The safety inspection identified several fall hazards, employees working without fall protection, electrical hazards, an impalement hazard, and inadequate protection against flying debris for equipment operators working at the tunnel's face. Crystalline silica, a basic component of sand and gravel, is often generated during tunneling and other construction activities. Continued exposure to crystalline silica can lead to silicosis, a lung disease which causes scar tissue formation in the lungs that reduces their ability to extract oxygen from the air.
Crystalline silica is also a known human carcinogen.
OSHA standards require employers to develop and implement engineering controls to reduce exposure levels to toxic substances and, where respirators are used, to implement an effective and continuous respirator program. Sources of Job Injuries Floors and other surfaces, worker motion or position, and containers were the sources of close to half of the occupational injuries and illnesses involving time away from work in 1999. Containers were the source of 14.4 percent of the injuries and illnesses resulting in time away from work. The study's goal is to test the feasibility of combining measurements of these new EMF exposure metrics with existing epidemiologic data to produce a more valid assessment of EMF health risks. Designated reviewers will individually critique the study protocol and provide comments on the conduct of the study and its prospects for achieving its goals.