Musculoskeletal Risks in Washington State Apple Packing Companies

1.0 INTRODUCTION

The Field Research and Consultation Group (Field Group) of the University of Washington Department of Environmental Health has focused some of its research efforts on the Washington State agriculture industry. Apples are Washington State’s most valuable agricultural commodities. More than half of the apples grown for fresh eating in the United States come from Washington. Fresh apples are produced at the rate of 2.75 million tons annually for the domestic and export markets (Washington Agricultural Statistics Service, 1999). Approximately 4,000 growers and an estimated 41,000 people work in the apple industry (U.S. Bureau of the Census, 1994). Closely allied with the apple production industry is the fruit packing industrial sector. Approximately 12,000 to 15,000 people work in 125 Washington State fruit packing houses; a large percentage of this work is performed by Hispanics (Jarosz and Qazi, 2000), most of whom are women (Teamsters, 1997).

Of particular interest to the Field Group has been the risk of musculoskeletal injuries in this industry. Musculoskeletal injuries are the most commonly reported ailments in the agricultural sector, with over-exertions accounting for 19% of all agricultural nonfatal occupational injuries and illnesses involving lost workdays (National Safety Council, 1998). Packing house workers are exposed to similar work-related musculoskeletal risk factors as agricultural workers, including repetition, awkward postures, and manual material handling. In 1996, fruit and vegetable packing was identified as one of Washington States ten highest risk industries for upper extremity work-related musculoskeletal disorder (WMSD) cases (Silverstein and Kalat, 1998). However, little has been published characterizing the specific risk factors associated with fruit packing, nor is there much published information with regard to control strategies to mitigate musculoskeletal risks.

In April and May of 1999, Field Group recruited three Yakima-region fruit packing houses to participate in a pilot study to characterize the musculoskeletal risk factors in the Washington apple packing house industry. In addition to characterizing the risks, the researchers were interested in identifying existing or new controls that might be used to reduce identified risks.

1.1 Literature Review

The relationship between fruit packing workstations and the worker has long been of interest to the industry; however, the primary focus of the research in this area has been to determine ways to improve productivity. Identification and remediation of musculoskeletal risk factors has been of secondary interest. Smith (1963) compared the human factors of frontal fruit packing stations and side packing stations. He found that citrus packers who worked face-on eliminated body bending and twisting, maintained an erect posture, and were less fatigued than those workers at side packing stations. Meyers (1990) found an increase in performance and accuracy among sorters (workers who inspect products visually for shape, color, and defects) when product moved from the end rather than from the side of an inspection conveyor. Other studies have investigated the relationship between worker fatigue, postural discomfort, and break schedules and fruit inspection performance (Pang, 1994; Purswell and Hoag 1974, Hendrix, 1989; Bhatnager, 1985; 1974; Colquhoun, 1959). A review article by Bollen et al (1993) described the design and operation of sorting equipment, ergonomic factors (e.g. lighting, table size, product loading, and sorter position), and sorter performance. Miller (1991) compared fruit grading performance to such factors as product volume, position of reject chutes, and fruit rotational speed.

A growing body of evidence suggests a relationship between WMSD and a variety of one or more work-related physical factors (e.g., repetitive lifting of heavy objects in extreme or awkward postures) (NIOSH, 1997). In the agricultural sector, the majority of this work has taken place in the food processing industry, particularly meat packing and canneries (Chiang, 1993; Messing, 1992; Kurppa, 1991; Luopajarvi, 1979). The annual incidence of soft-tissue injury among women fish and meat packers ranged from 7-25% (Chiang, 1993; Kurppa, 1991). High incidence of work-related carpal tunnel syndrome (CTS) has been found among middle-aged women who perform tasks that had high levels of repetitiveness and sustained forceful movements (Chiang, 1990; Sandzen, 1981). Few studies have documented the musculoskeletal hazards associated with body discomfort, impaired work performance, and chronic muscle, tendon and nerve disorders in fruit packing houses; however, one intervention study reported improved self-reported comfort among apple sorters when the extent of forward reach was reduced (Studman, 1998). Across all industries in Washington State, musculoskeletal injuries have resulted in increasing workers compensation costs and time-loss, prompting industry, labor, and regulatory groups to work toward better understanding and controlling work-related musculoskeletal hazards.

1.2 Washington State Regulatory Action

Recognizing the human and financial cost of work-related musculoskeletal injuries, the Washington Department of Labor and Industries has promulgated an ergonomics rule to address these injuries. The rule, adopted in May 2000, includes agricultural work places, such as the packing house industry (WAC 296 62 051). The rule has several elements. Employers are covered by the rule if they have jobs with typical work activities that are a regular and foreseeable part of the job and that meet the “caution zone job” (CZJ) criteria. “Caution zone job” criteria include awkward postures, high hand force, highly repetitive motion, repeated impact, vibration, and heavy, frequent, or awkward lifting. If an employer determines there are jobs that meet the CZJ criteria, several activities must be implemented including the following:

• All employees in “caution zone jobs” and their supervisors must receive ergonomic awareness education at least every 3 years.
• “Caution zone jobs” must be analyzed to identify WMSD hazards and identify ways to reduce exposures below the hazard level or to the degree feasible.
• Employees must be involved in the analysis of hazards, selection of control methods, and in evaluation. · Control priorities require that engineering or administrative measures should be considered first. Individual work practices or personal protective equipment are to be second priority controls.
• Employers must share information with employees through safety committees or safety meetings.
• Ergonomic activities must be reviewed annually.

The Washington State Ergonomics Rule has a phased implementation schedule. Large employers (more than 50 full time equivalent workers) must be in compliance with the awareness education and hazard analysis aspects of the rule by July 1, 2003, and must complete hazard reduction efforts as necessary by July 1, 2004. Mid-size fruit packing companies (11-49 FTE) must be in compliance with awareness education and hazard analysis aspects of the rule by July 1, 2004, and must complete hazard reduction efforts as necessary by July 1, 2005. Finally, small employers (fewer than 10 full time equivalent workers) must be in compliance with the awareness education and hazard analysis aspects of the rule by July 1, 2005, and must complete hazard reduction efforts as necessary by July 1, 2006. This report includes an evaluation of six apple packing jobs from the perspective of the Washington State Ergonomics Rule.

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