EESA10 Final Exam Lecture 7-9

17 Pages

Environmental Science
Course Code
Jovan Stefanovic

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EESA10 Lecture 7Biological Hazards and Human Health This lecture overlaps with next lecture on Food and Food borne Diseases because they both have same agents bacteria viruses These can be considered as biological hazards but also they can found in food substances and cause food borne hazards Biological Hazards Biological Hazards can be nontransmissible cannot be transferred from one human to another human Examples of such nontransmissible diseases include cardiovascular cancer diabetes asthma What are cardiovascular diseases These are diseases related to heart as a result of food high cholesterol lack of exercise lots of stress smoking etc Cancer has many different causes we cannot specify just one cause for it Every cancer is caused with many different agents environmental genetical etc There is no strong proof that these diseases can be transferred from human to human Diabetes can be caused because of genetics food and obesity There is no strong evidence that diabetes can be transferred from human to human Asthma is closely related with some allergens something in our environment Everyday many new agents and chemicals and applied to us and they may cause asthma There is no proof that asthma can be transmitted from human to humanTransmissible diseases Diseases caused by bacteria viruses or protozoa can be certainly transferred from humans to humans Bacteria can be cured using antibiotics Antibiotics are medicine that we take if we have bacterial infections However Antibiotics do not work with viral infections For example doctors will not prescribe antibiotics if you have flu or some other kind of viral infection If you take antibiotics for any viral infection or any other infection you will be overusing antibiotics using antibiotics when we do not need it or not prescribed by the doctor or taking antibiotics more frequently for not very serious disease What will happen as a result This can lead to very significant resistance of bacteria to these antibiotics Next time if someone is really serious and needs antibiotics those antibiotics will not work This is because growing germ produces resistance to antibiotics How do the bacterias develop resistance This is because they are growing very fast They reproduce very quickly Also they very quickly transfer that mutation that adjustment to the next generation This process goes through generation to generation very quickly much faster than any other organism on the planet can do High reproductive rate allow them to become genetically resistant quickly One more reason why bacterias grow resistance to antibiotics is because of the use of antibiotics in food additives to boost livestock Veterinarians agriculture specialists farmers they all use antibiotics to prevent diseases in animals Farmers use antibiotics to prevent disease from happening and if we consume that kind of meat with high concentration of antibiotics we might become more resistant to antibiotics Biological HazardsBacterial Diseases 1 Tuberculosis When we talk about this disease we always think about the past before World War 2 before discovery of antibiotics This was a big problem However it seems that this is not the case Even today it is a significant threat to humans But indeed this is a very old diseaseScientists found evidence that mummies from Egyptian era had symptoms of tuberculosis Thiswas a very big problem during 18th 19th and beginning of 20th centuries This disease used to run in families as it was transferred from one family member to another member of the family very easily For example back then when someone wants to marry someone they used to look at what family is the bride or groom coming from does that family have tuberculosis This is how disease was transferred from one family to another During 18th and 19th centuries this disease was related to vampires This is because sick people from this disease were very pale face they had watery bloody eyes and they sometimes spit blood cough a lot That time no one knew what tuberculosis was and people connected these symptoms with vampires Later on humans found out the truth but they could not find any cure until the discovery of antibiotics After this discovery most of the cases but not all of tuberculosis were cured These agents mutate easily and they change very quickly This can cause different types of tuberculosis Most of these kinds of tuberculosis are very resistant to known tuberculosis which makes it hard to cure Therefore they are a threat even today Some statistics In 2004 mortality statistics included 146 million chronic active TB cases 89 million new cases 16 million deaths mostly in developing countries What does chronic active mean If individual comes in contact with an agent with this bacteria that person does not get ill right away For very long time that person may not show any symptom of this disease Active means visible symptoms Chronic means for a long time Why is it mostly in developing countries This disease in the past and even today is a socially related disease Poor people with not adequate supply of food bad housing wet walls unsafe conditions these get sick more easily because their immune system is reduced lower and they catch this disease faster This disease is always related with social factor In developing countries their health system is not very organized not all people have access to proper health This adds to one of the reasons for tuberculosis How can this disease be transferred from person to person Transmissioncough sneeze speak kiss or spit of ill person breathing basically any direct contact This disease most commonly attacks the lungs through the breathing of the agent This bacterium is sensitive to UV radiation and oxygen These were the only ways how people prevented them in the past They took all clothes mattress or anything that came in contact with the ill person almost 100 years ago were exposed to the sun and oxygen for long periods of time because they realized that sun helps Symptoms include chest pain coughing up blood and a productive prolonged cough for more than three weeks fever chills night sweats appetite loss weight loss paleness and often a tendency to fatigue very easilyTuberculosis a growing threatProblem in Africa mostly southern Africa South America Asia Not a problem in North America AustraliaIf you want to travel in tuberculosis affected countries you have to get a vaccine AnthraxAfter 911 this disease was of big concerns that it can be used as a biological weapon Anthrax is normally found in soil spores of anthrax are usually found in soil What are the spores It is a form of bacteria When bacteria is in unpleasant something that does not support growth of the bacteria they become this form to survive until they are back in the conditions that will be good for them to grow Bacillus anthracis large grampositive sporeforming bacteria Gram test is used by microbiologists to test bacterias These bacterias produce toxins This toxin is really poisonous Three major clinical forms of this
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