Employers Advised to Provide Limits on Close Contact, Proper Ventilation

Sarasota, FL (WorkersCompensation.com) – As workers return to offices, employers might want to consider measures to minimize close contact and improve ventilation systems. A new study provides more evidence that frequent contact within six feet and poor ventilation are associated with higher incidents of SARS-CoV-2. 

“Findings from this prospective cohort study in England and Wales indicated that healthcare workers, indoor trade, process and plant workers, leisure and personal service workers, and transport and mobile machine operatives had around twice the total odds of seropositivity compared with participants in other professional and associate occupations, adjusted for age, sex, ethnicity, household income and national region,” the authors wrote in the BMJ journal Occupational and Environmental Medicine. “Healthcare workers and indoor trade, process and plant workers also had greater odds of reporting frequent exposure to poor indoor ventilation at work.” 

The Study

Much of the research on the coronavirus was conducted early in the pandemic. This particular study was more recent, incorporating data through June 2021.

In all, 3,775 adults from the UK-based Virus Watch community cohort study were included in the research. Virus Watch is a “community prospective cohort study of acute respiratory infection syndromes and SARS-CoV-2 infection in England and Wales,” the authors explained. “The study includes weekly reporting of symptoms, testing and vaccination status, as well as detailed monthly psychosocial/behavioural factors.”

Those included had a valid antibody test result between Feb. 1 and June 2021.

The questions the researchers sought to answer were:

1.    How do odds of SARS-CoV-2 anti-nucleocapsid seropositivity vary across occupations?

2.    Does frequency of work-related close contact mediate the relationship between occupation and seropositivity?

3.    How does exposure to poorly ventilated environments vary across occupations? 

They looked at the frequency of work-related close contact among employees and coworkers and/or customers with the question, ‘How often does [the employer’s] work require close contact with others – within 6 feet – including with precautions?’ The choices of responses were

• Never – which might include working from home
• Intermediate – at least once a month but not every day
• Daily

Those same three responses were also options for the question ‘How often do you work indoors in an environment that is never or rarely ventilated (windows or doors opened to let in fresh air or mechanical ventilation system)?’

Findings

Employees in healthcare, indoor trade, process and plant occupations, leisure and personal service occupations, and transport and mobile machine operatives had “greater total odds of SARS-CoV-2 seropositivity compared with participants in the ‘other professional and associate’ category,” according to the researchers. 

Specifically, the seropositivity rate was:

• 17.1 percent – workers with daily close contact
• 13.2 percent – workers with intermediate-frequency contact
• 10 percent – workers with no close contact or working from home

Additionally, workers in occupations with higher odds of infection after accounting for close contact “also had greater exposure to poorly ventilated workplaces,” the study said. Those with daily exposure to poorly ventilated workplaces had seropositivity rate of 18.4 percent, compared with 13.2 percent of those with intermediate exposure and 11 percent for those with no exposure to poorly ventilated workplaces. 

Interventions

The study strengthens previous finding that suggest elevated risk of infection for workers in certain occupations, mainly those who have frequent close contact with others. While working from home may “drastically reduce” the risk, that is not always an option and it may “exacerbate occupational and social inequalities,” the researchers wrote. 

Employers are encouraged to consider work from home, as well as limiting close contact through measures such as social distancing. 

“The relative importance of these measures will depend on infection levels, vaccination levels and the effectiveness of vaccines against current and future variants of SARS-CoV-2,” the authors wrote. “Measures to improve ventilation are likely to be important for control of nosocomial transmission of SARS-CoV-2 and other respiratory infections. Residual risk in indoor trade and process and plant workers, combined with greater self-reported exposure to poor ventilation, also represents an important area for further investigation and modification to reduce risk. The extent and effectiveness of ventilation is likely to vary considerably according to the design of such workplaces.”

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