This is the largest source of atmospheric pollutants. A) ...

[itsmyluck]

This is the largest source of atmospheric pollutants.
 
  A) volcanic eruptions
  B) human activities
  C) forest fires
  D) heavy winds in dry deserts

Question 2

Describe how carbon monoxide is produced by both humans and nature. Then discuss why it is so toxic to humans.
 
  What will be an ideal response?

[kingfahad97]

Answer to Question 1

Answer: B

Answer to Question 2

Answer: Carbon monoxide is a colorless, odorless gas. In the natural environment it is released as a primary pollutant by volcanic eruptions, forest fires, bacterial action, and other processes. Though natural processes emit far more CO into the environment than do human activities, soil microorganisms consume it effectively, and background values are very low. In cities, however, inputs can greatly exceed the rate of removal, and unsafe concentrations can accrue. In the United States, the most important source of CO is the automobile which releases the gas as a by-product of incomplete combustion. In well-maintained vehicles, carbon monoxide emissions are low, but poorly operating engines can cause CO concentrations to accumulate to unsafe levels. Carbon monoxide is extremely toxic. Even low levels can cause a person to immediately experience slowed reflexes, drowsiness, and a reduction or loss of consciousness. Exposure for three hours at 400 parts per million (ppm) is life threatening, and at 1600 ppm death comes within an hour. Over the long haul, it can contribute to heart disease.