Chainsaw Research Articles

Matter Out of Place

Matter Out of Place

Hand-arm vibration syndrome with use of anti-vibration chain saws: 19-year follow-up study of forestry workers

Hand-arm vibration syndrome (HAVS) consists of vascular and neurological component. Musculoskeletal component has not been delineated yet. In the present follow-up study, we evaluated the prevalence of HAVS and the cumulative exposure to vibration among a cohort of forestry workers. Special interest was given to numbness and musculoskeletal disorders of upper extremity and neck in forestry workers. A follow-up study starting from 1976 was conducted among forestry workers in Suomussalmi in Finland. Total exposure of hand-arm vibration was recorded during 11 cross-sectional surveys. The last study was carried out in 1995. The lifetime dose of vibration energy was calculated. A cohort of 52 forest workers participated to all 11 cross-sectional surveys 1976-1995. HAVS and musculoskeletal disorders were evaluated. The prevalence of active vibration white finger (VWF) decreased from 13 to 4% in the cross-sectional study. In the cohort VWF decreased from 17 to 8% and numbness increased from 23 to 40%. Rotator cuff syndrome (P=0.034) and epicondylitis (P=0.004) associated with numbness. Regional neck pain was diagnosed in 38% of workers and associated with low back pain. In modeling VWF, the lifelong vibration energy (OR 1.03, CI 1.01-1.05), and smoking (OR 7.36, CI 1.07-50.76) were significant. Numbness was modeled by pain in upper extremities (OR 12.43, CI 2.42-63.80) and neck pain (5.97, CI 1.25-28.39), not by lifelong vibration energy. Right rotator cuff syndrome was modeled by age (OR 2.58, CI 1.04-6.41) and lifelong vibration energy (OR 1.04, CI 1.00-1.07). The prevalence of VWF constantly decreased. Numbness did not follow the vibration exposure profile. Numbness also associated with upper extremity musculoskeletal disorders. Hand-arm vibration associated with the right rotator cuff syndrome in forestry workers.

Environmental impacts of harvesting white spruce on Prince Edward Island

An increased trend toward whole-tree harvesting in the Maritimes region of Canada, followed by the planting of different tree species, highlighted a need to investigate the potential impacts of different harvesting methods on nutrient loss and the growth rates of different tree species planted in the treated areas. Thus, in 1990, a harvesting study with three main treatments was conducted in an old-field white spruce ( Picea glauca (Moench) Voss) stand in Prince Edward Island, Canada. The treatments included whole-tree harvesting (WTH) with chain saws, in which almost all the aboveground biomass was removed from the site, stem-only (SO) harvest, consisting of chainsaw felling and removal of only the merchantable boles from the site, and control (CON), an uncut area. Glass-body lysimeters, connected to hanging-bottle vacuum generators, were installed at three depths to collect soil solution. The leachates collected over a 6-year period (1991–1997) were analyzed for pH and various anions and cations. Soil temperatures were also measured at three depths. The hourly mean temperature immediately below the organic horizon in the WTH blocks was 8–10 °C more than that in SO blocks. The daily mean temperature showed a similar pattern. Concentrations of nitrate and hydrogen ions were higher in the leachates collected from SO blocks than from WTH blocks. The estimates of calculated quantities of nutrients lost from WTH blocks were higher than those from SO blocks. Ground vegetation recovered within 2 years following harvest and the calculated Shannon–Weiner biodiversity index showed no difference in index values among different treatments. The height growth of trees planted during May 1992 in the harvested blocks is greater in SO blocks than in WTH blocks. Planted eastern white pine ( Pinus strobus L.) trees are generally taller than planted white spruce trees.

Nursing leaders, drop your tools

Karl E. Weick, distinguished professor of organizational behavior and psychology at the University of Michigan Business School, has described the failure of a total of 27 wildland firefighters to follow orders to drop their heavy tools so they could move faster and outrun exploding fires, which led to their deaths within sight of safe land. 1 Weick K Drop your tools: an allegory for organizational studies. Admin Sci Q. 1996; 41: 301-313 Crossref Scopus (377) Google Scholar The first such failure occurred in 1949 in Mann Gulch, Montana, where 13 firefighters lost their lives, and the second occurred in 1994 under similar circumstances in Colorado, resulting in 14 deaths. After the fires, the deceased firefighters were found with their tools (chain saws and axes) and packs still on them. Why would anyone slow their retreat from danger, even death, by hanging on to heavy tools that were no longer useful to them? The U.S. Forest Service analysis of the more recent incident revealed that the firefighters would have reached the top of a ridge before the fire did if they had perceived the threat from the start, dropped their tools, and made a run for it. Karl E. Weick, distinguished professor of organizational behavior and psychology at the University of Michigan Business School, has described the failure of a total of 27 wildland firefighters to follow orders to drop their heavy tools so they could move faster and outrun exploding fires, which led to their deaths within sight of safe land. 1 Weick K Drop your tools: an allegory for organizational studies. Admin Sci Q. 1996; 41: 301-313 Crossref Scopus (377) Google Scholar The first such failure occurred in 1949 in Mann Gulch, Montana, where 13 firefighters lost their lives, and the second occurred in 1994 under similar circumstances in Colorado, resulting in 14 deaths. After the fires, the deceased firefighters were found with their tools (chain saws and axes) and packs still on them. Why would anyone slow their retreat from danger, even death, by hanging on to heavy tools that were no longer useful to them? The U.S. Forest Service analysis of the more recent incident revealed that the firefighters would have reached the top of a ridge before the fire did if they had perceived the threat from the start, dropped their tools, and made a run for it.

Future Present: Ethics and/As Science Fiction by Michael Pinsky (review)

MLRy 100.3, 2??5 807 knowledge of the US horror film, and he writes with confidence about films from a wide range of cinematic eras and subgenres, Jones's analysis of these texts is more flimsythan his literary analysis, with some of the filmsections in the book appearing rather indexical. This renders the book methodologically uneven, given that the critical histories offeredofeach trope ofhorror literatureare so thoroughly researched. This study often glosses over the industrial contexts of production of the horror film (aside from occasional 'fan fact' anecdotes) and very little attention is paid to the specific detail of mise en scene within the horror genre, concentrating instead on plot and dialogue in the films in question. Furthermore, there is a wealth of critical literature on the horror genre in both film and literature which this study simply does not engage with, such as the wide-ranging work on Gothic horror for women which embraces both literary and filmic texts within its analysis (see, for example, Susanne Becker, Gothic Forms of Feminine Fictions (Manchester and New York: Manchester University Press, 1999); Judith Halberstam, Skin Shows: Gothic Horror and the Technology ofMonsters (Durham, NC, and London: Duke University Press, 1995); Karen Hollinger, 'The Female Oedipal Drama of Rebecca from Novel to Film', Quarterly Review of Film and Video, 14.4 (1993), 17-30). The book does deal with the critical issues which have surrounded this genre, such as the question of reader/viewer identification, but then fails to draw on the extensive literature available on this subject to inform its lines of enquiry. Ultimately, it is the closing paragraph of the book which best epitomizes the relationship between horror literature and filmin the mind of the author, when he expresses his surprise and delight at undertaking 'a (funded!) research trip' (p. 192) to view The Texas Chain Saw Massacre (1974.). As the shock exclamation mark suggests, horror cinema is, by the end ofthe book, still seen by Jones as a low-cultural extension of horror fiction,perhaps slightly unworthy of study and valuable research funding, thus representing the difficultywhich the author has in uniting his dual identities as serious scholar of Gothic fiction and horror-cineaste. University of Reading Helen Wheatley Future Present: Ethics and/as Science Fiction. By Michael Pinsky. Madison, NJ: Fairleigh Dickinson University Press; London: Associated University Presses. 2003. 215 pp. ?34. ISBN 0-8386-3924-0. The mode, Michael Pinsky suggests, in which we anticipate Otherness is through anticipation and speculation: the motive engines of science fiction. In this two-part text Space and Time are considered as aspects ofthe theoretical frameworks by which we construct ethics; then science fictions and proto-ethical systems are examined. Readers are encouraged to begin with whichever section they wish. The final chapter links both parts. While Pinsky skates around science as a narrative construct, and makes oddly su? perficial comments about sfcritics like James Blish, he is interesting when considering ethics as a 'science fiction'?as related to our concepts of scientific and philosophical 'laws'. Sf texts and philosophical texts are in some way partners?which may induce apoplexy in sf fans and philosophers alike, but philosophical 'thought experiments' are remarkably akin to science fictions. The firstchapters discuss Space and Time as locations of Self and Other, drawing on Heidegger and Levinas. The cause-and-effect relationship can be recognized only in hindsight, stressing future and futurity: perhaps we construct our identities and encounters with alterity with an eye to the future? Part 2, 'The Future in Focus', develops this question. Pinsky considers Wells's speculations, examining transgres? sion of rational and ethical law through temporal and special locales. From The Island 808 Reviews of Doctor Moreau and The War of the Worlds comes the 'Thing'?the machine, the animal, the irrational (and super-rational). In two 'case studies' of encountering the future Pinsky notes Wells showing prophecy 'reversed' as the very awareness of the future threatened in The Invisible Man cancels that future, while the endless open future of the 1936 film Things to Come offersuncertainty. The second 'study' is not fiction but the Disney Corporation's 'Tomorrowland' versions of the future. Chap? ter 5 gives us the...

It's On Days Like These When I Stare At The Chainsaws

It's On Days Like These When I Stare At The Chainsaws

Effects of coldness on the protective performance of earmuffs

The type test of hearing protectors (HPD) for certification purposes will be conducted in laboratory at room temperature. Optionally, the mechanical durability of HPDs will be tested in cold environment by a drop test. The purpose of this study was to find out the relevance of the drop test, the change of performance in HPD protection, and finally to estimate the possible change of protection efficiency against noise in cold environment. In total, 22 HPDs were selected to the measurements: 18 earmuffs, and 4 earmuffs attached to an industrial helmet. Attenuation of each earmuff cup was measured by applying insertion loss method for the test subjects in cold. The change of attenuation and temperature of cushion ring was followed up to nine minutes using 30-second intervals for sampling. Three HPDs were damaged in the test. The replaceable cushion was broken in two earmuffs and in one helmet-mounted HPD. The replaceable parts were replaced, and the HPD with attachment failure was removed from insertion loss measurement. In nine HPDs the relative change was less than 3 dB, and was at worst 10 dB. This change was typically at low frequencies, 125 Hz at the beginning when cooled HPDs were placed. In various HPDs the time to get the attenuation levelled varied from 1.5 minutes to 8 minutes. The recovery was dependent on the temperature of the cushion ring. In all cases the temperature of the full attenuation was achieved when the cushion ring reached 7 degrees C. This temporary decrease in attenuation will have a minor effect to the protection efficiency, when the HPD is used full time during the whole exposure duration. A typical group of forest workers will have their exposure interrupted. The chain saws have to refuel, and the chain needs to be sharpened about every 40 minutes. During 6 hour daily operational time there will be about 9-10 minute break, long enough to cool the cushion ring back to below zero at -10 degrees C, if the helmet mounted earmuffs are placed in stand-by position. In the worst case this will cause 1.6 dB increase in daily exposure level to noise.

森への視線

The purpose of this paper is to suggest the destination of tourism in Yaku Island, or Yakushima, by considering the bundle of various eyes or gaze to the forests, Yaku-cedar or Yakusugi and other unique natural environment.After World War II, the forest of Yakushima has been treated under the discussion of ideology dispute whether it should be developed or conserved for the islanders. Especially, from 1950s, large-scale logging using machinery such as chain saws and wire ropes was begun to supply the demand from around the country. The islanders mainly engaged in the logging operations as a worker. The industry was an important source of income for Yakushima people because of the fragile industrial situation in the island. However, at the same time, such operations certainly brought about deterioration of environment, especially damage of Yakusugi whose age was over one thousand years. Therefore, part of islanders, in 1970, established a society to conserve the natural environment of Yakushima whose name was Yakushima wo mamorukai as having conflicted with logging workers.Historical eyes of the islanders to the forest moved from awe in their traditional belief to environmental conservation or preservation through economic imperative such as subsistence and capitalism. The islanders basically have turned their eyes upon the forest on spectrum of relationship between destructive lumbering and natural conservation. In that process, they had come to require ideal situation satisfying both economic and natural environmental demands in the context of mutual relationship between nature and human beings. Ecotourism has been recognized and expected by certain islanders as one of methods to realize that since 1990s. However, such tourism is only conducted by immigrants and external capitals and thus arouses complaint from indiginous islanders who are not involved with the industry. Simultaneously, the context of tourism makes clear of difference of eyes to the forest between indiginous people and outlanders such as immigrants and tourists.By analyzing the meanings of various internal and external eyes to the forests and other natural environment through the cultural concepts such as “Kankyobunka-mura, ” “kankobunka or tourism culture, ” and “kankoshizen or tourism nature, ” I provide a basic stand for the development in Yakushima by stressing a new type of tourism which averts tourists' eyes from the ecological environment including Natural Heritage to the Islanders' lifestyle.

Occupational safety and health conditions of forestry workers in Turkey

The safety and health conditions of forestry workers in Turkey were surveyed, as there are currently no statistics on these topics despite the occurrence of accidents and health problems caused by forestry work. We used a questionnaire that inquired about safety and health conditions, job satisfaction, and cumulative fatigue symptoms of forestry workers. Of the respondents, 24% experienced accidents during work, many of which consisted of cuts by chain saws or axes. Also, most respondents indicated that they did not use any personal protective equipment (PPE), although the use of PPE is strongly recommended to avoid fatal or serious accidents. With respect to job satisfaction, 43% of the respondents were dissatisfied with their job mainly because of the low salary and heavy work. Marital status, educational background and period of employment had the potential to greatly affect job satisfaction. As a result of research using the Cumulative Fatigue Symptoms Index (CFSI), mental, physical and social aspects of cumulative fatigue were recognized in the respondents. Furthermore, it can be concluded that job dissatisfaction negatively affected the incidence of cumulative fatigue in forestry workers, and that taking measures to enhance job satisfaction among forestry workers would improve their quality of life through lessening of cumulative fatigue. It should also be noted that ‘sustainable forestry and environmental protection' were the greatest concerns beyond salary and insurance among the respondents.

Mechanisms of injury in operative brachial plexus lesions

The authors focus on injury mechanisms involved in 1019 operative brachial plexus injuries (BPIs) managed between 1968 and 1998 at Louisiana State University Health Sciences Center (LSUHSC). Data regarding these mechanisms of injury were obtained via retrospective chart reviews of patients who had undergone operations at LSUHSC. Five main mechanisms of injury to the brachial plexus occurred in the series. These included 509 stretch/contusion injuries (49%) with four patterns of presentation in 366 patients: 208 C5-T1 nerve injuries; 75 C5-7, 55 C5-6 injuries; and 28 involving the C8-T1 or C7-T1 nerves. Stretch/contusion injury was followed in frequency by gunshot wound (GSW), resulting in 118 injuries (12%). Most of the 293 involved plexus elements had some gross continuity when surgically exposed. Seventy-one lacerations involved the brachial plexus (7%), including 83 sharp lacerations caused by knives or glass; 61 blunt transections due to automobile metal, fan, and motor blades, chain saws, or animal bites. Nontraumatic BPIs included 160 cases of thoracic outlet syndrome or 16% of the total of 1019 BPIs. There were 161 tumors (16%) of neural sheath origin including 55 solitary neurofibromas (34%), 32 neurofibromas associated with von Recklinghausen disease (20%), 54 schwannomas (34%), and 20 malignant nerve sheath tumors (20%) removed. Obstetrical BPI was not included in the original series; however, the current literature is reviewed in this paper. The conclusion of this study is that the brachial plexus can be injured by multiple mechanisms of which stretch/contusion injury is the most frequently encountered, followed by GSWs.

Professional Update

Hospital noises during the night can approach the levels of chain saws or jackhammers, making it nearly impossible for patients to sleep, according to a study carried out at the prestigious American teaching centre, the Mayo Clinic.

職業性手腕振動曝露が立位平衡維持に及ぼす影響

In order to determine the relationship between exposure to hand-arm vibration through the use of vibration tools and dysfunction in the maintenance of postural balance, 106 male forestry workers were examined by stabilometry for deflection in the center of gravity and in the air conduction hearing levels. A questionnaire survey was also conducted among the workers in order to obtain details regarding their age, the types of tools used by them, and the duration for which they had used a chain saw. The vibration acceleration of a chain saw has been limited to a level of 3 G or less since 1976 in accordance with the notification from the Japanese Forestry Agency and the Ministry of Labor. In fact, chain saws with significantly reduced vibration acceleration in comparison with those used before 1976 have been available. Therefore, in 2000, we conducted a test on forestry workers who were divided into two groups-workers who had used a chain saw for 25 years or more (25-yr-or-more group) and workers who had used a chain saw for 24 yr or less (24-yr-or-less group). Compared to the 24-yr-or-less group, the 25-yr-or-more group exhibited significantly higher levels of average deflection in the center of gravity, expressed as the enveloped (aENV) and rectangular (aREC) areas, and in the hearing levels at 500, 1000, 2000, 4000 and 8000 Hz. For the aENV, the correlation coefficients revealed significant relationships between the hearing levels at 4,000 Hz, the duration of use of a chain saw, and age. Since the duration of use of a chain saw exhibited a significant relationship with age, it was necessary to eliminate the effect of age on the aENV. Subsequently, we divided all the workers into age groups spanning ten years each (from 20 to 70 yr) and compared the aENV among the same age groups in both the 25-yr-or-more and the 24-yr-or-less groups. The averages of the aENV for each age group were higher in the 25-yr-or-more group than in the 24-yr-or-less group. In particular, a significant difference was observed in the group of workers in their 40s. Moreover, the average of aENV value was significantly higher in the 25-yr-pr-more group than in the 24-yr-or-less group among the workers between 46 and 68 yr, with their ages being congruent in both groups. While investigating the impact on the workers who had used chain saws, it might be difficult to examine the effect of occupational vibration independent of the noise load. Nevertheless, this study suggests the possibility that a decrease in the maintenance of postural balance has a stronger relationship with exposure to thumping vibration in the past than with the age factor.

Temperature and humidity inside protective clothes for chain saws.

Temperature and humidity inside protective clothes for chain saws.

Summary of Field Equipment Requirements for Responding to Riverine Oil Spills in Ice

Oil spill response equipment and field experience in northern riverine and ice environments is limited. Successful responses have depended on planning and preparedness for quick deployment of response equipment into inland ice-covered waters in rivers. This paper is a summary of technology and equipment requirements for responding to riverine pipeline oil spills in ice, particularly as it relates to experiences and knowledge gained in responding to oil spills in Western Canada. A major requirement in planning is to survey and identify using recommended criteria, the potential Control Points in waterways to determine suitable places from which to mount and support containment and recovery deployment of equipment for spills. Key factors in responding to a riverine oil spill in ice are: planning, training exercises, flexibility, and specialized response equipment which includes OSCAR Units, jet boats, helicopters, and modified field equipment: skimmers, pumps, ice augers. In ice-covered rivers, control of spilled oil is required using special slot and deflector walls cut by chain saws in the ice. Human fatigue and safety are also critical elements in effective response.

Choosing the Wasteland

Choosing the Wasteland

Task-based assessment of occupational vibration and noise exposures in forestry workers.

Forty-two noise exposures and 164 whole-body (WBV) and hand-arm (HAV) vibration exposures were collected from 43 forestry workers in six trades employed by two forestry companies. Data were collected on 10 days over 8 weeks during various felling, logging, and log handling operations. Up to 5 volunteers were monitored for noise and vibration daily using datalogging noise dosimeters, which provided daily time-weighted averages (TWAs) and 1-min averages; and a precision sound level meter equipped to measure human vibration, which provided triaxial HAV and WBV event-weighted averages (AEQS). Workers completed a short questionnaire throughout the workday detailing the timing and number of tasks performed and equipment used. Substantial overexposures to noise and vibration were seen; for example, 60% of Occupational Safety and Health Administration (OSHA) TWAs and 83% of National Institute for Occupational Safety and Health (NIOSH) noise TWAs exceeded 85 dBA, 33-53% of the axis-specific HAV AEQS exceeded the 8-hour American Conference of Governmental Industrial Hygienists' HAV threshold limit value, and 34% of all summary weighted WBV AEQS exceeded the Commission of the European Communities' 8-hour exposure limit. The mean for 99 WBV summary weighted AEQ was 3.53 +/- 7.12 m/sec2, whereas the mean for 65 HAV summary weighted AEQ was 5.45 +/- 5.25 m/sec2. The mean OSHA TWA was 86.1 +/- 6.2 dBA, whereas the mean NIOSH TWA was 90.2 +/- 5.1 dBA. The task and tool with the highest exposure levels were unbelling chokers on landings and chain saws (noise), log processing and frontend loaders (WBV), and notching stumps and chain saws (HAV). An internal validation substudy indicated excellent agreement between worker-reported and researcher-documented tasks and tools.

Effects of Urban Tree Management and Species Selection on Atmospheric Carbon Dioxide

Trees sequester and store carbon in their tissue at differing rates and amounts based on such factors as tree size at maturity, life span, and growth rate. Concurrently, tree care practices release carbon back to the atmosphere based on fossil-fuel emissions from maintenance equipment (e.g., chain saws, trucks, chippers). Management choices such as tree locations for energy conservation and tree disposal methods after removal also affect the net carbon effect of the urban forest. Different species, decomposition, energy conservation, and maintenance scenarios were evaluated to determine how these factors influence the net carbon impact of urban forests and their management. If carbon (via fossil-fuel combustion) is used to maintain vegetation structure and health, urban forest ecosystems eventually will become net emitters of carbon unless secondary carbon reductions (e.g., energy conservation) or limiting decomposition via long-term carbon storage (e.g., wood products, landfills) can be accomplished to offset the maintenance carbon emissions. Management practices to maximize the net benefits of urban forests on atmospheric carbon dioxide are discussed.

Development of low-emission two-stroke engines for hand-held power products

Minimum weight combined with a very high specific power is one of the most important development targets for chain saws and power tools such as blowers, hedge trimmers, brushcutters or cut-off saws. As the user has to carry the product around when working, its weight is very critical. In recent decades, emission reduction was primarily driven by the aims of reduced fuel consumption and reduced blue smoke. Now, one of the main development targets with new developments is the reduction of hydrocarbon emissions. With these efforts, a variety of new two-stroke engines has arisen along with mini-four-stroke engines. All new two-stroke developments are based on an optimised two-stroke base engine with Schnurle-loop scavenging. These new two-stroke technologies require a profound design approach that is based on empirical approaches along with model experiments and computational fluid dynamics.

Factors influencing use of hearing protection among farmers: a test of the pender health promotion model.

Most farmers are exposed to potentially hazardous noise levels through many of their work activities, such as operating tractors, grain dryers, and chain saws. Rates of noise-induced hearing loss in this group are high. Although this condition is preventable through the use of hearing protection, rates of protective device use are low. Understanding factors influencing the use of hearing protection devices will provide direction for programs to increase their use and decrease risk of noise-induced hearing loss. A study was designed using the Pender Health Promotion Model to identify factors affecting farmers' use of hearing protection devices. Model testing was conducted with a convenience sample of 139 farmers. Prior to model testing, existing instruments designed to measure concepts from the Health Promotion Model were modified for use with farmers through interviews, validity testing with an expert panel, and reliability testing with first a small (n = 36) then a second larger (n = 139) convenience sample of farmers. Instruments measuring cognitive and affective factors related to hearing protection device use were administered to farmers at a regional farm show in the Midwest. A logistic regression analysis identified interpersonal support, barriers, and situational influences as statistically significant predictors of this health behavior, correctly predicting 78% of the cases. Results of model testing were consistent with results of previous studies of Health Promotion Model variables with other worker groups' use of hearing protection. Information from this study can be used to design and evaluate interventions to promote hearing protection device use among farmers and reduce the level of noise-induced hearing loss in this high-risk and underserved worker group.

Risk of hand‐arm vibration syndrome according to occupation and sources of exposure to hand‐transmitted vibration: A national survey

Background Although some occupational sources of hand-transmitted vibration (HTV) have been extensively investigated, the risks associated with others are poorly characterized. Methods A questionnaire was mailed to a community sample of 12,240 men aged 16– 64 years and 906 men from the armed forces. Questions covered current occupation, sources of HTV, numbness or tingling in the fingers in the past week, and finger blanching. In the 5,364 respondents who had been at work in the past week, associations between symptoms and exposures were examined by logistic regression, with odds ratios converted into prevalence ratios (PRs). Results Altogether, 513 men (10%) reported cold-induced finger blanching and 769 (14%) sensory symptoms in the fingers. The risk of blanching was increased in builders (PR 2.4, 95% CI 1.0–5.2), carpenters and joiners (PR 1.9, 95% CI 1.0–3.4), motor mechanics (PR 2.3, 95% CI 1.1–4.6), and laborers (PR 2.8, 95% CI 1.3–6.0); while the risk of sensory symptoms was elevated in laborers (PR 4.0, 95% CI 2.3–6.6) and plant operatives (PR 3.5, 95% CI 1.9–5.9). Use of hand-guided mowers, concrete breakers, chain saws, and jig saws was significantly associated with symptoms. Conclusions Little attention has been paid to the risks of vibration injury in construction workers, woodworkers, motor mechanics, and laborers, or to the risks from mowers, jig saws and several other common vibratory tools. These should be a focus for further investigation and preventive measures. Am. J. Ind. Med. 39:389–396, 2001. © 2001 Wiley-Liss, Inc.