If last week’s air pollution in Colnbrook breached WHO guidelines 98% of the time, why did it barely register against Slough’s air quality objectives?
The inadequacy of Slough Borough Council’s air quality objectives has again been highlighted this week. Despite the London mayor – and defra – urging vulnerable people to stay indoors as “dirty air from Europe” passed over Colnbrook on Tuesday, only ONE of our local monitoring stations breached Slough’s air quality standards (and then only barely).
Air quality recorded this week didn’t quite reach the DAQI level 8 forecast, but the level 7 recorded still put pollution levels at ‘High’ with the associated warnings triggered.
And, at times, pollution levels recorded in Colnbrook were, alarmingly, more than double “acceptable” limits.
But with “exceedences” not triggered until limits have been breached over a full 24 hour period, only one was registered this week. Slough Lakeside 2 recorded an average of 58 µg/m3 on Tuesday – officially only the second breach this year.
Between Sunday 15 and Friday 20 there were only 2 out of 144 continuous hours when air somewhere in Colnbrook did not exceed WHO guidelines (Monday, between 5 am and 7 am).
|Slough Colnbrook (SLH3)||1||5||1||0||0||0||0||0||0||0|
|Slough Lakeside 1 Osiris (SLH5)||0||3||2||0||0||0||0||0||0||0|
|Slough Colnbrook Osiris (SLH6)||1||2||3||0||0||0||0||0||0||0|
|Slough Lakeside 2 (SLH8)||1||2||3||1||0||0||0||0||0||0|
|Slough Lakeside 2 Osiris (SLH9)||1||4||1||0||0||0||0||0||0||0|
The World Health Organisation says there are no safe levels of particulates in the air, and it’s own guideline levels for PM10, at just 20 µg/m3 as an average over the year, are half the level of targets set by Slough.
… there is little evidence to suggest a threshold below which no adverse health effects would be anticipated.
(It also says the PM2.5 guideline value is preferred over PM10, but few local stations are equipped to measure it and, worse, Slough’s air quality strategy does not cover it).
5.6% of measurements taken so far this year across the five monitoring stations exceed the 40 µg/m3 limit. But when the WHO measure is used that increases to a shocking 35.3%. Slough Lakeside 1 Osiris and Slough Colnbrook Osiris (at Pippins) saw data exceed the WHO guideline 54.9% and 48.4% of the time respectively so far this year.
While real-time data reporting appeared to have been suspended during this week’s pollution spike across London and the South-East figures are now available for all monitoring stations in Colnbrook. However a 12-hour gap in data collection remains for the Slough Lakeside 1 Osiris station for Wednesday while some of the highest particulate levels were recorded at the other four stations.
There are also big gaps in the data recorded in the current year so far: over six hundred hours of data are missing. Over 16% of the data is missing from the Slough Colnbrook station alone. That will lead to the inevitable conclusion that Slough is still failing to take air quality seriously, while new air quality monitoring stations planned for Brands Hill have already been delayed to the end of 2015.
Strangely, data collection is recorded as 100% in the air quality portal now. Even more strange, all months for previous years have also been retrospectively updated to 100% – even though the data remains missing.
OUR SAY: There has been growing anger locally as residents have realised that isolated calls for transparency and improvement have not been scaremongering but based on hard facts in the public domain. In 2013 Grundon issued veiled threats to this website for exposing a pollution spike which peeked in Colnbrook but which Slough Borough Council said had been seen across the South East. Grundon claimed, variously, that it's own readings had shown excellent air quality; a snapped tape had corrupted readings; and that its turbines had been shut down at the time. Far from greater openness and transparency on the part of SBC and data providers things have got worse with an apparent attempt to retrospectively cleanse the dire data collection rates of previous years. The figures before were just bloody awful. Now, it seems, they lack credibility as well.
Ironically the Third Runway debate may have helped bring focus to the appalling pollution levels faced locally.
In September 2013 Parish Councillors waved through a new incinerator for DHL with no objection on the basis that it “would have to meet the air quality standards required by law and would be fully monitored” – after Colnbrook Views had already highlighted serious problems with the monitoring regime.
Last month it proved more convenient to highlight to Sir Howard Davies that “air quality is well below EU Directive targets and World Health Organisation safety standards, posing an undefined but significant health risk to tens of thousands of people living there”.
Welcome though the u-turn is, there has been no explanation for it.