Air Pollution: Urban Grime Recycles Toxics
2007
Urban Grime and Air Pollution
publication
Evidence: moderate
Author Information
Author(s): Carol Potera
Primary Institution: University of Toronto
Hypothesis
Grime on urban surfaces may release toxic nitrogen oxides when exposed to sunlight.
Conclusion
The study suggests that nitrogen oxides are recycled from urban grime, challenging previous assumptions about their fate.
Supporting Evidence
- Nitrogen compounds in grime may be transformed into active forms by sunlight.
- Previous assumptions stated that nitrogen compounds trapped in grime are washed away by rain.
Takeaway
Grime on city surfaces can turn into harmful gases when the sun shines on it, which we didn't know before.
Methodology
Slides coated with chemicals found in grime were exposed to nitric acid and irradiated with light to observe reactions.
Limitations
The study's initial results need to be verified with actual grime samples.
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