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Y <br /> Appendix A <br /> An operating exhaust ventilation system physically removes air from a room and thereby <br /> removes environmental pollutants. The operation of supply in conjunction with the exhaust <br /> ventilation system creates airflow through a room, which increases the comfort of the occupants. <br /> If all or part of the ventilation system becomes non-functional, a build up ofnormally occurring <br /> environmental pollutants may occur, resulting in an increase in the discomfort of occupants. <br /> The I MPH approach to resolving indoor air quality problems in schools and public <br /> buildings is generally two-fold: 1 improving ventilation to dilute and remove en ir-ommental <br /> pollutants and 2 reducing or eliminating exposure opportunities from materials that m .y be <br /> adversely affecting indoor air chirality. In the case of an odor complaint of;unknown origin, it is <br /> common for BEH staff to receive several descriptions from building occupants. A description of <br /> odor is subjective, based on the individual's life experiences and perception. Rather than test for <br /> potential series of thousands of chemicals to identify the unknown material, carbon dioxide is <br /> used to judge the adequacy of airflow-as it both dilutes and removes indoor air environmental <br /> -Pollutants. <br /> As previously mentioned, carbon dioxide is used as a diagnostic tool to evaluate air <br /> exchange by building ventilation systems. The presence of increased levels of carbon dioxide in <br /> indoor air of buildings is attributed to occupancy. As individuals breathe, carbon dioxide is <br /> exhaled. The greater the number of occupants, the greater the amount of carbon dioxide <br /> produced. Carbon dioxide concentration build up in indoor envirornents is attributed to <br /> inefficient or non-functioning ventilation systems. The occupational Safety and Health <br /> Administration(OSHA) standard for carbon dioxide is 5,000 parts per million parts of air(ppm). <br /> Workers may be exposed to this level for 40 hours/week, based on a tune-weighted average <br /> (OSHAI 1997). <br /> i <br /> Appendix A, page <br />