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April 2013

From Out of the Blue-Misconceptions about Lightning!

Jones Tony Posted by Tony Jones

People are working outdoors frequently, often year around.  We also enjoy recreational activities outside in the summer months.  The weather can pose hazards any time of year, but as we enter the spring months lightning becomes more prevalent.  While on a trip of a lifetime to Alaska last summer, I witnessed a distant lightning strike on the tundra on a nearly cloudless day. It took us all completely by surprise, and got me thinking. I never expected a lightning strike nearby that day. Later, while looking up the subject, I ran across some interesting articles regarding lightning myths and misconceptions. 

First: Under clear skies, you are safe from a strike. “Bolts from the blue” can travel and strike as far as 25 miles from storm clouds. Before heading out to a worksite, or simply preparing for the day's activities, check your area’s weather forecasts. Look for storms within 100 miles of your area and watch the direction they’re trending. If you can hear thunder, look for shelter before the thunder and lightning are 30 seconds apart. Stay under cover until 30 minutes have passed since the last thunderclap.

Second: You can hide from lightning. No place is 100-percent safe in the outdoors, but some locations are better than others. Get as low as you can relative to the surrounding topography. Avoid any open areas such as cleared lots, open meadows, or lakes. You should also consider avoiding taller natural structures such as trees, peaks, or ridges. You best option is to get inside a building or hard-topped car.

Third: While camping crouching on a sleeping pad will insulate you from a direct strike. Nothing in the backcountry will insulate you against a strike or ground current (the most common cause of lightning injury). Reduce exposure to both by assuming a tucked, tight crouch. Remember, objects close to the ground are less likely to be lightning strike targets. Keep your arms and feet close together. Spreading them increases the severity of injuries and burns if you’re struck. Don’t lie down. Minimize contact with the ground; keep your body’s footprint as small as possible.

Fourth: Lightning strikes are always fatal—and you’ll be electrocuted if you touch him.  Interestingly, about 90% of lightning strike victims survive. After being hit, they can’t shock you—but will likely benefit from first aid.  Administer CPR when appropriate; almost all lightning fatalities are due to cardiac arrest. Look for and address head injuries and fractures. Treat burns with water and a moist bandage. Call 911 and/or evacuate victims to a hospital as soon as possible.
Check out this resource from the National Oceanographic and Atmospheric Administration and be safe this summer at work and play.


Heads-up! "Text Neck" on the Rise

LaRochelle Greg 2 Posted by Greg LaRochelle


With today’s mobile devices – smart phones, laptops, and tablet computers, physicians, physical therapists and chiropractors are seeing a dramatic increase in musculoskeletal disorders of the neck and upper back.  The term “text neck” was coined in 2008 to describe the nerve pain and headaches associated with prolonged use of these electronic gadgets.  As a telling statistic, according to Cisco’s Global Mobile Data Traffic Forecast Update, the average amount of data used on a smart phone tripled from 2010 to 2011.

The average human head weighs 10-12 pounds when held upright in the neutral position.  The forces on the cervical spine increase significantly when tilting the head forward.  For example, holding a smart phone at mid-torso height creates 20-30 pounds of force on the supporting neck.  Maintaining a forward head posture can lead to pinched nerves, muscle strain, and disc damage.  Over time, the natural inward curve of the cervical spine can flatten with a loss of elasticity causing even more problems.  Additionally, prolonged forward head posture can contribute to cardiovascular disease from reduced lung capacity (shortness of breath) as well as gastrointestinal problems from increased pressure on organs.

Obviously, our mobile computing and communication technology isn’t going away so how does one avoid the detrimental effects of “text neck” disorder?

  • Physical therapists advise taking frequent breaks (every 20 minutes) while using mobile devices.  These micro-breaks should involve rolling the shoulders, stretching the neck’s primary flexor muscles (sternocleidomastoids) by extending the head back, and taking a short, brisk walk to stimulate increased blood flow.
  • For tablet and laptop use, add an external mouse, keyboard, and raise the device on a stand or stack of books.
  • Communicate verbally using the phone for its intended purpose rather than trading messages by texting or email.  
  • There’s even a mobile app called the Text Neck Indicator, created by the Text Neck Institute, which signals a green light when the phone is held at an acceptable viewing angle and a red light, conversely.  For more information click on The Text Neck Institute.

So take a tip from the title of the 1972 hit song by Argent and “Hold Your Head Up”.


Combustible Dust: An Airborne Hazard

Steven Badger  by Stephen Badger, CSP, OHST

On February 7, 2008, a large explosion occurred at a sugar refinery owned by Imperial Sugar, in Port Wentworth, Georgia.  The accident killed 14 workers and injured another 40.  The explosion, centered in the middle of the factory, was determined to have been caused by “combustible dust”.  Between 1980 and 2005 combustible dust explosion killed 119 people and injured an additional 718.  This blog reviews the definition of combustible dust, and how to prevent it from becoming dangerous.

Combustible dust is any combustible material that can burn rapidly when in a finely divided form. If such dust is suspended in the air, at the right concentration, under certain conditions, it can become explosive.1 

Many types of materials can be explosive when in dust form; these include but are not limited to: sugar, spice, starch, flour, grain, tobacco, plastics, wood, paper, pulp, rubber textiles, pesticides, dyes, coal and various metals (e.g. aluminum, chromium, iron, magnesium and zinc).  OSHA has created a poster that lists many of the potentially combustible materials.2

Combustible dust requires several factors for an explosion to occur:

  • Combustible dust must exist in the work environment
  • High enough concentrations of the dust must be airborne to support combustion
  • An ignition source is required
  • The work area must be sufficiently enclosed to allow concentration of the combustible dust to increase
  • Oxygen levels in the work environment must be sufficient to start and maintain combustion

Following are three, specific actions that can be taken to reduce the likelihood of a combustible dust explosion:

  1. Reduce the ability for material to become airborne.  Many companies use collection systems to take dust from the point of generation to bins, or hoppers, for ultimate disposal.  These systems must be designed by professionals to eliminate the risk of explosions within the dust collection system.
  2. Ensure that dust concentrations remain below levels that can combust, or explode, through air monitoring and interpretation by an industrial hygienist.  Particle size (typically less than 420 microns), material type, and even the presence of other airborne materials can affect the potential for an explosion.
  3. Control ignition sources.  OSHA requires areas where “dust” could potentially combust be considered a Class II Hazardous Location.3  In these areas, all sources of ignition such as lights, outlets, and machinery must be constructed and approved for that specific location.

Removing and/or controlling as many of these factors as possible is the best way to prevent dust from becoming explosive in your workplace.

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 1  http://www.osha.gov/dsg/combustibledust/index.html
 2  http://www.osha.gov/Publications/combustibledustposter.pdf
 3  http://www.osha.gov/doc/outreachtraining/htmlfiles/hazloc.html