Đang chuẩn bị liên kết để tải về tài liệu:
báo cáo hóa học: " Negligible heat strain in armored vehicle officers wearing personal body armor"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Negligible heat strain in armored vehicle officers wearing personal body armor | Stewart and Hunt Journal of Occupational Medicine and Toxicology 2011 6 22 http www.occup-med.eom content 6 1 22 _ JOURNAL OF OCCUPATIONAL MEDICINE AND TOXICOLOGY RESEARCH Open Access Negligible heat strain in armored vehicle officers wearing personal body armor Ian B Stewart and Andrew P Hunt Abstract Objectives This study evaluated the heat strain experienced by armored vehicle officers AVOs wearing personal body armor PBA in a sub-tropical climate. Methods Twelve male AVOs aged 35-58 years undertook an eight hour shift while wearing PBA. Heart rate and core temperature were monitored continuously. Urine specific gravity USG was measured before and after and with any urination during the shift. Results Heart rate indicated an intermittent and low-intensity nature of the work. USG revealed six AVOs were dehydrated from pre through post shift and two others became dehydrated. Core temperature averaged 37.4 0.3 C with maximum s of 37.7 0.2 C. Conclusions Despite increased age body mass and poor hydration practices and Wet-Bulb Globe Temperatures in excess of 30 C the intermittent nature and low intensity of the work prevented excessive heat strain from developing. 1. Background The human body requires a relatively constant core body temperature to function effectively. In order to maintain a stable temperature the body must continually lose heat to the surrounding environment at the same rate as heat is produced. Several factors influence the capacity for heat exchange to meet the required rate these include environmental factors air temperature wind speed relative humidity and radiant heat metabolic rate and clothing. In certain occupations the clothing that an individual is required to wear takes on a protective role. These clothing ensembles are generally very effective at preventing injury when a specific hazard is encountered however the added weight of the clothing and its effect on the transfer of body heat to the environment can significantly increase the .