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750 Introduction to Industrial Hygiene
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Indoor Air Quality

Indoor air quality refers to the presence or absence of air pollutants in buildings. There are many sources of indoor air pollutants.

Indoor Air Quality Training Introduction

The presence of sources of indoor air pollutants such as tobacco smoke and radon, or by conditions that promote poor indoor air quality such as inadequate ventilation or moisture intrusion that can lead to mold growth, are used as indications of potential health effects.

The quality of indoor air inside offices, schools, and other workplaces is important not only for workers' comfort but also for their health. Poor indoor air quality (IAQ) has been tied to symptoms like headaches, fatigue, trouble concentrating, and irritation of the eyes, nose, throat and lungs. Also, some specific diseases have been linked to specific air contaminants or indoor environments, like asthma with damp indoor environments. In addition, some exposures, such as asbestos and radon, do not cause immediate symptoms but can lead to cancer after many years.

Many factors affect IAQ. These factors include poor ventilation (lack of outside air), problems controlling temperature, high or low humidity, recent remodeling, and other activities in or near a building that can affect the fresh air coming into the building. Sometimes, specific contaminants like dust from construction or renovation, mold, cleaning supplies, pesticides, or other airborne chemicals (including small amounts of chemicals released as a gas over time) may cause poor IAQ.

The right ventilation and building care can prevent and fix IAQ problems.

In approximately 500 indoor air quality investigations in the last decade, the National Institute for Occupational Safety and Health (NIOSH) found that the primary sources of indoor air quality problems are:

  • inadequate ventilation 52%
  • contamination from inside building 16%
  • contamination from outside building 10%
  • microbial contamination 5%
  • contamination from building fabric 4%
  • unknown sources 13%

Recommended Ventilation Rates

The 62-1989 standard recommends a minimum of 15 CFM of outdoor air per person for offices (reception areas) and 20 CFM per person for general office space with a moderate amount of smoking. Sixty cubic feet per minute per person is recommended for smoking lounges with local mechanical exhaust ventilation and no air recirculation.

Knowledge Check Choose the best answer for the question.

2-2. Indoor air quality refers to _____.