AQI stands for Air Quality Index and it is the number or colour that indicates how good or bad is the air quality in your area. The problem with the AQI is the way each governments calculates the air pollution and what parameters it uses to project this Index number/colour. For example, the USA Environmental Protection Agency (EPA) considers as breakpoint for a “Moderate” NO2 concentration the value of 101μg/m3, but the UK Department for Environment, Food & Rural Affairs (DEFRA) considers as breakpoint for a “Moderate” NO2 concentration the value of 201μg/m3. The difference is huge and the Index changes dramatically for each country and at the end people get confused. The same rule applies for all the pollutants, PM2.5, SO2, O3, etc… Later they are combined all together to give us the final Index.
AQLI stands for Air Quality Life Index and only take into account the PM2.5 pollution. It is based on the finding that an additional 10μg/m3 of PM2.5 reduces life expectancy by 0.98 years. By combining this finding with satellite PM2.5 measurements around the world, the AQLI provides an insight into the global impacts of particulate pollution in local jurisdictions. The Index also illustrates how air pollution policies can increase life expectancy if pollution levels were reduced to the World Health Organization’s (WHO) safe guideline or existing national air quality standards, or by user-selected percent reductions.
Could the AQLI replace the different AQIs worldwide?
Although it gives a better insight into the impact the air pollution has to our lives, it will not be able to convince people in countries where the impact of air pollution doesn’t translate to high “Life Years Saved” numbers. For example, we can clearly see from the table below that if China adjusts their policies according to the WHO Guideline the population will have a benefit of 2.9 years. However, if Netherlands adjusts their policies according to the WHO Guideline the population will have a benefit of 0.3 years. This is rather a small number and I am afraid people won’t take it as serious in western countries as they should. In my opinion the AQLI has to take into account how our quality of life (not only life expectancy) is affected by the air pollution. We may live longer but sometimes inside hospitals, under expensive insurances and medicines that not everyone can afford even in US, Europe, etc.
Moreover, the data that you see on the table above (extracted from the original document which you can find below) do not reflect the real air quality an individual has been exposed in his a city/town/village. They have created an annual average PM2.5 concentration and the aggregations are population-weighted, which means this map won’t help an individual to understand the air quality in his/her area. For instance, there is a small town in my region called Carboneras, the population is small but there is a coal power plant there (equipped with 48 coal burners). People’s life expectancy from that village won’t reflect on the annual PM2.5 concentration because the populations is small.
Read the paper at https://aqli.epic.uchicago.edu/wp-content/uploads/2018/11/AQLI-Report.111918-2.pdf
I really admire this exceptional work which is done by Michael Greenstone and Qing (Claire) Fan because we need a global way to understand the air pollition and its effects. They have developed a tool which can help to inform local communities and policymakers in Asian countries about the benefits of air pollution policies in very detailed way.
5 thoughts on “Is the AQLI the new AQI?”
Setting air pollution targets when there’s no safe level of PM2.5 pollution requires careful consideration of costs and benefits. Rather than life years saved by achieving the WHO guidelines, why not report life years lost from all man-made pollution?
This will enable all relevant information on costs and benefits to be considered, so that strategies can be developed to achieve maximum benefits for available resources. The best possible outcome would be to maximize public benefits by implementing all clean air strategies with greater benefits than costs.
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I guess this is a start and they will add additional parameters in the future. It is a very hard work to do and as you said requieres careful consideration.
For us it is a big pain in the *ss since everybody uses different breakpoints, since we perform aiq analysis we have to rely on something. It is about time that EPA, WHO, EU and EU countries use the same numbers for IAQ.
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I totally get it and you are right, unfortunately they won’t come in an agreement because each one serves a different purpose and EPA under the current administration won’t collaborate. WHO on the other hand could easily create a global AQI, I have already suggested that.
It’s true that if the Netherlands adjusted their policies according to the WHO Guideline, the population would have an average benefit of 0.3 years.
But there’s nothing stopping the Netherlands from trying to achieve a lot cleaner air than the WHO Guideline and so increase their average life expectancy by up to 1.3 years. Some countries (e.g. Australia) already have set stricter standards that the WHO guideline. This is good policy, because people who are unlucky enough to get sick during a period of high pollution can die instead of living another 10 or 20 years. PM2.5 pollution also affects babies, who can lose 70 or 80 years.
Medical Net recently published a review of the evidence, concentrating on how air pollution affects brains as well as hearts and lungs. It cites evidence to show that some people are lucky enough to live in areas with annual average PM2.5 pollution less than 3 ug/m3, and they have much better health – http://www.news-medical.net/health/Air-Pollution-damages-brains-as-well-as-hearts-and-lungs.aspx
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