Heat stress assessment in artistic glass units

Abstract

Heat stress in glass industry is mainly studied in large and highly mechanized manufacturing Units. To the contrary, few studies were carried out in small factories specialized in hand-made products. To stress the need of combined objective and medical surveys in these environments, this paper deals with a simultaneous climatic and physiological investigation of working conditions in artistic crystal glass factories in Tuscany (Italy). The microclimatic monitoring, through a continuous survey has been carried out in early spring. The main physiological parameters (metabolic rate, heart rate, tympanic temperature and water loss) were measured over the whole shifts. The results show that, despite the arduousness of the working conditions, the heat stress levels are physiologically tolerable. The predictions made using the PHS model at the Analysis level described in ISO 15265 agree closely to the observed values, validating the use of PHS model in these conditions. This model was then used to analyse what is likely to be the situation during the summer. It is concluded that the heat constraint will be very high and that some steps must be taken from the spring to monitor closely the exposed workers in the summer and take measures to prevent any heat accident.

Accuracy of metabolic rate estimates from heart rate under heat stress—an empirical validation study concerning ISO 8996

“…Our results reinforce recent findings11, 16,17,18,19 ) on two essential requirements for the application of M HR estimation algorithms to work scenarios. First, individual HR -to- M -relationships derived from controlled cardiac stress tests are desirable, that should reflect the actual workload and type of work under consideration8, 11, 18 ) .…”

“…There are procedures to correct for ΔHR T , either using the correlation with core temperature, if those measurements were available11 ) , or by estimating ΔHR T from HR recorded during resting periods intermitting the heat exposure10, 17,18,19 ) . The latter method is advantageous under field conditions, as it does not require any core temperature measurements.…”

“…The basic idea is to calculate ΔHR T as the difference of the HR recorded after at least five minutes break from work to HR 0 , which could be measured before start of work or estimated by the 1st percentile of all measured HR 8 ) . Linear interpolation approximates intermediate values of ΔHR T over the working periods, which are then subtracted from recorded HR before estimating M HR 17,18,19 ) .…”

“…Thus a bias correction, e.g. by introducing intermittent resting periods of sufficient length of at least five minutes10, 17,18,19 ) should become mandatory for Level 3 studies in ISO 89965 ) and PHS 4 ) . Otherwise, the accuracy of Level 3 studies might fall behind simpler Level 2 methods, as indicated by the smaller error for M Pan in our study.…”

Climate Change, Occupational Heat Stress, Human Health and Socio-Economic Factors

“…These deeper "cultures of climate" play a role in shaping the everyday practicesincluding occupational practicesthrough which thermal comfort is managed, directly and indirectly. For example, Spain is well-known for its historical practice of "Siesta," or resting in the hottest part of the day, while Venice/Murano glass workers have traditionally not worked in August due to the late summer heat (d'Ambrosio-Alfano et al 2018). During hot and humid periods in tropical countries, e.g., Singapore, local people avoid carrying out intensive physical activities outdoors.…”