![3. Photon radiation (gamma [γ] and X-
ray).
• Photon radiation is electromagnetic radiation.
There are two types of photon radiation of
interest for the purpose of this document:
gamma (γ) and X-ray. Gamma radiation
consists of photons that originate from within
the nucleus, and X-ray radiation consists of
photons that originate from outside the
nucleus.](https://image.slidesharecdn.com/chapter7biologicalhazards-210511182652/85/Chapter-7-biological-hazards-38-320.jpg)
Chapter 7 biological hazards
- 1. Module 7: Biological and Physical hazards 1) Introduction 2) Types of Biological Hazards. 3) How do biological hazards enter the body? 4) How Biological Hazards are Spread. 5) Controlling Exposure to Biological Hazards. 6) Role of the health and safety representative. 7) Types and Sources of Radiation.
- 2. Introduction • Biological hazards are organic substances that pose a threat to the health of humans and other living organisms. Biological hazards include pathogenic micro-organisms, viruses, toxins (from biological sources), fungi and bio-active substances. Biological hazards can also be considered to include biological vectors or transmitters of disease. • Worldwide, it is estimated that around 320 000 workers die each year from communicable diseases caused by work-related exposures to biological hazards (Driscoll et al. 2005; OSHA 2007).
- 3. Types of Biological Hazards • Biological hazards can be put into different categories. The most common biological hazards include: • Bacteria – microscopic organisms that live in soil, water, organic matter or the bodies of animals. • Viruses – a group of pathogens that consist mostly of nucleic acids and that lack cellular structure. Viruses are totally dependent on their hosts for replication. • Fungal infections can affect anyone, and they can appear on several parts of the body. • Fungal infections can be contagious. They can spread from one person to another. In some cases, you can also catch disease-causing fungi from infected animals
- 4. Examples of different types of biological hazards: • Bacteria – Escherichia coli (E. coli), Mycobacterium tuberculosis (TB), tetanus • Viruses – common cold, influenza, measles, SARS, Hantavirus, rabies • Fungi – athlete’s foot.
- 6. How do biological hazards enter the body? • Factors that determine if a person will contract a disease and how bad it will be include the dose, type of organism and the resistance (or susceptibility) of the individual. Some organisms can live outside a host for hours or even days, while others require a host to survive. Some organisms are very small and lightweight, remaining in the air for long periods. Others quickly settle out onto surfaces, and are a contact concern. All of these issues affect potential exposure.
- 7. Cont……. • Biological hazards can enter the body by different routes. When determining appropriate protective measures, a clear understanding of how biological hazards enter the body is an important first step.
- 8. Routes of Entry Biological hazards enter the body through: 1) Inhalation; i.e., breathing 2) Absorption; i.e., direct contact through breaks in the skin, even chapped skin, or through mucous membranes/contact with eyes, nose, mouth 3) Ingestion; i.e., swallowing 4) Injection; i.e., through a puncture
- 9. Cont………. • The most common routes of entry for biological hazards are inhalation and absorption from direct contact. 1. Inhalation • Inhalation is a common way for biohazards to get into the body. The effect on the body depends on the biohazard and the amount that is breathed in.
- 10. Cont… • Although our immune system and lungs have mechanisms to fight germs, many biohazards are very strong and can overcome our defenses. 2. Absorption • A biohazard can enter the bloodstream through broken skin, such as a cut, chapped skin, or any other break in the skin. Cover broken skin with a bandage or gloves to seal the wound and wear appropriate protection to keep the wound area safe from biohazard us penetration. Splashes of blood/body fluids to the eyes is another way biohazards can be absorbed.
- 11. 3. Ingestion • Swallowing biohazards can sometimes occur without us knowing it, often simply from not washing our hands. Poor hand washing is one of the most common ways that biological hazards can be transmitted. Workers should always wash their hands before eating so that any hazardous material on the hands is not ingested.
- 12. Cont…….. • In labs or any areas where specimens and other materials that are toxic by ingestion are commonly used, there must be no drinking or eating. No food should ever be stored in refrigerators where hazardous biological materials are stored. 4. Injection • When something sharp punctures the skin, a biohazard can enter the body through the skin.
- 13. Cont…… • if that glass contained a biohazard, picking the pieces up with your bare hands could enable the biological agent to enter your body through the cut or puncture.
- 14. How biological hazards are spread • The transmission of biological hazards can be reduced by using certain precautions.
- 15. Biohazard Disease Spread Precaution/Control Virus Hepatitis B Human to human contact Immunization; avoid intimate contact with infected person; avoid tattooing and body piercing; follow standard precautions; dispose of sharps in sharps disposal container Virus Hepatitis C Human to human contact Avoid intimate contact with infected person; avoid tattooing and body piercing; follow standard precautions Virus Hepatitis A Human to human contact Do not ingest contaminated water or food; avoid direct contact with infected person
- 16. Controlling Exposure to Biological Hazards • There are three approaches to control hazards. The first consideration for controlling biological hazards, as with all other types of hazards, is to look at engineering controls. If a hazard cannot be eliminated or physically controlled through engineering methods, the second approach to controlling hazards is administrative controls. Finally, if exposure to a hazard cannot be prevented with either engineering or administrative controls, then personal protective equipment is necessary.
- 18. Engineering Controls • Engineering controls are the preferred defense and include built-in protection in buildings, work areas, equipment or supplies. Hazard protection is built in and, therefore, control is at the design stage. Examples of controlling biological hazards, using engineering controls in a building, are: - Bio-safety hoods, with specific ventilation systems.
- 19. Other engineering controls include: • Sharps disposal containers for needles and other sharps – eliminates the potential of getting cut or injected with potentially infected body fluids. These containers allow sharps to be disposed in a manner that minimizes the risk of puncture. In addition, the container itself is puncture-proof and is usually appropriately labeled during the manufacturing process. • Self-sheathing needles and lancets as well as needleless systems –engineered to eliminate and prevent puncture wounds.
- 20. Administrative Controls • Administrative controls are steps in work procedures or work processes that minimize the risk of exposure to a hazard. This type of control does not eliminate a hazard but can significantly reduce the risk of injury. Administrative controls are set up by management and workers and are used if a hazard cannot be eliminated or reduced through engineering controls. Examples of administrative controls include
- 21. Cont………. 1. worker training 2. Policies, such as rules that require regular hand washing. 3. Specific work schedules to rotate duties so that exposure times are limited. While management generally must make the rules, workers are responsible for following them. Administrative controls require constant diligence/persistent to be effective.
- 22. Cont……….
- 23. Cont……. • Vaccination is a type of administrative control; however, vaccines do not exist for all biological hazards. For example, hepatitis B vaccine is widely available and influenza vaccine is also common. Other biohazards, such as hepatitis C, hantavirus and many others, do not yet have vaccines.
- 24. Personal Protective Equipment • When a hazard poses a threat, even after engineering and administrative controls have been implemented, then personal protective equipment (PPE) is necessary. • The most common items of personal protective equipment to protect from biological hazards include: • latex gloves. • Proper mask for biohazards. • Eye protection.
- 25. PPE
- 26. Role of the health and safety representative
- 27. Ebola Virus
- 28. Cont…….
- 29. Transmission of Ebola virus
- 30. Types and Sources of Radiation • Radiation is energy in the form of waves of particles. There are two forms of radiation – non-ionizing and ionizing. • Ionizing radiation, either electromagnetic ionizing radiation (gamma radiation), or particle radiation. The major concern with exposure to ionizing radiation is severe tissue damage at very high levels and a risk of cancer in the future at lesser levels. • No ionizing radiation consists of electromagnetic radiation of longer wavelengths when the energy level is too low to ionize atoms but sufficient to cause physical changes in cells. Ultraviolet radiation is the most common form and causes sunburn and prolonged exposure over time causes cataracts and skin cancer.
- 31. Cont………. Examples of Ionizing Radiation Man made examples of Ionizing Radiation: Medical testing equipment such as x-rays, radiotherapy, and tomography Nuclear Reactors Examples of Non-Ionizing Radiation Man made examples of Non-Ionizing Radiation: Cell towers Wi-Fi Cell phones
- 32. Cont………. 1. Non-ionizing radiation • Non-ionizing radiation has less energy than ionizing radiation; it does not possess enough energy to produce ions. Examples of non- ionizing radiation are visible light, radio waves, microwaves, and sunlight.
- 33. Cont……. • Cellular telephones, television stations, FM and AM radio, Other forms include the earth’s magnetic field, as well as household wiring and electric appliances. These are defined as extremely low-frequency (ELF) waves and are not considered to pose a health risk.
- 34. 2. Ionizing radiation • Ionizing radiation is capable of knocking electrons out of their orbits around atoms, upsetting the electron/proton balance and giving the atom a positive charge. Electrically charged molecules and atoms are called ions. Ionizing radiation includes the radiation that comes from both natural and man-made radioactive materials.
- 35. Four Primary Types of Ionizing Radiation 1. Alpha 2. Beta 3. Photons • Gamma rays • X-Rays 4. Neutrons
- 36. 1. Alpha radiation (α) • Alpha radiation consists of alpha particles that are made up of two protons and two neutrons each and that carry a double positive charge. Due to their relatively large mass and charge, they have an extremely limited ability to penetrate matter. Alpha radiation can be stopped by a piece of paper or the dead outer layer of the skin. Consequently, alpha radiation from nuclear substances outside the body does not present a radiation hazard.
- 37. 2. Beta radiation (β) • Beta radiation consists of charged particles that are ejected from an atom’s nucleus and that are physically identical to electrons. Beta particles generally have a negative charge, are very small and can penetrate more deeply than alpha particles. However, most beta radiation can be stopped by small amounts of shielding, such as sheets of plastic, glass or metal. When the source of radiation is outside the body, beta radiation with sufficient energy can penetrate the body’s dead outer layer of skin and deposit its energy within active skin cells. However, beta radiation is very limited in its ability to penetrate to deeper tissues and organs in the body. Beta-radiation-emitting nuclear substances can also be hazardous if taken into the body.
- 38. 3. Photon radiation (gamma [γ] and X- ray). • Photon radiation is electromagnetic radiation. There are two types of photon radiation of interest for the purpose of this document: gamma (γ) and X-ray. Gamma radiation consists of photons that originate from within the nucleus, and X-ray radiation consists of photons that originate from outside the nucleus.
- 39. Cont…….. • Photon radiation can penetrate very deeply and sometimes can only be reduced in intensity by materials that are quite dense, such as lead or steel. In general, photon radiation can travel much greater distances than alpha or beta radiation, and it can penetrate bodily tissues and organs when the radiation source is outside the body. Photon radiation can also be hazardous if photon-emitting nuclear substances are taken into the body. An example of a nuclear substance that undergoes photon emission is cobalt-60, which decays to nickel-60.
- 40. 4. Neutron radiation (n) • A common source of neutrons is the nuclear reactor, in which the splitting of a uranium or plutonium nucleus is accompanied by the emission of neutrons. • Neutrons are able to penetrate tissues and organs of the human body when the radiation source is outside the body. Neutrons can also be hazardous if neutron-emitting nuclear substances are deposited inside the body.
- 41. Cont……….