The influence of the passive evaporative cooling vest on a chemical industry workers and physiological strain level in hot conditions/Uticaj prsluka za hladenje sa sistemom pasivnog isparavanja na nivo fizioloskog opterecenja radnika hemijske industrije u toploj sredini

The present study was conducted in order to evaluate efficiency of a personal body cooling system based on passive evaporative technologies and its effects on test subjects and their psycho-physiological suitability during exertional heat stress in hot environment. Performed results are based on conducted tests in climatic chamber in the Military Medical Academy Institute of Hygiene in Belgrade. Ten male test subjects were subjected to exertional heat stress test consisted of walking on motorized treadmill at a speed of 5 km/h in hot environment. Tests were performed with and without cooling system. As a physiological strain indicator the following parameters have been determined: mean skin temperature, tympanic temperature, heart rate and sweat rate. Results confirmed that cooling vest worn over the clothes was able to attenuate the physiological strain levels during exercise, when compared to identical exposure without the cooling system. Keywords: chemical industry, heat stress, cooling vest, working uniform, physiological strain. Rad predstavlja rezultate naucnih istrazivanja na polju efikasnosti sistema za hladenje tela iz grupe pasivnih sistema na bazi isparavanja i njegov uticaj na fiziolosku podobnost ljudi u uslovima izlozenosti fizickom naporu i ekstremno visokim temperaturama. Podaci i dobijeni rezultati zasnovani su na ispitivanjima sprovedenim u klimatskoj komori Instituta za higijenu VMA u Beogradu. Deset ispitanika muskog pola dobrovoljno je podvrgnuto testovima toplotnog opterecenja usled fizickog napora, izazvanog hodanjem na pokretnoj traci sa brzinom hoda od 5 km/h, u toploj sredini (temperatura vazduha 40°C). Testovi su realizovani sa ispitanicima srednjih godina (27.2 ± 2.6), slicnih antropometrijskih parametara (74 ± 7 kg, 184 ± 9 cm), u varijanti nosenja radne odece bez ikakvog rashladnog sistema (opcija NoCOOL) i uz upotrebu rashladnih prsluka za hladenje tela, model Arctic Heat® (opcija ACOOL). Kao pokazatelji fizioloskog opterecenja odredivane su: srednja temperatura koze ([T.sub.sk]), timpanicna temperatura (Tty) i frekvencija srcanog rada (HR), dok je intenzitet znojenja (SwR) izracunat kao pokazatelj vodeno-elektrolitskog statusa. U svim slucajevima izlaganje fizickom naporu u toploj sredini indukovalo je fizioloski odgovor, manifestovan kroz povecanje timpanicne temperature, frekvencije srcanog rada i intenziteta znojenja. U varijantama primene rashladnog prsluka (COOL), timpanicna temperatura i srednja temperatura koze su ima