Washington:Just a single sneeze can infest a room with deadly bugs and the contamination can last for hours, a new study by US researchers has suggested.A sneeze is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa.
Sneezing can also be triggered through sudden exposure to bright light, a particularly full stomach, or viral infection, and can lead to the spread of disease.
As many as 40,000 droplets can be produced by a sneeze, some of which leave the body at more than 160 kmph.
A sneeze contaminates the room for hours
Researchers have discovered that the microscopic infected droplets that come out during a sneeze or cough float around the air in large enough concentrations for hours and spread disease.
This means that breathing in airborne virus found in the typical office, doctor’s surgery, train, plane or other location where people commonly gather could infect a person after just one hour, according to Daily Mail.
The discovery also highlights why so many holidaymakers hit by coughs, colds, and sniffles at the start of their trip, following a flight, the tabloid reports.
Risk is much higher than thought
Flu transmits from person to person through direct physical contact, or when a person sneezes or coughs in front of another person.
Until now most studies have focused on large droplets, known as aerosols, which carry the virus in the air but quickly fall to the floor and nearby surfaces.
The latest study by US researchers, however, looked at the much smaller droplets, which can remain airborne for hours or even days, revealing that the threat of catching the flu virus through the air is much higher than thought.
Study details
For the study, the U.S. researchers at Virginia Tech collected samples of air from the waiting room of a healthcare clinic, three rooms in a daycare center and three cross-country flights, according to Daily Mail.
Half of the samples were containing small droplets affected with the flu virus.
The researchers found that a typical cubic meter of air contained an average of 16,000 particles of flu virus. Most were less than 2.5 thousandths of a millimeter across, which remain suspended in the air for hours on end, the Daily Mail reports.
“Given these concentrations, the amount of viruses a person would inhale over one hour would be ¬adequate to induce infection,” Daily quoted Dr Linsey Marr, who led the study, as saying.
“The virus-laden aerosols are small enough that the smallest ones can remain suspended for days.
“In this case, they are removed by other mechanisms such as ventilation, usually within one hour, from a building.
“An aircraft or office air-conditioning system does help remove the viruses by removing old air and bringing in fresh air.”
The latest findings appear in the 'Journal of the Royal Society Interface.'
