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Elk River Parks & Recreation Indoor Air Quality Assessment IE.~ Project No. 7805-1301 Page 10 Existing GuidelineslHealth Concerns for Fungi High levels of fungi in the indoor envirolllllent are kno\vn to cause a variety of hUlllan health concenlS and lllay constitute one aspect of envirolllilental sensitivity knO\\'11 as "sick building syndrollle." Several fungal species are knO\Vll to be allergenic, toxigenic and/or pathogenic if present at elevated levels. Ho\vever, the illost conmlon type of response is allergic in nature and is nlanifested by irritation to the respiratory system and eyes, sneezing, sinus congestion and rhinitis. The presence offungi on building nlaterials as identified by a visual assessnlent or by bulk/surface sanlpling results does not necessitate that people \vill be exposed or exhibit health effects. In order for hUlllan to be exposed indoors, fungal spores, fragment, or ll1etabolites must be released into the air and inhaled, physically contacted (dermal exposure), or ingested. \Vhether or not SynlptOll1S develop in people exposed to fungi depends on the nature of the fungal matter (e.g., allergenic, toxic, or infectious), the anlount of exposure, and the susceptibility of the exposed persons. Susceptibility varies \vith the genetic predisposition (e.g., allergic reactions do not al\vays occur in all individuals), age, state of health, and conCUITent exposures. For these reasons, and because 11leasurements of exposure are not standardized and biological 11larkers of exposure to fungi are largely unkIl0\Vn, it is not possible to detem1ine "safe" or "unsafe" levels of exposure in general.(l) Ho\vever, the follo\ving industry guidelines are helpful in determining if fungal gro\vth/contamination may be a concenl in a building: 1. Mycologists (nucrobiologists \vho specialize in the study of fungi) and IAQ practitioners generally agree that the health risks associated \vith exposure to and inhalation of common phylloplane (leaf-associated) fungi, such as species of Cladosporiunz or Alternaria, is less than that associated \vith exposure to potentially toxigenic or pathogenic fungi such as the genera Stach.,llbotrys, Aspergillus or Penicilliunl. 2. In 11lechanically ventilated buildings \vith adequate filtration, the American Conference of Governmental Industrial Hygienists (ACGIH) has indicated that indoor bioaerosollevels should be less than the outdoor levels and the predonunant species to be sin1ilar. (2) The publication also recomnlends the interpretation ofbioaerosol data based on a cOlllbination of the follo\ving: . indoor/outdoor concentration ratios, . a comparison of species composition indoors and outdoors, and . the presence of "indicator species" (those that indicate excessive 1110isture or a specific health hazard) isolated from the indoor environn1ent. "l :Y. Rodac contact plates and s\vab samples are used to assess the level of fungi on a surface \vhere fungal gro\vth or deposition is suspected. A contact sample plate \vith total colony forming units (CFUlPlate) over 50 signifies ll10derate fungal levels and over 100 can be considered a heavy level. (3) 4. For 1vlicrovac bulk dust samples from carpet tops analyzed by a dilution lllethod, the follo\ving nUlllbers are rough rules of thUlllb used to assess the level of culturable fungal counts (spores). The follo\ving guidelines are utilized in helping evaluate \vhether the level and composition of culturable fungal counts is suggestive of interior grovvLh, or of the migration of spores into a building from outdoors, especially of fungi that are conunonly found outdoors such as Cladosporiullz. Other organisll1S that may be suggestive of migration from the outdoors include Alternaria, Ph0111a, yeasts, and EpicocCUllZ nigrullz (4). Fungal organisms at elevated levels that are associated \vith fungal gro\vth on nloisture impacted building ll1aterials include Aspergillus, PenicilliullZ, Chaetonziullz, AcrellzoniullZ and TrichodernzCl. C:\Documents and Settings\tallard\Local Settings\Temporary Internet Files\OLKF\attach to 5 8.doc