Microbiology: Green Burials - Term Paper Example

My Prof. Loving BS-203 Microbiology 24 February 2007 Green Burials Green cemeteries are meant to be as natural and as ecologically- and environmentally-friendly as possible. The burials within green cemeteries, green burials, are intended to be a natural part of the ecological cycling of nutrients. As such, green burials do not use embalming fluid, steel vaults or airtight caskets (Austin 1); instead, the body is buried in a biodegradable wooden box or shroud (Valigra 1), and is meant to decompose and nourish the nearby trees. Many green burials also involve the planting of a new tree at the gravesite which can grow to become a living memorial or new natural environment. By avoiding many modern burial practices, green cemeteries avoid environmentally destructive practices. Green cemeteries avoid the use of large amounts of water, herbicides and pesticides used to maintain conventional cemetery grounds. Cremation, which uses energy and pollutes the air, is also usually avoided. Although cremation is sometimes used in burials that are referred to as green burials, such as in space burials and some underwater burials that mix a deceased persons ashes with concrete in a new artificial memorial reef. Although there is some discrepancy about what practices exactly can be included within a green burial, the idea is to leave the environment just as it was, or for ones body to become one with the surrounding environment. Green cemeteries are also called natural cemeteries, woodland cemeteries, or eco-cemeteries. In addition to providing more ecologically and environmentally sound burials, green cemeteries in the U.S. can also function as land restoration and preservation sites (Valigra 2). The modern origins of green cemeteries are the environmental and sustainability movements, as well as neo-paganism in some cases (“Eco-Cemeteries”), which are new religious movements that may have ancient indigenous roots. Although, green burials are reminiscent of simple American pioneer burials that took place in tall grass. Modern green cemeteries have only recently been built in the United States; as of 2005, four green cemeteries existed within the U.S. (Valigra 1). The oldest U.S. green cemetery is the Ramsey Creek Preserve in South Carolina, which was opened in the 1990s (CBC News). It is widely thought this type of burial has been common in England for a long time. However, the first modern eco-cemetery or woodland burial in the United Kingdom was Carlisle Cemetery, created in 1993 (“Eco-Cemeteries“). There were 80 green cemeteries in Great Britain by 1998 (Kaufman). Today there are about 200 natural burial sites in the UK (“Eco-Cemeteries”) and green burials have become a fast-growing movement within the UK. The concept has not caught on as widely in the U.S. This is commonly blamed on the death-care industry, which stands to profit from continual technological advancements in coffins and increasing funeral-related expenses. However, there are people and new organizations trying to change this situation, such as the Green Burial Council and the Commonweal Conservancy. These groups are trying to create conservation burial standards and eco-burial certification that will make it easier for consumers to judge the environmental soundness of their burial choices and the practices of the cemeteries they use. But besides for being ravaged by wild animals, what does green burial and natural decomposition entail for the human body? What processes enable the human body to become integrated into the environment during a green burial? These questions are answered by the science of decomposition of bodies, or taphonomy (“Decomposition“). Decomposition occurs in four stages: autolysis, when the chemicals and enzymes of the body break down tissues; putrefaction, when bacteria break down tissues and release gases that causes bloat; decay from carnivores and further putrefaction; and diagenesis, or dry decay. Autolysis occurs almost immediately after death. It begins when digestive enzymes leave the membranes of lysosomes. Cells then begin to self-digest. During autolysis, bacteria that already lived on the human body swell in numbers when liquid leaks from the ruptured cells broken down by enzymes. These increased numbers of bacteria set the stage for putrefaction to set in. In the process of putrefaction, proteins of the human body are decomposed, mainly by anaerobic microorganisms. Bacteria break down the body, rupture the intestine and other internal organs, and in the process produce gases. During putrefaction, odors are produced from amines such as putrescine and cadaverine, which result from the breakdown of proteins; other gases produced include hydrogen sulfide and ammonia. During putrefaction heterotrophic organisms such as bacteria break down “polysaccharides, lipids, nucleic acids, and proteins” (“Putrefaction”) of dead tissue into smaller organic molecules; bacteria often accomplish this by secreting enzymes. These smaller organic molecules that result are then absorbed by the bacteria and other heterotrophic organisms and used as an energy source or as building blocks to synthesize new polysaccharides, lipids, nucleic acids and proteins. Nitrogen is released during putrefaction, which can be used by nearby plants. This is the same concept as the use of nitrogen-releasing fertilizer made of decomposing organic matter that is placed on new plants. The diagenesis stage of decomposition includes changes made to the skeletal remains of the body, which is the only part of the body left at this last stage of decomposition. The organic content of bone is mainly protein collagen; the rest of bone is made of minerals, mainly calcium phosphate ("Diagenesis"). Diagenesis occurs by chemical deterioration of the bones organic and mineral content and by biological and microbiological attack on the bone. Low pH causes the loss of minerals in the bone; this allows microbes enzymes to reach the bone collagen and microbiological attack begins. What are the microorganisms involved in the decay of the human body? In the early stages of decomposition, many types of bacteria are involved, such as: Staphylococcus, Candida, Malasseria, Bacillus, and Streptococcus (Vass 191) . These are mainly bacteria which are ubiquitous in nature as well as being part of the natural flora of the human body, especially the intestines. The next stage of decomposition involves putrefactive bacteria, such as Clostridium, which is an anaerobe that produces hydrogen, but is incapable of completely decomposing organic matter (photosynthetic bacteria are capable). Clostridium is found both in the intestinal tract and skin of humans and in the soil worldwide. Clostridia ferment organic compounds and produce “butyric acid, acetic acid, butanol, acetone and large amounts of carbon dioxide and hydorgen gas” (Hammond). Clostridia contain the most different types of enzymes of any bacteria known, making it very effective in the breakdown of organic molecules. Other anaerobes quickly follow the putrefactive bacteria in the decomposition process, including: micrococci, coliforms, and diptheroids. Other organisms that are present in large amounts during decomposition include: Serratia spp., Klebsialla spp., Salmonella sp., the gliding bacteria Cytophaga, pseudomonads and flavobacteria. There are environmental microorganisms such as Agrobacterium, amoebae and colorful fungi varieties. Flies and other insects bring more microorganisms to the decomposing mix. Another putrefactive bacteria is the Proteus species, such as Proteus vulgaris and Proteus mirabilis. Proteus bacteria mainly live in the soil, and are common in decomposition (Deacon). They are also found in the human intestinal tract. Proteus is known to be highly motile, with the ability to swarm. Proteus is able to degrade urea to ammonia, through its urease activity. Proteus bacteria produce large amounts of the urease enzyme. Urease in turn hydrolyzes urea into ammonia. Proteus can also produce hydrogen sulfide gas. The ammonia products produced by Proteus are then used by other bacteria that can oxidize ammonia. Bacteria involved in decomposition of human bodies are heterotrophic, which means they break molecules down by respiration (aerobic bacteria) or fermentation (anaerobic bacteria). One of the main roles bacteria play during decomposition is the “recycling of carbon, nitrogen and sulphur” (“Corpse Fauna”) so they can be used again by plants. An example of a heterotrophic bacteria is Bacillus, which decomposes proteins in the human body. In the process, ammonia is released. Other bacteria oxidize the ammonia and turn it into nitrogen dioxide, and then into nitrate which can be used by plants. This process of turning ammonia into nitrates is called nitrification. Two different kinds of bacteria are involved (“Nitrification”): ammonia-oxidizing bacteria, which are the Nitrosomonoas species of bacteria, turn the ammonia into nitrite; and then nitrite-oxidizing bacteria, which are the Nitrobacter bacteria species, turn the nitrite into nitrate. Both of these bacteria species catalyze reactions that release energy the bacteria species utilize to build bacterial cell mass. The Nitrosomonoas sp. catalyze the reaction which takes ammonia, oxygen and hydrogen carbonate as inputs and outputs bacterial cell mass, nitrite, water and carbonic acid. The Nitrobacter sp. catalyze the reaction which takes nitrites, more ammonia, carbonic acid, hydrogen carbonate and oxygen as inputs and outputs bacterial cell mass, water and large amounts of nitrate. An example of an ammonia-oxidizing bacterium is Nitrosomonas europaea (Beaumont). Besides for catalyzing the oxidation of ammonia and producing nitrites, N.europea is also able to break down environmental pollutants such as benzene, vinyl chloride, and trichloroethylene. N.europea’s presence can be beneficial in multiple ways, performing a vital link in decay and the nitrogen cycle as well as potentially bioremediating environments. Besides for varying environmental conditions that can alter the speed or effectiveness of decomposition of a human body, there are decomposition processes that slow or halt the rest of the decomposition itself. Putrefactive bacteria can be inhibited, and decomposition thereby partly prevented, by the formation of a waxy substance called adipocere, in a process called saponification. Adipocere is caused by chemicals in the soil acting on the fats and proteins of the body through the process of hydrolysis. In some cases adipocere can completely cover a body and halt any further decomposing. In addition to the bacterial decomposition that occurs almost immediately after death, there are other processes that continue to integrate the human body into the environment. Within a year, algae or moss may grow on the bones (Vass 191). Within a decade, roots will grow into the bone and there will be rodent gnawing. Depending on the temperature, humidity, and other factors of the environment, the human body may be completely decomposed within that time, or atleast completely skeletonized, if a green burial or natural burial took place. In my opinion green cemeteries are wonderful for the environment but I would prefer my family and I to be as preserved as possible so that tissues can remain for possible future genealogical, historical or biological research on them. I would hope that my ancestors are as well preserved as possible so that tests could establish a link between them and our family now. I would also assume that atleast some of my distant descendants would feel the same way, and will want to be able to test the remains of my currently living family and I. I feel this way especially in light of the recent DNA advances that can establish whether two individuals are related. In the future, even more technological advances may be possible, that can use well preserved tissues. I would favor a burial that preserves the body without polluting or disturbing the surrounding land but I am against the restriction (of some green cemeteries) of monuments and tombstones to the dead, which play an important function in remembering the people of history. Societies such as Egypt have tried to preserve people as best they could, and there is a profound psychological attachment to this process for many people and cultures. Just as in Jurassic Park, when they isolated DNA from ancient amber, the preservation of the material of life, especially the DNA within body tissues, even in death may prove useful in the future. Works Cited Austin, Liz. Funerals Go Green. The Washington Times. Jan 23, 2004. News World Communications, Inc. Retrieved February 24, 2007, from http://washingtontimes.com/culture/20040122-102025-7753r.htm. Beaumont, Bertus. Nitrification. Retrieved February 24, 2007, from http://www.bio.vu.nl/vakgroepen/mcp/spanning/tab3/nitrification.htm#Anchor-41650 CBC News. Green Burials Offer Environmentally Conscious Alternative. The Associated Press. August 25, 2006. Retrieved February 24, 2007, from http://www.cbc.ca/news/story/2006/08/25/green-burials.html “Corpse Fauna: Bacteria.” Decomposition: What Happens to the Body After Death? Australian Museum. Retrieved February 24, 2007, from http://www.deathonline.net/decomposition/corpse_fauna/bacteria.htm. Deacon, Jim. The Microbial World: Proteus vulgaris and clinical diagnostics. Institute of Cell and Molecular Biology, The University of Edinburgh. Retrieved February 24, 2007, from http://helios.bto.ed.ac.uk/bto/microbes/proteus.htm. “Decomposition.” Wikipedia. February 22, 2007. Wikimedia Foundation, Inc. Retrieved February 24, 2007, from http://en.wikipedia.org/wiki/Bacterial_decay. “Diagenesis.” Wikipedia. February 6, 2007. Wikimedia Foundation, Inc. Retrieved February 25, 2007, from http://en.wikipedia.org/wiki/Diagenesis. “Eco-Cemetery.“ Wikipedia. February 22, 2007. Wikimedia Foundation, Inc. Retrieved February 25, 2007, from http://en.wikipedia.org/wiki/Eco-cemetery. Hammond, Sarah. Clostridium: Soil Microbiology. Retrieved February 25, 2007, from http://filebox.vt.edu/users/chagedor/biol_4684/Microbes/clost.html Kaufman, Martin. Dust to Dust? Green Burial in Great Britain. Emagazine.com. Nov 1998. Retrieved February 24, 2007, from http://209.85.165.104/search?q=cache:xucI7OBWRcoJ:www.emagazine.com/november- december_1998/1198curr_burial.html+%22green+burial%22+england&hl=en&ct=clnk& cd=1&gl=us “Nitrification: at the Heart of Filtration.” FishDoc: The Home of Fish Health. Retrieved February 25, 2007, from http://www.fishdoc.co.uk/filtration/nitrification.htm. “Putrefaction.” Answers.com. Retrieved February 24, 2007, from http://www.answers.com/topic/putrefaction#copyright. Vaas, Arpad A. Beyond the Grave - Understanding Human Decomposition. Microbiology Today. Vol. 28, Nov 01, p.190-192. Retrieved February 24, 2007, from https://www.socgenmicrobiol.org.uk/pubs/micro_today/pdf/110108.pdf. Valigra, Lori. Green Burials Offer Unique, Less Costly Goodbyes. September 9, 2005. National Geographic News. Retrieved February 24, 2007, from http://news.nationalgeographic.com/news/2005/09/0909_050909_greenburial.html Weaver, Michael. Re: What Happens to the Human Body After We Die? MadSci Network: General Biology. April 25, 2005. Retrieved February 25, 2007, from http://www.madsci.org/posts/archives/2005-04/1114460899.Gb.r.html Read More