Recommendations related to shift work

Svrha ovih preporuka jest što više smanjiti fiziološke, psihološke i socijalne probleme smjenskih radnika. Da bi se to postiglo, potrebno je, u prvom redu organizirati takvo radno vrijeme koje će maksimalno uzimati u obzir osobine radnika koje su povezane s tolerancijom prema smjenskom radu. Prilikom primanja na posao treba voditi računa o tome da neki radnici ne bi uopće mogli i smjeli raditi u smjenama. Kako smjenski rad predstavlja dodatno opterećenje, trebaju se organizirati redoviti liječnički i psihološki pregledi radnika. Radnici čije je funkcionalno stanje pogoršano trebaju biti trajno ili privremeno oslobođeni noćnog rada. Da bi se što više spriječilo negativno djelovanje smjenskog (noćnog) rada, potrebno je što je više moguće omogućiti smjenskim radnicima adekvatni odmor u slobodno vrijeme, a - ako je moguće - dopustiti im i kraće spavanje na radnom mjestu tijekom noćne smjene.The purpose of the recommendations is to decrease as much as possible physiological, psychological and social problems connected with shift work. To achieve this goal working hours should be organized to take account of shift workers\u27 tolerance to shift work. When recruiting new shift workers certain personal characteristics that make work in any shift work system inadvisable should be checked. As shift work can be considered to be an additional load, shift workers\u27 health requires regular checking up. If there are signs of health impairment, the workers should be removed from might shift work permanently or at least temporarily. The shift workers\u27 free time should be arranged so as to facilitate recovery from shift work, especially after night shift. To decrease the workload during the night shift, if possible, workers should be given opportunity to take naps during work

Effect of sympathomimetics upon work output in physical effort

U okviru općeg prikaza djelovan ja simpatikomimetika na radni učinak kod tjelesnih radova, autor iznosi niz terenskih i laboratorijskih ispitivanja. Naročito je istaknuta uloga nekih faktora (individualne razlike među ispitanicima, stupanj motivacije itd.) na postignute rezultate, koji otežavaju mogućnost da se utvrdi da li upotrijebljena sredstva imaju ili nemaju neko pozitivno djelovanje na radni učinak. Čini se da je djelovanje različitih farmakoloških stimulatora na radni učinak i tjelesnu izdržljivost tako slabo da ih različiti faktori u pokusima mogu lako prikriti.Within a general survey on the effects of sympathomimetics upon work output in physical effort relevant field and laboratory research has been dealt with. The importance of some factors for the results obtained individual differences among subjects, degree of motivation, etc.) has been particularly stressed, since they make it more difficult to ascertain whether or not the applied drugs have any positive effect upon work output The effects of various pharmacological stimulants upon work output and physical endurance seem to be so negligible that they are easily masked by various other factors

Effect of fatigue on the reproduction of arm movements and the stability of fist pressure

1. Ispitivanje utjecaja umora na varijabilnost rezultata pri reprodukciji pokreta bez vidne kontrole izvršeno je na 16 ispitanika. Svaki ispitanik je sudjelovao na dva pokusa: jednom u odmorenom stanju, a drugi puta nakon umaranja tjelesnim radom. Rezultati ne pokazuju statistički značajnu razliku. 2. Djelovanje umora na stabilnost pritiska šake ispitivala se pomoću dinamometra na živu. Rezultati pokazuju, da se za vrijeme umora, koji je nastao u povodu bilo fizičkog, ili intelektualnog rada, broj oscilacija žive statistički značajno povećava u odnosu na njihov broj u odmorenom stanju.1. Effect of fatigue on the variability of the results of the reproduction of arm movements without visual control was tested on 16 subjects. Each subject was tested twice: in .the state of rest and in the state of fatigue due to physical work. The results obtained showed no statistically significant difference. 2. Effect of fatigue on the stability of fist pressure was tested by means of a mercury dynamometer. The results obtained showed that the increase in -the number of mercury oscillations in the state of fatigue caused either by physical or intellectual effort was statistically significant in relation to the number of mercury oscillations in the state of rest

Circadian variations in alertness, readiness for work and work efficiency

U organizmu čovjeka odvijaju se ritmički procesi različitih frekvencija odnosno perioda. Među njima za funkcionalno stanje čovjeka najvažniju ulogu imaju ritmovi čiji je period oko 24 sata (tzv. cirkadijurni ritmovi). Oni su utvrđeni na svim funkcionalnim razinama: od supcelularnog i staničnog nivoa preko organa i organskih sistema pa do organizma kao cjeline. U svakodnevnim prilikama ove su cikličke promjene u organizmu pod utjecajem ritmičkih promjena u okolini. Vanjski ritmički utjecaji potpomažu da se ritmičke promjene u organizmu bolje sinkroniziraju i da se organizam kao cjelina bolje prilagodi na svoju sredinu. Kod noćnog rada dolazi do inverzije ritma budnost/spavanje u toku dana; radnik mora raditi u ono vrijeme tijekom 24 sata kad je organizam u stanju deaktivacije, a spavati u ono vrijeme kad je obično budan i aktivan. Ove promjene u aktivnosti čovjeka predstavljaju dodatno opterećenje na koje se radnik mora prilagoditi da bi mogao dulje vrijeme raditi u smjenama. Tolerancija prema smjenskom (noćnom) radu povezana je s nekim karakteristikama radnika. Mjerenje tih karakteristika može poslužiti u utvrđivanju interindividualnih razlika u toleranciji prema smjenskom radu.Among various rhythmic processes with different frequencies (periods), which are present in the human organism, for normal functioning the most important are the rhythms with a cycle length of about 24 hours (termed circadian rhythms). Circadian rhythms have been confirmed at all levels of physiological functions: from subcellular and cellular mechanisms, to the organic systems and organism on the whole. In normal everyday circumstances the rhythmic processes in the human organism are synchronised with the rhythmic processes in the environment. The external rhythmic variations support internal synchronisation between various rhythms, and in that way make it possible for the organism to better adapt to the environment. The sleep-wake rhythm is inverted during night work: the worker has co work in the period of low activity level, and sleep during the day, when he is usually active and alert. In order to work in shifts the worker has to adapt to such disruptions of the sleep-wake pattern. Tolerance to shift work was found to be associated with some features of the worker. The measurement of such features could serve as determinate of interindividual differences in shift work tolerance level

Analysis of absenteeism in a Zagreb factory

U jednom industrijskom poduzeću izvršena je registracija i analiza izostanaka s posla. Analiza je pokazala da je prosječni broj izgubljenih radnih dana kod žena znatno veći nego kod muškaraca. Uspoređivanje izostanaka mladih i starijih radnika pokazalo je da stariji radnici imaju prosječno manji broj izostanaka i manji broj izgubljenih radnih dana nego mladi radnici. S obzirom na stupanj obiteljske odgovornosti dobiveni rezultati pokazuju da kod radnika najveći prosječni broj izostanaka imaju samci, dakle oni koji imaju najmanju obiteljsku odgovornost, a kod žena je potpuno obrnuto: najveći prosječni broj izostanaka imaju žene s djecom, tj. one s najvećom obiteljskom odgovornošću.The analysis of absences in a Zagreb factory has shown: (1) that the average number of days lost in women is considerably higher than in men, (2) that in older workers the average number of both absences and days lost is lower than in younger workers, and (3) that as regards family responsibility, the highest average number of absences in men is observed in single men, i. e. in those with the lowest family responsibility, while the highest average number of absences in women is found to be in women with children, i e. in those with the highest family responsibility

Circadian variations in alertness, readiness for work and work efficiency

U organizmu čovjeka odvijaju se ritmički procesi različitih frekvencija odnosno perioda. Među njima za funkcionalno stanje čovjeka najvažniju ulogu imaju ritmovi čiji je period oko 24 sata (tzv. cirkadijurni ritmovi). Oni su utvrđeni na svim funkcionalnim razinama: od supcelularnog i staničnog nivoa preko organa i organskih sistema pa do organizma kao cjeline. U svakodnevnim prilikama ove su cikličke promjene u organizmu pod utjecajem ritmičkih promjena u okolini. Vanjski ritmički utjecaji potpomažu da se ritmičke promjene u organizmu bolje sinkroniziraju i da se organizam kao cjelina bolje prilagodi na svoju sredinu. Kod noćnog rada dolazi do inverzije ritma budnost/spavanje u toku dana; radnik mora raditi u ono vrijeme tijekom 24 sata kad je organizam u stanju deaktivacije, a spavati u ono vrijeme kad je obično budan i aktivan. Ove promjene u aktivnosti čovjeka predstavljaju dodatno opterećenje na koje se radnik mora prilagoditi da bi mogao dulje vrijeme raditi u smjenama. Tolerancija prema smjenskom (noćnom) radu povezana je s nekim karakteristikama radnika. Mjerenje tih karakteristika može poslužiti u utvrđivanju interindividualnih razlika u toleranciji prema smjenskom radu.Among various rhythmic processes with different frequencies (periods), which are present in the human organism, for normal functioning the most important are the rhythms with a cycle length of about 24 hours (termed circadian rhythms). Circadian rhythms have been confirmed at all levels of physiological functions: from subcellular and cellular mechanisms, to the organic systems and organism on the whole. In normal everyday circumstances the rhythmic processes in the human organism are synchronised with the rhythmic processes in the environment. The external rhythmic variations support internal synchronisation between various rhythms, and in that way make it possible for the organism to better adapt to the environment. The sleep-wake rhythm is inverted during night work: the worker has co work in the period of low activity level, and sleep during the day, when he is usually active and alert. In order to work in shifts the worker has to adapt to such disruptions of the sleep-wake pattern. Tolerance to shift work was found to be associated with some features of the worker. The measurement of such features could serve as determinate of interindividual differences in shift work tolerance level

Main and additional sleep characteristics of rotating shift workers

U radu su ispitane različite karakteristike spavanja rotirajućih smjenskih radnika (n=604) i radnika kontrolne skupine (n=113). Utvrđeno je da smjenski radnici imaju općenito lošiju kvalitetu spavanja te da nakon rada u jutarnjoj smjeni spavaju kraće, a u slobodne dane duže nego radnici kontrolne skupine. U skupini smjenskih radnika različite mogućnosti spavanja s obzirom na smjenu i slobodne dane značajno su utjecale na trajanje glavne epizode spavanja i učestalost dodatnog spavanja. Ova skupina kompenzirala je kratko trajanje spavanja nakon rada u jutarnjoj i noćnoj smjeni dužim spavanjem nakon rada u poslijepodnevnoj smjeni i u slobodne dane. Usto su kratko spavanje nakon rada u noćnoj smjeni kompenzirali još jednim dodatnim spavanjem, dok dodatno spavanje nakon jutarnje smjene nije imalo funkciju nadoknade kratkog spavanja. U kontrolnoj skupini radnika različite mogućnosti spavanja s obzirom na radne i slobodne dane također su utjecale na trajanje glavne epizode spavanja. Radnici ove skupine kompenzirali su kratko trajanje spavanja u radne dane samo dužim spavanjem u slobodne dane. Povezanost kvalitete spavanja i trajanja glavnog spavanja razlikovala se s obzirom na smjene i slobodne dane. Kvaliteta i učestalost dodatnog spavanja bili su povezani samo kod radnika kontrolne skupine.Various sleep characteristics were examined among rotating shift workers (n = 603) and control workers (n = 113). The results showed the shift workers to have poorer sleep quality than the control group. In addition their main sleep episode was shorter on morning shift and longer on days off in comparison to controls. Shift workers\u27 main sleep length and frequency of napping were affected by the situation in which they were taken (morning, afternoon, night shift or days off). In the group of shift workers the short main sleep episode on morning and night shifts was compensated by longer sleep on afternoon shift and days off. The short night shift sleep was additionally compensated by napping. However, naps taken on the meening shift did not prove to be compensatory. The length of the main sleep episode was affected by the situation in which sleep was taken also in the control group of workers. In this group only the longer main sleep episode on days off appeared to have a compensatory function for the short main sleep on working days. The relationship between sleep quality and main sleep duration was determined by the situation in which sleep was taken, while the relationship between sleep quality and napping was established only for the control group of workers

Shift work and worker\u27s health complaints

Cilj istraživanja bio je usporediti zdravstvene probleme radnika koji rade u smjenama i radnika koji ne rade i nisu nikad radili u smjenama. Ispitano je 609 smjenskih radnika i 97 radnika koji ne rade u smjenama. Radnici su bili muškog spola, zaposleni u rafineriji. Zdravstveni problemi radnika ispitani su kao broj posjeta liječniku tijekom pet godina i kao subjektivne procjene vlastitog zdravstvenog stanja. Rezultati o posjetima liječniku pokazali su da su radnici koji ne rade u smjenama općenito više puta posjećivati liječnika nego smjenski radnici. Međutim, kada se broj posjeta liječniku zbog pojedinih skupina bolesti promatrao u odnosu na ukupni broj posjeta i osobito kada su se uzele u obzir subjektivne procjene zdravstvenog stanja, pokazalo se da su smjenski radnici izloženi povećanom riziku od nekih bolesti, u prvom redu bolesti probavnih organa.A comparative study of health complaints was performed in a large oil-refinery among a total of 609 shift workers and 97 non-shift workers. Health complaints were assessed on the basis of the workers\u27 medical records, where details of every visit to the physician over a period of five years were noted, and as subjective health complaints obtained by a questionnaire. In general, the non-shift workers visited the physician more often than the shift workers. However, when visits to the physician for special groups of diseases were considered taking into account the overall number of visits, and especially when the subjective health complaints were compared between the two groups of workers, the results indicated that the shift workers were at greater risk of some diseases, especially the digestive ones

Effect of some pharmaca on work output in repetitive physical effort

Autori su ispitivali djelovanje različitih farmakoloških sredstava (fenamina, ritalina, preludina i veronala) na tjelesni rad čovjeka, upotrebljavajući metodiku repetitivnih radova statičkog i dinamičkog oblika. Ispitivanja su izvršena na tri načina: (1) Ispitanici su u toku dana, uz stalnu pauzu među susjednim radovima, radili više puta (od 9 do 16 puta), i to uvijek do kraja izvodljivosti; (2) ispitanici su radili 10 submaksimalnih radova uz stalnu pauzu, a onda su tek na kraju čitavog pokusa radili jedan rad do kraja izdržljivosti; (S) ispitanici su najprije uz stalnu pauzu radili 4 submaksimalna rada, a zatim uz jednaku pauzu još 9 maksimalnih radova. Rezultati su pokazali da uzimanje farmakoloških preparata kad je čovjek svjež i dobro motiviran za rad veoma slabo ili nikako ne utječe na njegovu izdržljivost u tjelesnom radu. Isto su tako farmakološki stimulatori slabo uspješni kad je rad koji čovjek vrši, submaksimalan. Jedino onda kad se organizam nalazi u određenom stupnju umora, uzimanje nekih farmakoloških sredstava može povećati izdržljivost u radu.An ever increasing use of pharmaca for stimulation in work or for prevention of fatigue feeling arouses the question of how these pharmaca affect man\u27s actual working capacity. In physical effort, the fundamental problem is in whether pharmacological stimulators increase work output by improving the inner condition of the organism, i. e. by making working effort more economical from the point of view of energy, or whether this increase of working capacity is only the result of a central effect (fatigue feeling inhibition} accompanied by persistent uneconomical use of the energy reserves necessary for a fast and successful recovery in the periods of rest. The studies carried out so far have given no satisfactory answer to this question, mostly owing to inappropriate methods usually applied in such studies. The basic methodological defect was that the efficacy of pharmacological stimulators was usually tested by comparing the maximum work output of a single effort performed under the influence of a pharmacological stimulator up to exhaustion with a maximum work output of a single effort performed without the use of a stimulator. In life, however, one hardly ever works up to exhaustion, and one\u27s work is usually done at intervals, i. e. the phases of action are periodically followed by the phases of rest. For working capacity in the course of a longer period, the rate and degree of recovery in the phases of rest are at least so important as the degree of mobilization of working synergies in the phases of action. In the course of the last five years the authors have studied the effect of various pharmaca on physical work by using the method of repetitive physical effort both of a static (hanging on one\u27s arms) and dynamic (bicycleergometer driving and running on a treadmill) kind. In main experiments three kinds of procedures were used: a) With a regular pause between successive efforts, the subjects worked several times a day (9-16 times), each time up to exhaustion; b) The subjects made 10 submaximum efforts with a regular pause between them, and worked up to exhaustion only at the end of the whole experiment; this final maximum effort served as a test of fatigue produced by their previous submaximum efforts; c) With a regular pause between each effort, the subjects made 4 submaximum efforts first, and then 9 maximum efforts. The pharmaca used in these experiments were: phenamine (phenyl-izopropilamin sulfas), ritaline (phenyl-/-piperidyl)-acetico-methylic. hydrochloric), preludin (2-phe-nyl-3-methyl-tetrahydro-1,4-oxazin-hydrochlorid), and veronal (5,5 diethylbarbituric acid). They were administered orally either in various phases of the experiment or prior to the experiment. The results may be summarized as follows: 1. The use of various pharmacological stimulators in. the state of physical freshness and good motivation for work has hardly any positive effect. In such cases the inner normal mobilization of working synergies is high enough for a successful adjustment of the organism to the increased work requirements. 2. Pharmacological stimulators do not seem to be much successful in submaximum efforts either, even if such efforts produce a certain degree of fatigue. A certain posoitive effect of pharmacological stimulators appears to exist only in the final phase of maximum physical efforts. 3. Pharmacological stimulators do not seem to slow down the process of restitution in the phases of rest between successive efforts. It also appears that within certain limits of physical effort the certain increase of work output due to pharmacological stimulators is not brought about at the expense of a greater exhaustion of the organism in a later stage. The energy reserves of the organism seem to be such that even if alarm signals of fatigue feeling are missing, they cannot be affected to such an extent as to cause a significant prolongation of restitution processes. 4. Under the effect of stimulators the subjects regularly feel less tired than in control experiments. The difference in the feeling of pain, localised in active muscles, is specially pronounced, this feeling being considerably milder in the experiments with the use of stimulators. This suggests that the effect of pharmacological stimulators is primarily central, their analgetic action raising the limen of the subjective tolerance of the subject in work. 5. Under the effect of phenamine the pulse frequency is increased before the effort is made, in the course of work, and in the rest intervals. While in successive maximum physical efforts in control experiments the subjects break the work at an ever lower pulse frequency, in the experiments with phenamine the pulse frequency remains on a more or less constant, comparatively high level. However, since there is no correlation between the degree of work output improvement and the difference in the pulse frequency at the end of each effort in the experiment with phenamine and the control experiments, the certain positive effect of phenamine on work output does not appear to be in direct connection with the increased pulse frequency

Diurnal variations in the activation level and some personality characteristics

Ispitivao se odnos između ekstraverzije-introverzije te navika svakodnevnog života (jutarnjost-večernjost) s jedne strane i dnevnih varijacija u stupnju aktivacije tokom dana s druge strane. Kao pokazatelji stupnja aktivacije upotrebljeni su frekvencija pulsa i oralna temperatura. Utvrđeno je da između dimenzije ekstraverzija-introverzija i svakodnevnih navika rada tokom dana (jutarnjost-večernjost) ne postoji značajna povezanost, ali da je svaka od tih dimenzija ponašanja pojedinačno povezana sa stupnjem aktivacije tokom dana. Najveće razlike u stupnju aktivacije tokom dana postižu se kad se kombinira sukladno djelovanje ispitivanih dimenzija ponašanja, jer su najveće razlike postignute između introvertiranih ispitanika koji su ujedno i jutarnji »radnici«, te ekstravertiranih ispitanika koji su ujedno i večernji »radnici«.The relationship between extroversion-introversion and every-day life habits (morningness-eveningness) on one hand, and diurnal variations in the activation level on the other hand were studied. Heart rate and oral temperature served as activation indicators. There was no significant correlation between the dimensions of extroversion-introversion and every-day working habits but each of these dimensions of behaviour was associated with the activation level during the day. The greatest differences in the activation level during the day were observed if congruent effects of the studied dimensions of behaviour were combined. This was the case with the subjects who were both introvert and »morning workers« and those who were both extrovert and »evening workers«