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<br /> The bacterial population we harbor in and on our bodies is diverse and numerous(ten
<br /> times the number of human cells in our bodies). For example, bacteria colonize our mouths,
<br /> skin, and gastrointestinal tract.45
<br /> Bacteria found indoors come from both outdoor and indoor sources. Building occupants
<br /> are a major source of bacteria since humans shed bacteria from their skin and respiratory
<br /> system. For example,bacteria of human origin include gram-positive cocci.46 Similarly,
<br /> Gram-negative bacteria are a natural part of the intestinal flora and can also be found in
<br /> almost all natural habitats. Gram-negative bacteria are common in house dust, soil, and plants,
<br /> and they are most likely carried indoors on pets and dust 47 Coliforms and other gram negative
<br /> bacteria are commonly found on indoor surfaces. They may be more numerous on damp
<br /> surfaces or objects (e.g., kitchen sponges,sink traps, showers,and dishcloths). A study of
<br /> over 200 homes reported the findings of bacteria in the baths,basins, sinks,washing
<br /> machines, nappy buckets, cleaning cloths, dishcloths, facecloths, floors,bathmats,and
<br /> vegetable racks.48
<br /> Endotoxin refers to the toxin characteristic of the outer membrane of Gram-negative
<br /> bacteria. Toxicity is primarily associated with Lipid A, the,lipid component of the
<br /> lipopolysaccharides portion of bacteria 49 It is released when the bacteria die or the cell walls
<br /> are damaged'.50 Endotoxins are ubiquitous in the environment; they are commonly found in
<br /> indoor and outdoor air, water, soil, and food. Humans are exposed to endotoxin on a daily
<br /> basis since it is a component of particulate matter in ambient air, in air and settled dust in
<br /> homes, in office buildings, and in industrial and agricultural settings.st
<br /> It is scientifically incorrect to suggest that the mere presence of bacteria creates a health
<br /> risk. Instead, one must look at(a)the type of bacteria, (b)the method of transmission, (c) its
<br /> quantity, and(d) its degree of potential harm.
<br /> I. Adverse health effects could not reasonably be expected from exposure to
<br /> bacteria and endotoxins at the Indian River County Fire Stations.
<br /> Bacteria are most likely to cause infections or disease in immunocompromised
<br /> individuals, and respiratory effects only occur at high exposure levels.
<br /> The human body is colonized with numerous microbes. Commensal bacteria are part of
<br /> the microbial flora in humans, such as on the skin and in the upper respiratory tract and
<br /> gastrointestinal system.52 Human infections and disease can occur upon exposure to
<br /> 45 Murray,P.R. et al. (2013).Chapter 2:Commensal and pathogenic microbial flora in humans.Medical
<br /> Microbiology,7th ed.Saunders,Philadelphia.
<br /> 46 Institute of Medicine and Committee on Damp Indoor Spaces and Health(2004).loc. cit.
<br /> 47 Institute of Medicine and Committee on Damp Indoor Spaces and Health(2004).loc. cit.
<br /> as Scott,E.et al. (1982).An Investigation of Microbial Contamination in the Home.Journal of Hygiene.89(2):
<br /> 279-293.
<br /> 49 Macher,J.et al. (1999).loc. cit.
<br /> s°Institute of Medicine and Committee on Damp Indoor Spaces and Health(2004).loc. cit.
<br /> S'Thome,P.S.and Duchaine,C.(2007).Chapter 78:Airborne bacteria and endotoxin.In(Hurst,C.J.et al.),
<br /> Manual of Environmental Microbiology,3rd ed.ASM Press,Washington,D.C.p.989-1004.
<br /> 52Murray,P.R.et al. (2013).loc. cit. p.6-10
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