Date of Award


Access Type

Thesis - Open Access

Degree Name

Master of Science in Safety Science


Graduate Studies

First Committee Member

Dr. Terrence Stobbe

Second Committee Member

Dr. Maxwell Fogleman

Third Committee Member

Juan Larios


The author researched 215 recorded injuries and illnesses to all field employees between January 1, 1991 and July 1, 2002 at an arboricultural company in California. Detailed interviews were conducted with each of the 38 field employees to determine employee perceptions of safety training, management, communication, and personal discomfort to provide a clearer picture of the company safety program. This information was correlated with the tree worker claims and industry standards to determine the effectiveness of the safety program based on employee discomforts and claim related descriptive statistics. The claims' tabulations show that back strains are the most prominent injuries in terms of lost days and total costs, but pruning has the greatest number of lost time injuries. Pruning involves equipment such as chainsaws, hand saws, and pole saws, which equate to 35% of the total lost time injuries and 38% of the total claims' costs. More specifically, pruning equipment such as hand saws and pole saws, result in only 8% of total lost time injuries and only 10% of the total cost of claims. The arborist discomfort surveys revealed that elbow and shoulder pain are just as common as lower back pain. The body motion from the use of pole saws and pole primers are the direct cause of this pain and this is consistent with employee opinion. This repetitive strain disorder is becoming an epidemic among arborists and has not been adequately addressed by arborist trade organizations, the State of California, or the American National Standards Institute. Because the safety program is based on the ANSI Z133 Tree Care Operations standards and the California Code of Regulations: Tree Work, Maintenance or Removal, significant deficiencies in the program can be correlated with the inadequacies of the standards. Based on the information collected for this thesis, recommendations were made regarding company safety training, arborist work practices, mechanical assists, equipment design, and industry standards.