Much of the landscape of Portland, Oregon is known to be burdened by dense amounts of nitrogen oxides, NO2 or NOX — all of which have negative effects on human, and plant, health.
The burning of fossil fuels are the main source of this aerosol nitrogen pollution. NOX is also a prime indicator of other “combustion-related pollutants”.
Since fossil fuel pollution also destroys our climate when it fills the global atmosphere, it also damages life in local and regional environments.
– For a fairly recent news article relating to a scientific study on this issue see: “PSU study shows Portland’s urban forest reduces air pollution but also finds hazards“
Nitrogen is also a strong plant fertilizer which promotes growth. These photos show an incongruous growth of moss and lichen on exposed urban surfaces.
– Below is a small sample of photos which illustrate the degree of NOX pollution in Portland, OR. (More to come at a later date.)