Presentation on Diseases and Preventive Measures.pptx

Good PPT on the topic of Environment

1. Environmental Education Compulsory Course EDI-11805 1

2. Lecture 5 “Diseases and preventive measures”

3. Environmental Health Sciences “The study of factors in the environment that affect human health”

4. Contributing Factors for Diseases

5. What is a Vector? A  vector  is an Organism or Medium that does not cause disease itself but which spreads infection by conveying pathogens or chemical agents from one host to another. It has two types Biological Vector Example Species of mosquito for example, serve as  vectors  for the deadly disease Malaria.

6. Environmental Vectors for the Factors 2. Environmental vectors

7. Entry Routes for the Factors Lungs / Breathin g Eating/ via Stomach Skin E.g. Bacteria Virus E.g. Toxic Gases Chemicals E.g. Radiations

8. 5 Step Pathway of a Disease Chemical Biological Physical Socioeconomic Air Water Food Soil Humans Plants Ecosystem Other species Acute effects Mild effects Adverse effects Death Inhalation Ingestion Absorption

9. Contributing Factors for Diseases

10. Chemical Factors (Abiotic Factor) The human body interacts permanently with a number of chemical substances. Some are essential for life (water, oxygen, mineral salts, vitamins and trace elements), while others can damage biological macromolecules and cause health disturbances. Those which cause serious health problems in minute amounts are poisons or toxicants. A  toxicant  is any toxic substance. In popular usage, the term is often used to denote substances made by humans or introduced into the environment by human activity . E.g. Lead, Co2, Mercury etc. in contrast to Toxins , which are toxicants  produced naturally by a living organism .  E.g. Toxins produced by Mushrooms and bacteria. Chemical Factor Biological Factor

11. Chemical Toxicants

12. 1. Toxic Metals LEAD Lead is widely used in storage batteries, and is a component of paints, pottery glaze, rubber products. Tetraethyl lead was widely used as a gasoline additive and until introduction of lead-free gasoline led to substantial pollution in regions with high intensity of automobile traffic. In the last 10 – 20 years this burden is rapidly diminishing. Metal toxicity  or  metal poisoning  is the toxic effect of certain metals in certain forms and doses on life.

13. Can Lead Pencil cause Lead Toxicity ? Lead pencil In old times pencil that used lead to write. As lead was related to toxicity it was replaced with graphite but the name stayed the same. Now the pencil is made up of graphite.

14. The fatal dose of absorbed lead has been estimated to be 0.5 g. Approximately 50 % of lead deposition in the lung is absorbed, whereas usually only 10 % of ingested lead passes into the circulation. Blood levels of Pb > 10 g/l are harmful and can damage the tissues. Lead is accumulating mainly in bones replacing calcium and therefore children with developing bones are very sensitive to lead intoxication. Several screening tests for lead poisoning make use of this by monitoring either inhibition of the affected enzyme - aminolevulinic acid dehydratase (ALAD) LEAD

15. Lead Accumulation in bones Calcium  is one of the most important nutrients to combat lead levels in bone, brain and the nervous system. Lead and calcium compete for the same locations within the body and are stored in the bone, though lead has a greater attraction for calcium binding sites than calcium itself, making the displacement of lead by calcium exceedingly unlikely. Higher quantities of calcium should increase the chance of binding sites being occupied by calcium before lead is bound to them. Small quantities of lead replace larger quantities of calcium Lead toxicity is believed to be a reason for lead neurotoxicity.

16. Calcium Binding sites Calcium Ions Lead ions Lead Toxicity Normal Bone

17. 2. Toxic Gases Many gases have toxic properties which cause harmful effects in human body. 1. Natural Gas Poisoning Sui gas field is the biggest natural gas field in Pakistan. It is located near  Sui in Baluchistan Province , in  Pakistan. Chemical Name of Sui Gas : METHANE GAS Is Natural Gas Odorless ?

18. Natural Gas is Odorless In its natural state, natural gas is odorless, colorless and tasteless. Mercaptan, the harmless chemical that is added to natural gas, contains sulfur , which makes it smell. Your nose knows—the smell of mercaptan that’s exactly why it is added to natural gas, helping you detect even the smallest amount of natural gas leaking into the air.

19. Hazards of Methane Poisoning

20. Carbon monoxide Carbon monoxide  ( CO ) is a colorless, odorless, and tasteless gas. Household appliances, such as gas fires, boilers, central heating systems, water heaters, cookers and open fires which use gas, oil, coal and wood may be possible sources of  carbon monoxide  gas.

21. GAS HEATERS ARE THE BIGGEST SOURCE OF CARBON MONOOXIDE POSIONING !

22. 1. Oxygen Intake 2. Oxygen + Hemoglobin = Oxy-hemoglobin   Red colored 3. Co2 + Hemoglobin = Carboxy -hemoglobin Purple Colored 4. C02 Exhaled

23. Process of Carbon monoxide Poisoning CO + Hemoglobin = Carboxyl Hemoglobin

24. Health Effects of CO Poisoning

25. 3. Insecticides/ Herbicides Insecticides/ Herbicides are usually halogenated organo -compounds. The name " halogen" means "salt-producing ". When halogens react with metals they produce a wide range of salts, including  calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. They are mostly stable lipid soluble compounds . Their stability poses an environmental threat because they can circulate many years in the nature and cause chronic intoxications far away from the site of their original application.

26. Toxic Insecticide DDT is an organochlorine insecticide that acts chiefly on the Central Nervous System . DDT was initially used by the military in WW II to control malaria . Farmers used DDT on a variety of food crops in the United States and worldwide. DDT was also used in buildings for pest control. The reason why DDT was so widely used was because it is effective, relatively inexpensive to manufacture, and lasts a long time in the environment. After the dangers were discovered, it was replaced by other compounds belonging to this group but even these can pose ecological and health danger.

27. Agent Orange is a herbicide used by the U.S. Army as a defoliant in Vietnam war. Agent Orange is a very stable compound and circulates in the biosphere for a long time causing : Cancer Miscarriage Birth defects other health damage years after the primary exposure. Defoliant : Any chemical sprayed or dusted on plants to cause its leaves to fall off. Toxic Herbicide

28. 4. Industrial Wastes Many industries use solvents that are harmful to the living organism when released into the Industrial waste water due to lack of proper treatment systems. Carbon tetrachloride (CCl4) CCl4 is used as a solvent in many industrial processes . CCl 4 injuries almost all cells of the body, including those of the central nervous system, liver, kidney, and blood vessels. CCL4 is a Hepato -toxin  (toxic to the liver)

29. 5. Alcohol (-OH group) Intoxication METHANOL Methanol ( methyl group and wood alcohol ) is a widely used commercial solvent and is often mistaken for ethanol. In poisoning, about 30% of the dose is excreted as methanol by the respiratory tract ; the remainder 70% is converted, principally in the liver. The characteristic symptoms and signs of methanol poisoning (dizziness, abdominal pain, vomiting, breathing difficulties, acidosis, blurred vision, dilated pupils, urinary formaldehyde smell) manifest. The local production of formaldehyde in the retina is thought to be responsible for blindness, the most characteristic signs of methanol poisoning.

30. Ethanol VS Methanol Differences

31. Ethanol is produced by Yeast Fermentation

32. Contributing Factors for Diseases

33. Biological Factors (Biotic factors) Anything which affects the function and  behavior  of a living organism and its health is known as a biological factor .   Environmental Biological Factors Toxins

34. 1. Bacteria They are single cellular (unicellular) organisms also known as prokaryotes . They are smaller than fungus but larger than viruses. They can be seen under a microscope. They are of many different shapes. They are found everywhere in the environment i.e. in food, in dirt, in air and in our body. Bacteria can live outside our body’s cells.

35. Probiotics are lactic-acid producing bacteria often called "good" or "helpful" bacteria because they help keep your gut healthy. The  normal flora  are bacteria which are found in or on our  bodies  on a semi-permanent basis without causing disease.. The  human body  is home to around 10 14  bacteria. Environmental factor Disease Causing Bacteria

36. Mechanisms of Infection Endotoxins are released inside the host cells Exotoxins are released outside the host cells

37. Treatment of Bacterial Infections using Anti-Biotics Antibiotics  also called  antibacterials , are used in the  treatment and prevention of bacterial infections. They may either kill or inhibit the growth of bacteria. Antibiotics are not effective against viruses  such as the common cold 

38. Cholera Infection (Toxin Infection) Cholera is an infectious disease that causes severe watery diarrhea, which can lead to dehydration  and even death if untreated. It is caused by ingestion of food or drinking water contaminated with a bacterium called  Vibrio cholerae .

39. 2. Virus Virus in Latin means “ Poison” A  virus  is a small infectious agent that replicates only inside the living cells of other organisms. Viruses are really small in size when compared to bacteria and can be seen on an electron microscope. Viruses aren’t made up of cells (acellular). Instead they are made up of a protein coat and nucleic acids.

40. Virus is alive or dead ? Viruses are considered not living things by the scientist . Viruses are complicated, but on their own they can do nothing until they enter a living cell. Without host cells, viruses would not be able to multiply. Therefore, viruses are not living things.

41. Mechanism of Infection When a virus enters your body, it attacks some of your cells and takes over the cell machinery, redirecting it to produce the virus.

42. Common Cold Common Cold is caused by the influenza virus. Influenza is highly spreadable, it can be spread easily from person to person.   Viruses that cause influenza spread from person to person mainly by droplets of respiratory fluids sent through the air when someone infected with the virus coughs or sneezes. The most common symptoms  include: a high fever, runny nose, sore throat, muscle pains, headache, coughing, and feeling tired. People with the flu are advised to get plenty of rest, drink plenty of liquids , take medications such as paracetamol to relieve the fever and muscle aches associated with the flue.   Since influenza is caused by a virus,  antibiotics have no effect on the infection ; unless prescribed for secondary infections such as bacterial pneumonia.

43. Antiviral Drugs Antiviral drugs  are a class of medication used specifically for treating viral infections rather than bacterial ones. Most antivirals are used for specific viral infections, while a  broad-spectrum antiviral  is effective against a wide range of viruses.

44. Vaccines A vaccine is a biological preparation that provides active acquired immunity  to a particular disease and destroy any of these microorganisms that it may encounter in the future.  A vaccine typically contains an agent that resembles a disease-causing microorganism. They are for both bacteria and viruses. e.g Polio Vaccines HBV Vaccines

45. Why there are no vaccines for most viruses? Such as HCV Different genotypes High mutation rate

46. 3. Fungi A  fungi includes microorganisms such as  yeasts, molds and mushrooms. Fungal diseases are often caused by fungi that are common in the environment These organism are made up of many cells and are eukaryotic organisms. Fungi or fungus is known as the largest microbe and can be usually seen with a microscope. They are able to produce toxins and can cause many infections.

47. Differences between virus, bacteria and Fungi Differences Virus Bacteria Fungi Size Smallest microbe Larger than Virus Larger than Bacteria and Virus , also called largest microbe Cell Type Neither (non living) Prokaryotic (living) Eukaryotic (living) How many cells ? Acellular Unicellular Uni or multicellular Treatment Antivirals Antibiotics Antifungals

48. Types of infections caused by Fungus Antifungal  medicines are used to treat fungal infections, which most commonly affect your skin, hair and nails.

49. Fungal Diseases : Athlete's foot Athlete’s foot occurs when the tinea fungus grows on the feet. Athlete’s foot is a contagious fungal infection that affects the skin on the feet . You can catch the fungus through direct contact with an infected person, or by touching surfaces contaminated with the fungus. The fungal infection is called athlete’s foot because it’s commonly seen in athletes. Treatments include antifungal creams.

50. Mycotoxin : Aflatoxin B1 A  mycotoxin   is a toxin produced by fungi and is capable of causing toxic effects and death in both humans and animals. Mold species (type of fungi) may produce many different mycotoxins. Aflatoxin B1 Aflatoxins are a type of mycotoxin produced by  Aspergillus (mold)   species of fungi. They are regularly found in improperly stored corn, cotton, peanuts and rice . When contaminated food is processed, aflatoxins enter the general food supply as well as in agricultural animals. Animals fed contaminated food can pass aflatoxin products into eggs, milk products, and meat. For example, Aflatoxin-contaminated chicken meat and eggs in Pakistan due to contaminated poultry feed.

51. Bioterrorism Bioterrorism  is terrorism involving the intentional release of biological agents. These agents are  bacteria, viruses, fungi, or toxins , and may be in a naturally occurring or a human-modified form, in much the same way in  biological warfare. E.g. Ebola Virus Small Pox Dengue Virus

52. 4. Allergic Reactions Allergic agents can be from various biological factors i.e. Bacteria, fungus, plants or insect bites. Stings and bites from insects are common. They often result in redness and swelling in the injured area. Sometimes a sting or bite can cause a life-threatening  allergic reaction  or transmit pathogens

53. Pollen Allergy Pollen is one of the most common triggers of seasonal allergies. Many people know pollen allergy as “hay fever.” Experts usually refer to pollen allergy as “ seasonal allergic rhinitis (nose) .” Each spring, summer and fall, plants release tiny pollen grains to fertilize other plants of the same species. These plants make small, light and dry pollen grains that travel by the wind. Grasses are the most common cause of allergy.   Ragweed  is a main cause of allergies. Thus Limit your outdoor activities when pollen counts are high and use masks to avoid allergic reactions . Use ANTI ALLERGIC DRUGS .

54. 5. Parasites A parasite is an organism that lives on or in a host and gets its food from or at the expense of its host. Parasites can cause disease in humans. Some parasitic diseases are easily treated and some are not. Parasitic infections also affect people in developed countries.

55. Malaria Malaria is a mosquito-borne parasitic infection spread by Anopheles mosquitoes .   The  Plasmodium  parasite that causes malaria is neither a virus nor a bacterium. The parasite first travels to a human's liver to grow and multiply. It then travels in the bloodstream and infects and destroys red blood cells. The illness presents with flu-like symptoms that include high fever and chills. Malaria is treated by using chloroquine drug which is an anti-malarial drug.

56. MALARIA TRANSMISSION CYCLE

57. Contributing Factors for Diseases

58. Physical Factors (Abiotic factors) Important issues concerning physical hazards include those relating to health effects of electromagnetic radiation and ionizing radiation.

59. 1. Noise Pollution Noise pollution  is the disturbing noise with harmful impact on the activity of human or animal life. The source of outdoor noise worldwide is mainly caused by machines, transportation systems, motor vehicles engines and trains .  Outdoor noise is summarized by the word  environmental noise. Poor planning may give rise to noise pollution , side-by-side industrial and residential buildings can result in noise pollution in the residential areas. Noise-induced hearing loss (NIHL) is hearing impairment resulting from exposure to loud sound. Noise-induced hearing loss can be caused by outside (e.g. trains) or inside (e.g. music) noise. High noise levels can contribute to cardiovascular (heart) effects in humans.

60. 2. Ionizing Radiations Ionizing radiation also called radioactivity , is electromagnetic ( EM ) radiation whose waves contain high energy and high frequency to ionize the particles. They are dangerous for the environment and have adverse health effects : i.e. Genetic defects, cancer (leukemia), burns and radiation sickness. These are the radiations released in an atomic bomb. They include : 1- UV rays (From the sun due to thinning of ozone layer) 2- X rays (X ray tests) 3- Gamma Rays (Radioactive metals : Uranium in atomic bombs)

61. 3. Non-ionizing Radiations We use and are exposed to nonionizing radiation sources every day. Non ionizing radiations have less energy and less frequency. These radiations are less harmful as compared to ionizing radiations that’s why they are used more commonly in our daily appliances. Some forms of nonionizing radiation can damage tissues if we are exposed too much . Microwave ovens use microwaves to heat food. Toasters use infrared waves to heat. We watch television, talk on cell phones, and listen to the radio through the use of radio waves .

62. Can Microwave oven Cause Cancer ? FOOD HEATED IN MICROWAVE OVEN Microwave ovens work by using microwaves . When microwaves are absorbed by food containing water , it causes the water molecules to vibrate, which produces heat. Microwaves do not use x-rays or gamma rays, and they do not make food radioactive . Hence answer is NO RAYS EMIITED FROM MICROWAVE OVEN Microwave ovens are designed so that the microwaves are contained within the oven itself . The oven only makes microwaves when the door is shut and the oven is turned on. When microwave ovens are used according to instructions, there is no evidence that they pose a health risk to people. Ovens that are damaged or modified, however, could allow microwaves to leak out , and so could pose a hazard to people nearby by potentially causing burns.

63. Differences Between Ionizing and Non-ionizing Radiations Differences Ionizing Radiations Non Ionizing Radiations Energy HIGH LOW Frequency HIGH LOW Wavelength SHORT LONG Effects on health Fatal/Death Harmful if exposed longer Daily Usage Rarely used Commonly Used

64. 6 Steps of Problem Solving

65. Improving human health by problem solving e.g. Antivirals Antibacterial Antifungals Surgery e.g. Vaccination Clean water Clean Air Clean food Mosquito control