UK media reported that the improvement in air quality over the past month of the coronavirus lockdown has led to 11,000 fewer deaths from pollution in Europe. This story is based on a study by the Centre for Research on Energy and Clean Air.
The study found measures to combat the coronavirus have led to an approximately 40% reduction in average level of nitrogen dioxide (NO2) pollution and 10% reduction in average level of particulate matter pollution over 30 days across Europe, resulting in 11,000 avoided deaths from air pollution (95% confidence interval: 7,000 – 21,000).
Using our recommended five tips, Global Action Plan reviewed the study:
|Questions to ask to get to the truth||Our response|
|1. Does the article refer to a report to back up its claims?||Yes, "11,000 air pollution-related deaths avoided in Europe as coal, oil consumption plummet", published April 2020.|
|2. Who is behind the study it refers to?||The Centre for Research on Energy and Clean Air is a new independent research organisation focused on revealing the trends, causes, and health impacts, as well as the solutions to air pollution. The team is comprised of researchers and analysts who focus on modelling, reviewing and assessing trends in air pollution globally. Given the centre is new, their work will need to be reviewed in order to determine how robust their research is.|
|3. How fantastical and radical is the claim that is being made?||The research is plausible given the reduction in air pollution during lockdown. However, the result was produced through estimation which relies upon assumption of the cause.|
|4. What geographical region does the claim refer to?||Europe|
|5. What is the sample size of the study?||
The study did not measure a sample but was an estimated calculation.
Our Air Quality expert panel reviewed the study. Key reflections include:
“Like all studies based on statistical associations and extrapolations, this type of study is open to considerable uncertainty. It assumes that there is a linear relationship between levels of pollution and health outcomes. The number of lives saved have been calculated using data obtained in different ways and they have therefore, taken large leaps of faith. It is likely that we are going to see a drop in certain health conditions such as asthma, CHD/strokes but this may be due to isolation and changes to lifestyles, rather than solely being due to reduced outdoor air pollution.
The research has not been peer reviewed but does use peer reviewed methodology. However, the methodology is for Global Burden of Disease – these methods are for snapshots of the overall burden of air pollution (usually using annual averages). They are also simpler methods not usually used for assessing changes in air pollution due to policies (usual ones aimed at reducing air pollution, but lockdown is still a policy). The authors appear to be economists and are therefore qualified at applying standard methodologies but perhaps not as strong at adapting methodologies for particular circumstances.”