Construction workers can be grouped into “skilled” trades such as painters, carpenters, plumbers, electricians, roofers, and iron workers, and unskilled construction “laborers” who perform a variety of job tasks in support of the former. Construction workers may be exposed to numerous physical and chemical agents like asbestos, silica,
other dusts, solvents and other chemicals. Indeed, a construction worker is potentially exposed not only to materials used in his own trade but also to substances used by other trades in shared work environments. NIOSH listed approximately 70 different substances to which U.S. construction workers are potentially exposed