MAY'S WAYS— September 2017
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The trails are also visible in places where you
might not expect to see them, such as on electric
cables and the tops of PVC pipes.
Mice use their urine as an important part of
their communication system.
U.S. Na onal Library of Medicine, Na onal Ins -
tutes of Health. h ps://www.ncbi.nlm.nih.gov/
pmc/ar cles/PMC2577770/
"Hantavirus pulmonary syndrome (HPS) is a
serious respiratory disease transmitted by in-
fected rodents through urine, droppings or sa-
liva. Humans can contract the disease when
they breathe in aerosolized virus….Rodent
infestation in and around the home remains
the primary risk for hantavirus exposure. Even
healthy individuals are at risk for HPS infec-
tion if exposed to the virus." (Southern Nevada
Health District;
https://southernnevadahealthdistrict.org/
health-topics/hantavirus.ph).
Unfortunately, in modern life, many (if not most)
people in our country spend up to 90% of their
lives indoors: in their homes, their work spaces,
and even cars, trains and planes (these are still
"indoor" spaces). Many people also exercise in-
doors – whether in health clubs or in basement
"work-out rooms."
A growing number of these spaces are tightly
constructed to save energy, and the mechanical
systems that are supposed to provide fresh air
into a building are often not operating as intended
due to poor maintenance practices.
We all want to breathe air that is clean: air that
does not contain contaminants like mold spores,
bacteria, soot particles, unpleasant odors, com-
bustion products, and formaldehyde.
A mouse infestation inside a building can be
a source of airborne contaminants. Several stud-
ies have noted that home occupants suffer sig-
nificantly more asthma symptoms in homes with
elevated levels of mouse allergens in droppings
and urine (Johns Hopkins Medicine).
h p://www.hopkinsmedicine.org/Press_releases/
2005/02_10a_05.html
There are also other health conditions and
diseases that can be caused by exposures to
rodent droppings, including, in North America,
Lymphocyctic Fever and Hantavirus Pulmonary
Syndrome (Centers of Disease Control and Pre-
vention).
h ps://www.cdc.gov/rodents/diseases/direct.
html).
In buildings with long-standing mouse infesta-
tions, I usually see reddish-purple stains in the paths
of well-trodden mouse trails. These patchy-colored
trails, dotted with droppings, are often found on the
tops of foundation walls or on the floors at the floor-
wall intersections in basements and garages.
Mouse Matters
©2017 Jeffrey C. May
Mouse urine trails in basement
May Indoor Air Investigations LLC
