Soot arising from chimneys in residential area© iStock How black carbon can increase the risk for respiratory diseases 25 May 2020PollutantsIceland Interview with Dr Ragnhildur Finnbjörnsdóttir, Iceland’s Head of Delegation for the Arctic Council’s Expert Group on Black Carbon and Methane How is air pollution – caused by particles such as black carbon – affecting human health? Black carbon is part of what we call particulate matter (PM), fine particles in the air, such as dust, dirt, soot, or smoke. It is accepted within the scientific community that exposure to particulate matter adversely affects human health in various ways: it can increase symptoms of respiratory- and cardiovascular diseases, it can increase the susceptibility towards different respiratory diseases, and scientists have also found an association between particulate matter and respiratory- and cardiovascular mortality. Especially people with underlying diseases, as well as children and older people, are vulnerable towards particulate matter exposure. In addition to the above, particulate matter exposure can also increase the likelihood that someone develops respiratory diseases. Thus, long-term exposure can lead to more people getting affected by lung- and cardiovascular conditions. Black carbon is amongst the smallest particles of particulate matter – and these are usually of the highest concern. Generally speaking: The smaller the particles, the more adverse the health effects, but studies have shown that it is difficult to distinguish the different effects of particulate matter whose individual particles are smaller than 2.5 micrometers (PM2.5) and black carbon. Some studies have shown that black carbon – the smallest particulate matter particles – can pass the blood brain barrier, and they have also been found in the fetal side of the placenta, where they can affect the development of a fetus. While there is still research needed on the adverse health effects of different particle sizes, the scientific community agrees that that overall particulate matter exposure is bad for you – just as everybody knows that smoking is bad for you.