Main Article Content
COVID-19, Occupation, Occupational disease, Bus drivers, Cohort study.
Background: Previous research has shown an excess risk of COVID-19 among several occupations, but data on public transport workers are scarce. To investigate the occupational risk posed by contact with the public, we followed up the incidence of COVID-19 in a cohort of public transport workers. Methods: We identified the incident cases of COVID-19 between 1 September 2020 - 6 May 2021 in a cohort of 2,052 employees of a public transport agency in Sardinia, Italy. The diagnosis of COVID-19 was based on a positive molecular test. To calculate the expected events, we applied the age- and gender-specific incidence rates of the regional population in the same time period to the correspondent strata of the study cohort. We estimated the relative risk (RR) of COVID-19 as the ratio between the observed and the expected events and its 95% confidence interval (95% C.I.) among the total cohort and in two sub-cohorts: bus drivers, and the rest of the personnel (administrative staff, train and metro drivers, workers in the mechanical shop, and in the railroad maintenance, and security). Results: Bus drivers run an elevated risk of COVID-19 (RR = 1.4, 95% C.I. 1.07 - 1.79). There was no excess risk among the sub-cohort including the rest of the personnel. Conclusions: Our study suggests an excess risk of COVID-19 among bus drivers even in a relatively low incidence area, which could imply inadequacy of the preventive measures in place. Further, larger size studies with detailed information on personal and lifestyle characteristics are warranted.
2. Lan FY, Wei CF, Hsu YT, et al. Work-related COVID-19 transmission in six Asian countries/areas: A follow-up study. PLoS One. 2020;15:e0233588. doi: 10.1371/journal.pone.0233588.
3. De Matteis S. COVID-19: are not all workers 'essential'? Occup Environ Med. 2021;78(5):305-306. doi: 10. 1136/oemed-2020-107272.
4. Rhodes S, Wilkinson J, Pearce N, et al. Occupational differences in SARS-CoV-2 infection: analysis of the UK ONS COVID-19 infection survey. J Epidemiol Community Health. 2022:jech-2022-219101. doi: 10.1136/jech-2022-219101.
5. Office for National Statistics. Coronavirus (COVID-19) Related Deaths by Occupation, England and Wales Statistical Bulletins. Available online at: https://www.ons.gov.uk/peoplepopulationandcommunty/ healthandsocialcare/causesofdeath/bulletins/coronaviruscovid19relateddeathsbyoccupationenglandandwales/previousReleases. (last accessed 16 June 2021).
6. Mutambudzi M, Niedwiedz C, Macdonald EB, et al. Occupation and risk of severe COVID-19: prospective cohort study of 120 075 UK Biobank participants. Occup Environ Med. 2020;78(5):307-314. doi: 10.1136/oemed-2020-106731.
7. Cocco P, De Matteis S. The determinants of the changing speed of spread of COVID-19 across Italy. Epidemiol Infect 2022:1-26. doi: 10.1017/S095026882200084X.
8. Presidenza del Consiglio dei Ministri. Dipartimento della Protezione Civile. COVID-19 Italian Situation. Available online at: https://opendatadpc.maps.arcgis.com/apps/dashboards/b0c68bce2cce478eaac82fe 38d4138b1 [In Italian] (last accessed 23 July 2022).
9. Miettinen O. Estimability and estimation in case referent studies. Am J Epidemiol. 1976; 103(2):226-235. doi: 10.1093/aje/kwx074.
10. Ogen Y. Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID-19) fatality. Sci Total Environ. 2020;726:138605. doi: 10.1016/j.scitotenv. 2020.138605.
11. Villeneuve PJ, Goldberg MS. Methodological Considerations for Epidemiological Studies of Air Pollution and the SARS and COVID-19 Coronavirus Outbreaks. Environ Health Perspect. 2020;128(9):95001. doi: 10.1289/ EHP7411.
12. Wang B, Liu J, Fu S, et al. Airborne particulate matter, population mobility and COVID-19: a multi-city study in China. BMC Public Health. 2020;20(1):1585. doi: 10.1186/ s12889-020-09669-3.
13. Zhu Y, Xie J, Huang F, Cao L. Association between short-term exposure to air pollution and COVID-19 infection: Evidence from China. Sci Total Environ. 2020;727:138704. doi. 10.1016/j.scitotenv.2020.138704.
14. Yao Y, Pan J, Liu Z, et al. Ambient nitrogen dioxide pollution and spreadability of COVID-19 in Chinese cities. Ecotoxicol Environ Saf. 2021;208:111421. doi:10.1016/j.ecoenv. 2020.111421.
15. Liang D, Shi L, Zhao J, et al. Urban Air Pollution May Enhance COVID-19 Case-Fatality and Mortality Rates in the United States. Innovation. 2020;1(3):100047. doi: 10.1016/j.xinn.2020.100047.
16 Veronesi G, De Matteis S, Calori G, et al. Long-term exposure to air pollution and COVID-19 incidence: a prospective study of residents in the city of Varese, Northern Italy. Occup Environ Med. 2022;79(3): 192-199. doi: 10.1136/oemed-2021-107833.
17. Office for National Statistics. Coronavirus (COVID-19) Related Deaths by Occupation, England and Wales: deaths registered between 9 March and 28 December 2020. Available online at: https://www.ons. gov.uk/peoplepopulationandcommunity/healthandsocialcare/causesofdeath/bulletins/coronaviruscovid19relateddeathsbyoccupationenglandandwales/deathsregisteredbetween9marchand28december2020#men-and-deaths-involving-covid-19-by-occupation. (last accessed 16 June 2022).
18. Istituto Superiore di Sanità – Istituto Nazionale di Statistica. [Impact of the COVID-19 epidemic on the total mortality of the resident population: January – November 2020]. https://www.istat.it/it/ files//2020/12/Rapp_Istat_Iss.pdf. (accessed 11 April 2021). [In Italian].
19. Italian Ministry of Transportation and Navigation. Ministerial Decree No. 88 of 13 February 1999. [Regu-lation of the assessment and control of the physical and psycho-attitudinal fitness of the public transport personnel as stated by article No. 9, points 3 and 4, of the President of the Republic Decree No. 753 of 11 July 1980]. Gazz. Uff. No. 84 of 12 April 1999, [In Italian]