ABSTRACT
Biological agents are natural components of the indoor environment where humans live; however, if their presence is undesirable, they may be considered pollutants. Therefore, to maintain the proper condition of the indoor environment and the full health and comfort of the occupants, it is necessary to properly control the exposure and parameters influencing the level of environmental pollution caused by harmful microbial agents. There are no criteria for assessing exposure to microbial agents, or threshold limit values and methodological recommendations that are generally accepted worldwide. This chapter describes the difficulties in formulating hygiene quality standards and discusses the strategy for developing acceptable concentration limits for microorganisms in the air as well as the criteria that play a key role in this process. Polish proposals for regulations regarding bioaerosols in industrial and public buildings are also presented, which may be helpful not only in the assessment of exposure to microbial agents in the indoor environment, but also in taking appropriate preventive actions. They are complemented by proposals of hygiene standards that define the hygiene condition of surfaces of residential and public utility premises contaminated with fungal conidia.
