Air Visibility

What Causes Poor Visibility?

Poor visibility is caused by tiny particles and gases in the air. These appear as haze that reduces the clarity and color of what we see. These particles come from natural sources such as forest fires and dust, and human sources such as vehicles and industrial processes.

Reduced visibility can affect tourism, air travel, quality of life, property values, general well being and our wilderness experience, and may result in a loss of future tourism revenue. The very fine particulate matter that reduces visibility the most is the type of matter that penetrates deepest into the lungs. Poor visibility is associated with an increased risk to human health.

Many factors contribute to reduced visibility is not a simple issue to address. Contributing factors include natural and human-caused sources of particles and gases, particle composition, chemical transformations, size, concentration, sun angle and relative humidity.

Clear Air BC Initiative

Air quality agencies in British Columbia have launched Clear Air BC, an initiative aimed at improving visibility across the province. It includes:

• Scientific studies on causes of impaired visibility in the Lower Fraser Valley
• A website with information about air quality and visibility
• Projects to test several strategies to improve visibility

The partners in Clear Air BC are the Ministry of Environment, Metro Vancouver, Environment Canada and the Fraser Valley Regional District.