February 18, 2021

Experts Urge Biden Administration to Address Inhalation Exposure to Coronavirus

Thirteen experts in aerosol science, occupational health, and infectious diseases are calling on the Biden administration to acknowledge inhalation as the key route of exposure to SARS-CoV-2 and take immediate action to limit aerosol transmission. In a letter (PDF) addressed to senior administration officials, the experts advocate a range of measures including updating CDC and OSHA guidelines to fully address transmission via small inhalable particles, directing healthcare organizations to cease decontamination of filtering facepiece respirators and other contingency practices, issuing an emergency OSHA standard on COVID-19, adopting standards for more effective face coverings for the public, improving distribution of NIOSH-certified respirators, and sharply increasing production of N95 filtering facepiece respirators (FFRs).

The recommendations come at a time when COVID-19 case rates are dropping across the United States. According to CDC data, the seven-day moving average of new cases has fallen from a high of nearly 250,000 on Jan. 8 to just over 81,000 on Feb. 16. However, the fatality rate over that period has barely changed, and the letter cautions that SARS-CoV-2 variants have the potential to fuel sharp increases in both new cases and deaths. A CDC report issued in late January predicts that the B.1.1.7 variant first identified in Great Britain, which is estimated to be more transmissible than preexisting variants, is likely to become the dominant strain in the U.S. by March.

In a press briefing held yesterday by AIHA, several of the letter’s signatories discussed the reasoning behind their recommendations. Dr. Donald K. Milton of the University of Maryland School of Public Health expressed concern over CDC guidance that emphasizes SARS-CoV-2 transmission through touch and large respiratory droplets while downplaying the role of smaller aerosols such as those emitted when people speak, breathe, cough, and sneeze. The participants in the briefing argued that workers whose jobs expose them to these aerosols should be provided respirators for use on the job.

The letter characterizes the term “respiratory droplets” in CDC’s COVID-19 guidance as “outdated and confusing” because it is used to describe both large particles that quickly settle on surfaces and those that can linger in the air for hours.

“We wrote this letter to put inhalation front and center,” Milton said. “A year into this pandemic, we must provide respiratory protection to all workers who need it.”

“The purpose of the letter was to draw attention to the fact that workers are not being offered the protection they need,” added Lisa M. Brosseau, ScD, CIH, of the University of Minnesota Center for Infectious Disease Research and Policy.

Many of CDC’s recommendations for protecting workers and the public from COVID-19 were adopted when NIOSH-approved N95 FFRs were in short supply. The agency’s guidance for healthcare facilities presents “contingency” and “crisis” strategies for increasing respirator capacity such as extended use and reuse of N95 FFRs, which were designed to be single-use items. Due to the shortages, some healthcare organizations developed methods to decontaminate N95 FFRs for reuse.

But recent news reports suggest that much of the FFR shortfall in the U.S. has been met by new domestic producers who nevertheless cannot find buyers because hospitals have already contracted with foreign manufacturers. In addition, bans placed on online advertising of N95s, which were intended to discourage profiteering during the shortage, are still in place and frustrating the new manufacturers’ efforts to bring their products to market.

“Without clear guidance and direction on the need for enhanced protection,” the letter states, “there is no demand for these N95 FFRs and some of these new manufacturers may go out of business.”

During the briefing, several participants discussed possible reasons why CDC and other health bodies such as the World Health Organization have been slow to acknowledge that SARS-CoV-2 spreads through the air. Dr. Robert T. Schooley of the University of California San Diego said that the word “airborne” has been “taboo” among some scientists who have long associated it with scaremongering. “People have been reluctant to use that word because of what it conjures up,” Schooley said.

Whatever the reasons, the public needs clear guidance from the federal government about the way the virus spreads, according to the participants at the briefing. “If we really want to end this pandemic, we have to acknowledge this virus is spreading through the air,” said Kimberly Prather, PhD, of UC San Diego. “We desperately need CDC to give the straight truth. There is still way too much confusion in the public about how this virus is getting around.”