206 Measurements of diesel exhausts - Comparing elemental carbon and black carbon

Diesel exhaust exposure is a known carcinogen even at low levels of exposure. The new occupational exposure limit for diesel exhausts is based on the measurement of elemental carbon (EC) which went into effect at the beginning of 2023 in EU. The analysis of EC is not extremely expensive, but specialised instrument is needed for the analysis, which may not be accessible everywhere. An alternative method for measure diesel exhaust exposure is black carbon (BC) with an aethalometer, a real time monitoring instrument, making it possible to identify working tasks that are more prone to cause exposure. The EC measurement on the other hand gives an integrated amount, an average over the whole sampling time. There is a large overlap between what is BC and what is EC, so BC could be a good proxy for the EC exposure. The study we have conducted aims to investigate how well the exposure measurement of an aethalometer and measurement of EC correlate in different work environments. In the current study we have measured BC and EC in three types of environments, two occupational and one test chamber study. The two occupational environments studied were in mines and in a warehouse where diesel trucks were used to move wares. The results shows that BC and EC signals have good correlation, but that BC usually gives a higher average exposure over the day. This could be due to multitude of reasons, but one of them could be presence of other light absorbing particles.