A major study published last week in The New England Journal of Medicine reported the novel coronavirus responsible for COVID-19 can survive on some surfaces for several days, and is even detectable in aerosols for several hours. This important research offers valuable insights into the lifespan of this new virus outside of a human body, however, some experts are suggesting the study does not mean the virus actually remains infectious on surfaces for days or can be transmitted easily through the air.

The new research was conducted by a collaborative team from the National Institutes of Health, the CDC, UCLA and Princeton University. To test the stability of SARS-CoV-2 the researchers used a nebulizer to imitate a human cough, propelling virus-carrying particles into the air. As well as testing how long the virus is stable in aerosol form, the researchers studied the virus's surface stability on four different mediums: plastic, stainless steel, copper, and cardboard.

The general conclusions from the study, distributed in press releases and widely reported in the media, suggest the virus survives for days on different surfaces, and several hours in aerosol form.

"Scientists discovered the virus is detectable for up to three hours in aerosols, up to four hours on copper, up to 24 hours on cardboard and up to two to three days on plastic and stainless steel," a press release from UCLA states.

While the above statement is technically correct, and reiterated in similar terms in the now published and peer-reviewed study, the data is not intended as evidence the virus is regularly transmitted through the air. The data also makes no suggestion a cardboard delivery box, for example, can act as a viral delivery device in real-world conditions.

The study primarily investigated the virus's rate of decay across various environmental conditions. This rate is known as a half-life, and it records the amount of time it takes for 50 percent of virus particles to die. Understanding the virus's half-life is fundamental to establishing effective public health measures, particularly in hospitals.