Chemistry

Obesity can be defined as a condition whereby an individual has an abnormally high proportion of body fat. It is considered a disease by the World Health Organization (WHO). It can also be defined clinically where an obese person is said to be having a BMI Body Mass Index- weight (kg) height(m)2 of greater than 30 while overweight is a BMI of 25-29.9. It is possible to have an individual who is overweight but not obese. This is so because someone overweight can be said to be having excess weight which might be a result of muscle, bone, fat andor body water. About two-thirds of adults in the United States are overweight, and almost one-third are obese, according to data from the National Health and Nutrition Examination Survey (NHANES) 2001 to 2004. The rising obesity rates have resulted in numerous health complications chiefly nutrition related diseases over the last few decades.
The above few statistics coupled with the fact that obesity is becoming more and more widespread has generated interest in obesity. Obesity has come to be regarded as a social problem. Obesity prevalence has lead to an urgent need for evidence to support advocacy and for corrective policies and intervention programs targeting an array of societal sectors (Kumanyika 2007).
A simplistic cause of obesity can be said to be consuming more calories than one is expending thus accumulating fat as a result. In a 2006 Pew Research poll asking Americans why the nation consumed so much junk food, convenience was the most popular answer. The same poll revealed that more children can identify Ronald McDonald than Santa Claus (Pew research poll qtd. in waterson 2009)Causes of obesity are more complex than this. It has become synonymous with economic and technological advancements. Obesity can be said to have a wide range of causes. Genes and individual psychobiology is one cause that has been greatly investigated over the years. Obesity can also be said to be caused by processes indispensable to human survival and interaction.
Obesity has become an important field of study today because the increase in nutrition related chronic disease morbidity and mortality have brought about significant burdens to families, communities and health care systems. Diseases associated with overweight and obesity include diabetes, coronary heart disease, high blood cholesterol, stroke, hypertension, gall bladder disease, osteoarthritis, sleep apnea and some forms of cancer. Implications brought about by being obese have immense consequences on the global as well as the American economy. According to the weight control information network, the estimated total cost of implications arising from being obese and overweight is  117 billion. Quite an astronomical figure by any standards (Weight control information Network 2007).
Knowing obesity causes will not necessarily lead to solutions. This is so because it is practically impossible to remove high calorie foods from our diets, do away with automobiles or return to our lean hunter gatherer eras. All these factors are deeply embedded in our lifestyles. The way to go would be to shift some environmental factors in a direction more favorable to achieving energy balance while also fostering individual behavior changes in the same direction (Kumanyika 2007).
Projections by Wang and Beydoun show that 75 percent of adults will be overweight (body mass index _25 kgm2) or obese (body mass index _30 kgm2) and that 41 percent will be obese by 2015 (Wang and Beydoun 2007).
These are truly shocking statistics that have contributed immensely to raising awareness and making studies on obesity and its probable solutions an immediate and important priority.
It was thought for a long time that weight issues and obesity was predisposed to people of high social standing. On the contrary, recent studies indicate that the low cost of high-calorie foods that are easy to over consume predisposes to obesity among the poor. In fact in high income countries, the gap in obesity levels between the high and low socioeconomic strata may be decreasing (Kumanyika 2007). Many people tend to purchase foods that offer the greatest caloric content for the price when hunger lurks and money is tight. This according to Plotkin is the very real link between being poor and being overweight and obese (Plotkin 2009).
Another interesting factor that has been linked to obesity is the built environment. Built environment refers to factors such as community design, location of retail food outlets, recreational facilities and the transportation infrastructure, which determine the availability and convenience of options for physical activity and food acquisition. According to papa et al.changes in the built environment are potential strategies for corrective interventions to improve the eating and physical activity patterns of populations (Papa et al. qtd in Kumanyika 2007).
Chemistry factors in quite strongly or becomes relevant in obesity issues when the processed foods factor is considered. Processed foods contain elements that are known to cause cardiac problems, obesity, overweight problems and a host of other lifestyle diseases. An example of such elements is trans fats or trans-fatty acids. According to the natural health information centre, these are unnatural compounds which are known to be detrimental to health. They are created by industrial processes where hydrogen is added to liquid vegetable oil to make it more solid. (Americanheart.org 2009)
They are referred to as unsaturated because they have double bonds between adjacent carbon atoms. Saturated fats have no double bonds and all the spaces available are taken up by hydrogen atoms.
When a natural unsaturated fatty acid is hydrogenated, it is not possible to control where the hydrogen atoms are added to the structure. If both hydrogen atoms are added to the same side of the structure, it is referred to as Cis fats. These are naturally occurring and able to allow other chemicals and enzymes to bind to them. When one hydrogen atom adds to one side of the structure and the other atom to the other side, then a trans fat comes into being.
Trans fats do not exist naturally except with a few exceptions. Their structure is not crowded and so they do not accommodate other enzymes and molecules. Trans fats being straight can solidify at room temperature (National-health-information-centre.com 2008).
Trans fats raise the bad cholesterol levels (LDL) and lower the good cholesterol level (HDL). This increases the risk of developing heart diseases, stroke and type 2 diabetes not to mention the increased fatty accumulation and therefore obesity. They are present in fried foods, baked goods, stick margarines and shortenings (Americanheart.org).
Other studies are being conducted into relatively new compounds like 2-furoylmethyl aspartic acid, 2-furoylmethyl pyrrolidone carboxylic acid and 2-furoylmethyl lysine (furosine) which have been detected in stored dehydrated orange juice and tomato products to determine their exact identities and their contribution to the obesity endemic.
Current frontiers on fighting obesity remain largely new uncoordinated. Discrepancies in social facilities that promote healthy living habits should be addressed. Sensitization starting in schools should be carried out on the entire populace to promote healthy eating habits and promote increased physical activities. Integration of schools as a key partner in the fight against obesity would be a good step in the right direction as success in tackling obesity and overweight in childhood and adolescent would translate into success in dealing with obesity in later years. Though obesity prevention is still in its infancy, it is an emerging field with a clear mandate.

Obesity has become the second leading preventable cause of disease and death in the United States, second only to tobacco use (Wang and Beydoun 2007). This trend is on an upward trend unless serious and urgent mitigation measures are taken.
Obesity is caused by many factors mostly lifestyle related. In most people, high calorie intake without adequate physical activity has brought about adding of weight. In order to maintain a healthy weight, a balance must be observed between energy consumption through dietary intake and energy expenditure through metabolic and physical activity. Studies have also revealed that chemistry is an emerging factor that has a role to play in obesity. Trans fats which are chemical compounds produced in industry are the main culprits. Studies are ongoing to determine effects of new compounds detected in dehydrated orange juice and stored tomato products.

Safety Concerns in dealing with Hazards involving Polymeric materials

Chemistry plays a significant role in modern society and specifically Organic Chemistry contributes to the Economy and Development of Nations. The uniqueness of Organic Chemicals originates from the special property of Carbon atom arising out of SP3 Hybridization and the possibility of Carbon atom linking with another carbon atom or other atoms, forming compounds or Functional groups which can again link with one another forming lengthy chain, called polymers. The property of the polymers can be engineered to cater to the specific need, by introducing proper groups / elements like OH, NO2, CN, F, or Cl. Physical parameters like Hardness, Melting point, Thermal conductivity, Electrical resistance and Chemical properties like Flammability, Detonatability, Flame retardancy can be modified by selecting suitable groups while producing the monomer and by conditioning the polymerization process, thus yielding a variety of materials for the use of society.

But the unfortunate side effects are the hazards involved in manufacture, transportation, storage and handling them like: Explosion, Fire hazard, Toxicity, Pollution and Environmental degradation as these Polymers are made up of Carbon and other hazardous materials like F, Cl, NO2, CN etc. The Fire Service and EH&S Personnel must be aware of the potential hazards, the hazardous materials encountered in their area of control and the means of mitigating the incident and very importantly the ways and means of self protection.


Safety Concerns in dealing with Hazards involving Polymeric materials
The Organic polymers find their use in almost every walks of modern life- be it clothing, furniture, automobiles, house interiors, house hold articles, Piping systems, computers etc. The manufacture, transport and storage of the products as well as the raw materials involve hazards like accidents, spillage, fire and environmental Pollution. Though these industrial polymers are not explosive in nature, they do burn at elevated temperature encountered in any fire mishap. The general characteristics of the polymers while burning are: melting of the polymer, depolymerization, volatilization of the monomers, burning / explosion of the vapors and emission / spreading of products of combustion. If the polymeric substance involved in the mishap is large, so is the CO formation due to partial combustion resulting from reduced Oxygen supply. There is a possibility of asphyxiation also because of the depletion of Oxygen during the fire mishap.  A few examples are discussed below.

PVC
PVC, Poly vinyl Chloride having Carbon, Hydrogen , Nitrogen (in the form of Cyanide group) and plasticizers like Di Octyl Phthalate,  is a very common material finding use in many Plastic articles, to name a few: Piping Systems, casing of electric wires, house hold articles and building materials. These materials, as well their raw material- Ethylene Chloride and the intermediate VCM (Vinyl Chloride Monomer, CH2=CH Cl), are being produced, transported, stored in large quantities, posing severe hazards. VCM is a highly hazardous material, explosive as well as carcinogenic. On thermal decomposition, PVC produces CO2, CO, soot (C), HCl gas, polychlorinated dibenzofurans and polychlorinated dibenzo-p-dioxins (as cited in Chemistry of Some Polymeric Materials, p. 688). All these are dangerous: CO is deadly poisonous, HCl gas is highly corrosive affecting lungs, CO2 is asphyxiating, the dioxins have acute as well as chronic ill effects and soot adsorbs these dioxins and ingests them into human body. PVC normally contain some un polymerized VCM. The VCM volatilizes at the elevated temperature encountered in any fire mishap, and it is very dangerous to inhale this as it is a known carcinogen (as cited in Chemistry of some polymeric materials, P688).   

Polyacrilonitrile

    Poly acrilonitrile is the polymer of Vinyl Cyanide, commonly known as Acrilonitrile, having Carbon, Hydrogen and Nitrogen (Cyanide group) in it’s molecule along with significant amount of Plasticizers. It is used in the manufacture of textiles, plastics and rubber (P689). Though it is fairly stable thermally, undergoes thermal decomposition at elevated temperatures, producing CO2, CO, soot and HCN. Tsuchiya (1977) asserts under smoldering conditions, say 300 to 400 OC, where there is limited supply of Oxygen, the concentration of CO as well as HCN is likely to be fatal (p. 272, 275, 276). Hathaway et al. 1991 reports “270 ppm of HCN is fatal after 6 to 8 minutes, 181 ppm after 10 minutes and 135 ppm after 30 minutes of inhalation”.

It is essential the personnel, attending to the mishap caused by fire or explosion involving such hazardous Polymers, should be aware of the modalities of handling the situation, ensure selection of relevant fire extinguishers, and use appropriate personnel protective equipments like Gas mask, Oxygen cylinder, Fire resistant clothing / Aprons to protect themselves and to effectively mitigate the effects of the mishaps.

Chemistry of Some Polymeric Materials and Some Explosives

Organic Polymers, natural or synthetic, are polymerized monomers consisting mainly of  Carbon and Hydrogen, often with other added functional groups/elements like, Halogen, Sulfur, Nitrogen, -C=O, -OH, -COOH, -NH2, -NO2, -SO2,  or –CN. The chemical properties, the thermal stability, the flammability and the products of combustion of these polymers depend on the carbon chain skeleton, structure (aliphatic, alicyclic or aromatic), the addends, and the position the addends occupy in the structure. The Combustion products are often toxic.

Explosives are that group of Chemicals which can react violently at a very high rate with the Oxygen available in situ in the explosophore like NO2 (as cited in Chemistry of some Explosives, p.708). The oxidation can be triggered under suitable condition, like mechanical shock or static electricity. This phenomenon is detonation, releasing lot of thermal energy at a very high rate producing shock waves. The nature of detonation, phenomena and the end products differ from one chemical to another depending on type of carbon chain - aliphatic or aromatic, quantum of the explosophore (NO2) etc. The aromatic explosives like TNT, because of their high Carbon content and less O2 for stoichiometric requirement for oxidation, is less active, and hence safe to handle as compared to Nitroglycerin where the available Oxygen is more than sufficient and hence highly active and unsafe to handle.

POLYMERS AND EXPLOSIVES                                                                                                 3
Chemistry of Some Polymeric Materials and Some Explosives
Organic Chemicals exhibit unique properties like polymerization, combustibility, detonatability etc. These properties are gainfully utilized often by the Human Society. How ever there are hazards like Explosion, Toxicity and Pollution in handling and using them.
Toxicity of Burning Tire
Automobile tire being made up of natural or synthetic rubber, poly cis 1,4 isoprene (C5H8)n  or poly cis-l,4-butadiene respectively (as cited in Chemistry of Some Polymeric Materials, p. 695,696), vulcanized with Sulfur, on burning produces a mixture of CO2, CO, and SO2. The concentrations of CO2, CO, and SO2 at the scene of burning of automobile tires are given as 7000 PPM, 1700PPP and 600 PPM respectively. The lethal dosages of these are taken from MSDS data available in the Net, and are tabulated.
 
Table.1Contaminant Concentration vs Lethal Dosage
Chemical:CO2COSO2
Contaminant Concentration PPM:70001700600
Lethal Dosage, PPM LC50:100,00018072520
MSDS Reference: NOVASpecialty Gases Of America, Inc.Linde

It can be seen that Carbon monoxide is more dangerous than others and the indicated concentration of 1700PPM is life threatening to FS personals responding to fires. The lethal concentrations of the other two are much higher than the prevailing concentrations.

Combustion products of Burning Polyacrylonitrile
The Poly acrilonitrile is a polymer of Acrilonitrile (Vinyl Cyanide). This is fairy stable
and hence used for the manufacture of Textile fibers. To enhance its safety, fire retardants are

POLYMERS AND EXPLOSIVES                                                                                                 4
added during the manufacture of the textile fibers. How ever when it is subjected to burning,
CO2 and CO are the emitted predominantly. Since the polymer contain -CN group, HCN will
also be emitted. Tsuchiya (1977) gives experimental findings showing that the emission of HCN from the burning Poly acrylonitrile increases with rise in burning temperature (p.273, 274,279). He concludes, “In non-oxidizing atmospheres higher temperatures favor greater formation of HCN. In an oxidizing atmosphere HCN increases to a maximum value and decreases with increasing temperature or increasing air supply” (p.280). So burning /smoldering Polyacrylonitrile is hazardous as it produces CO and HCN.

Uniqueness of TNT as a military explosive
Tri Nitro Toluene is a military explosive.  A cursory look at its formula shows high carbon content, being an aromatic compound as against Nitro glycerin. The Oxygen available, after oxidizing the Hydrogen is stoichiometrically not sufficient for complete oxidation of Carbon to Carbon dioxide. Hence this molecule is comparatively stable than the Nitroglycerine, which being aliphatic, has low carbon content and the Oxygen available in the explosophore (NO2) is more than sufficient for complete oxidation of both Carbon and Hydrogen. So Nitro glycerin is very active, sensitive and unstable and hence highly risky. But in the case of TNT, it is fairly stable and hence safe to handle and transport.  More over, TNT being an aromatic chemical it has got higher melting point, 81OC (as cited in Chemistry of some Explosives, p 708) than Nitroglycerine which exists as a liquid at ambient temperature. These properties of TNT come in handy for the use and it’s maneuverability in forming castable explosives and handling them safely by the military persons.

Drug laboratories


Clandestine Drug Laboratories: Knowing one is near
Clandestine drug laboratories are usually established to produce illegal narcotics, particularly metamphetamine. It is uncommon to find a covert facility making materials used by terrorists, such as TATP, ricin and sarin, all used by terrorist elements in their crimes. These laboratory facilities may be set up in a variety of locations, such motel rooms and mobile homes. The laboratories can be mobile, as they can be loaded in recreational vehicles or in the trunks of passenger cars.

Some of the signs that a clandestine illegal facility is operating in an area is the presence of scents akin to nail polish. This is because one of the chemicals used in the production of metamphetamine of Methyl ethyl ketone, a common chemical that is utilized by operators of clandestine drug facilities in the manufacture of illegal  narcotics. But one must be wary and avoid investigating the matter on one's own. There is the chance that the operators of the laboratories may be still on the premises, and may be heavily armed. Also, since the drugs give off a scent of the drugs that may be producing, it is not impossible that they may be paranoid and may harm the uninvited guest.

Also, it is noted that the property, if the laboratory is in a fixed location, such as a residence, the property may also display large amounts of traps that may be linked to bombs designed to kill any person that may intrude on the premises. These bombs may be connected to explosives or to chemical bombs. A large number of dogs on the premises may be another sign of a covert laboratory, as these may serve as guard dogs that the operators use in the guarding of the facility. Finally, a more visual sign is the presence of armed individuals on the property or ingressing or leaving the property, If these conditions are met, then the property may be home to a covert illegal drug manufacturing facility.

CHEMISTRY IN CONTEXT


Introduction
Obesity can be defined as a condition whereby an individual has an abnormally high proportion of body fat. It is considered a disease by the World Health Organization (WHO). It can also be defined clinically where an obese person is said to be having a BMI [Body Mass Index- weight (kg)/ height(m)2] of greater than 30 while overweight is a BMI of 25-29.9. It is possible to have an individual who is overweight but not obese. This is so because someone overweight can be said to be having excess weight which might be a result of muscle, bone, fat and/or body water. About two-thirds of adults in the United States are overweight, and almost one-third are obese, according to data from the National Health and Nutrition Examination Survey (NHANES) 2001 to 2004.  The rising obesity rates have resulted in numerous health complications chiefly nutrition related diseases over the last few decades.

The above few statistics coupled with the fact that obesity is becoming more and more widespread has generated interest in obesity. Obesity has come to be regarded as a social problem. Obesity prevalence has lead to an urgent need for evidence to support advocacy and for corrective policies and intervention programs targeting an array of societal sectors (Kumanyika 2007).

A simplistic cause of obesity can be said to be consuming more calories than one is expending thus accumulating fat as a result. In a 2006 Pew Research poll asking Americans why the nation consumed so much junk food, "convenience" was the most popular answer. The same poll revealed that more children can identify Ronald McDonald than Santa Claus (Pew research poll qtd. in waterson 2009)

Causes of obesity are more complex than this. It has become synonymous with economic and technological advancements. Obesity can be said to have a wide range of causes. Genes and individual psychobiology is one cause that has been greatly investigated over the years. Obesity can also be said to be caused by processes indispensable to human survival and interaction.

Obesity has become an important field of study today because the increase in nutrition related chronic disease morbidity and mortality have brought about significant burdens to families, communities and health care systems. Diseases associated with overweight and obesity include diabetes, coronary heart disease, high blood cholesterol, stroke, hypertension, gall bladder disease, osteoarthritis, sleep apnea and some forms of cancer. Implications brought about by being obese have immense consequences on the global as well as the American economy. According to the weight control information network, the estimated total cost of implications arising from being obese and overweight is $ 117 billion. Quite an astronomical figure by any standards (Weight control information Network 2007).

Knowing obesity causes will not necessarily lead to solutions. This is so because it is practically impossible to remove high calorie foods from our diets, do away with automobiles or return to our lean hunter gatherer eras. All these factors are deeply embedded in our lifestyles. The way to go would be to shift some environmental factors in a direction more favorable to achieving energy balance while also fostering individual behavior changes in the same direction (Kumanyika 2007).

Projections by Wang and Beydoun show that 75 percent of adults will be overweight (body mass index _25 kg/m2) or obese (body mass index _30 kg/m2) and that 41 percent will be obese by 2015 (Wang and Beydoun 2007).

These are truly shocking statistics that have contributed immensely to raising awareness and making studies on obesity and its probable solutions an immediate and important priority.
It was thought for a long time that weight issues and obesity was predisposed to people of high social standing. On the contrary, recent studies indicate that the low cost of high-calorie foods that are easy to over consume predisposes to obesity among the poor. In fact in high income countries, the gap in obesity levels between the high and low socioeconomic strata may be decreasing (Kumanyika 2007). Many people tend to purchase foods that offer the greatest caloric content for the price when hunger lurks and money is tight. This according to Plotkin is the very real link between being poor and being overweight and obese (Plotkin 2009).
Another interesting factor that has been linked to obesity is the built environment. Built environment refers to factors such as community design, location of retail food outlets, recreational facilities and the transportation infrastructure, which determine the availability and convenience of options for physical activity and food acquisition. According to papa et al.changes in the built environment are potential strategies for corrective interventions to improve the eating and physical activity patterns of populations (Papa et al. qtd in Kumanyika 2007).

Chemistry factors in quite strongly or becomes relevant in obesity issues when the processed foods factor is considered. Processed foods contain elements that are known to cause cardiac problems, obesity, overweight problems and a host of other lifestyle diseases. An example of such elements is trans fats or trans-fatty acids. According to the natural health information centre, these are unnatural compounds which are known to be detrimental to health. They are created by industrial processes where hydrogen is added to liquid vegetable oil to make it more solid. (Americanheart.org 2009)

They are referred to as unsaturated because they have double bonds between adjacent carbon atoms. Saturated fats have no double bonds and all the "spaces" available are taken up by hydrogen atoms.
When a natural unsaturated fatty acid is hydrogenated, it is not possible to control where the hydrogen atoms are added to the structure. If both hydrogen atoms are added to the same side of the structure, it is referred to as “Cis” fats. These are naturally occurring and able to allow other chemicals and enzymes to bind to them. When one hydrogen atom adds to one side of the structure and the other atom to the other side, then a trans fat comes into being.

Trans fats do not exist naturally except with a few exceptions. Their structure is not crowded and so they do not accommodate other enzymes and molecules. Trans fats being straight can solidify at room temperature (National-health-information-centre.com 2008).

Trans fats raise the bad cholesterol levels (LDL) and lower the good cholesterol level (HDL). This increases the risk of developing heart diseases, stroke and type 2 diabetes not to mention the increased fatty accumulation and therefore obesity. They are present in fried foods, baked goods, stick margarines and shortenings (Americanheart.org).

Other studies are being conducted into relatively new compounds like 2-furoylmethyl aspartic acid, 2-furoylmethyl pyrrolidone carboxylic acid and 2-furoylmethyl lysine (furosine) which have been detected in stored dehydrated orange juice and tomato products to determine their exact identities and their contribution to the obesity endemic.

Current frontiers on fighting obesity remain largely new uncoordinated. Discrepancies in social facilities that promote healthy living habits should be addressed. Sensitization starting in schools should be carried out on the entire populace to promote healthy eating habits and promote increased physical activities. Integration of schools as a key partner in the fight against obesity would be a good step in the right direction as success in tackling obesity and overweight in childhood and adolescent would translate into success in dealing with obesity in later years. Though obesity prevention is still in its infancy, it is an emerging field with a clear mandate.