Scientists have developed a crawling robotic baby that may help understand how dirt and germs on the floor affect human infants in the first year of their life.
The research showed that when babies crawl, their movement across floors, especially carpeted surfaces, kicks up high levels of dirt, skin cells, bacteria, pollen, and fungal spores.
The infants inhale a dose of bio bits in their lungs that is four times what an adult would breathe walking across the same floor. While this may sound alarming, scientists from Purdue University in the US said that this may not be a bad thing.
"Many studies have shown that inhalation exposure to microbes and allergen-carrying particles in that portion of life plays a significant role in both the development of, and protection from, asthma and allergic diseases," said Brandon Boor, assistant professor at Purdue University.
"There are studies that have shown that being exposed to a high diversity and concentration of biological materials may reduce the prevalence of asthma and allergies later in life," Boor said.
Scientists have previously done studies to determine how much dirt and biological material is kicked up and resuspended into the air when an adult walks indoors, but this is the first study to look at what happens with infants and their unique forms of locomotion.
As babies roll, slide and crawl on the floor, their movements stir up more particulates into the air, and their mouths and nostrils are much closer to the floor where the concentrations are greater.
To study just how much of the floor debris babies breathe, researchers built a robotic crawling baby and tested it crawling on actual carpet samples they had removed from homes. Then the researchers measured and analysed the particulates in the breathing zone.
"We used state-of-the-art aerosol instrumentation to track the biological particles floating in the air around the infant in real-time, second by second," Boor said.
"The instrument uses lasers to cause biological material to fluoresce. Most bacterial cells, fungal spores, and pollen particles are fluorescent, so they can be distinguished from non-biological material in the air," he said.
The researchers found that a concentrated cloud of resuspended particles forms around the robotic babies, and that the concentrations around them can be as much as 20 times greater than the levels of material higher in the room.
"For an adult, a significant portion of the biological particles are removed in the upper respiratory system, in the nostrils and throat," Boor said.
"But for very young children, they more often breathe through their mouths, and a significant fraction is deposited in the lower airways - the tracheobronchial and pulmonary regions. The particles make it to the deepest regions of their lungs," he said.
"Exposure to certain bacterial and fungal species can result in the development of asthma, but numerous studies have shown that when an infant is exposed to a very high diversity of microbes, at a high concentration, they can have a lower rate of asthma later in life," Boor said.
