Workers, particularly outdoor workers, are among the populations most disproportionately affected by climate-related hazards. However, scientific research and control actions to comprehensively address these hazards are notably absent. To assess this absence, a seven-category framework was developed in 2009 to characterize the scientific literature published from 1988 through 2008. Using this framework, a second assessment examined the literature published through 2014, and the current one examines literature from 2014 through 2021. The objectives were to present literature that updates the framework and related topics and increases awareness of the role of climate change in occupational safety and health. In general, there is substantial literature on worker hazards related to ambient temperatures, biological hazards, and extreme weather but less on air pollution, ultraviolet radiation, industrial transitions, and the built environment. There is growing literature on mental health and health equity issues related to climate change, but much more research is needed. The socioeconomic impacts of climate change also require more research. This study illustrates that workers are experiencing increased morbidity and mortality related to climate change. In all areas of climate-related worker risk, including geoengineering, research is needed on the causality and prevalence of hazards, along with surveillance to identify, and interventions for hazard prevention and control.

Occupational exposure limits (OELs) are a critical component of the risk assessment and risk management process and their use remains a staple of occupational hygiene practice. There are dozens of organizations and agencies that derive OELs worldwide. Yet, while most of these groups describe their administrative procedures as well as the rationale for the derivation of OELs for individual substances, few provide equally complete documentation of the underlying scientific methodology for conducting the quantitative risk assessment employed in OEL development. The paucity of written descriptions of OEL development methodology has resulted in a lack of transparency related to implementation of important scientific principles for OEL development and inconsistent practices for OEL development within and among organizations. The absence of such transparency limits the opportunities for international harmonization of existing values and OEL setting practices among organizations. | Given these and other challenges, the National Institute for Occupational Safety and Health (NIOSH) began an effort to identify and characterize leading issues pertaining to OELs and their development through research which culminated in a collection of articles focused on each key issue. Those articles and the key issues they explore comprise this supplement of the Journal of Occupational and Environmental Hygiene. Utilizing subject matter expertise from researchers and thought leaders in the occupational hygiene profession and affiliated fields of environmental public health, the goal of this effort is to describe the issues related to education and communication of science principles and to understand how they can be incorporated into (and thereby impact) the practices of OEL development and interpretation. Focusing specifically on the state-of-the-science in the fields of exposure science, occupational hygiene, risk assessment, and toxicology this effort sought to provide a clear description of how advances in these research areas can contribute to the practice of OEL setting—by reviewing the methods used for most OELs that are currently available as well as new methods that are actively being incorporated in the OEL process. An essential topic included within the set of complementary and interrelated articles dedicated to this pursuit is the consideration and interpretation of OELs in the context of evolving risk management practices. The articles are intended to serve as a current critical review of occupational risk assessment methods that will enable occupational hygiene professionals to have a clear understanding of the science methods incorporated in the OELs they develop or use. A brief introduction to each article in this collection is provided in the following paragraphs.