Air quality data is based on a model generated from data collected. The UK is divided into 1 km by 1 km grids, with each grid getting a modelled value. Quality limits are set by numerous directives.
NOx (nitrogen oxides)
Maximum accepted level
30 μg/m3 [source]
What are they?
NOx are a group of different moleucules that all feature nitrogen atoms bonded to varying numbers of oxygen atoms. NOx are generally produced during combustion, when oxygen and nitrogen in the air are forced to react together at high temperatures. This commonly occurs in car engines.
Typically, high levels of NOx are found near to major or busy roads.
Health implications
There is strong evidence linking elevated levels of NOx to increased asthma levels.
NO2
Maximum accepted level: 30 μg/m3 [source]
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SO2
Maximum accepted level: 30 μg/m3 [source]
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Benzene
Maximum accepted level: 30 μg/m3 [source]
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PM2.5
Maximum accepted level: 30 μg/m3 [source]
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