A scientist is warning that social-distancing guidelines to stay 6 feet from others may be woefully inadequate as the coronavirus can travel 27 feet and linger for hours.

MIT associate professor Lydia Bourouiba, who has researched the dynamics of coughs and sneezes for years, warns in newly published research that the current guidelines are based on outdated models from the 1930s.

Rather than the assumed safety of 6 feet, Bourouiba warns that “pathogen-bearing droplets of all sizes can travel 23 to 27 feet”.

Her research, published in the Journal of the American Medical Association, also warns that “droplets that settle along the trajectory can contaminate surfaces” — and “residues or droplet nuclei” may “stay suspended in the air for hours”.

She notes a 2020 report from China that showed that “virus particles could be found in the ventilation systems in hospital rooms of patients with COVID-19”.

Bourouiba fears that the current guidelines are “overly simplified” and “may limit the effectiveness of the proposed interventions” against the deadly pandemic. She says it is particularly urgent for health care workers who, she argues in her report, face an “underappreciated potential exposure range” while treating the sick and dying.