WHEN ARE WE MOST LIKELY TO HAVE HIGHEST POLLUTION?
Based on three months of data, we now have a clear idea of when we are most likely to experience damaging levels of pollution along the A2. If the level of pollution reaches "Very High", then we need only breathe it in for one hour to break the 'safe limits'.
For daily records of pollution - visit the Pollution Diary Page. If you want to know what the four coloured bands of pollution mean - visit the Air Quality Indicators Page.
As I take more measurements, two facts really worry me:
- There are no known lower safety limits for the finest Particulate Matter - PM2.5 - once we ingest these pollutants, we are stuck with them inside our bodies; and
- We are exposed to at least Moderate pollution every day (only one "Low" Pollution day in three months!) - this is a problem for anyone with a pre-existing chronic condition on the A2 or on either side of the A2.
Remember, as far as SBC is concerned, my measurements are outside the AQMA5. The AQMA5 is supposed to be the worst effected area!
THE RESULTS ARE IN!!
After three months of recording the times of day when there were noticeable 'peaks' in pollution,
I can now share the specific times when we are at most risk.
No more guessing, no more assuming.
MORNING: The riskiest period falls between 6.30am and 09.15am. People and goods are on the move - commuters (road & driving to stations, delivery of goods, school runs, and so on.
What about the "mini-peak" around 3.00am? A friend who is an HGV driver thought it might be early 'get aways' with cold (inefficiently burning) engines to avoid rushes on main roads? Since pollution travels, can you think what else starts up at that time? Any thoughts?
MIDDAY: 11.00am to 1.00pm: People trying to fit 'stuff' into their busy days - shopping? eating out? changing shifts? traffic reaching us from other places?
AFTERNOON MINI-BLIP: The 3.30pm 'mini-blip' coincides with the school runs joining the flows of 'other traffic' on the A2. School runs may be only a 'small' (but still significant) part of the whole of A2 traffic.
But the more important point is that school-related traffic is highly concentrated at the very local level and for a narrow period of time - roads near schools congested, idling engines polluting, walking versus driving, hedge planting, and so on. That is another conversation to be had.
EVENING: The reverse flow of people and goods....5.15pm to 8.15pm.
