“…(10)(11)(12) Hazard surveillance encompasses all health and safety hazards, including chemical, physical, ergonomic, safety, and psychosocial. (6,7,9,13,14) Exposure surveillance can be performed at many levels: within a department or section of a company (e.g., by the company itself (15) ); on a companywide basis (e.g., single or multisite, national or multinational company (16) ); on an industrywide basis (by a trade association, labor union, branch of military service (17) ); or by broad geographic levels, such as region or nation (e.g., by a government entity (18) ). Surveillance is most useful for prevention when aggregate, or grouped, analysis is performed with information about determinants of exposure at the work site level, with analysis and communication tailored to specific audiences.…”