as a general rule, does it matter which government supplies data as long as it is supplied by either a government or an official contractor, particularly where a department does not have the skillset internally or locally in the required timescale or budget?
UK SMOGWATCH is not an official contractor but interesting that Isle of Man air quality readings appear to be supplied from the IOM government (tbc IOM Met Office or IOM Department of Infrastructure) to UK DEFRA and available via the UK Open Government Licence: