ISSN 0362-1197, Human Physiology, 2008, Vol. 34, No. 6, pp. 722–727. © Pleiades Publishing, Inc., 2008.Original Russian Text © T.M. Gus’kova, 2008, published in Fiziologiya Cheloveka, 2008, Vol. 34, No. 6, pp. 78–84.

722

INTRODUCTION

The existing cause–effect interrelations between thelinks of the occupational environment–worker healthsystem and low reserves of workers' health determinethe importance of studying the state of adaptive physi-ological systems in young workers contacting withharmful and dangerous occupational factors. In theopinion of a number of authors, the type and degree ofdamage caused by factors of the occupational environ-ment are determined by the adaptive and compensatorycharacteristics of a worker’s body. At the same time, arather low level of health is characteristic of this groupeven in the period of study at vocational schools [1–3].The World Health Organization considers that studieson the sensitivity of young subjects to factors of theoccupational environment deserve special attention, astheir results are not always unambiguous. Studies onthe state of health and occupational adaptation of youngworkers are also extremely few.

The Irkutsk Aircraft Plant is one of the largest indus-trial enterprises of the region and is attractive for youngpeople from the viewpoint of employment, wages, andsocial protection. Workers account for the greatest pro-portion of the personnel of the enterprise (65%); 20- to29-year-olds account for one-third of workers. Moderntechnological processes of aircraft production entailharmful and dangerous occupational factors. The influ-ence of these factors on young workers may lead tooverstrain of adaptive and compensatory mechanismsand limit their psychophysiological potential, reducingthe efficiency of occupational adaptation. In this case,the risk of occupational morbidity and formation ofoccupational pathology increases.

Therefore, we researched the psychophysiologicalpotential of young workers exposed to harmful factorsof aircraft production in the process of occupationaladaptation.

METHODS

The study was carried out at the healthcare center of theenterprise before the beginning of a working shift. Twenty-three male assemblers/riveters aged

22.3

±

0.4

years thathad been working there for

2.1

±

0.2

years after graduationfrom a vocational school were examined.

An integrated estimate of workplace conditionsaccording to the indices of harmfulness and danger wasperformed according to Guideline R 2.2.2006-05 [4]. Aset of methods was used to study the psychophysiolog-ical status. The body mass index was calculated accord-ing to Quetelet [5]. The blood pressure (BP) of the sub-jects was measured in triplicate by Korotkoff’s method,and the heart rate (HR) was measured by palpation ofthe radial artery in the sitting position. The followingindices were calculated: actual indices including theaverage dynamic pressure (ADP), stroke volume (SV),cardiac output (Q), total peripheral resistance (TPR) ofblood vessels, endurance factor, vital capacity (VC) ofthe lungs, tension index (TI) of the myocardium, exter-nal myocardial efficiency (EME), and myocardial per-formance index (MPI), as well as the reference valuesof the systolic (BP

s ref.

= 0.4

×

age, years + 109) anddiastolic pressures (BP

d ref.

= 0.3

×

age, years + 67),ADP (ADP

ref.

= BP

s ref.

+ BP

d ref.

/age, years), Q (Q

ref.

=2.2

×

body surface area, m

2

), TPR (TPR

ref.

= ADP

ref.

×

body surface area, m

2

/Q

ref.

), and VC (VC

ref.

= bodyheight, cm

×

0.052 – age, years

×

0.022 – 3.60) [6, 7].

The adaptive potential of the cardiovascular systemwas estimated for each subject by the method of Bae-vskii (the index of functional changes) [8]. Functionaltests with graded exercise were performed to study thephysical working capacity and training status of thecardiovascular system: the Harvard step test and thesquat test according to the method of Apanasenko [9,10]. A quantitative estimate of the level of physical(somatic) health was carried out using the indirect

Psychophysiological Characteristics of Young Workersat an Aircraft Plant

T. M. Gus’kova

Research Institute of Occupational Medicine and Human Ecology (Angarsk Branch), Research Center of Medical Ecology, East Siberian Scientific Center, Siberian Branch, Russian Academy of Medical Sciences, Irkutsk, Russia

Received February 27, 2007

Abstract

—The results of an evaluation of the psychophysiological characteristics of young workers exposedto factors of aircraft production indicate functional stress, inefficiency of work, detraining of the cardiovascularsystem, limited psychophysiological potential, and dissatisfaction with work in the majority of examined youngworkers.

DOI:

10.1134/S0362119708060091

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PSYCHOPHYSIOLOGICAL CHARACTERISTICS OF YOUNG WORKERS 723

method for determining the aerobic capacity with theuse of basic physiological parameters [10].

An automated system for quantitative estimation ofthe risks of the main pathological syndromes(ASQERS) [11] was used to diagnose premorbid states.The subjects were divided into three groups accordingto the results of the ASQERS measurement: apparentlyhealthy subjects, or those with risks of all syndromes nohigher than 0.75; a risk group, or those with risks in therange from 0.76 to 0.95; and conventionally sick sub-jects, or those with a risk of at least one syndrome nolower than 0.95.

A set of psychodiagnostic procedures was used tostudy the psychological characteristics of the workers:questionnaires for self-estimation of stress resistance[12] and self-estimation of trait anxiety, frustration,aggression, and rigidity and Ehlers’ questionnaires forestimating the motivation for achievement and success,the willingness to take risks, and the motivation for fail-ure avoidance and the tendency toward self-defense [13].

The tapping test was used to estimate the variationof psychomotor reaction and the level of aspiration.The stability of psychomotor reactions was determinedby the intensity of a decrease in the voluntary speed: adecrease of more than 50% was considered significant;a decrease of 30–50%, considerable; a decrease of 15–30%, moderate; and a decrease of 15% or less, insignif-icant. Schwartzlander’s psychodiagnostic scale wasused to estimate the level of aspiration (unrealisticallylow, low, moderate, high, or unrealistically high) [13].

The capacity for intellectual work and its productiv-ity and efficiency were estimated by the results of thecorrection test with the use of Anfimov’s tables. Thespan and concentration of attention were estimated bythis method [14].

The study of mnemenic/intellectual characteristicswas carried out by testing with the Memory for Num-bers and Capacity for Logical Thinking and DrawingComplex Analogies procedures from [13].

A sociological questionnaire that was developed onthe basis of typology by the All-Russia Public OpinionResearch Center (1996) and Yu. Bardvik (1991) andadapted to the specific conditions of our study byT.V. Khlopova, Dr. Sci. (Econ.), and M.P. D’yakovich,Dr. Sci. (Biol.), was used to study the socioeconomiccharacteristics and the structure of the subjects' motivesand attitudes in the occupational sphere.

RESULTS AND DISCUSSION

The profession of aircraft assembler/riveter is themost common at the enterprise. The working process isconnected with manual and automated assembly ofunits and assemblies with the use of manual, electric,and pneumatic tools generating high levels of noise andvibrations and is characterized by considerable diffi-culty and an inconvenient working posture. The inte-grated hygienic evaluation of the working environment

of assemblers/riveters has shown that most of theirwork is classified as class 4 (extreme conditions) withrespect to harmfulness to health and danger and the dif-ficulty and intensity of work; i.e., the levels of influenceof occupational factors may be considered stressful.Work under harmful working conditions imposes strictoccupational requirements on the body and personalityof a worker. The success of adaptation depends to aconsiderable extent on the level of functioning of thecardiovascular system, the integrated evaluation ofwhich involves a large spectrum of hemodynamic indi-ces. This approach is logical because the circulatorysystem is a connecting link between all organs and sys-tems, or between “controlling centers and controlledelements” [8, 15].

The actual and reference values of BP

s

, whose levelis influenced by the state of the arterial blood flow, SV,physical activity, the psychoemotional state, neuroen-docrine changes in the body, and pernicious habits [15–17], were considered to generally characterize the workof the cardiovascular system. We found that the actualindividual BP

s

indices exceeded the calculated refer-ence values in

39.1

±

10

.2% of cases, the BP

s

values ofyoung workers being correlated with the risk of arterialhypertension (

R

= 0.32,

≤

0.05

). BP

d

exceeded the ref-erence values in

30.4

±

9

.2% of the examined workers.Increased values of both indices were found in

21.7

±

8

.6% of cases (Table 1).

A deviation from the reference values of ADP,which was found in 52.1% of workers (in most cases(

47.8

±

10

.4%), towards higher values) pointed to insta-bility of the mechanisms regulating the activity of thecardiovascular system of the young workers. ADP isone of the most stable indices of the activity of the car-diovascular system; the inability of the body to main-tain the ADP upon exertion can be an early sign of cir-culatory disorders.

Comparative estimation of the individual indices ofthe actual and reference cardiac outputs showed that theproportion of workers in which the blood supply toorgans and tissues may be considered adequate is only17.4%. An increase in the actual Q relative to the refer-ence Q was found in

60.9

±

10

.2% of subjects, whichpoints to overstrain of the cardiovascular system.Weakening of the cardiac contractile function in almosthalf of the subjects (47.8%) is evidenced by a decreasein systolic output. The increase in Q compared to thereference value in 30.4% of the subjects was connectedwith an increase in HR. Consequently, a chronotropicreaction against the background of a negative inotropiceffect is the main mechanism of adaptation of the car-diovascular system in young workers. The increase inthe TPR compared to its reference value observed in43.5% of the subjects also confirms a decrease in thefunctional potential of the cardiovascular system ofyoung workers. Hence, most of the heart work in thesesubjects was spent on overcoming the peripheral vascu-

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lar resistance, which promotes further overstrain of thecardiovascular system.

Thus, young workers are characterized by ineffi-cient functioning of the circulatory system and over-strain of compensatory and adaptive mechanisms.

The results of analyzing the index of functionalchanges, whose levels were correlated with the risk ofarterial hypertension (

R

= 0.25,

≤

0.05

), point to func-tional overstrain of the cardiovascular system in

78.3

±

8

.6% of cases. We found significant differences withrespect to a number of hemodynamic indices betweensubjects with satisfactory adaptation and workers inwhich functional overstrain of the circulatory systemwas observed (Table 2). For example, the BP was sig-nificantly higher in the group of workers with func-tional overstrain (

< 0.05). Comparative estimation ofthe indices of the EME and TI showed their signifi-cantly large values in workers with overstrain of adap-

tive mechanisms, which also determined lower myo-cardial performance indices (

< 0.01).

The endurance factor, reflecting the level of toler-ance of the cardiovascular system to exertion, is one ofthe indicators characterizing the efficiency of adapta-tion to unfavorable occupational factors. It should benoted that high values of this index were determined in39.1% of subjects, which suggests a limited potential ofthe cardiovascular system. Estimation of the trainingstatus of the cardiovascular system by the time of HRrestoration after graded exercise (by the method ofApanasenko) also points to its low level in 69.6% ofyoung workers.

The investigation of external respiration, whichexerts a significant influence on the functional state ofthe body, showed that the actual VC was lower than thereference VC in

60.8

±

10

.2% of workers; the differ-ence was considerable in

31.0

±

9

.6% of workers.

Table 1.

Characteristics of the state of central hemodynamics in the examined workers

Index Average value of the index

Proportion of persons with deviating indices, %

higher than the reference value lower than the reference value

Systolic BP, mm Hg 129.6

± 3.5

39.1

±

10.2* 4.3

±

4.2

Diastolic BP, mm Hg 78.7

±

2.2 30.4

±

9.6 13.0

±

7.0

ADP, mm Hg 80.9

±

2.2 47.8

±

10.4* 4.3

±

4.2

Cardiac output, l 4.58

±

0.19 60.9

±

10.2* 21.7

±

8.6

SV, ml 60.8

±

1.9 0.00 47.8

±

10.4

TPR, dyn s cm

–5

1504.7

±

116.3 43.5

±

10.3 43.5

±

10.3

* Differences between indices are significant,

p

< 0.01.

Table 2.

Average hemodynamic indices in workers with different states of adaptation of the cardiovascular system

Index Subjects with satisfactory adaptation Subjects with functional overstrain

IFC, arb. units 1.91

± 0.06

2.75

±

0.27*

Systolic BP, mm Hg 112.20

±

3.85 134.39

±

3.54*

Diastolic BP, mm Hg 69.60

±

5.16 81.22

±

2.29*

ADP, mm Hg 71.77

±

4.88 83.39

±

2.17*

Cardiac output, l 4.51

±

0.65 4.60

±

0.17

SV, ml 62.50

±

6.68 60.33

±

1.68

TPR, dyn s cm

–5

1553.82

±

499.51 1491.12

±

77.55

EME, arb. units 4.36

±

0.28 5.00

±

0.11*

TI, arb. units 7.90

±

0.51 10.33

±

0.43*

MPI, arb. units 0.55

±

0.01 0.49

±

0.01*

Notes: IFC, index of functional changes. *Differences between indices are significant,

p

< 0.05.

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The evaluation of the autonomic status with theKérdö index [18] allowed us to draw a conclusion onthe prevalence of the parasympathetic influence on thecardiovascular system in

52.2

±

10.4% of subjects; thisinfluence was pronounced (vagotonia) in 26.1 ± 9.4%,which may further increase the risk of arterial hyperten-sion [16].

It should be noted that, according to the results ofthe ASQERS, the risk of arterial hypertension amongyoung workers was significantly higher compared towould-be workers, i.e., students of a vocational schoolcontacting with adverse occupational factors only dur-ing practical training (0.21 ± 0.06 versus 0.07 ± 0.01%).

The tolerance of the body to hazardous factors,including occupational factors, is determined by itsenergetic and biological potential since the aerobiccapacity is the physiological basis of the total endur-ance and physical working capacity. We found that theproportion of subjects that had “low” and “below-aver-age” levels of somatic health (as estimated by themethod of Apanasenko) accounted for 65.2 ± 12.3%( ≤ 0.05). This agrees with the opinion of Academi-cian of the Russian Academy of Medical SciencesN.F. Izmerov that young workers are less tolerant toexertion, more sensitive to harmful occupational fac-tors, and more liable to occupational risks [19].

It is known that the functional potential of the car-diovascular system determines the physical workingcapacity [8], which was estimated to be below-averageor low in 85.6 ± 7.3% of the young workers in our study.The decrease in the functional potential of the cardio-respiratory system was also promoted by behavioralrisk factors that were found in the examined group ofworkers: 86% of the young workers smoked, 27%abused alcohol, and 39% were under- or overweight.

The results of estimation of the indices of centralhemodynamics, adaptive potential of the body, andrisks of arterial hypertension in the examined group ofyoung workers are confirmed by the data obtained byIzmerov [20] on a high prevalence of arterial hyperten-sion in persons exposed to local vibration at work-places, which gives grounds for considering the risk ofhypertension to be occupationally determined. Theunfavorable changes in hemodynamics that were foundduring the research may lead to a decrease in the cere-bral blood circulation and affect in this way the highernervous activity and the formation of the dynamicworking stereotype that forms the physiological basisof occupationally important psychological characteris-tics of young workers. Thinking, memory, and develop-ment of motor functions are components of the psycho-physiological status and are directly related to health.Only after estimation of the psychophysiological statusand social and psychological characteristics could wecomprehensively estimate the functional reserves of thebody (Table 3).

The attention span and capabilities for concentra-tion and switching attention from one object of work to

another are important for the occupational activity of anassembler/riveter. The attention potential of 50–76% ofthe young men was lowered. Low estimates of thecapacity and accuracy of short-term visual memory andthe ability to think logically and draw complex analo-gies were found in 80–90% of the subjects. Integratedevaluation of the results of the correction test showed adecrease in the capacity for intellectual work in one-third (33.3%) of the subjects.

A significantly and considerably decreased stabilityof psychomotor reaction (Table 3) was found in 43.5%of young workers; according to the results of theASQERS, 88.9 ± 3.6% of them were classified with the

Table 3. Psychophysiological characteristics of the exam-ined workers

Index Proportion of subjects, %

Attention characteristics

Attention span

low 76.2 ± 9.3*

normal 23.8 ± 9.3

Concentration

low 71.4 ± 9.9*

normal 28.6 ± 9.9

Capacity for switching attention

poor 50.0 ± 10.9

good 50.0 ± 10.9

Intellectual/mnemenic characteristics

Short-term memory

poor 80.9 ± 8.6*

moderate 14.3 ± 7.6

Capacity for logical thinking and drawing complex analogies

poor 90.5 ± 6.4*

moderate 9.5 ± 6.4

Integrated evaluation of the correction test

poor 33.3 ± 10.3

good 9.5 ± 6.4

Attenuation of psychomotor reaction

insignificant (less than 15%) 34.8 ± 9.9

moderate (15–30%) 21.7 ± 8.6

considerable (30–50%) 30.5 ± 9.6

significant (50% or more) 13.0 ± 7.0

* Differences between indices are significant (p < 0.01).

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risk group. The values of the risk of arterial hyperten-sion in workers with a significantly decreased stabilityof psychomotor reaction were higher than in workerswith a slightly decreased psychomotor reaction(0.58 ± 0.15 versus 0.14 ± 0.07, < 0.05).

Psychological characteristics that negatively affectthe formation of professional attitudes were found inthe majority of subjects with high stress tolerance.Average and above-average levels of rigidity and frus-tration were found in 71–76% of the subjects. Personswith an increased rigidity often inadequately estimatetheir abilities and are inclined to set their level of aspi-ration, which determines the activity, behavioral strat-egy, and self-esteem of a young person, too high or toolow. An unrealistically low level of aspiration wasfound in 34.8% of the subjects, and an unrealisticallyhigh level, in 47.8%. It should be noted that one-thirdof young workers (30.8%) had a high level of aggres-sion, which negatively affects the psychophysiologicalstate of young persons.

According to Anokhin [21], motivational excitationis a component of the activity of various functional sys-tems that mobilizes the body to behave actively in theenvironment. Analysis of the young workers' motiva-tions in occupational activity showed that 39% of theworkers had a material motivation and 35% had a socialmotivation for work. Only 35% were completely satis-fied with their work, while 61% wished that they hadanother specialty; more than half (57%) moonlighted toimprove their material well-being. The majority ofworkers (91%) mentioned high wages as the mostimportant characteristic of a job; acquisition of profes-sional skills was important for 65%, and only 30.4% ofsubjects considered it important that their job shouldcorrespond to their personal inclinations and skills.

The efficiency of human occupational activity andsatisfaction with work are determined to a considerableextent by motivation for achievement, which deter-mines a positive attitude to one’s profession, lower anx-iety, and effective mental adaptation. Success in anactivity requires the prevalence of the motivation forsuccess over that for avoiding failure in combinationwith a high level of regulation of activity, i.e., psycho-physiological potential of a worker. Less than one-thirdof the examined young workers (30.8 ± 10.0%) had thistype of motivation.

CONCLUSIONS

Analysis of the obtained results demonstrates a lowpsychophysiological potential, overstrain of the func-tional reserves that ensure preservation and develop-ment of occupationally important qualities, and dissat-isfaction with work in the majority of examined youngworkers. This promotes a decrease in the efficiency ofoccupational adaptation and labor motivation and fur-ther growth of social frustration and aggression, which

increases the number of people with the syndrome of“social tiredness,” mainly at young ages [22].

The problem has a definite socioeconomic aspectsince “social tiredness” syndrome involves conse-quences that are negative for the development of soci-ety, such as the unprecedented deterioration of healthand growth of disability and mortality in the employ-able population, a decrease in professional aptitude, adecrease in the quality of the labor pool, and great eco-nomic losses in the future. Taking into considerationthe existing negative demographic trends, one canhardly overestimate the gravity of the situation for theSiberian region. Therefore, there is no doubt that it isnecessary to monitor the state of health of young work-ers, including their psychophysiological and psychoso-cial characteristics, in order to implement timely pre-ventive measures. Overcoming dissatisfaction with thecurrent state of material well-being can serve as a seri-ous stimulus not only for enhancing occupational activ-ity and stimulating the personalityís inner creativepotential, but also for improving the health of the youngpopulation [23].

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