Close physical proximity on the job—An exposure matrix

Abstract

Background: The workplace is a setting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission via respiratory droplets and aerosols for those working in close proximity to others. Currently, limited methods exist for assessing SARS-CoV-2 exposure. Since occupation serves as a surrogate measure, job exposure matrices (JEMs) can be useful for population-based exposure assessment for a portion of exposure.Methods: We developed a JEM to assess physical proximity at work. Scores for questions related to frequency of face-to-face discussions, working closely with others, and working with a team were extracted from a US-based, comprehensive source of descriptive occupational information (Occupational Information Network [O*NET]). We described score distributions using univariate analyses, devised thresholds, and assigned exposure levels for 968 O*NET occupations. Three exposure measures were constructed using combinations of O*NET data, with expert judgment, and accounting for telework. National and California employment estimates were used to assess the workforce proportions by proximity level and demographic characteristics.Results: We categorized 535 US Census occupations (2010) into four-level ordinal exposure levels (not close to very close). Overall, an estimated 56% of the California workforce worked in very close proximity, which decreased to 46% when accounting for telework. The occupational groups working very close across all three measures were: healthcare support, healthcare practitioner, food preparation and serving, building and grounds cleaning and maintenance, and protective service occupations. Latinos and women were overrepresented within occupations working in very close physical proximity. Conclusion:JEMs can inform SARS-CoV-2 exposure assessment for epidemiologic studies, assist in resource allocation, and inform prevention strategies.

COVID‐19 mortality among Massachusetts workers and the association with telework ability, 2020

“…It might also explain the weaker effect in Q4 relative to that in Q3. 39,49 While there is consistency across our study and others 33,54 | 371 workers) might have been more likely to be laid off or leave work due to the pandemic (temporarily or permanently). Therefore, we might have overestimated the denominator (i.e., number of workers at risk) for these groups, and likewise underestimated the rates.…”

“…For instance, the relatively low rate in Q2 might in part reflect the fact that this quadrant included workers in many health care and education occupations who may have had the ability to work from home during 2020, and were therefore at lower risk of workrelated SARS-CoV-2 exposure. 33,50,54,56 In their study, Yuan et al 56 found that, overall, working in frontline essential occupations was positively associated with COVID-19 incidence, hospitalization and mortality, but closer examination of occupation groups revealed a negative association among education, training and library occupations (essential), which in our analysis were largely included in Q2. The authors speculated that online teaching technology might have allowed for remote learning, thereby reducing the risk of occupational exposure for workers in education.…”

“…A review of individual occupations classified by Baker 39 as likely able to telework (Q1), revealed that some occupations, particularly those in the were classified as working outside the home by Vergara and Gibb. 33 If these occupations were misclassified and had a higher risk of COVID-19associated mortality, then the rate in Q1 would be overestimated and the effect of working outside the home on COVID-19-associated mortality would be underestimated (i.e., the RR of Q3 vs. Q1 would be biased toward the null). Additionally, if the deaths in these misclassified occupations were more likely to be among Black Non-Hispanic or Hispanic workers, then the RRs for these workers would be most altered (i.e., most biased to the null).…”

“…In addition, population‐based studies have shown differences in risk of infection and mortality by industry and occupation, 18–25 and findings from surveys of infected workers in several US states noted occupational exposures 5,6 . Factors that influence occupational exposure risk to SARS‐CoV‐2 include those related to the nature of work, such as working indoors or in close proximity to others (e.g., coworkers, patients, clients, customers), as well as access to employer‐provided protective measures, and paid sick leave 1,6,8,11,13,19,25–38 …”

“…5,6 Factors that influence occupational exposure risk to SARS-CoV-2 include those related to the nature of work, such as working indoors or in close proximity to others (e.g., coworkers, patients, clients, customers), as well as access to employer-provided protective measures, and paid sick leave. 1,6,8,11,13,19,[25][26][27][28][29][30][31][32][33][34][35][36][37][38] Throughout the pandemic many workers had to leave home to do their jobs, putting them at risk of infection and of transmitting SARS-CoV-2 to their families and communities. Nationally, just before the pandemic, only an estimated 25% of the US workforce were in jobs that could be done by teleworking, and workers in these jobs earned higher median wages compared to those in jobs that could not be performed remotely.…”