Collier; Coal Miner
This page is the CodyCross answer for the clue below from Farm, Group 480, Puzzle 4 (Controlled Atmosphere).
Question
Collier; Coal Miner
Answer
PITMAN
Word Meaning:
PITMAN — (plural "pitmen") One who works in a pit, as in mining, in sawing timber, etc.
Definitions from Wiktionary.