The examination of chronic occupational noise on cardiovascular illness has been complicated by: (1) the powerful modifying effect of hearing protection, more vigilantly worn in consistently high-noise environments, (2) strong correlations among workplace noise, job strain, contaminant exposures, heat, and physical exertion in manufacturing jobs, and (3) multiple possible causal pathways (auditory function and physical stress;annoyance and psychosocial stress). I propose to leverage our rich multi-site dataset of employment records, medical claims, on-site medical exams, job demand surveys, W-2 records, and industrial hygiene measures, provided through our unique partnership with the Alcoa Inc. We will validate noise exposures using unique in-ear dose measures being collected on a subset of 400 employees, develop multi-level longitudinal models to consider effects of time-varying noise across plants, and examine confounding by other workplace stressors (e.g., job strain, contaminants). Finally, we will consider the effect of noise, as a chronic stressor, to influence susceptibility to correlated contaminant exposures. This grant will transition me from my current position at Harvard to a full-time position at Yale. I have worked with Yale colleagues for two years on the Alcoa study, and continue to benefit from their rich expertise in occupational epidemiology and noise exposure assessment. I plan to develop a rich epidemiology research career built around my expertise in examining multiplicative effects between social stressors and contaminant exposures. Public Health Relevance: Cardiovascular illness is a leading cause of death among American adults. Though chronic noise and noise-induced hearing loss are among the most prevalent occupational hazards, it remains unknown whether noise-related stress alters response to other workplace contaminants, or whether hearing protection interventions, which modify the noise-hearing loss relationship, may reduce hypertension risk as well.
