The University of Malta has highlighted how air pollution affects the quality of life of people, their daily routine and globally, leading to millions of premature deaths per year. It said that locally and world-wide, several regulated pollutants are monitored continuously. Substantial effort is devoted to monitoring oxides of nitrogen, ozone and particulate matter.

These are the most popular pollutants which are strongly linked with activities carried out in industrial or urban areas, generally involving burning fossil fuels.

The University explained that very recently, the European Commission on advice from the World Health Organisation (WHO) will be revising the Ambient Air Quality Directive (2008/50/EC and 2004/107/EC) demanding more stringent limit or target values of the well known pollutants and will demand monitoring of “unregulated pollutants of concern-”

One of the pollutants who got this label is Black Carbon (BC). In the coming months, a new Masters project at the Department of Chemistry at the University of Malta, under the supervision of Prof. Noel Aquilina will delve into how BC levels vary throughout the day across multiple sites in Malta and Gozo and what this means for our health.

What is Black Carbon?

BC is a subset of fine particulate matter, commonly referred to as PM2.5 ( particles of size equal or less than 2.5 micrometres), and which is not visible to the naked eye. To put into perspective how small these particles are (2.5 micrometres), a human hair is about 100 micrometres thick.

It was explained that the main concern associated with this invisible dust is that it has the ability to penetrate and carry nasty chemicals deep into the respiratory systems, the heart and the lungs, down to the alveoli and from there enter our bloodstream, causing a lot of health issues.

Not only does BC contribute to multiple negative health outcomes, but it also plays a role in global warming by absorbing sunlight and heating the atmosphere but that is a topic for another day.

The UM said that BC is produced during incomplete combustion. Burning fossil fuels such as in petrol and diesel engines, ship engines and even fuels for cooking or space heating are some common sources of this pollutant apart from natural ones such as volcano activity, biomass burning in agricultural practices and forest wildfires.

Why do we want to study black carbon in Malta? – UM

The University said that the Maltese urban road network is becoming notorious for continuous traffic and hence this is expected to be the main source of BC in the Maltese Islands. This study will evaluate how the BC levels would change over the day in our typical busy roads (street canyons) and others which are in the background of urban areas or in more rural settings. To date there have been no studies looking into this variability and how the levels compare in different areas in the Maltese Islands.

The health impacts of black carbon exposure

Understanding the way BC levels change throughout the day is crucial in assessing its health impacts. Prolonged and repeated exposure to BC can worsen several health outcomes linked to the respiratory system but not only. For vulnerable groups the risks of exposure are even higher and normally health outcomes will be worsened. Studying the levels of BC in specific urban environments is the first step in understanding the potential health effects derived from this concerning pollutant.

The study to be carried out

The sampling campaign will be carried out across both Malta and Gozo, starting from February 2025, and will aim to capture the current situation of BC emissions from rural, less populated areas where there is limited traffic (such as Dingli, Marsaxlokk, Mgarr and Gharb, Gozo) to the busiest, most congested roads in both islands (such as Msida, Floriana, Valletta Fgura, Gzira, Sliema, St.Julian’s, St. Paul’s Bay and Victoria, Gozo).

In most of the above mentioned places, the corresponding local councils accepted to participate in this study. Once the BC data is collected, we will attempt a first health impact assessment which will aim to quantify the all-cause mortality on the Maltese Islands linked specifically to the exposure to BC.

The Future of air quality guidelines

The UM said that the EU directive on ambient air quality, following the Zero Pollution Action Plan released in 2021 will soon require that member states begin monitoring for previously unregulated air pollutants of emerging concern such as BC.

This study will be the first of its kind in the Maltese Islands and will offer valuable, currently inexistent information, to the environmental and medical stakeholders on the current state of BC levels in Malta and the related mortality implications. Also, such data will be an important scientific basis to transport management and policy makers on how to promote cleaner air in our urban areas, the University of Malta said.

Photos above UM: (Left) Diesel exhaust, (Right) Sampling instrument

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