Sleep -- benefits and value
The relationship of fatigue to industrial disasters such as the 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster, the Chernobyl nuclear accident, the Three Mile Island nuclear power plant disaster and the Bhopal India chemical disaster


[http://abc.net.au/science/sleep/facts.htm; 2006.12]
Science Week 2000::The National Sleep Research Project
(re-ordered in this webpage to emphasize dangers of sleep-deprivation, late night work; factors that make it hard to sleep)

- The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role.
[also Three Mile Island nuclear disaster and Bhopal India industrial chemical disaster; see below]

- The NRMA estimates fatigue is involved in one in 6 fatal road accidents.

- Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. Unfamiliar noise, and noise during the first and last two hours of sleep, has the greatest disruptive effect on the sleep cycle.


Tiny luminous rays from a digital alarm clock can be enough to disrupt the sleep cycle even if you do not fully wake. The light turns off a "neural switch" in the brain, causing levels of a key sleep chemical to decline within minutes.


- To drop off we must cool off; body temperature and the brain's sleep-wake cycle are closely linked. That's why hot summer nights can cause a restless sleep. The blood flow mechanism that transfers core body heat to the skin works best between 18 and 30 degrees. But later in life, the comfort zone shrinks to between 23 and 25 degrees - one reason why older people have more sleep disorders.



- Some studies suggest women need up to an hour's extra sleep a night compared to men, and not getting it may be one reason women are much more susceptible to depression than men.

- Experts say one of the most alluring sleep distractions is the 24-hour accessibility of the internet.

- The extra-hour of sleep received when clocks are put back at the start of daylight in Canada has been found to coincide with a fall in the number of road accidents.

-The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses.

- It's impossible to tell if someone is really awake without close medical supervision. People can take cat naps with their eyes open without even being aware of it.

- Anything less than five minutes to fall asleep at night means you're sleep deprived. The ideal is between 10 and 15 minutes, meaning you're still tired enough to sleep deeply, but not so exhausted you feel sleepy by day.

- A new baby typically results in 400-750 hours lost sleep for parents in the first year

- One of the best predictors of insomnia later in life is the development of bad habits from having sleep disturbed by young children.

- The continuous brain recordings that led to the discovery of REM (rapid eye-movement) sleep were not done until 1953, partly because the scientists involved were concerned about wasting paper.

- REM sleep occurs in bursts totalling about 2 hours a night, usually beginning about 90 minutes after falling asleep.

- Dreams, once thought to occur only during REM sleep, also occur (but to a lesser extent) in non-REM sleep phases. It's possible there may not be a single moment of our sleep when we are actually dreamless.

- REM dreams are characterised by bizarre plots, but non-REM dreams are repetitive and thought-like, with little imagery - obsessively returning to a suspicion you left your mobile phone somewhere, for example.

- Certain types of eye movements during REM sleep correspond to specific movements in dreams, suggesting at least part of the dreaming process is analagous to watching a film

- No-one knows for sure if other species dream but some do have sleep cycles similar to humans.

- Elephants sleep standing up during non-REM sleep, but lie down for REM sleep.

- Some scientists believe we dream to fix experiences in long-term memory, that is, we dream about things worth remembering. Others reckon we dream about things worth forgetting - to eliminate overlapping memories that would otherwise clog up our brains.

- Dreams may not serve any purpose at all but be merely a meaningless byproduct of two evolutionary adaptations - sleep and consciousness.

- REM sleep may help developing brains mature. Premature babies have 75 per cent REM sleep, 10 per cent more than full-term bubs. Similarly, a newborn kitten puppy rat or hampster experiences only REM sleep, while a newborn guinea pig (which is much more developed at birth) has almost no REM sleep at all.

- Scientists have not been able to explain a 1998 study showing a bright light shone on the backs of human knees can reset the brain's sleep-wake clock.

- British Ministry of Defence researchers have been able to reset soldiers' body clocks so they can go without sleep for up to 36 hrs. Tiny optical fibres embedded in special spectacles project a ring of bright white light (with a spectrum identical to a sunrise) around the edge of soldiers' retinas, fooling them into thinking they have just woken up. The system was first used on US pilots during the bombing of Kosovo.

- Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%.

- The "natural alarm clock" which enables some people to wake up more or less when they want to is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up.

- Some sleeping tablets, such as barbiturates suppress REM sleep, which can be harmful over a long period.

- In insomnia following bereavement, sleeping pills can disrupt grieving.

- A night on the grog will help you get to sleep but it will be a light slumber and you won't dream much.

- After five nights of partial sleep deprivation, three drinks will have the same effect on your body as six would when you've slept enough.

- Humans sleep on average around three hours less than other primates like chimps, rhesus monkeys, squirrel monkeys and baboons, all of whom sleep for 10 hours.

- Ducks at risk of attack by predators are able to balance the need for sleep and survival, keeping one half of the brain awake while the other slips into sleep mode.

- Ten per cent of snorers have sleep apnoea, a disorder which causes sufferers to stop breathing up to 300 times a night and significantly increases the risk of suffering a heart attack or stroke.

- Snoring occurs only in non-REM sleep

- Teenagers need as much sleep as small children (about 10 hrs) while those over 65 need the least of all (about six hours). For the average adult aged 25-55, eight hours is considered optimal

- Feeling tired can feel normal after a short time. Those deliberately deprived of sleep for research initially noticed greatly the effects on their alertness, mood and physical performance, but the awareness dropped off after the first few days.

- Diaries from the pre-electric-light-globe Victorian era show adults slept nine to 10 hours a night with periods of rest changing with the seasons in line with sunrise and sunsets.

- Most of what we know about sleep we've learned in the past 25 years.

- As a group, 18 to 24 year-olds deprived of sleep suffer more from impaired performance than older adults.


ABC Science Online
© Australian Broadcasting Corporation 2000


Other references to dangers of sleep deprivation and late-night work:

The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role.

Three Mile Island nuclear accident/near-meltdown [and sleep-deprivation] See http://www.cnn.com/TECH/computing/9904/09/sleep.ent.idg/index.html


April 9, 1999
Web posted at: 5:19 p.m. EDT (2119 GMT)

by Mel Mandell
Network World Fusion
(IDG) -- The early morning nuclear disasters at Chernobyl and Three Mile Island prove that sleep deprivation is a serious problem, but it's not one that network executives care to openly discuss. "We're all sleep deprived," admits one network manager who doesn't want to be named. Is exhaustion the great veiled headache in round-the-clock network operations? Large organizations contacted for this article deny the problem, claim night-shift employees prefer those hours, or don't want to talk about the issue.

Yet compared with their better-rested counterparts, tired workers are more irritable and prone to stomachaches, more likely not to report to work -- or to quit without warning -- and more accident prone, according to medical researchers. Sleep-deprived workers are also more likely to make mistakes that could bring down your network.
The three types of network professionals who are likely to suffer job-related sleep deprivation are night-shift network operators, technicians who put in lots of overtime to cope with emergencies, and jet-lagged net executives who travel through several time zones."

Bhopal Union Carbide industrial disaster in India 1984


"The leak was first detected by workers about 11:30p.m. when their eyes began to tear and burn. They informed their supervisor who failed to take action until it was too late. [http://www.american.edu/ted/bhopal.htm]
http://www.icmr.icfai.org/casestudies/catalogue/Business%20Ethics/BECG009.htm

The Bhopal Gas Tragedy

Abstract
The case gives an overview of the Bhopal gas tragedy. On December 3, 1984, poisonous gas leaked from Union Carbide India Limited (UCIL's) pesticide plant in Bhopal, which killed thousands of people. The case brings out the ethical issues involved in the disaster. It discusses in detail the reasons behind the disaster. The case discusses the role played by Union Carbide Corporation after the disaster, which seemed to be unethical. It also talks about the role of the GOI and Madhya Pradesh government in the disaster. The case is intended for MBA/PGDBM level students as a part of the Business Ethics Curriculum. From the case, students are expected to understand the ethical issues involved in the Bhopal gas tragedy and the role played by the governments in the disaster. With the help of the Theory of Image Restoration, students are expected to understand how Union Carbide responded to the situation. They should also analyze how Union Carbide should have responded to the Bhopal gas tragedy.
"The numerous safety systems with which this type of plant is equipped enable us to control any of the MIC's potentially dangerous reactions."
- A Union Carbide official commenting on the safety systems in the Bhopal pesticide plant. "It's not a deadly gas, just irritating, a sort of tear gas."

- Dr Loya, Union Carbide's official doctor in Bhopal, commenting on Methyl Isocyanate, after the tragedy.
INTRODUCTION

In the early morning hours of December 3, 1984, a poisonous grey cloud (forty tons of toxic gases) from Union Carbide India Limited (UCIL's) pesticide plant at Bhopal spread throughout the city. Water carrying catalytic material had entered Methyl Isocyanate (MIC) storage tank No. 610.

What followed was a nightmare. The killer gas spread through the city, sending residents scurrying through the dark streets. No alarm ever sounded a warning and no evacuation plan was prepared. When victims arrived at hospitals breathless and blind, doctors did not know how to treat them, as UCIL had not provided emergency information.

It was only when the sun rose the next morning that the magnitude of the devastation was clear. Dead bodies of humans and animals blocked the streets, leaves turned black, the smell of burning chilli peppers lingered in the air. Estimates suggested that as many as 10,000 may have died immediately and 30,000 to 50,000 were too ill to ever return to their jobs.

The catastrophe raised some serious ethical issues. The pesticide factory was built in the midst of densely populated settlements. UCIL chose to store and produce MIC, one of the most deadly chemicals (permitted exposure levels in USA and Britain are 0.02 parts per million), in an area where nearly 120,000 people lived.

The MIC plant was not designed to handle a runaway reaction. When the uncontrolled reaction started, MIC was flowing through the scrubber (meant to neutralize MIC emissions) at more than 200 times its designed capacity. MIC in the tank was filled to 87% of its capacity while the maximum permissible was 50%. MIC was not stored at zero degree centigrade as prescribed and the refrigeration and cooling systems had been shut down five months before the disaster, as part of UCC's global economy drive. Vital gauges and indicators in the MIC tank were defective. The flare tower meant to burn off MIC emissions was under repair at the time of the disaster and the scrubber contained no caustic soda.

As part of UCC's drive to cut costs, the work force in the Bhopal factory was brought down by half from 1980 to 1984. This had serious consequences on safety and maintenance. The size of the work crew for the MIC plant was cut in half from twelve to six workers. The maintenance supervisor position had been eliminated and there was no maintenance supervisor. The period of safety-training to workers in the MIC plant was brought down from 6 months to 15 days. Last modified Sun May 25 00:10:16 PDT 2008