ISSN:
1439-6327
Schlagwort(e):
Thermal radiation
;
Recovery pulse rate
;
Cardiac stress
;
Glass bangle factory
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary The cardiac cost of work and recovery pulse rates were evaluated in 38 glass bangle workers (mean age 27.8 years, SD 3.4) exposed to radiant heat (46.2°C, SD 5.1) and high ambient temperature (38.2°C, SD 3.4) for a mean period of 11.0 years, SD 3.5 in the glass bangle industry. A reference group of 15 controls (mean age 27.0 years, SD 3.5 unexposed to occupational heat stress served as a comparison. The results showed that the pulse rate increased from a mean basal value of 80.0 beats·min−1, SD 2.7 to 113.2 beats · min−1, SD 11.4 in the exposed workers while in the controls the increase was negligible. Thus the cardiac cost of work was found to be 33.2 beats · min-', SD 11.1 in the exposed group which was significantly higher (P 〈 0.001) than 7.8 beats·min−1, SD 4.2 observed in the control group. Among the exposed workers, ‘belanias’, who were engaged in the strenuous job of manually rotating the iron roller in the Belan furnace so that the molten glass could be wound in a spiral form, showed the maximum increase in the pulse rate (42.0 beats·min−1, SD 7.5) over the work-shift followed by ‘muthias’ (31.1 beats · min−1, SD 4.0) who were engaged in removing the glass spirals from the Belan furnace. However, wiremen (‘tarkashs’), who were engaged in the highly skilled job of making very fine threads of molten glass with the help of an iron roller, showed the smallest increase (19.5 beats · min−1, SD 3.4) in pulse rate over the work-shift. To assess the effect of heat stress on the cardiovascular system in the glass bangle workers, the pulse rates were counted in a sitting posture from 30 s to 1 min (R1), from 2.5 to 3 min (R3) and from 4.5 to 5 min (R5) after the completion of their work. The recovery pulse rates at R1, R3 and R5 intervals remained significantly higher than the pre-work value in the exposed group and was most pronounced in ‘belanias’. The ‘tarkashs’, in contrast, exhibited almost a complete recovery at R5. The increased cardiac cost of work and the incomplete recovery in pulse rates indicated that these workers exposed to high ambient temperature and thermal radiation in the glass bangle industry suffered from cardiac stress. These findings suggest that the work practices in the glass bangle industry need revising to include a proper work-rest schedule to avoid circulatory strain in the excessive heat to which glass bangle workers are exposed, together with the implementation of suitable engineering controls in order to reduce the level of environmental heat and thermal radiation prevailing in the work environment of the glass bangle industry.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00357608
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