Health Risks of Underground Construction WorkUnderground construction work includes tunnelling for roads, highways and railroads and laying pipelines for sewers, hot water, steam, electrical conduits, telephone lines. Hazards in this work include hard physical labour, crystalline silica dust, cement dust, noise, vibration, diesel engine exhaust, chemical vapours, radon and oxygen-deficient atmospheres. Occasionally this work must be done in a pressurized environment. Underground workers are at risk for serious and often fatal injuries. Some hazards are the same as those of construction on the surface, but they are amplified by working in a confined environment. Other hazards are unique to underground work. These include being struck by specialized machinery or being electrocuted, being buried by roof falls or cave-ins and being asphyxiated or injured by fires or explosions. Tunnelling operations may encounter unexpected impoundments of water, resulting in floods and drowning.
interchange 英[ˈɪntətʃeɪndʒ] 美[ˈɪntərtʃeɪndʒ] vt. 互换,交换; 交替; (位置等) 使更叠发生; 交替发生; vi. 交换; 相互交换; n. 交换,交替; 互通式立体交叉,道路立体枢纽; [网络] 互换; 剑桥国际英语教程; 立交桥; [例句]What made the meeting exciting was the interchange of ideas from different disciplines.会议上令人兴奋的是来自不同学科的思想交流。[其他] 第三人称单数:interchanges 复数:interchanges 现在分词:interchanging过去式:interchanged 过去分词:interchanged形近词: sexchange intrachange rechange