Water Well Journal

February 2015

Water Well Journal

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Page 43 of 75

E ach of us wakes up 365 times a year. We go to work approximately 200 times a year. We anticipate finishing our day as healthy as when we started, every single time. We go about our day being careful and keeping an active watch for dangers and pitfalls. Unfortunately, sometimes this isn't enough. One of the most common killers at home and at work is carbon monoxide—the silent killer. Carbon monoxide (CO) is a colorless, odorless, and tasteless gas slightly less dense than air. This means it's impossi- ble to detect it. Often, people associate CO with automobile exhaust and believe this exhaust smell is a useful warning sign of high levels of carbon monoxide. While it is true auto exhaust does con- tain plenty of CO, it is the multitude of hydrocarbons that can be smelled. What CO Is Carbon monoxide is most commonly produced through incomplete combus- tion including the combustion of gasoline exhaust, organic material (firewood), and flammable gases (grills or heaters). It is generated in the human body through normal bodily functions such as cell me- tabolism and digestion. It's also created in some chemical reactions such as when hydrogen peroxide or acids are applied to wells as part of a rehabilitation process. Each of these instances has its own asso- ciated telltale odors, but none of those odors are actually CO. Since carbon monoxide is less dense than air, it tends to rise. This means an activity occurring at some distant loca- tion of a building can cause CO to accu- mulate on upper floors—impacting completely unaware occupants. I have seen this occur on the upper floors of buildings that house welding or burning processes on the lower floors. Carbon monoxide can also accumulate in rooms located above garages or maintenance shops where engines might be idling. Why CO Is Dangerous Since carbon monoxide is a normal byproduct of the body, it makes sense there's an actual beneficial purpose for it. At normal concentrations, CO is a key substance that controls respiration and heart rate. However, at higher levels it actually blocks the body from using the oxygen that is in the air. Carbon monoxide has a greater at- traction to hemoglobin (red blood cells) than oxygen does. Therefore, if both are present in the lungs, the blood will ab- sorb the CO first. And as CO is so easily absorbed in the hemoglobin, it resists dropping off as the blood travels through the body, creating a potentially fatal condition called carboxyhemoglo- bin. This means not only will the cells not receive the oxygen they need, but they will also not be able to dispose of the waste they have generated. This will cause the cells to starve. How Much CO Is Too Much? We actually inhale carbon monoxide all day long. Normally, we will be exposed to about 0.1 parts per million in clean outdoor air. In urban areas and inside homes, the level will generally range from 0.5 to 5 ppm. If the home has a gas stove, it would not be uncom- mon to approach 10 ppm. That level in- creases to 15 ppm in a well-maintained vehicle. Poorly maintained vehicles using cheap grades of gasoline can easily exceed 100 ppm. Direct exhaust from burning wood or a gasoline engine will reach 5000 to 10,000 ppm. The average residential CO detector will sound an alarm when it senses around 9 to11 ppm. At this concentration most people will observe no adverse health effects. However, it is much higher than you would expect in a home and is indicative that something is amiss. This is a good time to quickly check your pilot lights in your oven, stove, hot water heater, gas fireplace, and furnace. If these are found to be operating nor- mally, you would be well advised to leave the house and call your local fire department for a professional evaluation. The National Institute for Occupa- tional Safety and Health recommends that workers are exposed to no more than an average of 35 ppm over a 10- hour period and are never exposed to greater than 200 ppm. The Occupational Safety and Health Administration has set its permissible exposure limit to 50 ppm over an 8-hour workday. The National Research Council has set an emergency permissible level of 1500 ppm for 10 minutes. Obviously, this is a pretty wide range of concentration that someone could find themselves exposed to. Health Effects As the concentration of CO passes 10 ppm, it's common to notice some in- creased yawning or a slight loss of con- centration. As the level rises past 35 ppm, a person will experience confusion, tired- ness, and loss of motivation. As the CO levels and the time in the area increase, this tiredness will increase and will likely be accompanied by a significant headache, mental confusion, nausea, and vomiting. Exposure to more than 800 ppm will cause loss of muscle control, unconsciousness, brain damage—and even death in only a few minutes. On average, about 170 people in the United States die every year from carbon monoxide produced by non- automotive consumer products. CARBON MONOXIDE: THE SILENT KILLER Don't underestimate this deadly health hazard. SAFETY MATTERS JACK GLASS 42 February 2015 WWJ waterwelljournal.com

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