Innovative Methods of Monitoring of Diesel Engine Exhaust Toxicity in Real Urban Traffic

PROJECT DESCRIPTION

BACKGROUND

Diesel exhaust emitted by internal combustion engines is a key source of urban air pollution. It is not just the traditionally-regulated total mass of particulate matter that is of public concern, but also ultrafine particles of pollution. These can readily penetrate deep into the lungs and pass through cell membranes into the bloodstream. Engine exhaust has adverse effect on many key bodily functions (respiratory, circulation and nervous system) and proximity to its source has been correlated with increased risk of tumours, asthma, various chronic respiratory ailments, heart attack, and other illnesses.

OBJECTIVES

The main objective of the MEDETOX project was to demonstrate innovative methods for assessing the possible health risks connected with exposure to diesel exhaust particles under real-life traffic conditions in the city of Prague (Czech Republic). Specific objectives included identifying health risks related to emerging fuels and fuel additives; demonstrating standardised toxicity tests as an appropriate tool for regulatory decisions; building an effective interdisciplinary network targeted at the overall assessment of the health risk potential of engine exhaust during the real-time operation of road vehicles; and monitoring the effects of various policy decisions. The project comprised a team of experts in the areas of engines and emissions, toxicity assessment, and public policy

RESULTS

The MEDETOX project demonstrated innovative methods for monitoring the toxicity of diesel engine exhaust emissions under real urban driving conditions, with a detailed focus on the effects of congested traffic on the ring road of Prague, Czech Republic. The project constructed and validated several monitoring and/or sampling systems for the assessment of roadside emissions; and it prepared and validated simplified toxicity assays that can be carried out on the samples. It collected data on emissions and the toxicity of particle-bound organic compounds during real-world operation, and during laboratory simulations, and also compared these with engines running on various candidate replacement fuels. The project’s findings could have a big influence on both policies and technical approaches to traffic emissions.

During the project, a range of key technologies and methods were demonstrated:

Miniature and low-cost portable on-board systems for vehicle emissions monitoring;

Miniature ultra-low-cost detector of particle length, used for vehicle emissions monitoring, and also tested within the European Metrology Programme as a novel tool for periodic emissions inspections of motor vehicles;

Portable FTIR (Fourier Transform Infra-Red) spectrometer for measurement of unregulated pollutants of interest, such as nitrogen dioxide, ammonia, formaldehyde, acetaldehyde, methane and nitrous oxide;

Particle size distributions and particle counts that measured vehicle exhaust and ambient air near roads using instruments mounted on hand carts;

Acellular tests of DNA adducts and oxidative DNA damage that, relative to the toxicological tests in general, are relatively easy, fast, inexpensive screening tests, requiring small amounts of material; and

Standardised protocols for sampling and toxicity testing of diesel emissions under various real-traffic conditions, as tools for hazard identification and risk assessment.

These tests are described in details on www.medetox.cz/methods and include sampling, analysis of cytotoxicity, analysis of DNA adducts, micronucleus test, oxidative stress, and comet assay.

The project’s results confirmed the initial hypotheses that there were gaps between measuring emissions under laboratory conditions and in real-traffic conditions. The monitoring prototype was successfully tested in real traffic, and this received much attention from national and international experts, and also the media, general public and local authorities. This raised awareness of the health risks from diesel pollutants.

Although its policy implications can only be assessed in the long term, the project contributed important evidence and arguments for further policy consultations. Its activities have already contributed to the advancement of real driving emissions (RDE) legislation set forth in the European Commission regulations no. 2016/427 and no. 2016/646. It is expected that the results may also contribute, through the demonstration of enabling technologies, to an expansion of RDE legislation on motorcycles and other L-category vehicles, small non-road engines, and the measurement of ammonia (a secondary particle precursor), methane and nitrous oxide (greenhouse gases). MEDETOX findings and information gathered during the project have been used in citizen actions against land-use choices that have likely resulted in a deterioration of air quality, including the construction of a large shopping centre that brings large amounts of traffic into the historical city centre. In the long term, by contributing to reductions in emissions and related health effects, the project should lead to air quality improvements and a reduction in adverse health effects.

There are possible economic benefits from reduced external costs associated with air pollution, and the adoption of less expensive measurement techniques.

Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).