Dive Brief:

• A new study tracking the results of more than 730,000 COVID-19 tests found that construction workers had the highest positivity rates for asymptomatic cases of any occupation, including healthcare staff, first responders, correctional personnel, elderly care workers, grocery store workers and food service employees.
• The study, conducted in Los Angeles between August and October, paired positive test results with the answers to a questionnaire that asked about occupation. Construction workers had a positivity rate of 5.7% for individuals who were asymptomatic, and 10.1% for those with symptoms, according to the study, which was administered by testing firm Curative and has not been certified by peer review.  
• “In the construction industry, people may still be coming to work if they have symptoms because some have no paid sick leave," wrote Dr. Jeffrey Klausner, a professor at UCLA’s School of Public Health, co-author of the study and Curative's medical director, in an email to Construction Dive. “The findings are concerning, and warrant a better understanding of the measures put in place to control infection.”

Dive Insight:

The study encompasses one of the largest datasets yet of positive test results among construction workers and comes at a time when an advisory committee to the Centers for Disease Control and Prevention weighs whether essential workers, including those in construction, should be second in line to receive the first available doses of approved vaccines in the United States.

The positivity rates among construction workers in the study were strikingly high when compared to other industries. For example, while construction had a 5.7% positivity rate for individuals who were asymptomatic, the next highest industry, food services, had just a 3.8% rate, or a third lower. For symptomatic cases, only correction workers had a higher positivity rate, at 12.5%, compared to construction’s 10.1%.

Construction industry advocates argue that the traditional use of personal protective equipment in construction during normal times has made compliance with its adoption during the pandemic easier than in other industries. Paired with staggered work shifts, regular site disinfecting and social distancing, they have argued, those steps have successfully mitigated COVID-19 spread on jobsites.

But there is no national clearinghouse that tracks COVID-19 infections by occupation, and data from studies like this one point to construction's role in coronavirus spread. In addition, public health departments in Washington state, Michigan and Nashville, Tennessee, have found construction to be among the top three occupational settings where outbreaks occurred, while a CDC study in Utah found construction to have the second highest number of cases among all industries studied.

Another recent study from the University of Texas concluded that construction workers were five times more likely to be hospitalized with COVID-19 than workers in all other industries, including those who can work from home. 

Brian Turmail, vice president of public affairs at the Associated General Contractors of America, acknowledged COVID-19 case numbers are increasing in the industry, but said there is still no definitive data that connects infection among construction workers to jobsite spread.

“Given the rising coronavirus case counts across the country, and its particularly high rates among the demographic groups that make up much of the industry’s workforce, we are definitely seeing more workers testing positive,” Turmail said. “The distinction is that the virus is not spreading occupationally — in other words, workers are not getting the virus from their jobsites — but instead is being transmitted via local communities and then workers are showing up, asymptomatic, and testing positive.”

He said the industry has been particularly challenged in the weeks following Thanksgiving, when workers may have gathered to celebrate with families. Overall, the study found that among all the subjects who tested positive, 42.3% were asymptomatic. That has been the biggest issue for construction companies now as well, according to Turmail.  

“What firms are struggling with is how to get workers to not show up on the jobsite with coronavirus, when so many cases of coronavirus are asymptomatic,” Turmail said.

Turmail pointed out that the number of construction workers tested in the study, 529, was relatively small. He also cited data from New York Governor Andrew Cuomo that showed construction as the source of exposure in only .66% of COVID-19 cases in New York State from September to November, according to contact tracing data. 

As a counterpoint to Klausner’s comment about some construction workers still coming to work in the absence of paid sick leave, Turmail noted that the Families First Coronavirus Response Act (FFCRA), which requires employers with less than 500 employees to pay two weeks of sick leave for workers in quarantine or experiencing COVID-19 symptoms, was in effect during the study. There are exemptions in the FFCRA, however, for certain employers with fewer than 50 employees. 

California recently implemented its own emergency order requiring workers to receive COVID-19 sick pay as well, though that was after the study’s data collection period. 

The study noted that it didn’t conduct contact tracing of individuals who tested positive, but instead sought to to determine the frequency and prevalence of asymptomatic infection among certain sub-populations. 

“We found a higher prevalence of asymptomatic infection among individuals who reported work in construction and among racial and ethnic minorities,” the study said. 

More testing on jobsites could also prove effective, Klausner said.

“Routine, twice weekly testing to identify those with infection to prevent the spread to others might help,” the UCLA professor said. “Many essential industries now do that."