This reference book contains the past five years' worth of questions from the National Examination for Pollution Control Managers and is fully compatible with the 2022 exam. - Title: National Examination for Pollution Control Managers: Correct Answers and Hints - Target Years: 2017-2021 - Contents: Includes past 5 years' worth of questions - Exam Preparation: Fully compatible with the 2022 exam - Related Fields: Air Pollution, Specific Dust, General Dust Slight stains and dirt present.