Thermoregulatory aspects of adipose tissue 

                                                                              Eric LaMont Gregory MSC Oxon

Abstract
Two important functions of adipose tissue have been discussed earlier in this work, ie, white fat tissue storage of fatty acids and brown fat tissue use of fatty acids for energy purposes, especially heat production.  Heat production in response to cold, known as cold-induced thermogenesis, is maximal in newborns who at 24 °C increase their thermometabolic ratio by 60–80%.1  Though less in adults, it can be shown to occur in men,2–4 and in normal young women.5  Some obese subjects exposed to an environmental temperature of 20 °C for 2 hours show a fall in core temperature.6,7   It is now well established that lean persons are more efficient heat producers.8   The presence of brown fat is an explanation for the increased response to cold in some individuals, while clothing, housing, and sophisticated heating techniques make heat production by the adipose tissue an unnecessary or an unrequired response to cold in others.  Poverty, disease, and accidents do nevertheless expose men to cold environments.  Foreign travel makes all of us aware that some degree of adaption occurs seasonally, so that if we arrive in a cooler environment unprepared, we feel disproportionately cold.  Immersion in cold water largely eliminates the value of external thermal insulation such as clothing. Such exposure causes vasocontriction in the presence of which most insulation depends on subcutaneous fat in the area of the trunk and on fat and muscle in the limbs.  At 12 °C, fat people can maintain core temperature, while at 25–29 °C some thin people cool progressively.  A relative increase in surface area to size makes children do badly in cold water.9

In addition to its role in heat production, subcutaneous adipose tissue also forms an insulating barrier around the shell of the body and is therefore an important means of regulating heat loss. As an organ of substrate storage, heat production and heat conservation adipose tissue plays a major role in body temperature regulation.

Available online 22 April 2004.

From the Department of Dermatology, The Slade Hospital, Headington, Oxford, United Kingdom

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                   OVERHEATING IN BED AS AN IMPORTANT FACTOR IN MANY COMMON DERMATOSES

                                      MOLLOY, H. F., LAMONT GREGORY, E., IDZIKOWSKI, C. and RYAN, T. J. (1993), 
                               International Journal of Dermatology, 32: 668–672. doi: 10.1111/j.1365-4362.1993.tb04024.

Abstract Background.

Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders.

Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet.

Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area.

Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive.


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                                                            Refugee Participation Network 18 published January 1995
                    

                                                             The environment, cooking fuel and UN Resolution 46/182 

                                                                                          by Eric LaMont Gregory


 The majority of refugees today are to be found in arid and semi-arid areas of the poorest countries of the world. The concentration of large populations in such areas leads to a tremendous strain on these fragile environments and on the meagre resources available. On the other hand, such environments are hostile to refugees and can affect their health and well-being. Under normal circumstances, populations are free to move in search of more environmentally friendly areas of relocation. In the case of refugees, such liberty of movement is not usually available. Here lies the particular environmental confinement within which refugees must be cared for and assisted.(1)

It is a familiar story. In the developing world where biomass - in the form of woodfuel and charcoal - is the primary cooking fuel for most households, forest resources in and around the most heavily urbanised regions have been depleted to meet the demand for traditional cooking fuels. This phenomenon is no different from the situation in which large concentrations of refugees collect fuelwood for cooking and wood for construction in the immediate surroundings of their settlements or camps.

Unfortunately, humanitarian assistance providers have not become sufficiently aware of the necessity to meet the cooking fuel needs of recipients in emergency situations as an integral part of `first phase' emergency programming. As Bernard Ross points out in his letter to the editor in this RPN, environmental protection is thought of as one of the `niceties' that is only addressed after the emergency phase of disaster relief has passed. However, it is no longer wise for aid providers to ignore the environmental or health consequences of fuel availability and consumption in disasters. When humanitarian assistance providers do formulate plans to meet the cooking fuel requirements of the recipients of aid, these same providers seem to be aware neither of the health implications of their choice of fuel nor of the provisions of UN General Assembly Resolution 46/182 which affirms that international disaster assistance should serve long-term preventive, as well as relief, functions. In particular, the resolution states that `emergency assistance should be provided in ways that will be supportive of recovery and long-term development'.

The silence of the children

Current strategies to meet the cooking fuel requirements of recipients in the Rwandan crisis are focused upon the exploitation of local biomass resources: ie wood and grass(2). The collection of dung for cooking fuel has also been contemplated. Significant health consequences associated with using these fuels seem to be entirely overlooked.

The argument usually advanced for providing woodfuel is that the providers have to take refugees' normal domestic practices as a starting point and that, therefore, in central Africa, where most rural households use fuelwood and agricultural residues almost exclusively, wood and crop residues should be provided as cooking fuel. It is worth noting, however, that in the urban sector of central Africa the situation is very different: the vast majority of households use charcoal and not wood as their principal cooking fuel(3). In addition, part of the concept of social mobility in this region is attached to the ability to acquire cleaner cooking fuels and move up the fuel chain from wood to charcoal.

Biomass fuels such as wood, crop residues and dung release large amounts of respirable particulates and pollutants when burned in their raw state. According to the World Health Organisation, human exposure levels to these pollutants exceed recommended levels by factors of 10, 20 or more and have been identified as a significant cause of health problems. Studies in North America, Europe and Japan indicate that acute respiratory infections in children can be caused by urban environmental pollution at levels 30 times less than the levels to which children are normally exposed in developing countries from open wood, residue and dung fires(4). In fact, after diarrhoea, acute respiratory infections are the chief killers of children in developing countries and cause more episodes of illness than any other single disease. It simply is not proper to argue the maintenance of traditional practices as a reason for exposing children to known health risks. Caring for the environment includes caring for the quality of the air that children breathe.

Children and other `at risk' groups must also be in an environment that provides them with adequate nutrition. The primary reason for assuring that there is adequate cooking fuel is to ensure that the food provided is properly cooked. Many basic foods are not fully digestible without adequate cooking; this is especially true of the semi-liquid foods required by babies, young children, the ill and wounded and the elderly(5). In this regard, it must be remembered that nutritional assessments based purely on the quantity of food delivered can be misleading.

The association between exposure to raw biomass smoke, acute respiratory illness and the death of malnourished children has received very little attention by humanitarian assistance providers. In 1992 Moore et al found mortality rates among the highest ever documented for a civilian population in camps near Baidoa, Somalia. 74% of children under five died in eight months(6). Similar under five mortality rates have been documented in Ethiopia, Sudan and recently in Katale, Zaire(7). In each of these crises, wood was the principal cooking fuel and diarrhoea, acute respiratory infections and malnutrition were contributing factors to the alarmingly high rates of under five mortality.

Cooking fuel and UN Resolution 46/182

The provision of smokeless fuel is a must in the developing world and, in accordance with UN Resolution 46/182, humanitarian assistance providers should work to introduce the means for the production of smokeless fuel both on health and environmental conservation grounds. The woodfuel crisis in the developing world is not new. In fact, there are many national and international agencies working on this problem. However, in spite of a decade of wood energy activities in Africa, charcoal manufacture remains highly inefficient and employs techniques that are incompatible with the carbonisation of alternative and more sustainable biomass supplies.

Crop residues can and ought to play a significant role, not only in meeting cooking fuel requirements in disasters but also in providing a sustainable means for the manufacture of clean burning cooking fuel. The most frequent argument against the use of crop residues is that they should be put back into the ground to improve soil fertility. Certain residues should be put back but some residues are better used for other purposes. Crop residues, such as chick pea stalks, coffee husks, cotton stalks and coconut shells do not decompose in soil and should not be dug back into the ground. The use of carbonised crop residues for fuel is one of the alternatives that should be explored as more and more forest resources are removed for agricultural purposes, the primary cause of deforestation in the developing world.

The fallacy of improved stove fuel savings

Most programmes to address the fuelwood shortage have concentrated on demand management strategies (ie improved stoves and cooking practices). Current evidence suggests that recent claims of fuel savings with improved stoves have been systematically overestimated(8). Most efficiency claims involving improved stoves are based on rather simple comparisons between the fuel consumed using traditional cooking methods and an improved stove in performing a specific task conducted under laboratory conditions. These simple comparisons do not however take into consideration the ways in which fuelwood or charcoal is actually used in daily life and ignore that fact that their use is not limited solely to cooking purposes. The evidence that savings of up to 40% can be attained with an improved stove has not been replicated in any field trials. A recent survey of fuelwood consumption in three refugee camps in Tanzania reported that the amount of fuel used on either a three stone fire or with an improved stove were identical: 2.4 kg per person per day(9).



The cooking fuel issue must be expanded to incorporate the concept of improved fuel. Improving the efficiency of the stove and efficiency in wood use do not eliminate the negative health effects of exposure to raw biomass smoke.

The relative advantages of the elemental carbon briquette, on the other hand, especially in its densified form, in comparison to wood is demonstrable in field studies. One piece of essential evidence, in this regard, is the amount of fuel needed to maintain a open cooking fire for three hours.

Two to three hours is the normal cooking time for the beans that are a staple among the population of Burundi and many other African countries. When two kilograms of medium density wood is ignited, the temperature at pan height above the fire quickly rises to approximately 580° centigrade. This temperature is maintained for some ten minutes after which the temperature falls precipitously to around 400° degrees. Over the next 45 minutes the temperature of the wood fire falls steadily to below the minimum cooking temperature of 200° centigrade. In approximately one hour the wood is completely exhausted. To maintain the minimum cooking temperature for three hours requires approximately 6 kilograms of medium density wood on an open fire. The temperature at pan height above a densified carbonaceous briquette fire, on the other hand, quickly rises to the minimum cooking temperature of 200° and then over the next half hour reaches a plateau of approximately 360°. The plateau is maintained for about 2 hours and then the temperature falls gradually over the next 1 hour until the temperature descends below that required for cooking on an open fire - 200° centigrade. The densified carbonaceous briquettes will not have been completely consumed for about another hour. (Lump-wood charcoal - the traditional urban fuel of central Africa - is more efficient than wood but less efficient than carbonaceous densified briquettes.)

Women and children suffer most from a shortage of fuelwood

Women are the primary fuelwood gatherers. When the fuel needs of recipients are considered by humanitarian assistance providers, especially in the African context, fuelwood is invariably the choice. Few attempts are made to deliver fuelwood to the camps; most strategies are directed to supplies near the camps from which the recipients gather the supplies they need. As the settlement matures these trips involve greater distances and consume more and more time and energy. No consideration of the health effects of such traditional fuelwood gathering or of the health effects of exposure to raw biomass smoke in a refugee settlement has ever been documented, although the consequences of fuelwood gathering on the health status of women and children is starting to find its way into the medical and refugee literature(10). In addition to the risks incurred through exposure to smoke, women and children walk long distances carrying heavy loads often under very adverse conditions and not infrequently becoming the victims of violent attack(11).

Conclusion

Although the World Food Programme is mandated to provide food, fuel and cooking utensils, there is usually little provision of fuel or cooking utensils. Current practise suggests that managers of humanitarian emergency assistance believe that the standing fuel stocks in the immediate vicinity of refugee settlements will provide sufficient fuelwood and building materials to meet the requirements of recipients and that all the recipients have to do is to exploit their surroundings. Fuel provision must be planned in advance and stocks of fuel must be kept in readiness for emergency interventions. None of this will occur, however, until humanitarian assistance providers realise that fuel, especially cooking fuel, is a life-saving intervention that is essential to reduce the alarmingly high rate of mortality in the under five age group and other at-risk populations and until realistic strategies are implemented to effect fuel delivery from the beginning of a crisis.

The provision of cooking fuel should be addressed in accordance with UN Resolution 46/182. Past successes and failures should be fully recorded and analysed and evidence should be gathered as to the best means to achieve the provision of cooking fuel in humanitarian crises. Adequate supplies of safe, smokeless cooking fuel must be made available as an integral part of `first phase' emergency programming if we are to save the most vulnerable members of the recipient community.

E La-Mont Gregory is based in the Institute of Social and Cultural Anthropology, University of Oxford, Oxford, UK.



1. GTZ/UNHCR Domestic energy and reforestation in refugee affected areas, 1992.

2. UNHCR Environmental issues in Benaco refugee camp, 1994.

3. UNDP/World Bank Activity Completion Report, Burundi, 1985; UNDP/World Bank ESMAP Activity Completion Report, Tanzania, 1988; World Bank ESMAP Energy Assessment, Rwanda, 1991.

4. Smith K Biofuels, air pollution and health: a global review, Plenum Press, 1987.

5. LaMont-Gregory E `Cooking fuel and the Rwanda crisis', The Lancet, 344, 1994.

6. Moore P S et al `Mortality rates in displaced and resident populations of central Somalia during 1992 famine', The Lancet, 341, 1993.

7. Paquet C, van Soest M `Mortality and malnutrition among Rwandan refugees in Zaire', The Lancet, 344, 1994

8. GTZ/UNHCR Domestic energy and reforestation in refugee affected areas, 1992.

9. Care Britain Environmental impact assessment of Rwandan refugees, Kagera Region, Tanzania, 1994.

10. Waldron S R `Working in the dark: why social anthropological research is essential in refugee administration' in Journal of Refugee Studies, 1, 1988.

11. Musse F Refugee women victims of violence, UNHCR, Nairobi, 1993; see also `Women victims of violence: rape in Kenya's refugee camps' in RPN, 16, March 1994. 


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UN BACKS OXFORD GREEN MACHINE


From the archive, first published Tuesday 7th July 1998



THE Oxford inventor of a green machine that could solve the energy needs of the Third World is being backed by the United Nations,
writes Chris Koenig.

Eric LaMont Gregory, working with Professor Terence Ryan, of Green College, Oxford,
has invented a device that reduces organic waste to carbonised briquettes, which can then be used as smokeless fuel.

Now the United Nations Environment Programme is supporting the introduction of the machine to Nairobi, Kenya.

A smaller version of the system is already in successful use in a rural part of Kenya.

The apparatus operates by pyrolisis, burning without oxygen. The process produces gases and oil as by-products.

The machine could put an end to the heaps of rubbish that cause disease in many parts of the world.

It could also improve people's health by allowing them to live in a less smoky atmosphere.

UN programme officer Christian Lambrechts attended a lunch at Green College
before inspecting a prototype of the machine,
produced at Pipaway Engineering, Milton Park, near Abingdon.

He said: "The project has the potential to address the issues of indoor air pollution, energy and forestry,
waste and sanitation all together by converting organic waste into useful products."


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