"In the UK, air quality is monitored by several organizations, primarily:
1. **Department for Environment, Food & Rural Affairs (DEFRA):** DEFRA manages the UK’s national air quality monitoring network, known as the Automatic Urban and Rural Network (AURN). They oversee the collection and analysis of air quality data across the country.
2. **Environmental Agencies and Local Authorities:** Many local councils and environmental agencies operate their own monitoring stations to assess air quality in specific areas, especially in urban centres.
3. **Independent Organizations and Research Institutions:** Universities, environmental NGOs, and research groups may also conduct air quality measurements and studies."
In the case of particulate matter it is relatively easy to collect samples and analyse them.
To set recommended limits, animals have been or are exposed to ever increasing doses or a constant dose over a long time, by now we have built up a fairly accurate model of how particle size influences the damage done.
Tyres are still a problem, due oil, carbon black, and other additives.
I think the pollution of runoff water, and the effects of particulate matter are the main problems.
When I was in the Glass Fibre industry we were careful not to produce fibres less than 3µm diameter and 5µm long as anything smaller could damage the alveoli in the lungs and get into the blood stream.
