Picking your nose. Whether you're in the trusted company of your spouse, or sneaking a quick one when you think nobody's looking, we all pick our noses. Other primates do it too. The social stigma around nose picking is widespread. But should we really be doing it – and what should we do with our boogers? IU Earth Sciences Professor Gabriel Filippelli, along with colleagues at the Environment Protection Authority and Macquarie University in Australia, are scientists who've researched the environmental contaminants often found in our everyday lives. They recently shared insights on what you're really jamming up your nose when you pick it. The researchers say nose picking is an entirely natural habit -- children who have not yet learned social norms realize very early on that the fit between their forefinger and a nostril is pretty good. But there's lot more than just snot up there. During the approximately 22,000 breath cycles per day, the booger-forming mucus up your nasal passage forms a critical biological filter to capture dust and allergens before they penetrate our airways, where they may cause inflammation, asthma, and other long-term pulmonary issues. Cells in your nasal passage called goblet cells, which are named after their cup-like appearance, generate mucus to trap viruses, bacteria and dust containing potentially harmful substances like lead, asbestos and pollen. Nasal mucus and its antibodies and enzymes are the body's front line immune defense system against infections. The nasal cavity also has its own microbiome. Sometimes these natural populations can be disturbed, leading to various conditions such as rhinitis. But in general, our nose microbes help repel invaders, fighting them on a mucus battlefield. The dust, microbes and allergens captured in your mucus eventually get ingested as that mucus drips down your throat. This is typically not an issue, but it can exacerbate environmental exposure to some contaminants. For instance, lead, which is a neurotoxin prevalent in house dust and garden soils, enters children’s bodies most efficiently through ingestion and digestion. So, you may worsen particular environmental toxic exposures if you sniff or eat boogers up instead of blowing them out. However, sticking a finger up your nose can jam germs further into your body, or spread them around your environment with your snotty finger. Studies show that Golden Staph, a germ that can cause a variety of mild to severe infections, is often found in the nose (this is called nasal carriage). Nose picking may also be associated with an increased risk of Golden Staph transmission to wounds, where it poses a more serious risk, or as a vehicle for transmission of Streptococcus pneumoniae, a common cause of pneumonia among other infections. There's also the risk of gouging and abrasions inside the nostrils, which can allow pathogenic bacteria to invade your body. So what should you do the next time you feel the urge to pick your nose? The researchers suggest honoring the tireless labor done by our remarkable noses, mucus and sinus cavities and remember they're trying hard to protect you. Don't make their jobs harder by jamming your fingers up your nose – blow discreetly with a tissue, dispose of the tissue thoughtfully, and wash your hands afterwards.