Working condition and health status of employees of the aviation enterprise

Introduction

Maintaining and strengthening the health of the working population are priority tasks of healthcare in the Russian Federation. Working conditions at numerous aircraft manufacturing enterprises do not meet sanitary standards, causing the development of professional and work-related pathologies [1-6]. Currently, the problems of their prevention and reduction remain relevant in occupational medicine [7]. The aviation industry of the Republic of Tatarstan includes enterprises producing aircraft engines, airplanes, and helicopters. Every year, high rates of occupational diseases are registered at PJSC Kazan Helicopter Plant, S.P. Gorbunov Kazan Aviation Plant – a branch of PJSC Tupolev¹.

The study aims to make a hygienic assessment of working conditions and to study the incidence of workers in the aircraft industry based on the results of mandatory periodic medical examinations.

Materials and Methods

A comprehensive hygienic assessment of the production environment and work process factors was based on the results of a special assessment of working conditions and production control data in the tool manufacturing shop and in the product repair and modernization shop, which included an assessment of chemical factors, noise, vibration, and the severity of the work process.

The data analysis of air pollution in the working area was based on the current regulatory and methodological framework: GOST 12.1.005-88² and SanPiN 1.2.3685-21³. Vibroacoustic factors were analyzed in accordance with GOST 12.1.003-83⁴, GOST ISO 9612-2016⁵, GOST 12.1.012-2004⁶, GOST 31319-2006⁷, and SanPiN 1.2.3685-21³. The severity of the work process, as well as a comprehensive assessment of working conditions, is given in accordance with R 2.2.2006-05⁸. Industrial control was carried out in accordance with the Sanitary Rules SR 1.1.1058-01⁹.

The working conditions of the following main professions were assessed: fitters and assemblers of electrical equipment in the repair shop, product modernization, as well as toolmakers, fitters of mechanical assembly works (MAW), and milling machine operators in the tool manufacturing shop.

The assessed health status of workers was based on the results of mandatory periodic medical examination of 187 workers with a questionnaire survey to collect anamnesis, identify aggravated heredity, complaints and symptoms, risk factors for the development of non-communicable diseases, nutritional status, and physical activity. The primary medical examination of workers included that by a physician, neurologist, ophthalmologist, dermatovenereologist, otolaryngologist, surgeon, psychiatrist and psychiatrist-narcologist, obstetrician-gynecologist, and laboratory and functional studies: calculation of body mass index, complete blood count, clinical urine analysis, determination of total cholesterol and the blood glucose level, electrocardiography, fluorography, measurement of blood pressure, intraocular pressure in individuals aged 40 years and older, mammography of both mammary glands in two projections, ultrasound examination of the pelvic organs, and bacteriological (for flora) and cytological (for atypical cells) examination.

A total of 138 men and 49 women underwent the primary medical examination: 42 people (22.5%) aged 20–29, 29 people (15.5%) aged 30–39, 43 people (23%) aged 40–49, 30 people (16%) aged 50–59, 38 people (20.3%) aged 60–69, 5 people (2.7%) over 70; 69 people (36.9%) had work experience of up to 10 years, 47 people (25.1%) 11–20, 40 people (21.4%) 21–30, and 31 people (16.6%) over 30. The ranking by profession was as follows: fitters (74) – 39.6%, electrical equipment fitters (61) – 32.6%, toolmakers (28) – 15.0%, milling machine operators (13) – 7.0%, MAW fitters (11) – 5.9%.

The information obtained was summarized, systematized, and analyzed using descriptive statistics methods with the determination of shares in percentages.

Results

During their work, workers in repair shops, in product modernization, and manufacturing of technological equipment are exposed to the combined effects of harmful production factors. At a significant number of workplaces during the work shift, noise is observed, the sources of which are technological equipment, pneumatic tools, and a stand for processing hydraulic systems. By origin, the noise is predominantly mechanical, by spectral composition broadband, and by exposure time inconsistent.

Analysis of the results of noise level measurement protocols in the repair and product modernization shop showed that the noise level of fitters was 83.7 dBA, while for working with pneumatic tools it was 86.5 dBA, at the workplace of electrical equipment fitters – 83.8 dBA, and for soldering work – 84.1 dBA. In the toolmaking shop at the production site, the equivalent sound level of 76.3 dBA was established for toolmakers, while for a pneumatic grinding machine it was 97.2 dBA, for milling machine operators – 81 dBA, while working on a console-milling machine – 83.4 dBA. At the workplaces of MAW fitters, for a radial drilling machine, the noise level was 81 dBA (84.4 dBA in the work area), and for pneumatic tools it was 87.5 dBA.

Thus, all the studied professional groups are exposed to adverse noise effects, the equivalent levels of which exceed the maximum permissible level. Moreover, for MAW fitters and toolmakers, the working conditions in terms of noise are second-degree harm, and for other professional groups – first-degree harm.

Contact with local vibration is found among fitters-assemblers, MAW fitters, and toolmakers. The sources of local vibration for MAW fitters and toolmakers are grinding machines, and for fitters-assemblers – pneumatic tools. In these professions, vibration was inconsistent. The analysis of local vibration parameters by vibration velocity for a pneumatic grinding machine in the production area of ​​the toolmaking shop showed that the maximum permissible level was exceeded by 1 dB. The equivalent corrected vibration acceleration value for an 8-hour working day was 116.1–127 dB with a maximum permissible level of 126 dB, which corresponds to harmful working conditions of the first degree. Measurements of local vibration levels at the workplaces of assemblers and MAW fitters did not reveal any deviations from the standard values.

An unfavorable production factor is chemical air pollution in the working area [3]. Chemical compounds were identified in the product repair and modernization shop. In the air of the working area of ​​the fitter-assembler during metal degreasing, the average shift values ​​of kerosene concentration at 100% of the exposure time were 163.5 mg/m³, which did not exceed the maximum permissible concentration (MPC) (300 mg/m³). In the air of the working area of ​​the electrical equipment installer during soldering, the content of lead and its inorganic compounds, nitrogen oxides, and carbon monoxide at 35% of the exposure time did not exceed the MPC.

In the product repair and modernization shop, in the air of the working area of ​​the MAW fitters when working on a sharpening and grinding machine, the maximum one-time and average shift values ​​of silicon dioxide concentration did not exceed the MPC.

The predominant indicator of the severity of the work among those surveyed is the posture (uncomfortable, forced, or standing), the class of working conditions is 3.1-3.2.

Assessment of working conditions by the degree of harmfulness and danger of production environment factors, the severity and intensity of the work process [8] allowed classifying working conditions in a number of professions as first- and second-degree harm¹⁰ (Table 1).

Among the most common diseases identified in the periodic medical examination were diseases of the eye and ocular adnexa 23% (43 people) – refractive and accommodation disorders (myopia and hyperopia) and early senile cataract, as well as arterial hypertension 17% (32 people) and bilateral sensorineural hearing loss (SHL) 12.8% (24 people). Obesity and hypercholesterolemia were detected in 12.3% (23 people), and diabetes mellitus in 2.7% (5 people). Anemia was observed in 3.7% (7 people). Pathology of the genitourinary system and musculoskeletal system was 2.7% (5 people) and 9.1% (17 people), respectively. A study of fasting blood glucose levels revealed unspecified hyperglycemia in 3.7% (7 people) of those examined.

In 12 people, occupational SHL was suspected, which amounted to 6.4% of the number of workers examined. In 41.7% of cases, SHL was observed in toolmakers (5 people) aged 57–65, with 16–36 years of work experience in contact with noise, in 33.3% in assemblers (4 people) aged 58–74 with 10–21 years of work experience, in 8.3% among MAW fitters, electrical equipment assemblers and milling machine operators.

Ranking of workers by health groups showed that 55.8% (70 people) had Groups IIIa and IIIb, 28.3% (53 people) and 34.2% (64 people) had Groups I and II, respectively.

An analysis of the prevalence of chronic diseases (depending on the profession) in the workshops for technological equipment production, repair and products modernization showed their higher proportion among fitters-assemblers, fitters-toolmakers, and milling machine operators (Table 2).

Discussion

The research showed that the working conditions in the aviation industry were characterized by the impact of a complex of unfavorable production factors, the main being noise and local vibration. Local vibration levels exceeded the standard values ​​at the workplace of a toolmaker (class of working conditions – 3.1). The greatest excess of permissible noise parameters was noted among toolmakers and MAW fitters (class of working conditions – 3.2). The predominant indicator of the severity of the work process among assemblers, toolmakers, mechanical assembly fitters, aircraft electrical equipment fitters, and milling machine operators was the working posture (uncomfortable, forced, or standing).

The “leaders” in the identified structure are diseases of the eye and ocular adnexa, of circulatory and hearing organs. In 5 professional categories of workers, occupational SHL was suspected. Ranking by profession and age showed SHL prevalence among toolmakers and assemblers over 60 years of age. The dependence of occupational and general somatic morbidity on the working conditions of employees of the aviation enterprise was established.

Conclusion

The study indicates a risk of developing occupational pathology as a result of exposure to physical factors, mainly bilateral sensorineural hearing loss. The materials of the study allow giving recommendations to the employer on ensuring industrial control over factors of the working environment in accordance with the requirements of Paragraphs 1.5 and 2.5 of the sanitary rules “Organization and implementation of industrial control over compliance with sanitary rules and the implementation of sanitary and anti-epidemic (preventive) measures – SR 1.1.1058-01”, preventing employees from performing their work duties without undergoing mandatory medical examinations, as well as in case of detecting medical contraindications¹¹.