Dust and Smoke (COH)

The coefficient of haze is a measurement of the amount of dust and smoke in the atmosphere. Sources of dust and smoke include motor vehicle emissions, industrial emissions, road dust, wind blown soil, dust resulting from other human activities (i.e., agriculture), smoke from forest fires, and smoke from recreational sources (i.e., camp fires and fireplaces).

Dust and smoke values are generally higher at urban stations located in Edmonton and Calgary than at the small urban stations such as Fort Saskatchewan and Fort McMurray. This is indicative of vehicular exhaust and traffic movement which contribute to dust and smoke in the atmosphere. Values are typically highest during the morning and afternoon rush hours during the fall and winter seasons.

Monitoring Method
To measure ambient levels of dust and smoke, a known volume of air is continuously drawn through a filter paper for a period of 1 hour. The soiling properties of the sample are measured by the reduction of light transmission through the filter. This reduction is reported as the coefficient of haze per 1000 linear feet of air sample. This method does not measure the absolute concentration or the deposited mass of particulates, but rather is an indicator of particulate matter suspended in the air.

Objectives
The monthly air quality Objectives for dust and smoke is based on visibility reduction:

90% of the readings per month shall be less than 1.0 COH unit.

	Dust and Smoke (COH) The coefficient of haze is a measurement of the amount of dust and smoke in the atmosphere. Sources of dust and smoke include motor vehicle emissions, industrial emissions, road dust, wind blown soil, dust resulting from other human activities (i.e., agriculture), smoke from forest fires, and smoke from recreational sources (i.e., camp fires and fireplaces). Dust and smoke values are generally higher at urban stations located in Edmonton and Calgary than at the small urban stations such as Fort Saskatchewan and Fort McMurray. This is indicative of vehicular exhaust and traffic movement which contribute to dust and smoke in the atmosphere. Values are typically highest during the morning and afternoon rush hours during the fall and winter seasons. Monitoring Method To measure ambient levels of dust and smoke, a known volume of air is continuously drawn through a filter paper for a period of 1 hour. The soiling properties of the sample are measured by the reduction of light transmission through the filter. This reduction is reported as the coefficient of haze per 1000 linear feet of air sample. This method does not measure the absolute concentration or the deposited mass of particulates, but rather is an indicator of particulate matter suspended in the air. Objectives The monthly air quality Objectives for dust and smoke is based on visibility reduction: 90% of the readings per month shall be less than 1.0 COH unit.