HILLSBORO, Ill. — The owner of an Illinois coal mine where an underground fire has smoldered for nearly a year is asking state regulators to approve an expansion that some local residents fear could jeopardize public health and cause environmental damage.Foresight Energy ceased production at its Deer Run Mine in early January after what it calls a “combustion event” that elevated carbon monoxide levels below ground and kept out workers for most of the past 11 months. The St. Louis-based company responded …