or when weather fronts pass through.
One should also recognize that air movement through window frames and cracks
in walls can be substantially limited using blower door-directed air sealing
methods. Such methods can both reduce the likelihood of dust moving from
behind walls and reduce unconditioned air from entering heated spaces.
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