This presentation will focus on respiratory diseases in the workplace, as the International Agency for Research on Cancer (IARC) recently classified welding fumes as carcinogenic to humans. Two projects on welding fumes were done at the University: the first one on the use of a particle counter to determine similar exposure groups in a steel construction facility and, the second one on urinary metals and metabolites in welders. During the first project, manual and automated processes were characterized using a particle counter. Area samples were also collected to know which areas in the workshops were contaminated. For the second project air and urine samples were collected for a test group and a control group. The test group comprised of apprentice in other trades. Subjects were recruited at the Northern Alberta Institute of Technology (NAIT). Air samples were analyzed for metals and metabolites. Results shows that general ventilation does not allow for an efficient removal of welding fumes since background concentrations were elevated in all workshops where welding, gouging, and grinding occurred in the steel construction facility. In addition, local exhaust ventilation systems may not work well for welding fumes since high levels of particles were found in NAIT workshops using LEV. Iron and manganese concentrations were highly correlated with particle concentrations in air samples. Elevated chromium, manganese and antimony was found in the urine of welders while no difference was found for urinary metabolites between welders and controls. Antimony was more elevated at the end of the training for both urine and air samples suggesting Sb might be used as a biomarker of exposure in welders.