Shepherd, S (2006) Evaluation of an engineering intervention to prevent silica exposures in construction. ScD thesis, University of Massachusetts Lowell, USA.
Abstract
The overall aim of the study was to evaluate the use of local exhaust ventilation on hand held tools for controlling silica exposure of construction workers. The study was conducted in three parts. The first part was a randomized field experiment at the Laborers training center. Apprentices drilled concrete under controlled conditions with the direction of the researcher. A local exhaust ventilation system for hand held tools consisted of a cowl attached to the tool to capture the dust, flexible hose and a vacuum cleaner to provide suction and containment of the dust. Two types of cowls and two vacuum cleaners were tested in random order. Personal dust and silica exposures while using the controls were compared to uncontrolled exposures. It was found that all combinations of cowls and vacuum cleaners reduced respirable silica exposures to below the recommended Threshold Limit Values (TLV) while uncontrolled exposures exceeded the TLV. The second part of the study examined the measured design parameters of the cowls and vacuum cleaners used in the first part, with the addition of a new cowl which became available. This study describes the capture velocity, hose friction factors and hood entry losses of the local exhaust ventilation system components. Using this data, the effects of varying hose length, cowls and vacuum cleaner flow can be predicted for use in the field. The final segment of this study was a qualitative case study evaluating the implementation of a dust control on a working construction site. The implementation of a control intervention was found to be influenced by four groups of factors: individual actions, technical and equipment issues, organizational environment, and external and political environment. The case study revealed that the relationship between the safety manager for the general contractor and the superintendent and safety officer for the concrete subcontractor was a key factor. Other factors were the location of the worksite, external pressures for dust control and cost-savings in the overall project. These results will be useful in approaching new situations where a similar intervention is needed.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Thesis advisor: | Woskie, S R |
| Uncontrolled Keywords: | case study; construction site; equipment; experiment; safety; subcontractor; training |
| Index terms: | implementation, construction worker, design parameter, savings, case study, threshold limit value, controlled conditions, exposure, subcontractor, organizational environment, general contractor, construction site, experiment, ventilation, manager, dust control |
| Subjects: | public and environmental health, environmental engineering, sociology, testing methods, air quality, data collection methods, work location, health safety and environment, design constraints, practitioner, economic analysis, contractual arrangements |
| Topics: | Business Strategy, Research Practice, Roles and Professions, Design Practice, Site Management, Organizational Design, Health and Safety, Engineering Principles, Sustainability, Procurement |
| Descriptive scope: | 3 PCE |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here