Maximum allowable noise exposure limits for a man working for 8 hours a day in a noisy chemical plant is about ______________ decibels?

A. Suppression of noise at the source itself
B. Path control of noise
C. Protection of operating personnel
D. All A., B. & C.

A. Volcanic eruptions and lightening discharges
B. Biological decay of vegetable matter
C. Photochemical oxidation of organic matter
D. None of these

A. 10-7
B. 7 × 10-7
C. 107
D. 7 × 107

A. Arizona (U.S.A.)
B. Chernobyl (undivided U.S.S.R.)
C. Pennsylvania (U.S.A.)
D. Moscow (U.S.S.R.)

A. 50
B. 1000
C. 2000
D. 5000

A. Potable water
B. Cooling water
C. Distilled water
D. Industrial effluents