TABLE 1.

—Estimated Health Impacts of Contaminants in Indoor Work Environments in the United States, and Potential Benefits of Improved Environments

	Health Impacts
Contaminant-Related Health Effect	No. of Workers With Health Effect Due to Work or Nonwork Exposuresa (of 89 Million Total Indoor Workers in US)	Severity	Frequency (Duration)	Estimated Potential Annual Reduction (% and No.) in Health Effect From Improved Work Environments Among Indoor Workers
Communicable respiratory infections: building–influenced, occupant sources (e.g., influenza, common cold, tuberculosis)	Influenza and common cold: 52 million cases; tuberculosis not in health care or prison settings: unknown	Usually moderate, fewer than 70 000 hospitalizations and unquantified fatalities	~0.58 cases of common cold and influenza per year among working–age population (duration varies, days to months)	Estimated 10% to 14%; 5–7 million cases (estimate has substantial uncertainty)
Asthma, hypersensitivity pneumonitis, and allergic disease	Asthma: 4.7 million; allergies: 18 million	Allergies: mild to severe; asthma: mild to fatal	Asthma and allergies: many to all days per year (duration of both usually chronic)	Estimated 6% to 15%; asthma episodes among 0.3–0.7 million cases; allergy episodes among 1–3 million cases (estimates have substantial uncertainty)
Nonspecific building-related symptoms (acute effects of indoor exposures or conditions, including so-called sick building syndrome)	35–60 million workers with one or more weekly building-related symptoms (effects from work exposures only)	Usually mild to moderate	Often while at work (chronic with chronic exposure)	Estimated 20% to 50%; 8–30 million cases (estimate has substantial uncertainty)
Respiratory infections: building sources (Legionnaires’ disease, Pontiac fever, fungal infections)	2700–6000 estimated cases per year of Legionnaires’ disease; unknown number of Pontiac fever and fungal infection cases	Legionnaires’ disease: often severe, 5% to 15% of documented cases are fatal; Pontiac fever: moderate; fungal infections: can be severe or life threatening	Legionnaires’ disease and Pontiac fever: usually once per lifetime (duration varies); fungal infections: varies	Unknown, probably fairly high (e.g., > 50%); Legionnaires’ disease: 1400–3000 cases, including >70 deaths; Pontiac fever, fungal infections: unknown
Health effects of environmental tobacco smoke	Among 10–30 million exposed, acute irritation, respiratory effects, reproductive effects: unknown; cardiovascular effects: 2000–11000 deaths; lung cancer: 100–600 cases (effects from work exposures only)	Acute irritation: mild to moderate; respiratory and reproductive effects: moderate to severe; cardiovascular effects: severe to fatal; lung cancer: fatal	Acute irritation with exposure; respiratory effects: chronic; cardiovascular effects and cancer: chronic, often fatal	100%; 2000–11 000 cardiovascular disease deaths; 100–600 lung cancer cases including 90–530deaths

Note. Sources for and details on effect estimates are available from the authors and as a supplement to the on-line version of this article.

^aEstimates in this column that reflect the effects of work-related exposures only are identified.