I think the cell phone at gas stations is also from a myth of CB Radio and Ham Radio at the gas pump. A 100 watt system with a mis matched (VSWR) antenna and the corona ball missing off the whip antenna (The broken whip will cause the high VSWR) will make a spark that will be more then a few inches. This can cause the fire. This has been around longer then cell phones. Also depends on the water content in the air.