Factors Influencing Dust Exposure: Finishing Activities in Drywall Construction

Abstract

Sanding drywall joint compound is a dusty construction activity. We studied potential factors influencing exposure to respirable and total dust for sanders and bystanders in the area of drywall joint compound finishing in 17 test events within a room-scale isolation chamber. We found the air change rate to be negatively correlated with dust C_twa both in the sander's personal breathing zone and surrounding area. We could not conclude that sanding tool type systematically influences dust C_twa, but the use of 80-grit abrasive was associated with the highest dust C_twa. We found respirable dusts were uniformly dispersed 1–8.2 m from sanding activities at a fixed location. As anticipated, both respirable and total dust C_twa in the sander's personal breathing zone are higher than in the surrounding area. The respirable fraction of the total dust mass C_twa was greater in the surrounding area than in the sander's personal breathing zone. Respirable dust concentrations measured in real time increased over the duration of sanding, exhibiting a temporal trend that is similar to that predicted by the well-mixed box model with contaminant removal by mechanical ventilation only, and continuous emission. Dust concentrations returned to pre-activity (background) levels 2–4 hr after cessation of the sanding activity.

Keywords:

• drywall joint compound
• exposure assessment
• isolation chamber
• modeling
• respirable dust
• total dust

ACKNOWLEDGMENTS

All authors are employees of ENVIRON International Corporation, and we acknowledge the contributions of our colleagues in the implementation of this work. The underlying research was funded by Georgia-Pacific (Atlanta, Georgia). Georgia Pacific did not participate in the design of the study, analysis of the data, or preparation of the manuscript.