According to World Health Organization (WHO), the industrial limit of sound in the industries must be?

According to World Health Organization (WHO), the industrial limit of sound in the industries must be?

ورلڈ ہیلتھ آرگنائزیشن کے مطابق صنعتوں میں آواز کی صنعتی حد کتنی ہونی چاہیے؟
Explanation

According to the World Health Organization (WHO), the industrial limit of sound in industries must be 75 dB (Decibels).