OCCUPATIONAL-RELATED INJURIES OF THE PERIPHERAL NERVOUS SYSTEM IN MECHANI- CAL ENGINEERING WORKERS IN NORTHERN BULGARIA

Irena Y. Stoilova1, Radostina P. Madjarova2, Vanya A. Birdanova1 1) Department Hygiene, medical ecology, occupational diseases and disaster medicine, Medical University Pleven, Bulgaria. 2) Department Physical medicine and rehabilitation, occupational therapy and sports, Medical University Pleven, Bulgaria. Journal of IMAB Annual Proceeding (Scientific Papers). 2021 Oct-Dec;27(4) Journal of IMAB ISSN: 1312-773X https://www.journal-imab-bg.org


BACKGROUND
Mechanical engineering is an important branch of the Bulgarian economy.
It includes a large number of sub-sectors -heavy engineering, vehicle production, automotive, aircraft, metal cutting machines, agricultural machinery and more. The production processes that take place in machinebuilding enterprises are diverse and complex [1]. Nevertheless, many homogeneous production processes are used in different sub-sectors. The work of workers in mechanical engineering is characterized by light, and medium physical exertion often requires forced working posture, increased attention and precision in performing production operations [2,3].
The production stages in mechanical engineering include: obtaining parts with a certain shape by casting, forging and pressing; the processing of the obtained details through the use of various metal-cutting machines; installation of the processed details and receipt of the machines and equipment; painting of the manufactured machines and metal coating of their parts [4].
The occupational risk of investigated persons reduces systemic overvoltage of the peripheral nervous system under labor conditions [5].

TARGET:
The aim of the study is to examine the damage to the peripheral nervous system in workers in mechanical engineering and to propose measures for the prevention of accidents at work and occupational diseases.

MATERIALS AND METHODS:
The subject of the study is 65 cases of damage of the peripheral nervous system in patients hospitalized in the Department of Occupational diseases, University Hospital -Pleven in the period 2018-2020. The subjects are workers of enterprises in the districts of Pleven, Lovech, Vratsa, Gabrovo and Veliko Tarnovo. All the persons investigated were given information regarding the aim and the nature of the investigation and signed an informed consent form for undergoing the investigation.
Clinical, laboratory, functional, imaging and statistical methods have been used [6]. The clinical methods of diagnosis are professional anamnesis and production characteristics, clinical anamnesis, general status, neurological status, palpation, percussion, auscultation. The laboratory methods are hematological tests -CBC (complete blood count), the morphology of erythrocytes; biochemical tests -fat metabolism, enzymes, electrolytes, liver samples, etc.; immunological and serological tests [7]. The statistic processing of the primary data was done by software packages Microsoft Office Excel 2010 and SPSS ver. 13.

RESULTS:
The total number of respondents is 65. From the inquired person, 83% were men, and 17% were women  The respondents are aged from 21 to 62 years, and the average age is 44,00 (n=65) ± 2,88 years. More than half of the inquired persons are between 41 and 60 years, followed by the ones between 31 and 40 years -21,54%, and 16,92% of them are between 21 and 30 years. The distribution of the surveyed persons by age is shown in Figure 2.   According to the place of residence, the participants are distributed as follows: -Urban residents -62% of persons -Rural residents -38% of persons The distribution of participants according to the place of residence is shown in Figure 5. Depending on the total length of service, the participants are distributed as follows: Most are the cases of the group with 21 to 30 years of a total length of service -27,69%.
The least cases are observed in the age group with over 40 years of a total length of service. Average total length of service is 22,02 (n = 65) ± 2,94 years.  The distribution of participants, according to the intensity of pain, is shown in Figure 9.

DISCUSSION:
A significant statistical dependence was found (p<0.05), showing a directly proportional relationship between the age of the persons and the degree of pain reported on the visual-analog scale (VAS). As the age of the person increases, the degree of pain increases. [8,9,10] A correlation was found between the exposure and the degree of pain (p<0.05), showing a directly proportional relationship. The degree of pain increases with the increasing length of service of the subjects.
There is a correlation between residence and the presence of vertebral syndrome (p<0.05).
The vertebral syndrome is more common in study participants living in rural areas.
No significant correlation was found between the other studied indicators in the study participants [11].

CONCLUSION:
Damage to the peripheral nervous system is an actual health problem for people working in mechanical engineering in Northern Bulgaria.
The aging of the workforce is associated with involvement of the peripheral nervous system, characterized by pain syndrome.
An additional harmful factor for the occurrence of diseases of the peripheral nervous system in workers in mechanical engineering is the household load associated with the place of residence in the village.

RECOMMENDATIONS FOR PREVENTION MEASURES:
Physiological means -sleep, rational nutrition, active rest, hardening, training. Intensive work is recommended to take easily digestible oligosaccharides, which improve physical and mental performance and B vitamins and vitamin C.
Medical prophylaxis -includes primary and periodic medical examinations. During the initial medical examinations, a physical and psychophysiological assessment of the candidate for work in mechanical engineering should be performed, taking into account the risk factors of production. Periodic medical examinations should record the exact condition of the worker, establishing the early manifestations of occupational injuries of the PNS and taking measures to prevent complications or chronicity of the disease.
Ergonomic and organizational measures: • Rational organization of the labor process -by observing the established working hours; introduction and observance of a physiological regime of work and rest; conducting passive and/or semi-passive breaks while working in suitable premises.
• Control of the condition of the working premises: provision of sufficient area and volume; condition of walls, floors, ceilings.
• Control of the location of the equipment in accordance with the technological sequence; delineation of sufficient work areas and traffic area.
• Control of the parameters of the working environment: illumination, control of the zones of glare and glare; production microclimate, incl. ensuring a suitable temperature in the working premises; prevention of air currents.
Providing sanitary and living conditions: bathrooms, toilets, rest room.
Ergonomic control in the organization of the workplace.
For standing positions: • Providing an opportunity to change the working position from upright to sitting by introducing a high, adjustable, fixed, swivel chair with a step.
• For workplaces where the work technology does not allow changing the working position to a sitting one, it is recommended to provide a chair for short-term rest.
• The work surfaces must be height-adjustable and positioned so as to allow the body to lean forward up to