AQS Pollution Sources 3

Question 1

Which industrial process is the dominant anthropogenic source of sulfur dioxide (SO2) emissions in the United States?

Accepted Answer

Fossil fuel combustion at electric utilities

Answer

Electric utility fossil fuel combustion, especially from coal-fired power plants, historically accounts for the largest share of U.S. SO2 emissions.

Question 2

Biogenic VOC emissions from vegetation are significant because they contribute to the formation of which secondary pollutant?

Accepted Answer

Tropospheric ozone

Answer

Biogenic VOCs such as isoprene react with nitrogen oxides in the presence of sunlight to form ground-level ozone.

Question 3

A petroleum refinery that processes more than 10 tons per year of a single HAP is classified under the CAA as a:

Accepted Answer

Title V major source

Answer

Under Title V, sources emitting 10 tpy or more of a single HAP (or 25 tpy of combined HAPs) are classified as major sources subject to operating permit requirements.

Question 4

Which sector is the leading source of NOx emissions in the U.S. according to the National Emissions Inventory?

Accepted Answer

Highway mobile sources

Answer

Highway mobile sources, including cars, trucks, and buses, are consistently the largest contributor to NOx emissions nationally.

Question 5

Chromate cooling towers at industrial facilities are regulated air emission sources primarily because they release:

Accepted Answer

Hexavalent chromium (Cr VI) as a toxic aerosol

Answer

Chromate cooling towers emit hexavalent chromium droplets into the air, a known human carcinogen regulated under the NESHAP program.

(AQS) Air Quality Specialist Certification Practice Test

(AQS) Air Quality Specialist Certification Practice Test

AQS Pollution Sources 3