The introduction of Euro 5 legislation in Europe in 2009 required the reduction by 80% of Particulate Matter (PM) mass present in diesel vehicle exhausts and introduced a new particle number (PN) standard. To comply with these regulations, car manufacturers introduced Diesel Particulate Filters (DPFs) into exhaust pathway of new diesel vehicles. However, tampering, damage and poor maintenance of DPFs has been known since their introduction. In 2018, there was a 411% increase in the number of diesel vehicles failing the MOT emission test following the introduction of tighter testing protocols[ ]. The “Dieselgate’ emission scandal has highlighted to the general public the performance gap between ‘official’ and ‘real-world’ vehicles emissions [ ] and the health risks associated with those discrepancies. As the control of vehicle’s emission is periodic the introduction of new detection method is necessary to protect air-quality and to detect DPF failures early on.
In this study, we evaluate the potential to use simultaneous remote sensing of Black Carbon (BC) and Lung Deposited Surface Area (LDSA) at a to identify vehicles with high particle emissions resulting from the failure of DPFs. This is the first study to use remote sensing techniques to detect the failure of DPFs. Our main conclusion is that the estimated failure rate of DPFs was found to be higher than 10%. Repeat measurements of the same vehicles indicated that DPF failures were not always detected and the likelihood to detect a faulty DPF using this method was less than 45%. This leads to the conclusion that the failure rate of DPFs is critical and needs to be further investigated.