Construction painters have not been well studied in terms of their exposures or the impact of work on their health. The reason so little work has focused on this group is that they are highly mobile, difficult to trace for follow-up, and perform tasks that do not fit the typical 80-hour time weighted average exposure scenario. Additionally, construction painters may be exposed to solvent based products that are present in both the vapor and liquid (mist) phases. The goal of this investigation was to utilize new techniques in exposure assessment to characterize exposures to volatile organic compounds during construction painting activities. The research was divided into four projects each addressing separate aims. Project I was conducted to develop the video exposure monitoring technique and customize its application to construction painting tasks for which exposures to volatile organic compounds (VOCs) are very high. Project 2 tested the utility of using a newly developed portable photoionization detector (PID) with task. Previous investigations have indicated that traditional methods of measuring exposure may lead to an underestimation because they fail to account for VOCs in the aerosol phase. Prototype vapor-aerosol samplers were obtained from SKC Inc., and samples were collected side-by-side also using traditional charcoal tubes, prefiltered charcoal tubes, and passive vapor samplers. No significant differences between VOC concentrations from charcoal tube and vapor-aerosol samplers was found. This finding was unexpected but may have occurred because the components of the sprayed material were extremely volatile resulting in only a small proportion of inhalation exposure due to the mist. Data collected during 107 painting processes involving 85 employees from 62 companies was analyzed as part of Project 4. The overall geometric mean VOC concentration indicated that painters in the study were substantially exposed to organic vapors. Although there has been a tremendous shift to water borne architectural coatings in commercial and residential construction, this study found that there are specific tasks in which exposures to VOCs may be extremely high. Solvent based coatings are used on metal and bare wood where finish and durability are required to exceed that achieved with water born products. In residential construction, exposures to VOCs are most common during the application of stain and lacquer. In the commercial construction sector, solvent based products are uncommon in typical building construction (offices) with use limited to lacquering of doors and application of alkyd paint on metal door frames. The use of solvents throughout the duration of the painting process was associated with very high exposures to VOCs. Because of high exposures during the spray application of lacquers, samples obtained on painters in residential construction were higher than those obtained on workers on other projects. When the data were grouped by painting process or by specific work tasks, the differences in means were statistically significant. Application of lacquer and sander sealer were associated with very high exposures both in residential and commercial construction projects. There was considerable variability in exposure data and very few independent variables were statistically significant predictors of an employees' VOC exposure. Similarly symptom scores were, for the most part not associated with level of VOC exposure. Two exceptions, "been feeling run down" and "felt high or intoxicated at work" were significantly positively associated with exposure level. These symptom scores increased with increasing level of VOC exposure. Overall the investigation found that construction painters on Colorado have the potential for intermittent but very high exposures to VOCs. The use of a portable PID is extremely useful in assessing exposure to construction painters as it provides data which is highly correlated to that obtained from charcoal tube sampling. Additionally, the PID with datalogger provides information on ceiling and short term exposures which are of concern from both a health and safety point of view. Most painters work for small contractors and these small businesses place little emphasis on health and safety and generally do not have respiratory protection programs. It is recommended that additional datalogger in assessing overall VOC exposures in construction painting. Project 3 was conducted to specifically address the issue of the contribution of aerosol in the overall V OC exposure of the construction painter during the application of lacquer. Project 4 developed and used the task-exposure matrix to assess the relationships between project, process, and task variables and VOC exposure. Additionally, symptom data with reflected acute health effects of exposures to organic solvents was collected and models were developed to determine if symptom scores were associated with VOC exposure. Project 1 demonstrated that video exposure monitoring could be effectively used to determine which specific activities within a work task make the greatest contribution to overall VOC exposure. A drawback of the system was the size and awkwardness of the equipment that must be worn by the worker. The use of equipment for detailed video exposure monitoring was not well received by construction painters who volunteered for the study. Proj ect 2 was undertaken to assess the utility of a much smaller Pill and datalogger for collection of data that would be suitable for less rigorous video exposure analyses. Additionally, a goal of this project was to determine if data from a Pill are reflective of overall VOC exposures. A high degree of correlation between results obtained using the two methods was found. Since the highest exposures were encountered during the spray application of solvent based lacquers, Project 3 was conducted to determine the most appropriate method of characterizing exposures for this information be provided to employees and small painting contractors regarding the hazards of using solvent based products.
Department of Environmental Health, Colorado State University, 104 Environmental Health Building, Fort Collins, CO 80523