Air pollution and public health vulnerabilities, susceptibilities and inequalities in Wales, UK.

Background: Outdoor air pollution is the largest environmental risk to health. Air pollution, deprivation and poor health status are inextricably linked; highlighting issues of environmental injustice, social and health inequalities.

Methods: Air pollution (nitrogen dioxide, NO2 and fine particulate matter, PM2.5), population and deprivation data were identified at Lower Super Output Area level in Wales, UK, for 2012-18. Air pollution data were categorized according to different air pollution concentrations. Population and deprivation data were considered simultaneously to describe population vulnerabilities, susceptibilities and inequalities. Simple statistical analyses were performed using a difference in proportions method with 95% confidence intervals.

Results: Over time, the majority of Welsh people transitioned to living in areas of lower NO2 and PM2.5 pollution. Areas of worse air pollution comprised more young people than people aged 65+; both populations are known to be susceptible to air pollution exposure. By 2018, significant socioeconomic inequality gaps were found where 'most deprived' population groups for both pollutants experienced greater disadvantage.

Conclusion: Air quality in Wales is improving. However, local-level variations in exposure risk still exist. System-wide action must ensure that air quality improvement-related benefits are equitable and acknowledge current evidence about the harms that even low levels of air pollution can have on health.