A group of 239 scientists in 32 countries is calling for the World Health Organization to revise its recommendations to account for airborne transmission as a significant factor in how the coronavirus spreads, the New York Times reports.The big picture: The WHO has said the virus mainly spreads via large respiratory droplets that fall to the ground once they've been discharged in coughs and sneezes. But the scientists say evidence shows the virus can spread from smaller particles that linger in air indoors.Why it matters: If airborne transmission is indeed a significant factor, it would call for major adjustments in efforts to contain the virus, according to the Times.Masks would be needed indoors, even if people are socially distancing.Health care workers may need N95 masks that filter out the smallest droplets as they care for coronavirus patients.Air ventilation systems in public spaces would need powerful new filters.It would likely call for ultraviolet lights to kill viral particles floating indoors.The other side: Benedetta Allegranzi, the WHO's technical lead on infection control, called the evidence for the coronavirus being airborne unconvincing.“Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence,” she said, per the Times. “There is a strong debate on this.”