By: Rosemary Stephen PMed, (cert) EOH, IPM, Elements: Environmental Health Intelligence
When watching news clips from Haiti about people who were rescued from the rubble, one person, Wismond Exantus, stood out in my mind. He is a 24 year old man who was stuck inside Hotel Napoli’s grocery store and who survived on cookies, beer and cola. Wismond was finally freed after spending 11 days under the rubble. When asked about what he did while he was under the debris, Mr. Exantus answered that he occupied himself by praying, reciting psalms and sleeping [1]. He mentioned that soon after the tremors, he lost consciousness [2]. When he was finally freed, and told how long he had been under the rubble, he could not believe that he had been buried so long; in his mind only five to six days had passed [3]. Why is that?
Each person is equipped with their own set of biological clocks. One of these clocks, called the circadian rhythm, is described as “ physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment” [4]. Change in circadian rhythms will affect our sleep-wake pattern, our hormone release, our body temperature and other body functions [5]. When light hits the retina and the body temperature falls to its lowest level (around 5 am) or when the level of melatonin [1F], an hormone secreted by the pineal gland, decreases (usually between 6 to 8 am or 6 to 9 am) people wake up [6]. Research was done at Harvard University in the late 1990s on human circadian rhythms. Charles A. Czeisler, professor of medicine at the Harvard Medical School, and his colleagues discovered that regardless of age and sex of the subjects (young or old, male or female), we humans have a daily circadian rhythm that is 24 hours and 11 minutes long (when it is not disrupted) [7].
External clues such has daylight reaching about 1,000 Lux (roughly 100 foot candles) or a light source falling on the lower area of the retina where the image of the sky is formed, puts our circadian rhythm in a wake-up mode [8,9]; the light triggers the circadian system to respond, slowly decreasing the secretion of melatonin, an hormone that naturally sustains sleep. Some researchers have discovered that, if light enters the eyes from below the circadian rhythm is not affected, but if the light comes from above, the circadian rhythm will respond and start the reduction of melatonin [10, 11]. In the case of Wismond,the lack of light allowed the continued secretion of melatonin [12], shifting his biological rhythm to longer sleep episodes [13]. It is possible that Wismond, and other people trapped in similar situations with no light stimulus at all, actually have a better chance at survival due to this sleep response. They do not know how much time is passing and they sleep for longer periods thereby conserving energy and protecting the body.
Do these lucky survivors now look forward to a life long disruption of their cicardian rhythm? Surprisingly, there are no side effects in healthy people; their biological clock will reset in a matter of a few days to a week as soon as they are exposed to the stimulating affects of daylight [14].
Up Date
Darlene Etienne, age 16, was rescued after being trapped for 15 days under the rubble. She had access to bath water and also to Coca-Cola [15]. Is it possible that the same phenomenon also helped Darlene ?
Rosemary Stephen PMed, (cert) EOH, IPM (2010). Circadian Rhythm changes in Haitian survivor Elements: Environmental Health Intelligence
References:
[1] Man pulled out alive 14 days after Haiti quake (2010) World News, MSNBC. (On-line) Available: http://www.msnbc.msn.com/id/35086799/ns/world_news-haiti_earthquake/?gt1=43001. Cited 2010 Jan 27
[2] Burried for 11 days, man survived on Coke and snacks (2010) (On-line) Available: http://www.smh.com.au/world/buried-for-11-days-man-survived-on-coke-and-snacks-20100124-ms3z.html. Cited 2010 Jan 27.
[3] Acharya, D. Man Rescued From Rubble After 11 Days (2010) Headlines News and programs, DCnepal. (On-line) Available: http://www.dcnepal.net/news.php?nid=13194. Cited 2010 Jan 28.
[4] Circadian Rhythms Fact Sheet (2008) National institute of General Medical Sciences. (On-line) Available: http://www.nigms.nih.gov/Publications/Factsheet_CircadianRhythms.htm. Cited 2010 Jan 26.
[5] Circadian Rhythms Fact Sheet (2008) National institute of General Medical Sciences. (On-line) Available: http://www.nigms.nih.gov/Publications/Factsheet_CircadianRhythms.htm. Cited 2010 Jan 26.
[6] Simeonova, M. Healthy Lighting, from a lighting designer’s perspective (2003) Enlighter Magazine (On-Line) Available: http://www.enlightermagazine.com/images/2009/01/healthyLighting.pdf. Cited 2010 Jan 27.
[7] Cromie, J.W. Human Biological Clock Set Back an Hour(1999) Harvard Gazette Archives, The Harvard University Gazette. (On-line) Available: http://news.harvard.edu/gazette/1999/07.15/bioclock24.html. Cited 2010 Jan 27.
[8] Circadian Rhythms Fact Sheet (2008) National institute of General Medical Sciences. (On-line) Available: http://www.nigms.nih.gov/Publications/Factsheet_CircadianRhythms.htm. Cited 2010 Jan 26.
[9] Circadian Rhythm (2010) Wikipedia the free encyclopedia. (On-line) Available: http://en.wikipedia.org/wiki/Circadian_rhythm. Cited 2010 Jan 27.
[10] Simeonova, M. Healthy Lighting, from a lighting designer’s perspective (2003) Enlighter Magazine (On-Line) Available: http://www.enlightermagazine.com/images/2009/01/healthyLighting.pdf. Cited 2010 Jan 27.
[11] Circadian Rhythm (2010) Wikipedia the free encyclopedia. (On-line) Available: http://en.wikipedia.org/wiki/Circadian_rhythm. Cited 2010 Jan 27.
[12] Melatonin (2010) University of Maryland Medical Center. (Onm-line) Available: http://www.umm.edu/altmed/articles/melatonin-000315.htm. Cited 2010 Jan 28.
[13] Circadian Rhythms Fact Sheet (2008) National institute of General Medical Sciences. (On-line) Available: http://www.nigms.nih.gov/Publications/Factsheet_CircadianRhythms.htm. Cited 2010 Jan 26.
[14] Cromie, J.W. Human Biological Clock Set Back an Hour(1999) Harvard Gazette Archives, The Harvard University Gazette. (On-line) Available: http://news.harvard.edu/gazette/1999/07.15/bioclock24.html. Cited 2010 Jan 27.
[15] Williams, D. Teenage Girl who survived on just bath water is pulled alive from Haiti Rubble after FIFTEEN DAYS (2010) Mail Online. (On-line) Available: http://www.dailymail.co.uk/news/worldnews/article-1246652/Haiti-earthquake-disaster-Teenage-girl-pulled-alive-Port-au-Prince-rubble.html. Cited 2010 Jan 29.
Endnotes
[1F] Melatonin is an hormone that helps regulate sleep. It is made from an amino acid called tryptophan. When stimulated by light, the eye will relay a message to a cluster of nerves located in the brain just above the optic nerve. These nerves, called the suprachiasmatic nucleus (SCN), set our internal body clock and control our circadian rhythms. The SCN determines human sleep patterns by regulating the amount of melatonin secreted [1F, 2F].
References to Endnotes
[1F] Wong, C., What is melatonin? (2007) About.com. (On-line) Available: http://altmedicine.about.com/od/melatonin/a/melatonin.htm. Cited 2010 Jan 27.
[2F] Circadian Rhythms Fact Sheet (2008) National institute of General Medical Sciences. (On-line) Available: http://www.nigms.nih.gov/Publications/Factsheet_CircadianRhythms.htm. Cited 2010 Jan 26.
