Employees in the construction sphere are frequently exposed to vibration and mechanical hazards. The latter can provoke the reduction of performance, health damages, or even lethal outcomes. Therefore, appropriate preventative measures are required to avoid situations connected with vibration and mechanical hazards.
Vibrations stand for mechanical fluctuations, which are hazardous for human health when affecting the whole body or on the hand-arm system constantly. In fact, vibrations might provoke blood circulation issues, joint or bone ailments, muscular or neurological diseases, backache, or spinal column damages. The health hazards depend on the introduction point of the human body (for instance feet, hands, or buttocks), the vibration strength and severity, and the frequency of exposures during the period given. In other words, vibration effect stands for its intensity and frequency function. Thus, vibrations in the low-periodicity diapason result in muscular and skeletal system disorders (joints traumas). In contrast, high-frequency diapason injures the nervous system and peripheral blood vessels, causing defective blood circulation in the fingers/hands or insensibility among other disorders. The facts demonstrate that even low vibration levels might provoke inconveniences and lowered performance levels.
In order to secure the workers’ health, there are different preventive measures that need to be taken. For instance, the employers should plan how and in which period of time the worker exposure will be lowered if the subjection limit value of 2.5 m/s² is overrun in terms of the hand-arm vibrations. In addition, if the hand-arm subjection reaches the limit value of 5.0 m/s², the worker in question should no longer be assigned to any activities incorporating vibration subjection. The analogous regulations shall be applied regarding the whole-body vibrations. Thus, firstly, it is important to prepare and execute the vibration reduction programs that should include technical and organizational measures. Secondly, employers should instruct employees concerning the probable health risks and health examinations. Thirdly, the employees should undergo medical examinations on a daily basis. However, the preventative measures will differ if the subjection limit value is reached. Firstly, it is important to immediately define the possible hazardous activities and launch further measures to lower the subjection to a level below the exposure limit values. Secondly, it is crucial to organize orderly medical examinations for employees. Thus, preventative measures will be different for arm-hand and whole-body vibration subjection.
Mechanical hazards can be caused by different factors. They typically incorporate inadequate stability, inappropriate mechanical strength, inadequate instructions or safeguards, inappropriate finishing or the accessible constituents of the enclosure, inadequate lifting and carrying means, and expelled elements.
There are five major categories of mechanical hazards connected to health risks and serious injuries and traumas in terms of equipment, machinery and location features. Namely, rotating shafts and gears can lead to entanglement, hard moving surfaces can result in crushing, shear actions can cause severing, moving and stationary sharp edges typically result in cutting or puncturing, and finally, hose and cable connections led to slips and falls. Moreover, mechanical hazards can be subdivided into two major categories in terms of health threats. The injuries usually incorporate cuts, falls, contusions, abrasions, concussions, and lethal outcomes. Ergonomic disorders concern muscular-skeletal and cumulative-trauma-disorders and working situations, which elevate the possibility of disorder occurrence. Thus, mechanical hazards can lead to solid injuries, disorders, and even fatal outcomes.
Taking into consideration the abovementioned mechanical hazards, it is highly important to take several crucial measures in order to prevent them. For instance, the equipment should not be or become physically unstable to the degree when it might appear as hazardous to the operator or service personnel. Moreover, the equipment should not pose any hazards when it is subjected to shock, vibration, droping and handling, which are a part of the daily operation. In addition, the equipment and machinery should have an appropriate mechanical strength, meaning that the elements need to be reliably secured. In other words, their handling and usage in normal procedures should not be hazardous. In addition, the employers should provide protection against the hazards appearing from the expelled part, especially when singe-fault conditions are taken into account. Moreover, sufficient stability is required for all the equipment, except the one that is already secured to the building structure. Also, moving elements should not cut, crush, or puncture the body parts of an operator or a worker who is likely to contact with them. Neither should these elements seriously clamp the operator’s skin. In case when the hazardously moving parts incorporated in the working process cannot be made completely inaccessible during operation, and in case when the hazard associated with these parts is necessary for the proper operation and appears to be obvious to the operator, provision of a warning is necessary for the adequate protection.
In addition, if the equipment is portable and appears to have a weigh higher than a certain limit (18 kg), the employer should provide the means for handling and lifting it with appropriate mechanical strength. It practically means that these means should be capable of withstanding a force that is several times stronger (standing for the safety factor) regarding the mass of the equipment. Finally, all the easily touched edges, corners, openings, guards and handles must be rounded and smoothed in order to avoid the possibility of injuring for the operator or service personnel. Thus, preventative measures concerning mechanical hazards typically demonstrate which protective measures should be applied to secure the processes connected to machinery and working equipment.
The current paper will analyze vibration and mechanical hazards, demonstrate four examples of these hazards, and show how preventative measures can help in excluding the possibility of hazard occurrence.
Four Examples of Vibration and Mechanical Hazards
Vibration Hazard: Hand-Arm Vibration
One building employee, who has been working on construction locations starting from the age of 14 years old, utilized pneumatic and drilling hammers for approximately four days a week during several hours. Due to this reason, he, currently being 42 years old, suffers from an occupational disease. The worker states that the ache in his wrist is so severe that he cannot perform work during long periods. In addition, he suffers from very cold hands. The condition worsens during the winter or highly cold and windy periods, but numbness and sensation of cold remains even on warm days. When the worker utilizes pneumatic implements in a frosty weather, they accentuate the feeling of numbness. In addition, the worker reports some difficulties in grabbing small objects and pushing buttons. Thus, daily subjection to vibration has led to serious health hazards and reduced his performance level.
The current case demonstrates that the worker suffered from manually guided machines vibration, which is transferred via the surface and handles of the machinery, through the fingers and palms into the hands and arms. The mentioned employee has been regularly exposed to this type of vibration, which provoked hand-arm vibration syndrome, leading to motor and neurological disorder in the hands and circulatory disorder in the fingers.
In order to prevent the above-mentioned situation, the employers should assess and define the measures that can eliminate or lower the hazards from subjection to hand-arm vibration. Moreover, they should ensure that control restrictions to lower vibration are executed appropriately, while the important information, training and health surveillance are provided to all the employees who might suffer from hand-arm vibration. An employer should observe and suggest the alternative methods of working, which eliminate the requirement to utilize vibrating equipment and implements. It is also helpful to supersede the working process or task with the one that incorporates less vibration. It is also beneficial to utilize the implements, specifically designed for low vibration levels, such as tools with anti-vibration mountings and vibration-isolating handles. The effective and efficient maintenance of equipment and its servicing in accordance with the manufacturer's instructions, together with the implementation of effective fault reporting procedures are also regarded as beneficial preventative measures. In addition, the employers should ensure that employees avoid uninterrupted subjection to vibration during long periods. Work should be organized in a manner that allows breaking the periods of exposure by periods of work, which does not incorporate vibration. In addition, job rotation can also prevent the injuries connected with hand-arm vibration. Finally, it is highly significant to provide the individual protective equipment, which assists employees in keeping warm and sustaining good blood circulation.
Vibration Hazard: Whole-Body Vibration
This example demonstrates one machine operator, who has been driving a loader and excavator for approximately 20 years. Currently, he has been forced to quit this job due to the chronical and severe back pain. The employee has been regularly exposed to whole-body vibration, which led to the increased spinal loads, resulting in backache. Moreover, such factors as constant body in constrained seated postures and spine exposure to vibration shocks led to additional strain upon the spine. Thus, daily exposure to vibration led to solid health detriment and job loss.
It has been established that only a daily exposure of 115m/s2 is permitted. This is an exposure limit value, which demonstrates the maximal quantity of vibration an employee may be exposed to on any day. The analyzed operator exceeded the limit value due to the required tasks, vehicle speed, ground conditions, and operation duration.
In fact, the situation could be prevented if the employer had controlled the daily exposure level of the analyzed employee. In addition, the employer can make arrangements, which might help in reducing the grip, push and other forces impacting the constrained working setting in loaders and excavators. Furthermore, the situation could be prevented by providing support for tools and work pieces, ensuring that the equipment is ergonomically designed. Indeed, the analyzed situation could have been avoided if the worker was supplied by a modern, well-designed and adaptable seat on the vehicle. The employer could also suggest alternative methods of working, which help to eliminate the need to utilize vibrating equipment and machinery. The situation could also be omitted if the employee eluded subjection to vibration over long time periods. Thus, the employer should organize work in a way that would provide the possibility of breaking the periods of vibration exposure by the periods of work that do not involve vibration. Therefore, ergonomically designed and adjustable seat in a combination with job rotation could appear as highly beneficial solution of the problem.
Mechanical Hazard: Caught Within Machinery
This example demonstrates one 18-year-old employee who died after being caught in a transportable mortar mixer, situated in a residential construction area. The worker was cleansing the mixer at the end of his shift in order to arrange it for the next working day. Another worker (painter), who was working close to the analyzed employee, heard screams for help and saw that the victim’s arm was stuck in the machinery, while the body was pulled into the rotating mixer paddles. Despite the fact that the other worker approached to the mixer and attempted to turn it off, he failed to disengage the gears. Another co-worker also attempted to turn the machinery off and finally succeeded. However, even with the emergency medical services having responded within minutes, the dismantling of the drive mechanism in order to reverse the mixing paddles and extricate the worker required much time. Thus, the analyzed worker died before receiving medical assistance.
This situation demonstrates that the employees should be educated and trained to work in safe conditions and settings. A safety procedure, which concerns the analyzed situation, incorporates “lockout/tag-out”. It practically means that the machinery and equipment should be turned off and disconnected from the energy source before executing any service or maintenance, as the employee died because of being pulled into a mortar mixer, which was actively operating and was not locked out.
Thus, employers should ensure that equipment and machinery is turned off and disconnected from its energy source before an employee is allowed to perform cleaning or sustenance in order to impede the occurrence of analogous situations. It is also important to educate and train employees to recognize and control the possible mechanical hazards. Moreover, preventative measures incorporate ensuring that the machinery and equipment guards sustain in place. Furthermore, it is highly significant to establish the lockout/tag-out processes to secure employees from the rapid machinery or equipment startup or the release of dangerous energy in the process of maintenance or operations execution. In addition, the employer should ensure that all warning labels on the machinery and equipment are clearly visible, while both the machinery and equipment are appropriately maintained. Finally, it is highly significant to assign safety accountabilities to a competent individual at each job location. This person should have the authority to enforce safety precautions and take accurate and rapid measures in order to correct unsecure conditions and situations.
Mechanical Hazard: Falling from Height
This situation demonstrates that a story of 20-year-old carpenter, who was working for a building company, which was constructing an apartment building. This employee attempted to install provisional sustenance for the roof framework, but he unexpectedly fell through the second store stairway hole. The employee landed on the first floor concrete passageway. This employee suffered from a skull fracture and several serious brain traumas. The situation occurred due to the fact that the employee neglected using fall protection system.
Thus, the situation could have been prevented if the employer made sure that the employees utilize fall protection systems, regardless the height they are working on. There are three major fall protection regulations, which allow impeding falling from height for the employees exposed to vertical drops of 6 feet or more. Firstly, it is important to position guardrails around the hazardous working area. Secondly, it is highly crucial to utilize specific safety nets. Finally, the employer should equip each employee with individual fall protection systems. They would include a complete body harness, an anchor, and lifeline. Therefore, an appropriate protection system can help in preventing mechanical hazards connected with the possibility of falling from the height of more than 6 feet.
The current paper vividly demonstrates that vibration and mechanical hazards can have serious impacts on the employees’ health and life. Vibration hazards can be subdivided into hand-arm and whole body vibration issues. The first one can lead to occupational syndrome, which reduces or disrupts the employee’s performance, while the second one can stimulate a worker quit his/her job because of chronic conditions and diseases. Nevertheless, all the problems associated with vibration can be omitted if the employer utilizes appropriate preventative measures. For instance, an employer can suggest alternative working methods, which practically eliminate the need to utilize vibrating equipment and implements. Job rotation is also helpful, as it can organize the work in a way that allows breaking the periods of vibration exposure by periods of work that do not incorporate vibration. Finally, it is essential to provide the individual protective equipment to the workers. The analysis of mechanical hazards revealed the caught within machinery and fall from height situations, as they statistically account to the most fatal-resulting examples of analyzed hazards. Appropriate preventative measures, including protection systems, establishment of lockout/tag-out processes, and relevant training and education can help to avoid the above-mentioned situations.