The warning limit for noise pollution is generally considered to be 85 dB. Exposure to sound levels above this can cause hearing impairment and other health issues over prolonged periods. The noise level of 85 dB is a common threshold set by environmental health standards to indicate that noise levels are dangerously high for human health.
Step 1: Analyze the options.
(A) 85dB: This is the correct answer. The warning limit for noise pollution is typically set at 85 dB to prevent hearing damage and other negative health effects.
(B) 90dB: Although this is close, it is generally considered a high-risk level rather than a warning limit.
(C) 70dB: This is below the warning threshold. Noise at 70 dB is considered moderate and does not generally pose a health risk over short periods.
(D) 80dB: This is also below the standard 85 dB threshold, though it may still contribute to discomfort in noisy environments.
Step 2: Conclusion.
The correct answer is (A), as 85 dB is the widely accepted warning limit for noise pollution.
Final Answer: