August 6th 1945: Hiroshima bombed
On this day in 1945, the first nuclear attack in history occurred when the United States dropped an atomic bomb on the Japanese city of Hiroshima. The American plane Enola Gay dropped the bomb called ‘Little Boy’, which killed around 70,000 people instantly. The effects of the radiation killed thousands more in later years, resulting in a catastrophic death toll of around 140,000 people. Three days later the ‘Fat Man’ bomb was dropped on Nagasaki, resulting in the loss of around 75,000 lives; in both cases, the majority of casualties were civilian. Whilst other Axis powers including Nazi Germany had already surrendered earlier that year, ending the war in the European theatre, Japan had continued to fight the Allied forces. The bombings were therefore deemed necessary by the United States to end the war and avoid a costly invasion of Japan. In the aftermath of the devastating attacks, Japan surrendered to the Allies on 15th August, thus ending the war in the Pacific theatre of World War Two. Today, 69 years on, the atomic-bomb scarred cities of Hiroshima and Nagasaki provide a sharp reminder of the horrors of nuclear warfare.
"My God, what have we done?"
- Enola Gay’s co-pilot Robert Lewis upon seeing the impact
In an extensive study of sleep monitoring and sleeping pill use in astronauts, researchers from Brigham and Women’s Hospital (BWH) Division of Sleep and Circadian Disorders, Harvard Medical School, and the University of Colorado found that astronauts suffer considerable sleep deficiency in the weeks leading up to and during space flight. The research also highlights widespread use of sleeping medication use among astronauts.
The study, published in The Lancet Neurology on August 8, 2014, recorded more than 4,000 nights of sleep on Earth, and more than 4,200 nights in space using data from 64 astronauts on 80 Shuttle missions and 21 astronauts aboard International Space Station (ISS) missions. The 10-year study is the largest study of sleep during space flight ever conducted. The study concludes that more effective countermeasures to promote sleep during space flight are needed in order to optimize human performance.
"Sleep deficiency is pervasive among crew members," stated Laura K. Barger, PhD, associate physiologist in the BWH Division of Sleep and Circadian Disorders, and lead study author. "It’s clear that more effective measures are needed to promote adequate sleep in crew members, both during training and space flight, as sleep deficiency has been associated with performance decrements in numerous laboratory and field-based studies."
Despite NASA scheduling 8.5 hours of sleep per night for crew members in space flight, the average (mean) duration of sleep during space flight was just under six (5.96) hours on shuttle missions, and just over six hours (6.09) on ISS missions. Twelve percent of sleep episodes on shuttle missions and 24 percent on ISS missions lasted seven hours or more, as compared to 42 percent and 50 percent, respectively, in a post-flight data collection interval when most astronauts slept at home.
Moreover, the results suggest that astronauts’ build-up of sleep deficiency began long before launch, as they averaged less than 6.5 hours sleep per night during the training interval occurring approximately three months prior to space flight.
The research also highlights widespread use of sleeping medications such as zolpidem and zaleplon during space flight. Three-quarters of ISS crew members reported taking sleep medication at some point during their time on the space station, and more than three-quarters (78 percent) of shuttle-mission crew members used medication on more than half (52 percent) of nights in space.
"The ability for a crew member to optimally perform if awakened from sleep by an emergency alarm may be jeopardized by the use of sleep-promoting pharmaceuticals," said Barger. "Routine use of such medications by crew members operating spacecraft are of particular concern, given the U. S. Federal Drug Administration (FDA) warning that patients using sleeping pills should be cautioned against engaging in hazardous occupations requiring complete mental alertness or motor coordination, including potential impairment of performance of such activities that may occur the day following ingestion of sedative/hypnotics. This consideration is especially important because all crew members on a given mission may be under the influence of a sleep promoting medication at the same time."
Charles Czeisler, PhD, MD, FRCP, chief, BWH Division of Sleep and Circadian Disorders, and senior study author, adds: “Future exploration spaceflight missions to the moon, Mars or beyond will require development of more effective countermeasures to promote sleep during spaceflight in order to optimize human performance. These measures may include scheduling modifications, strategically timed exposure to specific wavelengths of light, and behavioral strategies to ensure adequate sleep, which is essential for maintaining health, performance and safety.”