Complex sentence: Officers are exposed to other risks beyond being killed by hunters, trappers and armed fishermen--heart attacks, motor vehicle, boating, snowmobile and airplane accidents, drowning, hypothermia, etc.--which also take their toll while on duty.
Split into simpler sentences: Officers are exposed to other risks beyond being killed by hunters, trappers and armed fishermen. Heart attacks, motor vehicle, boating, snowmobile and airplane accidents, drowning, hypothermia, etc. also take their toll while on duty.