London (TIP)- As nightmares go, being trapped in a small box deep underwater is probably high on many peoples’ lists. But one US professor is doing this on purpose. Joe Dituri, a former US navy diver and expert in biomedical engineering has been living in a 55 square meter space 30 feet below the surface of the Florida Keys since March 1, and plans to stay for 100 days. If he manages this, he will break a record for most time spent in a habitat beneath the surface of the ocean. Dituri conducts research into the effects of hyperbaric pressure – when air pressure is greater than it would be at sea level – on the human body. He is hoping to use his time spent below the surface to examine what impact living in this high-pressure environment has on his health. Interestingly, Dituri’s endeavour will be very different from living on a submarine. Submarines are sealed when submerged and maintained at sea level pressure. This means there’s no significant difference in pressure, even when a submarine is at depths of hundreds of meters. But Dituri’s underwater habitat won’t have any solid hatches or air locks between the ocean and the dry living space, as a submarine does. Think of it like when a glass of water is turned upside down and pushed into a sink full of water. A pocket of air will still exist at the top of Dituri’s living space, with a pool of water in the floor of one room that comes from the ocean outside. This means that the air inside his habitat is squeezed by the ocean’s weight, increasing the air pressure around him. At a depth of 30 feet, the air pressure inside this habitat is about twice as much as what he’d be used to on land.

Under pressure

Little research has investigated what effect long-term exposure to hyperbaric pressure has on the body. As every certified diver is well aware, though, hyperbaric pressure can pose a very real threat to us. Our bodies have been adapted by generations of evolution for sea level conditions, where the two major gases involved in breathing (oxygen and carbon dioxide) are the only two that freely cross between our lungs and our blood. But as pressure increases, nitrogen in the air is forced across the delicate walls of our lungs and into our blood. This can cause a range of adverse effects. At depths of ten to 30 meters, this may cause mild euphoria and positive moods. After about 30 meters below sea level and beyond, it can lead to intoxicated-like behaviour – hence the name “narcosis”. Scientists don’t fully understand why this happens, but it could be due to changes in the way neurotransmitters signal between neurons in our brain. Fortunately, this won’t be a risk to Dituri, as he’s only at a depth of ten meters.

Health changes

But Dituri can expect to experience other physical changes while living in his underwater habitat. Although the habitat has large windows, Dituri will still only be exposed to half the amount of sunlight as on land. This could cause issues with his circadian rhythm – the internal “clock” that controls many body functions, including our sleep-wake cycle – which relies on daylight. This may mean disrupted sleeping. Another challenge for Dituri will be getting enough vitamin D. The skin must receive UV exposure to make this vitamin, and this typically comes from the sun. It’s likely that Dituri will not be exposed to enough vitamin D while living in his underwater environment.

Source: IANS