A new study revealed that a baby crawling on the floor can inhale into their lungs dirt that is four times as much as what adults would when walking across the same floor.

The Infant and Adult Inhalation research led by Purdue University assistant engineering professor Brandon Boor showed that babies collect and inhale millions of microscopic bits or bio-gunk as they crawl on the floor. Among these bio-gunk are dirt, skin cells, bacteria, pollen, and fungal spores.

Babies stir a massive amount of bio-gunk as much as 20 times than a volume normally seen when they crawl, roll, wobble, and drool on the floor.

When babies crawl on the floor, their nostrils and mouths are much closer to the floor where dirt and microbes are more concentrated.

Using a 'creepy' legless robot baby wrapped in aluminum foil, enough to make many cringe, the study was conducted to determine if early exposure to microbes and allergen-carrying particles can protect the baby from asthma and allergies later in life.

"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," says Boor.

Robot Baby Crawling Experiment 

Boor's team created a legless robotic baby wrapped in aluminum foil that mimicked the crawling movement of an infant across a section of a used carpet that was taken from a real home.

During the experiment, the researchers used a laser instrument to classify what kinds of particles are floating around the robotic baby.  

A human adult volunteer was also made to walk on the same carpet.

Biological materials like bacterial cells, fungal spores, and pollen particles became fluorescent when beamed with the special laser instrument. The process allowed the researchers to determine the biological and non-biological materials.

Hygiene Hypotheses

There were two sides to the research. First was to show parents that carpets and floors are indeed dirty and babies crawling on the floor are highly exposed to microbes and allergens as they cross across the carpet. The second objective of Boor's study was to prove that exposure to such bio-gunk has adverse and protective effects.

Previous studies like the hygiene hypotheses indicate that children kept in an immaculately clean environment are most susceptible to hay fever, asthma, and other conditions. This finding that was first introduced by epidemiology expert David Strachan suggested that exposure to unclean conditions can have positive results for a child's immune system.   

The study was published in the journal Environmental Science & Technology.