Relationship between air pollution and health
About 3 mins
Key points
- With the exception of London, English neighbourhoods with lower levels of air pollution tend to have higher life expectancy.
- In London, air pollution levels are higher across all the deciles, and they do not appear to be as strongly associated with life expectancy.
- In England (excluding London) the mean air quality score in places with the least air pollution (the lowest air pollution decile) is 0.54, compared with 1.26 in places with the most (the highest air pollution decile).
The relationship between an area’s health and air pollution is complex. On one hand, exposure to air pollution can increase someone’s risk of developing cardiovascular disease, respiratory disease and cancer. It may also cause damage to the reproductive and central nervous systems. Exposure to air pollution in childhood can have lifelong limiting effects on cognitive development, as well as increasing a child’s risk of developing various long term conditions.
At the same time, people living in areas with higher levels of air pollution are more likely to be in poor health, as air pollution is higher in more deprived areas, and deprivation is itself strongly associated with poor health.
This chart shows the relationship between levels of air pollution and health, as measured by life expectancy. Air pollution data shows local air pollution levels, rather than someone’s estimated exposure.
- With the exception of London, neighbourhoods with lower levels of air pollution tend to have higher life expectancy.
- In England (excluding London), men’s life expectancy in the least polluted neighbourhoods is 80.3, compared with 76.8 in the most polluted.
- In England (excluding London), women’s life expectancy in the least polluted neighbourhoods is 84, compared with 81.5 in the most polluted.
- In England (excluding London) the mean air quality score for the lowest air pollution decile is 0.54 compared with 1.26 in the highest air pollution decile.
- In London, air pollution levels are higher across all the deciles: the mean air quality score for the lowest air pollution decile is 0.99, and 1.63 for the highest. Neighbourhoods in London with the very highest levels of air pollution buck the trend entirely and show the highest life expectancy. However, unlike in the rest of England, these neighbourhoods also have the highest average incomes. As higher incomes are associated with better health, this would confound the relationship between air pollution and health.
Most areas of the UK have higher than recommended levels of air pollution. Recent mapping of data from the Expanse project at the University of Utrecht shows that only a few areas in the north of Scotland have pollution levels at or below World Health Organization recommended levels.
Air pollution is just one of many neighbourhood-specific characteristics that affect health. Availability and affordability of healthy food and access to green space are some of the others. As with air pollution, the relationship between these factors and health is affected by wider higher-level neighbourhood factors such as income levels, housing and education, some of which can be captured by the composite measure of deprivation.
- Neighbourhoods are defined as Middle layer Super Output Areas (MSOAs), based on 2011 Census areas. MSOAs are geographical areas that comprise 2,000–6,000 households (5,000–15,000 people).
- The analysis is restricted to MSOAs in England only, due to the availability of life expectancy data at this geographical level.
- Life expectancy is defined as the number of years a person of a specific age in a specific area in a specific time period can be expected to live, if mortality rates for that area and time period remain constant. Due to the small population numbers of MSOAs, life expectancy is calculated for a period of five consecutive years in order to reduce the effect that seasonal events (such as the flu) might have on the number of people dying.
- Air pollution is measured in terms of air quality score. This is available within the local air quality dataset from the English Indices of Multiple Deprivation (IMD) and it reflects pollutant concentration for four air pollutants – nitrogen dioxide, benzene, sulphur dioxide and particulates. The pollutants are measured relative to their highest allowed legal threshold; a score of 4 would indicate that all 4 pollutants in an area would be at their highest legally allowed level.
- MSOAs are grouped into air pollution deciles within London and the Rest of England separately based on this air quality score. For each air pollution decile, mid-year population estimates are used to calculate a weighted average life expectancy.
Data source: Health Foundation analysis of Department for Levelling Up, Housing and Communities, Indices of Multiple Deprivation, England, 2019; Office for National Statistics, Mid-year population estimates, UK, 2019; Office for National Statistics, Life Expectancy at Birth for Middle layer Super Output Areas (MSOAs), England, 2016–20
