Very few studies have been undertaken on the health and safety of tree plantation workers around the world. In addition, this sector generally tends to be addressed as part of the larger sector of the forestry industry, which also encompasses logging and wood harvesting activities in natural forests.
Nevertheless, a chapter on the forestry industry in the International Labour Organization (ILO) Encyclopaedia of Occupational Health and Safety includes some noteworthy data that it is well worth presenting here, focussing on information related to the sector we are particularly concerned with.
The ILO recognizes that forestry work, including work on industrial tree plantations, is strenuous and dangerous. Because they work outdoors, workers are exposed to extreme weather conditions: cold, heat, snow, rain and ultraviolet (UV) radiation. Work often continues even in bad weather, and night-time work is becoming increasingly frequent in mechanized operations. Worksites are usually remote and have poor communications, which makes the rescue and evacuation of workers difficult in emergency situations. In many countries it is still common for workers to live for long periods in camps, isolated from their families and friends.
The difficulties are aggravated by the nature of the work, which involves the use of dangerous tools and heavy physical effort. Bad weather, noise and vibration are common physical risk factors in forestry work in general. Exposure to physical risks largely varies in accordance with the type of work and the equipment used. Other factors like work organization, employment patterns and training also play an important role in increasing or decreasing the hazards involved in forestry work.
Manual forestry work typically implies a heavy physical workload, which in turn leads to a high energy expenditure, depending on the specific task done and the pace at which it is carried out. Forestry workers need to consume a much greater quantity of food than “ordinary” office workers in order to cope with the demands of their jobs.
Different studies have revealed that forestry workers are exposed to high rates of illness in addition to injuries and accidents.
Although few in number and conducted with small numbers of workers, studies of physiological indicators of physical strain (heart rate, haematological parameters, elevated blood enzyme activity) have all concluded that tree planting is an extremely strenuous occupation in terms of both cardiovascular and musculoskeletal strain.
Musculoskeletal and physiological load
Although there is no epidemiological literature that specifically links tree plantation work with musculoskeletal problems, the forceful movements involved in carrying loads, in addition to the range of postures and muscular work involved in the planting cycle, undoubtedly constitute risk factors that are heightened by the repetitive nature of the work.
Repetitive strain injuries continue to be a significant problem. Studies have shown that between 50% and 80% of machine operators suffer from neck or shoulder problems. Comparisons of figures tend to be difficult because injuries develop gradually over long periods of time.
Tree planters also face numerous biomechanical hazards to the upper limbs, including extreme flexing and bending of the wrists – such as when grabbing seedlings from trays – and the sudden impact on hands and arms when the planting tool hits a hidden rock.
Meanwhile, the manual piling of logs involves the repeated lifting of heavy weights. If the proper working technique is not used and the pace is too fast, there is a very high risk of suffering musculoskeletal injuries. Carrying heavy loads over long periods of time, as when harvesting and transporting wood for pulp production, has similar effects. The total weight carried, the frequency of lifting and the physical and repetitive nature of the work are factors that contribute to the muscular strain exerted on the upper limbs.
On the other hand, working with portable machines such as chainsaws may require an even greater energy expenditure than manual work, due to their considerable weight. In fact, the chainsaws used tend to be too large for the task being carried out. Highly specialized motor-manual tasks entail a very high risk of musculoskeletal injuries because the work cycles are short and the specific movements are repeated many times over.
Working in awkward positions can result in problems such as lower back pain. One example of this is the use of an axe to delimb trees that are lying on the ground, which involves working bent over for long periods of time, leading to great strain on the lower back area and static work for the back muscles.
Another potential risk for those who work planting trees is posed by the unloading of trays of seedlings from delivery trucks, since these can weigh between 3 and 4.1 kg each when full. Carrying loads with harnesses can also lead to back pain, especially if the weight is not well distributed on the shoulders and around the waist.
It is also important to point out the muscular load on the lower limbs: walking several kilometres a day carrying loads over irregular terrain, sometimes uphill, can rapidly become exhausting work. In addition, this task implies frequent flexions of the knees and the constant use of the feet. Most tree planters use their feet to clear away detritus with a lateral movement before making a hole, and also to apply weight on the tool’s footrest to plunge it into the soil and to compact the soil around the seedling once it has been inserted.
In the case of motor-manual forestry work, workers are also subjected to specific risks due to the machinery they use. Noise represents a problem when working with chainsaws or similar equipment. The noise level of the majority of chainsaws used in normal forestry work is over 100 decibels. Operators are exposed to this noise level for two to five hours a day, which can result in hearing loss.
Continuous work in the outdoors, exposed to the rigours of climate, often without proper protection against the sun (sunglasses, hats and sunblock) and against insects, can result in dehydration, sunburn and heat stroke. Working in a hot climate puts pressure on forest workers who carry out heavy work. Among other effects, the heart rate increases to keep body temperature down. Sweating leads to the loss of body fluids, and heavy work in high temperatures means workers may need to drink a litre of water an hour to maintain the balance of these fluids.
In cold climates, the muscles do not function well, and this increases the risk of suffering musculoskeletal injuries and accidents. Furthermore, energy expenditure increases considerably, since it takes a great deal of energy simply to stay warm.
One of the illnesses specific to this sector is “tree-planter burnout”, a disorder provoked by haematological deficiency and characterized by lethargy, weakness and dizziness, similar to the “sport anaemia” developed by athletes in training.
There is a high incidence of premature loss of working capacity and consequently of early retirement among forestry workers. Chainsaw operators and workers who manually load logs are prone to hearing loss and back injuries. A disorder that traditionally affects chainsaw operators is so-called “white finger” disease, a painful condition provoked by the vibration of the saw which can leave them unable to work: the fingers turn white and become numb, making it impossible to carry out more delicate tasks. The disorder can also cause tingling and pain in both arms, especially at night.
On the other hand, the long work days, commuting and strict quality control to which tree planters are subjected, together with the demands posed by piece work (a widespread practice among tree plantation subcontractors) can affect the worker’s physiological and psychological equilibrium and result in chronic fatigue and stress.
Accidents and injuries
The setting in which tree plantation work is done makes workers particularly prone to trips and falls. Forestry work can result in injuries to almost every part of the body, but injuries tend to be concentrated in the legs, feet, back and hands, roughly in that order. Cuts and open wounds are the most common type of injury among chainsaw operators, while bruises tend to predominate in other work areas, although there is also the risk of fractures and dislocations as well as injuries associated with forceful movements or caused by cutting scraps or debris.
Ranking of the most frequent tree-planting accidents grouped by body parts affected (percentages based on 122 reports by 48 subjects in Québec, Canada)
|Falls, contact with tool, soil compaction
|Equipment contact, biting and stinging insects, sunburn, chapping
|Insects, insect repellent, twigs
|Frequent bending, load carrying
|Soil compaction, blisters
|Chapping, scratches from contact with soil
|Falls, contact with tool
|Trips and falls, hidden obstacles, contact with tool
Another study on occupational safety on tree plantations in Nigeria revealed that on average, workers suffered two accidents a year, while in a given year, between one in four and one in ten workers suffered a serious accident.
Two situations which further heighten the already high risk of serious accidents during the harvesting stage on tree plantations are “hung-up” trees and wind-blown timber. Wind-blow tends to produce timber under tension, which requires specially adapted cutting techniques. Hung-up trees are those that have been severed at the stump but do not fall to the ground because their crowns have become entangled with other trees. Hung-up trees are so dangerous that in some countries they are referred to as “widow-makers” due to the large number of deaths they cause. Bringing these trees safely down to the ground requires the use of tools like winches and turning hooks. However, a highly dangerous practice known as “driving” is used in some countries, through which other trees are felled so as to fall onto the hung-up tree and thereby bring it down.
In many countries, manual workers work together with or close to chainsaw or machine operators. Machine operators are seated in cabins or use hearing protection and good protective equipment, but in most cases, manual workers wear no protective gear whatsoever. They also do not maintain a safe distance from the machines, which results in an extremely high risk of accidents and hearing loss for unprotected workers.
The other side of the coin with regard to mechanization is the emerging problem of neck and shoulder strain injuries among machine operators, which can be as incapacitating as serious accidents.
The risk of an accident varies not only in accordance with the technology used and the degree of exposure involved in the job, but with other factors as well. In almost all cases for which data are available, there is a very significant difference between segments of the workforce. Full-time, professional forestry workers directly employed by a forest enterprise are far less affected than those who are self-employed or employed by contractors.
Transportation on highways also accounts for a large number of serious accidents, especially in tropical countries.
The trend towards mechanization of forestry work is increasing. During maintenance and repair operations, the hands of machine operators are exposed to lubricants, hydraulic oils and fuel oils, which can cause irritant dermatitis.
The portable machines used in the forestry industry are powered by two-stroke engines, in which lubricating oil is mixed with gasoline. Generally, around 30% of the gasoline consumed by a chainsaw engine is emitted unburned. The main components of exhaust emissions are hydrocarbons, which are typical components of gasoline, as well as additives like organic lead compounds, alcohols and ethers. Some of the exhaust gases are formed during combustion, and the main toxic product among them is carbon monoxide. Fuels also represent a fire hazard.
Forestry workers are also exposed to chemical products like pesticides, insecticides and herbicides. On tree plantations, pesticides are used to control fungi, insects and rodents. Products used include phenoxy herbicides, glyphosate or triazines, as well as insecticides such as organophosphorus compounds, organochlorine compounds or synthetic pyredroids. In nurseries, dithiocarbamates are used regularly to protect softwood seedlings against pine fungus.
The methods used to apply pesticides include aerial spraying, application from tractor-driven equipment, knapsack spraying, ultra low volume (ULV) spraying and the use of sprayers connected to brush saws. The risk of exposure is similar to that in other pesticide applications. The symptoms caused by excessive exposure to pesticides vary greatly depending on the compound applied, but occupational exposure to pesticides most often causes skin disorders. Personal protection equipment tends to be very hot and to cause excessive sweating.
People who work outdoors, as in the case of tree plantation workers, are exposed to health hazards from animals, plants, bacteria, viruses, etc. to a greater degree than the rest of the population. Allergic reactions to plants and wood products, especially pollen, are very common. There is also the possibility of injuries during processing operations (for example, from thorns, spines, bark) and from secondary infections, which cannot always be avoided and can cause additional complications.
Another potential hazard is being bitten by poisonous snakes, as well as the possibility of a life-threatening allergic reaction to the antidote used in such cases.
Social and psychological factors
The health and safety situation in tree plantation work depends on a range of factors such as stand and terrain conditions, infrastructure, climate, technology, work methods, work organization, economic situation, contracting arrangements, worker accommodation, and education and training. But social and psychological factors also have an impact. In the context of forestry work, these factors include job satisfaction and security, the mental workload, susceptibility and response to stress, the capacity to cope with perceived risks, work pressure, overtime and fatigue, the need to endure adverse environmental conditions, social isolation in work camps with separation from families, work organization, and teamwork.
Traditionally, forestry workers have come from rural areas and have felt a sense of identification with the independent, outdoors nature of the work. However, modern forestry operations no longer fit such expectations. Those who are unable to adapt to mechanization, subcontracting and the rapid technological and structural changes in forestry work since the early 1980s are often marginalized. Many new entrants still come ill-prepared to the job.
Social and psychological factors are likely to play a major role in determining the impact of risk and stress. A German study revealed that around 11% of forestry industry accidents were attributed to stress, and another third to fatigue, routine, risk taking and lack of experience.
Forestry workers generally consider risk-taking to be part of their job. Where this tendency is pronounced, risk compensation can undermine efforts to improve work safety. In these situations, workers adjust their behaviour and return to what they perceive as an acceptable level of risk. For example, this may be part of the explanation for the limited effectiveness of personal protective equipment (PPE). Knowing that they are protected by cut-proof trousers and boots, workers go faster, work with the machine closer to their body and take short cuts, thereby violating safety regulations because they “take too long to follow”. Normally, risk compensation seems to be partial. There are probably differences among individuals and groups of workers, and reward factors are probably important to trigger risk compensation. Such rewards could include reduced discomfort (such as when not wearing warm protective clothing in a hot climate) or financial benefits (such as in piece-rate systems), but social recognition in a “macho” culture is also a conceivable motive.
Among the most common stress factors in the forestry industry are high work speed, repetitive and boring work, heat, an overload or underload of work in unbalanced work crews, young or old workers trying to achieve sufficient earnings on low piece-work rates, isolation from workmates, family and friends, and a lack of privacy in camps.
The transformation of forestry work that has drastically increased productivity has also increased stress levels and reduced overall welfare in the sector.
Two types of workers are especially prone to stress: harvester operators and contractors. Operators of sophisticated harvesters are in a multiple-stress situation, due to the short work cycles, the quantity of information they need to absorb and the large number of quick decisions they need to make. Harvesters are significantly more demanding than more traditional machines like skidders, loaders and forwarders. In addition to machine handling, the operator is usually also responsible for machine maintenance, planning and skid track design as well as bucking, scaling and other quality aspects that are closely monitored by the company and that have a direct impact on pay.
Quite commonly, the operators of these machines are also their owners and work as small contractors, which can lead to added strain. This is particularly due to the financial risk entailed, which can involve loans of up to USD 1 million in a highly volatile and competitive market. Among this group, working weeks often exceed 60 hours.
There are significant differences between the various segments of the forestry workforce in terms of the form of employment, which have a direct impact on workers’ exposure to safety and health hazards. The share of forestry workers directly employed by forestry companies has been declining. More and more work is done through contractors (that is, relatively small, geographically mobile service firms employed for a particular job), which may be owner-operators (either single-person firms or family businesses) or may have a number of employees. Both the contractors and their employees often have very unstable employment. Because contractors are under pressure to cut costs in a very competitive market, they sometimes resort to illegal practices such as moonlighting and hiring undocumented immigrants. Accidents and health complaints tend to be more frequent among workers employed by contractors.
Contract labour has also contributed to increasing the high rate of turnover in the forestry workforce, further exacerbating the lack of qualified workers. The lack of structured training and short periods of experience due to high turnover or seasonal work are decisive factors in the significant health and safety problems facing the forestry sector.
The dominant wage system in forestry continues to be piece-rates (in other words, payment based exclusively on output). This payment system tends to lead to a faster pace of work, which is believed to contribute to increasing the number of accidents. An undeniable side effect is that earnings decrease once workers reach a certain age, because their physical abilities decline.
Wages in the forestry sector are usually much lower than the industrial average in the same country. Employees, the self-employed and contractors often try to compensate for this fact by working 50 or even 60 hours a week, which increases strain on the body and the risk of accidents because of fatigue. Organized labour and trade unions are rather rare in this sector. The traditional problems of organizing geographically dispersed, mobile, sometimes seasonal workers have been compounded by the fragmentation of the workforce into small contractor firms.
Labour inspections are rarely carried out in most countries. In the absence of institutions to protect workers’ rights, forestry workers typically have little knowledge of their rights, including those stipulated in existing health and safety regulations, and therefore face great difficulties in exercising them.
The information presented in this article was extracted from the ILO Encyclopaedia of Occupational Health and Safety, Fourth Edition, Volume III, Part X, Industries Based On Biological Resources, Forestry. http://www.ilo.org/encyclopaedia/?d&nd=857200345&prevDoc=857000002