WHO recommendation cut off for noise in industrial city:
**Core Concept**
The World Health Organization (WHO) has established guidelines for noise exposure in industrial settings to prevent hearing loss and other health problems. The recommended noise cutoff is based on the average noise level over a specific period, usually 8 hours, to minimize the risk of noise-induced hearing loss (NIHL).
**Why the Correct Answer is Right**
The WHO recommends a noise exposure limit of 85 decibels (dB) over an 8-hour period to prevent NIHL. This is because prolonged exposure to noise levels above 85 dB can cause permanent damage to the hair cells in the inner ear, leading to hearing loss. The recommended cutoff is based on the concept of the "noise dose," which takes into account the intensity and duration of noise exposure.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a valid WHO recommendation for noise exposure in industrial settings.
**Option B:** This option is not a recognized noise exposure limit for preventing NIHL.
**Option C:** This option is not a correct representation of the WHO's recommended noise cutoff.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the WHO's noise exposure limits are based on the average noise level over an 8-hour period, not the peak noise levels. This distinction is crucial in industrial settings where noise levels can fluctuate significantly.
**Correct Answer:** 85