ABSTRACT Occupational injuries represent a tremendous burden to US workers and employers; each year, thousands of workers are killed, and millions injured, with total costs approaching $200 billion annually. Many factors may contribute to occupational injury risk, but several – noise exposure, hearing loss (HL), and use of hearing protection devices (HPDs) – have not been adequately explored. Tens of millions of workers are exposed to noise high enough to warrant use of hearing protectors, and more than 10 million workers have HL. We propose to combine noise exposure estimates we have previously developed in our online Job Exposure Matrix (JEM) for occupational noise in the US and Canada with national occupational injury surveillance data from both countries. This 2-year study will evaluate the relationship between occupational injuries and noise, and to assess the potential contributions of hearing loss and use of HPDs on this relationship. We propose two specific aims: • We will assess the risk of nonfatal and fatal occupational injuries associated with occupational noise exposure over a 20-year period (1998-2018). We will estimate risks of injuries associated with full-shift Time-Weighted Average (TWA) noise exposures over the study period, adjusting for job title and industry. We will also calculate the attributable risk of injury due to noise exposure and evaluate whether a threshold exposure level exists above which injury risk is substantially elevated. This aim has one subaim: to explore different noise metrics for evaluation of injury risk, including mean, maximum, and standard deviation of TWA level and percent of workshifts >85 dBA and >90 dBA, measured using both US and Canadian measurement criteria. We will add the results of these analyses to our noise JEM. • We will use published estimates of HPD use and HL to evaluate the contributions of these factors to risk of nonfatal and fatal occupational injuries. HPD use and HL prevalence estimates will be gathered from literature and available data for each job title and industry. We will then modify our Aim 1 models to include these characteristics and assess their individual and joint impacts on estimated injury risk, as well potential interactions. As with Aim 1, we will add the estimated risks to our noise JEM. This R2P study addresses a number of priorities of the National Occupational Research Agenda, including the Cross-Sector agenda for Traumatic Injury Prevention, as well as hearing loss prevention goals of the Construction, Manufacturing, and Services sector agendas. This proposal also addresses NIOSH strategic goal 6, improve workplace safety to reduce traumatic injuries. The outputs of the study will be publications and noise- related injury risk estimates that we will add to our existing noise JEM website to allow practitioners access to actionable information. The intermediate outcomes of the study will be changes in how noise exposure, HL, and HPD use are addressed in injury and hearing loss prevention programs, and the end outcomes are reductions in occupational injuries and noise-induced HL.

PUBLIC HEALTH SIGNIFICANCE This study will efficiently leverage existing data resources to evaluate the contribution of workplace noise exposures to injuries, and will also address the potential impacts of HL and HPD use on this risk. The results of this study will potentially influence injury and hearing loss prevention programs. This research-to-practice study targets two priority areas for the HealthyPeople2020 initiative: hearing disorders and injury prevention.