Protecting workers from radiation on the job
You may not be able to see radiation, but you’re probably aware that it can be deadly in high doses. Many people who came of age during the Cold War have a strong fear of nuclear weapons. And when a tsunami crippled Japan’s Fukushima nuclear power plant nearly a decade ago, leading to one of the largest accidental releases of radiation in history, people began to panic. Here in the U.S., some residents of the Pacific coast bought iodine pills to protect themselves from the effects of any radiation that would blow across the ocean.
Radiation can be terrifying, but it’s also a part of everyday life. On an average day, most of us are exposed to far more radiation than we could ever receive from an accident halfway across the world. Many of us are exposed to even more radiation through our jobs.
Radiation is energy that travels through the air, occurring in one of two types: ionizing or non-ionizing. Ionizing radiation is able to change the atoms to which it is exposed by removing electrons. Because human cells are made up of atoms, they can be affected by ionizing radiation.
Non-ionizing radiation can cause atoms to move or vibrate, but it cannot remove electrons. Non-ionizing radiation is all around us. Radio waves and visible light are two common examples. When you put a sandwich in a microwave oven, non-ionizing radiation vibrates the atoms in the sandwich, causing it to heat up. The temperature and texture of the sandwich change, but its atoms remain the same, so it’s safe to eat. Or, when you place a call with a cell phone, non-ionizing radio waves travel from the phone to the nearest tower to connect you with other towers and the person you’re calling.
When we discuss the hazards of radiation, we’re generally referring to ionizing radiation. When it removes electrons from atoms, it creates charged particles that are known as ions. If ions are used in a controlled manner, they can serve useful purposes, whether that’s generating electricity or wiping out cancer cells in the body. But when the body is exposed in other ways, those useful ions can become quite damaging.
Ionizing radiation falls into three basic types: alpha particles, beta particles, and a group that includes gamma rays and x-rays. Each operates at different frequencies and has different effects. For example, x-rays can be sent through an object such as person’s arm or a welded pipe. Areas in the object that are denser will absorb the x-rays, so fewer of them will reach the film, which creates a lighter image. The resulting dark areas can pinpoint problems such as fractures.
How radiation can affect people
All forms of ionizing radiation can have significant health effects, but the potential impact depends upon the type of radiation and the amount to which a person is exposed. The different types of radiation affect different kinds of body tissue, primarily because of the amount of energy involved and the nature of each type of radiation. As an example, if a person is exposed to equal amounts of alpha and gamma radiation, the alpha particles will concentrate their energy in a much smaller area, and the gamma rays will spread out.
Ionizing radiation can affect any type of living tissue. The severity of the damage depends upon both the amount of radiation being received and the amount of time involved.
Stochastic health effects are those that result from long-term exposure to low levels of ionizing radiation. The most common of these is cancer. A healthy body can regulate the growth of new cells and repair those that have been damaged. But when radiation affects those regulation and repair processes, cells can grow at an uncontrolled rate. That uncontrolled growth is what we call cancer.
Another stochastic effect involves changes to DNA, which is the set of instructions that tells our cells how to form and behave. Changing DNA creates what are known as mutations. Some mutations affect only someone who has been directly exposed to radiation, while others can be passed on through the womb to children.
Non-stochastic health effects are usually the result of exposure to significantly higher levels of radiation, even for just a short time. They include burns and what’s known as radiation “poisoning,” which can be fatal. High doses of radiation can destroy bone marrow, shut down the nervous and/or digestive system, and lead to the loss of limbs.
Where you’ll find workplace radiation
As we mentioned, ionizing radiation appears in the form of x-ray machines in healthcare facilities and manufacturing settings. In healthcare, radiation is also used in diagnostic devices, such as CT scanners, and concentrated for the treatment of tumors and cancers.
In industrial settings, radiation can be used in testing devices, to sterilize products, for determining soil moisture levels, in weapons production, and in nuclear power plants. None of those uses is inherently dangerous, if the required safety devices and processes are in place and used properly. Those working with radiation need to understand the safety procedures, the consequences of failing to follow them, and what to do in the event of an incident.
Fortunately, radiation levels encountered in the workplace tend to be very small. In fact, the levels that are high enough to cause non-stochastic health effects rarely occur in workplaces. Even workers in towns close to the Fukushima plant received daily doses that were smaller than what most people receive with a dental x-ray. That’s why radiation safety focuses on protecting workers from long-term exposure to lower doses.
Safety around radiation
Effective safety training focuses on the three ways workers can limit their exposure to radiation: maintaining a safe distance, limiting the time around the source, and using shielding to limit the exposure.
Depending upon the work conditions and the type of radioactive material, other safety measures may also be needed. One example is the use of dosimeters that measure radiation and sound an alarm when specific thresholds are reached. If workers are around radioactive dust, respirators help to keep the dust from being inhaled. Gloves or other kinds of personal protective equipment may also be needed.
Like fire, radiation is both a valuable tool and a potential hazard. There’s no need to be terrified of radiation, but as with fire, it’s good to develop a healthy respect for its power and use practices that minimize potential dangers.