噪音污染
Noise pollution which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar. The noise for Karachi came to 80 dB (A), the General Noise Index x (G.N.I.) to 460, and the noise pollution level (N.P.L.) to 99 dB (A). These values are significantly higher (P less than 0.01) than the available international data.