What are we learning about…? Upon completion of this part, you shall be able to: Recognize the “Radiation” symbol Recognize areas that may contain radioactive materials Identify the difference between Radiation and Contamination Describe background radiation Describe the potential long term and short term risks associated with radiation exposure

What does the RADIATION Symbol look like? All radioactive materials and radiation generating devices must be labeled with the universal symbol for radiation Only authorized individuals who are properly trained should handle materials or devices with this radiation symbol

What is Radiation? Radiation is energy emitted from a substance. There are two types of radiation: 1) Non-ionizing Radiation: Everyday examples of non-ionizing radiation are Microwaves used to cook food Radio waves Television Light 2) Ionizing Radiation: Means alpha particles (α), beta (β), gamma (γ) and X-rays (among others) that are capable of producing ions. These types of energy can cause chemical changes to living things. Large exposures to ionizing radiation may damage cells or tissues. Real-life examples of ionizing radiation are X-ray machines and radioisotopes used in biomedical research.

What is Contamination? Contamination is radioactive material in a location where it is not desired Lab bench, door knobs, telephone, computer, offices, etc. Loose Contamination, like dust, can be easily removed Fixed contamination is embedded in the material’s surface and is more difficult to remove.

What is an “Occupational Dose”? Occupational exposure or dose is the amount of ionizing radiation received by individuals from their assigned duties during their normal course of employment. Doses received from background radiation from nature, medical examinations and treatments, or as members of the public are not considered occupational exposures.

What is a radiation dose ? A radiation dose is an amount of ionizing radiation that is absorbed by human body. Regulations limit radiation doses to members of the general public or non-radiation workers to 100 millirem per year. State and Federal regulations limit radiation doses to radiation workers to 5000 millirem per year.

Natural Background Radiation

EXPOSURE LIMITS Background Background varies depending upon the altitude and ground and building materials. DOSE (mR/yr) SOURCE 0.3 ‑ 1 watching TV for 4 hours daily at 12 feet (x‑ray emission from screen) 4 reading glossy magazines for 1 hr/day (uranium and potassium in clay paper coating) 5 eating 1 banana per day (potassium (K‑40) in banana) 10 living in a brick house instead of a wood one (potassium, uranium and thorium in clay in the bricks) 70 living in Denver instead of at sea level (increased background radiation due to elevation and igneous rocks) 100 flying ~5000 miles per month (reduced atmospheric radiation shielding) 100 ‑ 200 radon gas inhalation (national average) 100 ‑ 200 foods and fertilizers (naturally-occurring potassium(K‑40) and uranium in super-phosphate fertilizers 150 medical technicians (yearly average) 170 flight crews (reduced atmospheric radiation shielding) 2000‑5000 dose to lungs – smoking 1 pack of cigarettes/day polonium (Po-210) and lead (Pb-210) from U decay series from U decay series

Radiation Risk All radiation exposure is accompanied by some risk. The lower the exposure, the lower the risk. Keep exposure to radiation ALARA – “As Low As Reasonably Achievable.”

Acute Exposure Risk Acute Exposure – Relatively high exposure over a short time Threshold for any effect - 100,000 mrem Flu-like symptoms that self resolve in a few days (nausea, vomiting, malaise, headache, etc) LD 50/30 – 500,000 mrem (without medical treatment), 50% of the exposed will die in 30 days

Chronic Exposure Risk Increases likelihood of cancer US Cancer rate is approximately 25% Each 1000 mrem of exposure increases chance of cancer by 0.03%

How do we measure Radiation Dose ? We measure the dose received by radiation workers by reading their Dosimetry (radiation badges) each month Two types of dosimeters are available: a badge and a ring. Wear the badge face-out between your neck and waist Only wear the badge issued to you Only wear the badge while at work Wear the ring on the index finger of your non-dominant hand Wear the ring with the barcode facing inward (towards your palm).

How do I keep my exposure low? Each Individual (this means YOU) is responsible to ensure that exposures are kept As Low As Reasonably Achievable (ALARA) Reduce Time in radiological area Increase Distance to radioactive materials Use Shielding between you and sources of radiation

What Rules Should I Follow When Working In the Labs? The risk of receiving a radiation overexposure from work practices on campus is minimal. The risk is no greater than other common activities such as using power tools, climbing a ladder or using electricity. By following a few basic rules, you can ensure you work safely while in areas posted with the radiation symbol: Follow all room postings carefully. Announce yourself and state your purpose when entering the lab. If no one is present in the lab, contact the Principal Investigator or lab supervisor. Ask lab personnel which areas of the lab, if any, should be avoided. Do not handle anything labeled with the Radiation symbol (unless directed by Radiation Safety staff or the Principal Investigator).

What Should I Do If Equipment needs Repair or Service? You should never attempt to repair any equipment. Any equipment with a radiation symbol must be surveyed and declared free of contamination by Radiation Safety before repair or service can begin. This includes (but is not exclusive to): All structures (tables, sinks, fume hoods, etc.) potentially contaminated with radioactive materials will be labeled with the Radiation Symbol.

What Should I Do if There is an Emergency? Injury - If there is a personal injury, follow normal emergency procedures and DISREGARD any concern about radiation exposure. The potential for receiving any measurable radiation dose is minimal. Render First Aid if trained and able - Medical Attention is ALWAYS the FIRST priority over exposure control.

What Should I Do If There is an Emergency? Spills - If there is a spill in a radiation laboratory or any spill that involves radioactive material, do not attempt to clean up the spill yourself. Secure the area Contact Radiation Safety people