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A study of indoor carbon dioxide levels and sick leave among office workers.

Myatt TA, Staudenmayer J, Adams K, Walters M, Rudnick SN, Milton DK - Environ Health (2002)

Bottom Line: The weekly mean, workday, CO2 concentration differential ranged from 37 to 250 ppm with a peak CO2 concentration above background of 312 ppm as compared with the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) recommended maximum differential of 700 ppm.We found no association between sick leave and CO2 differential The CO2 differential was in the range of very low values, as compared with the ASHRAE recommended maximum differential of 700 ppm.Although no effect was found, this study was unable to test whether higher CO2 differentials may be associated with increased sick leave.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA. tmyatt@hsph.harvard.edu <tmyatt@hsph.harvard.edu>

ABSTRACT

Background: A previous observational study detected a strong positive relationship between sick leave absences and carbon dioxide (CO2) concentrations in office buildings in the Boston area. The authors speculated that the observed association was due to a causal effect associated with low dilution ventilation, perhaps increased airborne transmission of respiratory infections. This study was undertaken to explore this association.

Methods: We conducted an intervention study of indoor CO2 levels and sick leave among hourly office workers employed by a large corporation. Outdoor air supply rates were adjusted periodically to increase the range of CO2 concentrations. We recorded indoor CO2 concentrations every 10 minutes and calculated a CO2 concentration differential as a measure of outdoor air supply per person by subtracting the 1-3 a.m. average CO2 concentration from the same-day 9 a.m. - 5 a.m. average concentration. The metric of CO2 differential was used as a surrogate for the concentration of exhaled breath and for potential exposure to human source airborne respiratory pathogens.

Results: The weekly mean, workday, CO2 concentration differential ranged from 37 to 250 ppm with a peak CO2 concentration above background of 312 ppm as compared with the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) recommended maximum differential of 700 ppm. We determined the frequency of sick leave among 294 hourly workers scheduled to work approximately 49,804.2 days in the study areas using company records. We found no association between sick leave and CO2 differential

Conclusions: The CO2 differential was in the range of very low values, as compared with the ASHRAE recommended maximum differential of 700 ppm. Although no effect was found, this study was unable to test whether higher CO2 differentials may be associated with increased sick leave.

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Related in: MedlinePlus

Contributions of CO2 to sick leave odds ratio controlled for covariates (dashed lines show the 95% pointwise confidence intervals)
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Figure 2: Contributions of CO2 to sick leave odds ratio controlled for covariates (dashed lines show the 95% pointwise confidence intervals)

Mentions: We did not observe a consistent association between CO2 differential and absence at the levels of CO2 under study (Figure 2). In general, portions of the fitted smooth curves are significantly different from zero if the curve and the confidence interval curves are all above or below zero. When data from the two buildings were combined, no association was observed between CO2 concentrations above background and sick leave.


A study of indoor carbon dioxide levels and sick leave among office workers.

Myatt TA, Staudenmayer J, Adams K, Walters M, Rudnick SN, Milton DK - Environ Health (2002)

Contributions of CO2 to sick leave odds ratio controlled for covariates (dashed lines show the 95% pointwise confidence intervals)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC149392&req=5

Figure 2: Contributions of CO2 to sick leave odds ratio controlled for covariates (dashed lines show the 95% pointwise confidence intervals)
Mentions: We did not observe a consistent association between CO2 differential and absence at the levels of CO2 under study (Figure 2). In general, portions of the fitted smooth curves are significantly different from zero if the curve and the confidence interval curves are all above or below zero. When data from the two buildings were combined, no association was observed between CO2 concentrations above background and sick leave.

Bottom Line: The weekly mean, workday, CO2 concentration differential ranged from 37 to 250 ppm with a peak CO2 concentration above background of 312 ppm as compared with the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) recommended maximum differential of 700 ppm.We found no association between sick leave and CO2 differential The CO2 differential was in the range of very low values, as compared with the ASHRAE recommended maximum differential of 700 ppm.Although no effect was found, this study was unable to test whether higher CO2 differentials may be associated with increased sick leave.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA. tmyatt@hsph.harvard.edu <tmyatt@hsph.harvard.edu>

ABSTRACT

Background: A previous observational study detected a strong positive relationship between sick leave absences and carbon dioxide (CO2) concentrations in office buildings in the Boston area. The authors speculated that the observed association was due to a causal effect associated with low dilution ventilation, perhaps increased airborne transmission of respiratory infections. This study was undertaken to explore this association.

Methods: We conducted an intervention study of indoor CO2 levels and sick leave among hourly office workers employed by a large corporation. Outdoor air supply rates were adjusted periodically to increase the range of CO2 concentrations. We recorded indoor CO2 concentrations every 10 minutes and calculated a CO2 concentration differential as a measure of outdoor air supply per person by subtracting the 1-3 a.m. average CO2 concentration from the same-day 9 a.m. - 5 a.m. average concentration. The metric of CO2 differential was used as a surrogate for the concentration of exhaled breath and for potential exposure to human source airborne respiratory pathogens.

Results: The weekly mean, workday, CO2 concentration differential ranged from 37 to 250 ppm with a peak CO2 concentration above background of 312 ppm as compared with the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) recommended maximum differential of 700 ppm. We determined the frequency of sick leave among 294 hourly workers scheduled to work approximately 49,804.2 days in the study areas using company records. We found no association between sick leave and CO2 differential

Conclusions: The CO2 differential was in the range of very low values, as compared with the ASHRAE recommended maximum differential of 700 ppm. Although no effect was found, this study was unable to test whether higher CO2 differentials may be associated with increased sick leave.

Show MeSH
Related in: MedlinePlus