Cloud-to-ground lightning occurs 20 to 25 million times a year in the United States! But what exactly is a lightning strike? As thunderstorms develop, many small particles of ice within the storm clouds collide, which create a positive charge at the top of the cloud and a negative charge of at the bottom.
As this continues, a second positive charge builds up on the ground beneath the cloud, and when the difference between the electrical charge in the cloud and on the ground becomes great enough to overcome the resistance of the insulating air between them…an electrical current flows instantly – a lightning strike! The electrical potential can be as much as 100 million volts!
During the past 30 years, about 50 people, on average, have been killed by lightning strikes every year, and many more suffer permanent disabilities, including memory loss, fatigue, chronic pain, dizziness, sleeping difficulty, and the inability to complete several tasks at one time. Worker activities at higher risk for lightning hazards include:
• Explosives handling or storage
• Heavy equipment operations
• Building maintenance
• Power utility field repair
• Steel erection/telecommunications
• Farming and field labor
• Lawn services/landscaping
• Airport ground personnel operations
• Pool and beach lifeguarding
Following these simple safety practices can help keep your outdoor workers safer during thunderstorms and lightning strikes:
• Designate a worker per shift to monitor daily weather forecasts, observe local weather conditions and alert all other workers when a possible lightning threat develops.
• When a storm moves nearby, don’t start or continue any work that cannot be stopped immediately
• Anticipate and take action early by moving everyone to a low-risk location. Don’t wait until you see lightning.
• Good motto: If you see it (lightning), flee it. If you hear it (thunder), clear it. Either one, get indoors and to a safe location!
• Remain in a safe location for 30 minutes after the last sight of lightning or the last sound of thunder. The safest location is inside a fully enclosed building. If that is unavailable, the second safest location is inside a full enclosed car, van, truck or bus with a metal roof and metal sides.