Industrial Hygiene and Toxicology
Thermal radiation also known as infrared which is a form of light that can not be seen, we can only see visible light. Infrared gives us information that we would not be able to get from visible light. Because all object gives off some type of heat, yes, all objects even if the of cold or frozen. Cold or frozen objects only gives off a very small amount of heat, but this heat can be detected by infrared. We can use infrared to gather information about the heat and temperature an object has. Anything that has a temperature whether it is cold or hot will give off will give off infrared light or heat.
When looking at these objects the hotter they are the brighter they are. The less bright they appear they cooler the object is. For example if you used infrared to look at a cold or frozen object you would notice the object does not appear bright at all, but the further away from that object you move it will start to get brighter because the area is warmer than the object. The opposite is true for a hotter object the further you move from the heat the less bright the area appears. It was discovered in an 1800 experiment by William Herschel, the same astronomer that discovered Uranus.
He used a cut-glass object to separate the sunlight into a spectrum of colors. While taking the temperature of the visual colors, he noticed when he placed the thermometer bulb just beyond the red colors the temperature would raise, this was the birth of thermal radiation. There are types of radiations in the electromagnetic spectrum, a lot of which we can not see. The little portion that we can see is called light. This spectrum is identified by either short or long wavelength, infrared is non-ionizing radiation found in the long wavelength between microwaves and visible light. Infrared radiation (IR) has wavelengths ranging from 780 nm to 1 mm.
The fire department uses infrared or thermal imaging to see through smoke during fires to help find personnel that may injured or trapped in the fire and find hot spots after a fire has been put out. The military uses it to help support in night surveillance and missions. The police department uses it for ground and aerial search, for example a thief hiding or running from the police at night The workplace is host to a variety of IR hazards, including both short-and long-term exposures that represent real health risks.
Examples of operations that produce infrared radiation include welding, cutting, brazing, furnace operations, pouring, casting, hot dipping, glassblowing, lasers and high-intensity light sources (Sankpill, 2009)”. Working in the sun can cause sunburn from the rays of the sun. Infrared exposure has been know to cause cataracts. Two occupations that are most know for this is glass-blowers and furnace operators. Infrared exposure can also cause a loss of site. When it absorb in the eye, the area of the retina is damaged which cause you to loss site in that area. The American Conference of Governmental Industrial Hygienists (ACGIH) guideline for IR-A exposure of the anterior of the eye is a time-weighted total irradiance of 100watts per square meter for exposure durations exceeding 1,000 seconds (ACGIH 1992 and 1995) (Sankpill, 2009)”. All employees should try and engineer these hazards out or find a way to protect the employees by shielding them from the hazards. If this is unable to be accomplished than personal protective equipment (PPE) should be used as a last result.
Also due to the new technologies plastic and polycarbonate lenses have been developed to absorb infrared across the entire lens at a consistent level. “Concerns have been raised about a possible link between some types of non-ionizing radiation and cancer. The way in which it might do this isn’t clear. Non-ionizing radiation doesn’t damage DNA directly, but it may be able to affect cells in other ways. The possible links between some of types of non-ionizing radiation and cancer are discussed below.
But at this time, non-ionizing radiation has not been established as being able to cause cancer” (Society, 2010). In conclusion, infrared there are still a mixed opinions about the effect it has on the body. So it is best as always to take the proper steps to keep you safe. That means wearing the proper personal protective equipment when it is required. Also if you have to work with or around infrared you should always take it a pond yourself to learn the limitations of any type of radiations so that you will know how to protect yourself.
Reference Page
- Matthes, R., & Stellman, J. M. (2011). Infrared Radiation. Retrieved May 25, 2013, from ILO Encyclopaedia of Occupational Health & Safety: http://www.ilo.org/oshenc/part-vi/radiation-non-ionizing/item/654-infrared-radiation
- Sankpill, J. P. (2009, October). U.S. Safety. Retrieved May 28, 2013, from U.S. Safety Web site: http://www.ussafety.com/media_vault/documents/1258397660.pdf
- Society, A. C. (2010, March 29). Radiation Exposure and Cancer. Retrieved May 28, 2013, from American Cancer Society web site: http://www.cancer.org/cancer/cancercauses/othercarcinogens/medicaltreatments/radiation-exposure-and-cancer
