Has it?
How?
All I am aware of is that there is a great deal of loose talk about thousands of deaths, which as we have already seen (if we have read the article we both linked too quite independently) points out that it is based on very poor evidence and flawed methodology. The whole idea that it makes any sense to look at life expectancy in a group of American cities and use the rates of Air pollution found in different districts to cobble together a mortality statistic based on different air pollution levels without doing anything to take into account the socio-economic differences of the people, and their lifestyle habits, such as smoking rates is utterly laughable to anyone who has any grasp of research methods and statistics. ALL the crazy death rate figures we see being attributed to air pollution are based on this Pope and Colleagues 'research' paper. It is a real croc Peter.
So from the (2017) article we both linked to :
"What does this actually all mean for our health?
The crucial issue, repeatedly emphasised by COMEAP, is that we cannot identify these 29,000 as individuals– there are no recorded deaths to count, as nobody has ‘pollution’ on their death certificate as the cause of death. They state that:
Given this complexity, it is not plausible to think of the figure of ‘attributable’ deaths as enumerating an actual group of individuals whose death is attributable to air pollution alone, i.e. the victims of outdoor air pollution.
Such a number may be suitable for comparing the overall health burden of air pollution with things such as alcohol (22,000 attributable deaths in England) or smoking (80,000 in England), but it may wrongly suggest that people drop dead from pollution, just as they used to back in the days of London smogs. In contrast, air pollution tends to make existing illnesses worse, and COMEAP say that the actual number of people whose death is brought forward by pollution is likely to be much bigger than 29,000, and suggest it is better to say the estimated harm is “equivalent to 29,000 deaths”.
They suggest it would be even better, although not so memorable, to focus on the estimate that 340,000 ‘years of life’ are lost each year through particulate pollution. There are different ways of allocating all these life-years lost, some shown in Table 1 below, including COMEAP’s recommended intervals
When the 340,000 life-years lost is spread over the whole adult population of 38,000,000, it’s only 3 days a year each, which does not sound much. Or we can say that all deaths are brought forward by an average of 7 months. But air pollution mainly influences cardiovascular (CV) health, and so it is perhaps more realistic to say that 190,000 CV deaths are brought forward an average of 2 years."
And he concludes
"There are huge uncertainties surrounding all the measures of impacts of air pollution, with inadequate knowledge replaced by substantial doses of expert judgement. These uncertainties should be better reflected in the public debates.
In addition, the situation in the UK is not what we would usually think of as a ‘crisis’. It can still be good to seek improvements in air quality, but only provided these are based on a careful analysis of the costs per life-year saved."