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Study of 349 Accidents in Tree Operations: Risk Factors and Solutions

Tree care is an essential and risky profession that requires careful attention at all stages of the work, whether pruning, cutting or removing trees. Between April 2020 and August 2024, data from 349 tree care accidents in the United States were collected through the Tree Care Industry Association (TCIA) reporting platform, available at www.accidentbriefs.tcia.org/ , for this article, providing valuable insights into the causes, risk factors and potential solutions to mitigate these incidents. The Tree Care Industry Association (TCIA) is a U.S. trade association representing more than 1,800 tree care companies, and its purpose is to promote safety and education in the arboriculture industry. More information can be found at www.treecareindustryassociation.org/ .

Tree Operations in Brazil


This article is motivated by the need to understand and mitigate the risks associated with arboriculture operations. The analysis of accidents recorded in the United States offers insights that can be applied in global contexts, including Brazil, where tree pruning and removal operations also involve significant risks for workers. Although the Brazilian context has its particularities, such as specific labor laws, climate differences, and socioeconomic conditions, many of the risks identified are similar. It is essential that lessons learned in other countries are adapted and applied locally, promoting a safer and more efficient work environment for arboriculture professionals in Brazil.


Accident Data Analysis: Severity and Causes

The accidents analyzed in the study ranged in severity from fatal incidents to minor incidents. The classification was based on the following parameters:

  • Fatal Accidents: 209 cases (59.8%)

  • Serious Accidents: 100 cases (28.7%)

  • Rescue Accidents: 22 cases (6.3%)

  • Minor accidents: 10 cases (2.9%)

  • Serious Fatal Accidents: 8 cases (2.3%)


The high proportion of fatal accidents (almost 60%) highlights the dangerous nature of tree operations, where an error or equipment failure can have devastating consequences. Of the 349 accidents, 192 involved male workers, 9 involved female workers and 148 were unidentified. Of the 349 accidents recorded, the gender of the victims was distributed as follows:


Main Causes of Accidents


Main Causes of Accidents


Accidents were classified by their main causes, identifying the following risk factors:

  1. Impact by Object: 139 accidents (39.8%) - Most accidents occurred due to the impact of branches, trunks or other objects that struck workers during pruning or removal operations. These types of accidents highlight the importance of using proper techniques to control falling materials, in addition to the consistent use of personal protective equipment, such as helmets and face shields.


  2. Falls: 54 accidents (15.5%) - Falls accounted for a significant proportion of accidents, often occurring during tree climbing or the use of aerial platforms and ladders. The lack of secure anchorage points, improper use of safety harnesses and insufficient training are all contributing factors to this type of accident. Proper use of fall protection equipment and regular training are essential to reduce these risks.

  3. Electric Shock: 43 accidents (12.3%) - Working in close proximity to power lines posed a risk. The main causes were the lack of prior inspection of the area and safety measures, such as de-energizing the lines or adequate signage. To mitigate these accidents, workers must be trained to identify and avoid electrical hazards and follow strict safety protocols in urban areas.

  4. Trapped or Crushed by Something: 38 accidents (10.9%) - Workers were trapped or crushed under logs or branches while moving or falling. This highlights the importance of proper handling techniques and clear communication among the team.

  5. Vehicle: 25 accidents (7.2%) - Accidents related to the use of vehicles such as trucks and heavy machinery during operations. These incidents usually occur during the transportation of materials or when there are failures in the operation of vehicles close to workers.

  6. Rescue: 19 accidents (5.4%) - These accidents involve workers who were rescued from situations where they were trapped, usually high up in trees, after becoming immobilized. The high risk is due to the complexity and urgency of these situations. Ensuring safety during these operations involves specialized training in rescue techniques and efficient team coordination.

  7. Uncertainty: 11 accidents (3.2%) - Some accidents had causes that could not be clearly identified or documented, which highlights the importance of improving accident recording and investigation procedures.

  8. Cutting: 7 accidents (2%) - Accidents involving the use of saws and other cutting equipment, often due to improper handling or lack of adequate training of workers.

  9. Workplace Violence: 3 accidents (0.9%) - Incidents involving physical assault during operations, highlighting the need to promote a safe and respectful work environment.

These data indicate that most accidents occur due to impact with objects such as branches and trunks, followed by falls from a height and contact with power lines. The presence of electric shocks as one of the main causes highlights the need for caution when working near electrical infrastructure.


Equipment as a Cause of Accidents

Equipment played a crucial role in the accidents recorded. Below is a detailed analysis of the main equipment involved in the accidents:

  • Truck: 112 accidents (32.1%) - Trucks are used to transport timber and equipment or as work platforms. Problems such as brake failures, incorrect maneuvers and lack of operator visibility are frequent causes of accidents involving trucks. Preventative maintenance and operator training are essential to avoid such incidents.

  • Elevator/Platform: 30 accidents (8.6%) - Elevator platforms are essential for reaching great heights, but they are equipment that present high risks, such as worker falls and mechanical failures. Stability of the support surface and correct use of safety belts are essential for safe operation.

  • Basket: 16 accidents (4.6%) - Baskets attached to platforms or cranes are responsible for accidents when there is equipment failure or when workers fall due to lack of adequate protection. Regular inspections and the use of safety equipment are important to prevent accidents.

  • Saw: 12 accidents (3.4%) - Saws, including chainsaws, are critical but dangerous tools. Accidents often occur due to improper handling, lack of maintenance, and inattention during use. Proper training is crucial to ensure operators are prepared to handle this equipment safely.

  • Chipper: 11 accidents (3.2%) - Wood chippers are used to shred wood debris but pose significant risks, especially during the branch feeding procedure. Operational failures, distractions and lack of PPE are common causes of wood chipper accidents.

  • Trimmer: 7 accidents (2%) - Trimmers are used to cut small branches and foliage. Accidents involving trimmers generally occur due to improper use or lack of adequate protection, especially for the eyes and hands of the operators.

  • Rope: 6 accidents (1.7%) - Ropes are essential for controlling branches during pruning and for climbing. Accidents occur due to faulty ties, rope wear or improper use. Keeping ropes in good condition and ensuring proper training in their use are important steps to reduce risk.

  • Ladders: 5 accidents (1.4%) - Ladders are widely used in arboriculture operations, but lack of stability and use on uneven surfaces are frequent causes of falls. Ladders need to be firmly supported, and operator safety must be ensured.

  • Logs: 4 accidents (1.1%) - Accidents like these occur mainly during the cutting and movement of logs. Crushing and impact injuries are common due to the lack of adequate planning for the safe movement of these materials.

  • Vehicle: 3 accidents (0.9%) - In addition to trucks, other vehicles were also involved in accidents, usually while transporting workers or equipment. Driver training and preventative maintenance are vital to minimize these risks.

  • Safety Harness/Belt: 2 accidents (0.6%) - Accidents involving safety belts occurred due to incorrect use or lack of safe anchorage points. Training in safety at height is necessary to reduce these incidents.

  • Chippers: 2 accidents (0.6%) - Chippers are used to shred tree debris, and accidents often occur due to improper operation and lack of operator protection. Training on safe use and the need for PPE is essential.

  • Stump: 2 accidents (0.6%) - Tree stumps can become obstacles and cause accidents, especially trips and falls, when they are not removed or properly marked after cutting.

  • Crane: 2 accidents (0.6%) - Cranes are used to lift large branches and logs. Communication breakdowns between operators and ground crews, as well as mechanical problems, are contributing factors to accidents.

  • Tractor: 2 accidents (0.6%) - Tractors are used to drag logs and clear areas, and accidents usually occur due to improper operation and lack of maintenance of the equipment.


  • Mechanical Arm: 2 accidents (0.6%) - Mechanical arms are useful for heavy tasks, but present high risks, especially if operated without due care or without adequate communication with the team.

    Accident Months and Seasonality

Analysis of accidents by month shows significant variations in the frequency of incidents over the period evaluated, from April 2020 to August 2024. These variations can be associated with seasonal factors, weather conditions and periods of greater demand for arboriculture services. Here are the calculated monthly averages:

  • January: 6.25 accidents

  • February: 6.75 accidents

  • March: 7.5 accidents

  • April: 7 accidents

  • May: 8 accidents

  • June: 6.6 accidents

  • July: 9 accidents

  • August: 8.25 accidents

  • September: 8 accidents

  • October: 5.75 accidents

  • November: 7 accidents

  • December: 7.33 accidents

High Demand for Tree and Landscaping Services in the American Summer During the summer months in the United States, which run from June to September, there is a significant increase in the demand for tree pruning, trimming, and garden maintenance services. This increase is associated with favorable weather, encouraging people and businesses to carry out outdoor projects. This period, especially between June and September, is marked by a high volume of activity, which results in more accidents. In addition, the months close to summer, such as April, May, and October, are also considered favorable for this type of work, due to the mild weather that facilitates the execution of outdoor activities and preparation for the high demand that occurs in the summer. Other factors that contribute to the increase in accidents in the summer include: Extreme Weather Conditions: Severe storms, hurricanes, and other extreme weather conditions in the United States, especially in the southern and eastern states, create an urgent demand for the removal of fallen trees, increasing the risk to workers. Increased Use of Hazardous Equipment: There is an increase in the use of equipment such as chainsaws, wood chippers, and boom lifts. These machines are responsible for a large number of accidents, especially when operated by untrained workers or those who do not use proper PPE. Seasonal Work and Temporary Hiring: Many companies hire temporary workers during periods of high demand. Seasonal workers often lack adequate training, increasing the likelihood of accidents. These data highlight the importance of careful planning and ongoing training, especially during periods of high demand, to reduce risks and promote safe operations in arboriculture.

Word Cloud: A Closer Look at Accidents

A word cloud is a visual representation that shows the most frequent words in a text or dataset, where the size of each word is proportional to the number of times it appears. For example, when analyzing the 349 reports of accidents in tree operations, we created a word cloud that highlighted terms such as “tree,” “accident,” “fall,” and “worker.” This helped us quickly identify that a large proportion of the accidents were related to falling trees and the improper use of safety techniques and equipment. The word cloud allows us to clearly visualize what the main risk factors are and how these elements are connected.

The words extracted from reports of 349 tree care accidents in the United States provide important insights into the frequency of the most common terms and their associations. Analyzing these terms helps identify patterns and gaps that may be contributing to accidents, as well as identify critical areas for improving worker safety. Below is an interpretation of these occurrences:


The most frequent terms such as "tree" (142 occurrences), "accident" (132 occurrences) and "worker" (129 occurrences) clearly highlight that we are dealing with incidents involving people directly linked to tree management operations. The term "injured" appears 120 times, and "fatal" appears on 118 occasions, which underlines the seriousness of the accidents recorded, in many of which workers were seriously injured or even lost their lives.

The word "fall" was mentioned 110 times, while "rope" was mentioned only 14 times. This disparity leads us to conclude that the low use of ropes or safe climbing techniques may be associated with the high number of falls. The lack of adequate anchoring systems and the insufficient use of safety techniques during activities at height seem to be recurring factors for accidents of this type.

Similarly, the low number of incidents involving “safety harnesses” (9 times) indicates that many workers were likely not wearing appropriate protective equipment when working at heights. This, combined with the high number of falls, highlights a significant gap in compliance with safety protocols, which needs to be addressed urgently to protect workers.

Other terms such as "cutting" (98 occurrences), "saw" (31 occurrences) and "chainsaw" (5 occurrences) indicate that accidents involving cutting tools are also frequent. Many of the injuries, whether serious or fatal, are related to the inappropriate use of cutting equipment, such as saws and chainsaws, due to improper handling, insufficient maintenance or lack of adequate protection.

Furthermore, "vehicle" (78 occurrences), "truck" (71 occurrences), "lift" (30 occurrences) and "platform" (57 occurrences) indicate that a large proportion of accidents are associated with the use of vehicles and work platforms at height. Incorrect use or lack of maintenance of these equipment are frequently observed problems, resulting in injuries or serious accidents.

Also noteworthy is the significant number of occurrences of terms such as “trapped” (70 times) and “rescue” (19 times), which refer to situations where workers were trapped under logs or in elevated locations. These cases highlight the importance of having well-established rescue procedures and clear communication between team members to avoid situations that could quickly escalate.

Finally, words such as "fire" and "incendio" (both with 66 occurrences) indicate that there are risks associated with the use of equipment that can cause fires, either due to sparks or improper storage of fuels. This correlation points to the need for rigorous fire prevention measures, such as proper maintenance of equipment and the provision of fire extinguishers in the workplace.

The word cloud analysis highlights several risk areas that need to be addressed to make arboriculture operations safer. The relationship between the high frequency of “fall” and the low incidence of terms such as “rope” and “safety harness” clearly highlights the need for improvements in safety practices, particularly in the use of PPE and climbing and anchoring techniques. Taking these measures could result in a significant reduction in the number of accidents and provide a safer working environment for all involved.


With all this in mind, it is clear that tree management and arboriculture operations are activities that involve high risks and require preparation, attention and safety. Each reported incident, whether a fall, an electric shock or an impact by an object, reinforces the need for constant improvements in worker practices and training.


Just like climbing a tree, this article has shown us that it takes a careful balance between technical knowledge, proper use of equipment, and a safety-first mindset. Every detail, from positioning ropes to checking equipment, can be the difference between a safe day’s work and an accident.


Therefore, for everyone involved in this exciting and challenging field, keep learning, evolving and practicing safety. After all, the goal is simple: climb, do the job well and come down safely. Whether pruning, cutting or any other operation, staying safe is a priority.



Felipe Silveira

  • ISA Certified Arborist - N. BR-0024A

  • Tree Climber Specialist TCIA

  • Two-stroke engine mechanic

  • Postgraduate in Urban Forestry from UFRRJ

  • Husqvarna Brazil Team Arborist

  • BLS Certificate

  • Climbing Equipment Inspector

  • Occupational Safety Technician

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