Date of Award

January 2014

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Meredith H. Stowe

Abstract

Objective The objectives of this paper are to characterize solvent exposure on an individual basis by auto body shop tasks, establish if solvent concentrations fall below current regulatory standards, and to determine predictive factors for solvent exposure levels. Predictive factors being analyzed are: indoor temperature, outdoor temperature, indoor relative humidity, outdoor relative humidity, booth type, ventilation (bay door use and general exhaust use), paint type, and specific task.

Methods Data for this paper was obtained from The SPRAY (Survey of Painters and Repairers of Autobodies by Yale) study. All statistical analysis was performed in SAS. A log transformation was first applied on all the solvent concentrations to normalize the substantial skew in the distribution. Descriptive statistics were calculated. Regression models were created for each solvent and total solvent concentration. A bivariate model was first created for each solvent and predictor. Then stepwise regression (backwards elimination) was employed to create parsimonious models.

Results The solvents with the greatest maximum concentrations are acetone, toluene, and m&p xylene. Benzene had the lowest average (0.07 mg/m3) concentration and range (0-3.13 mg/m3). All of the samples fell below current regulatory limits with the exception of one toluene sample. With the exception of m&p xylene, task was a significant predictor variable for all solvents and total solvent concentrations. The tasks that produced the highest levels of solvent concentrations are: gun cleaning, spraying, and mixing.

Conclusion Most solvent concentrations in the SPRAY study fall well below regulatory standards. However, this is not an indicator of safety as many regulatory standards are outdated. Future studies should explore the health effects of chronic exposure to permissible levels of solvents.

Comments

This is an Open Access Thesis.

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