Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what assessment his Department has made of the potential impact of excess diesel emissions from vehicles using defeat devices on (a) the prevalence of respiratory diseases and (b) public health.

Diesel vehicles significantly impact air pollution in the United Kingdom, primarily through emissions of nitrogen oxides (NOₓ) and particulate matter. Poor air quality is one of the largest environmental risks to public health in the UK, and epidemiological studies have shown that long-term exposure to air pollution, over years or lifetimes, reduces life expectancy, mainly due to cardiovascular and respiratory diseases and lung cancer. Short-term exposure, over hours or days, to elevated levels of air pollution can also cause a range of health impacts, including effects on lung function, exacerbation of asthma, increases in respiratory and cardiovascular hospital admissions and mortality.

The Department for Transport is responsible for setting and enforcing standards for NOx emissions from diesel vehicles. The Market Surveillance Unit within the Driver and Vehicle Standards Agency is undertaking a programme looking at possible non-compliant diesel emissions in Euro 5 and Euro 6A/B/C diesel cars and vans where there is reason to believe that they contain a prohibited defeat device. The programme is designed to ensure any non-compliance found is fixed as soon as reasonably possible, working together with manufacturers to achieve real-world impacts on air quality. There is no current assessment of the potential health impacts specifically related to the use of defeat devices in diesel vehicles.