Dental The threshold value for workers in the mercury industry is: A 200 to 400 µg per day B 100 to 200 µg per day C 350 to 500 µg per day D 500 to 700 µg per day 💡 Explanation The threshold value for workers in the mercury industry is: ✓ Correct Answer: C. 350 to 500 µg per day