Atmospheric pollution is one of the biggest threats facing humanity today. It is not only responsible for the climate crisis we are seeing – with record-breaking heat, forest fires, rising sea levels, and more unpredictable weather patterns – it also negatively impacts the quality of the air we breathe, creating a health crisis responsible for around 4.2 million deaths in 2015 alone.
Every part of the world is being affected by climate change and can be affected by low air quality, but some areas are much more susceptible than others – typically those where fossil fuel use is high, for example from transport or manufacturing. Climate conditions can exacerbate this vulnerability, with wind speed and direction responsible for moving pollutants across wide areas.
As countries apply themselves to reaching the goals set by the Paris Agreement, it’s critical that we understand the complex factors contributing to climate change, and how they are interacting to produce the effects people are experiencing. With that understanding, nations can then work out the best sustainable approaches to tackling those effects.
Project ELECTRON
As part of the EU-funded ELECTRON project, Dr Ioannis Logothetis and his colleagues Christina Antonopoulou, Georgios Zisopoulos, Dr Adamantios Mitsotakis, and Dr Panagiotis Grammelis from the Chemical Process and Energy Resources Institute/CERTH, Greece, have carried out timely studies to understand how tourism activities, traffic emissions, climatic conditions, and forest fires interact to affect air quality in Rhodes. Their research centres on collecting air quality, weather, and climate data from Rhodes city and the wider region over the summer of 2021.
“Some areas are much more susceptible than others – typically those where fossil fuel use is particularly high.”
Air quality in Rhodes: 2021
The Mediterranean is particularly susceptible to the effects of climate change, and the Greek island of Rhodes, in the eastern Mediterranean, is at significant risk from air pollution. With its rich history and pristine beaches, Rhodes is an important tourism and trade hub for Greece and therefore a socio-economic region of significance. Rhodes city, on the north of the island, is a particular tourism hot-spot and heavily trafficked as a result. The region is also prone to large-scale forest fires, especially in the summer months. During the summer of 2021, Rhodes suffered not just from its own episodes but from pollutants carried by local wind patterns from forest fires in south-west Turkey.
The dangers of these fires may seem obvious, but they carry an invisible threat too, as research carried out in Southern California (Aguilera et al, 2021) suggests that particulate matter from wildfires is more toxic than the same size particles from other sources. Rhodes city, then, suffers from not just one but a confluence of factors that contribute to poor air quality.
A good indication of air quality is the concentration of particulate matter (PM): tiny airborne particles which, when inhaled, enter the lungs and bloodstream causing breathing problems and even cardiovascular diseases and cancer. Previous studies have already shown a causal link between the number of tourists and the concentration of pollutants in tourist areas, demonstrating that increased vehicle emissions and tourism activities increase the concentration of PM in the urban area. To combat this, local authorities are interested in adopting policies to reduce traffic in urban areas, to improve the quality of the ambient air and protect the population’s health.
Traffic, tourism, and forest fires
Dr Logothetis and his colleagues carried out their study between 17 July and 31 August 2021, using a mobile air-quality monitoring system set up in the middle of Rhodes city. They measured the hourly concentration of a variety of pollutants such as PM2.5 and PM10 (particles with a diameter of 2.5 and 10 micrometres/µm respectively). They also retrieved hourly data of wind speed (WS), relative humidity (HR), and temperature (T), taken from the ERA5 reanalysis data set in the frame of the European Center for Medium-Range Weather Forecasts (ECMWF), to determine how these factors might affect the variability of PMs. They used the mapped WS, HR, and T to compare periods when fires occurred with non-fire periods, to see more clearly how these climate factors influence the risk of fire. Additionally, they studied the impact of meteorological factors on ambient air quality.
To tease out the impact of both heavy traffic and forest fires on the concentration of PM, the team used the Common Air Quality Index (CAQI) – a rating system designed to compare air quality across European cities which uses five classifications of pollution, from very low to very high.
The team then used the climate data and weather maps to further assess what weather conditions make wildfires particularly likely, and how those conditions affect fire severity, using statistical analysis to create a Fire Weather Index (FWI) to estimate the likelihood of fires from prevailing weather conditions. This analysis could then be used to assess the relationship between the likelihood of wildfires in the region and pollutant variability in Rhodes city (Figure 1).
To study the impact of climate conditions on the human sense of comfort the team also calculated what’s known as the Discomfort Index (DI) – a simplified way of quantifying the levels of discomfort experienced by the average person under different climate conditions.
Impacts on air quality
The study confirmed previous conclusions that wind speed has a significantly positive effect on the air quality of Rhodes city, with the region’s Etesian wind system effectively ventilating the area and reducing the levels of pollutants during the summer. In 2021, however, low humidity and high temperatures made forest fires more likely, and the region’s low tropospheric air circulation then blows PM from forest fires in south-east Turkey across to Rhodes city.
Air quality (PM2.5 concentrations) during forest fire periods was ‘medium’ on the CAQI scale, while outside these times PM2.5 concentrations were ‘fairly low’ or ‘low’, ie, air quality was fairly good – a clear indication that forest fires significantly affect PM 2.5 concentration.
Interestingly, the research team noticed spikes in PM2.5 concentration on some August days in the post-forest fire period, which they conclude was the result of particularly heavy traffic, tourism, and other human activity in the study area, highlighting the potential air quality and health benefits of green technologies such as electric vehicles (Figure 2).
The team’s research indicates that climatic conditions can reduce the concentration of PM in Rhodes city through high wind speeds. However, human activities and traffic density, coupled with PM blown towards Rhodes from forest fires by regional air circulation, significantly contribute to the city’s poor air quality – and the fire impacts are likely to worsen as climate change brings warmer, drier weather to the region.
The outcomes of this research support the results of the team’s other work under project POSEIDON MED II, comparing air quality during periods of high and low activity in the ports of Heraklion on the island of Crete, and Igoumenitsa in western Greece, an important trade route between western Europe and the Balkans.
“Human activities and traffic density, coupled with particulate matter blown towards Rhodes from forest fires, significantly contributed to the city’s poor air quality during the summer of 2021.”
Air-quality solutions
As air pollution is likely to worsen with predicted increases in traffic emissions, shipping and forest fires in the region and globally, climate change and adverse health effects will continue to increase. With climate change bringing warmer, dryer weather, forest fires are more likely to start and be more severe. This could drive a positive feedback loop of higher temperatures, more forest fires, and further air pollution and global warming. Additionally, the growing tourist industry and increasing traffic emissions further contribute to air quality degradation. On days with high concentrations of PM the researchers found the DI was medium, indicating that poor air quality and the population’s sense of comfort could be negatively affecting human health.
To keep PM concentrations below levels that the World Health Organization considers hazardous to human health, air-quality research can play a key role in informing local and national government air-quality policies. Approaches could include technological and natural methods, such as sustainable transport, or strategically planting trees and other vegetation close to high transport areas. Electric vehicles and the development of green technologies (for example in public transport) can contribute to optimal solutions, saving energy and further improving current air-quality conditions.
Further research will be critical to develop best practices for improving the air-quality outlook for Rhodes city, including developing a more in-depth understanding of how climate conditions and traffic emissions affect the variation of pollutants and how best to mitigate them.
The work by Dr Logothetis and his colleagues can have important implications for driving air-quality and climate-change policy in the wider Aegean and the Mediterranean, by helping policymakers understand the complexities of the factors affecting air quality and what can be done to ensure more sustainable development.
We aim to develop digital tools and data libraries that help us to understand better the variation of pollutants over this air pollution- and climate change-prone region. The study of traffic scenarios in combination with model results, air-quality recordings from UAVs, and the use of pure electric vehicles, could give us the opportunity to further understand the drivers of air quality and the variability in the concentration of pollutants. Our primary goal is to provide the authorities the context for green development and sustainable management plans for the region of south-eastern Greece.
References
- Logothetis, I, et al, (2022) The impact of climate conditions and traffic emissions on the PMs variations in Rhodes city during the summer of 2021. Proceedings of the 7th World Congress on Civil, Structural, and Environmental Engineering (CSEE’22) Paper No ICEPTP 181 DOI:10.11159/iceptp22.181
- Aguilera, R, et al, (2021) Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California. Nature Communications, 12, 1493. doi.org/10.1038/s41467-021-21708-0
- Logothetis, I, et al, (2021) A comparative case analysis of meteorological and air pollution parameters between a high and low port activity period in Igoumenitsa Port. Engineering Proceedings, 11, 33. doi.org/10.3390/ASEC2021-11118
- Logothetis, I, et al, (2021) Comparison analysis of the effect of high and low port activity seasons on air quality in the port of Heraklion. Environmental Sciences Proceedings, 8, 3. doi.org/10.3390/ecas2021-10329
- Logothetis, I, et al, (2021) The impact of wildfires of southwestern Turkey and Rhodes island on the air quality of Rhodes city in the summer of 2021. 8th International Conference on Civil Protection & New Technologies, SAFEGREECE, DOI:10.13140/RG.2.2.25902.23364
10.26904/RF-142-2896146660
Research Objectives
Dr Logothetis and colleagues are researching the impact of atmospheric pollution on Rhodes.
Funding
We acknowledge the support of project ‘Laboratory of Excellence for the monitoring of environmental impact from transport and promotion of electromobility in islandic regions – ELECTRON’ (MIS 5047136), implemented under the Action ‘Reinforcement of the Research and Innovation Infrastructure’, funded by the Operational Programme ‘Competitiveness, Entrepreneurship and Innovation’ (NSRF 2014-2020) and co-financed by Greece and the EU European Regional Development Fund.
Collaborators
Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki:
- Professor Kleareti Tourpali
- Professor Dimitrios Balis
- Professor Dimitris Melas
Bio
Dr Ioannis Logothetis has been a research associate at the CERTH/CPERI since 2021. He is a scientific collaborator to the Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Greece. Ioannis’ research focuses on climatology, atmospheric circulation, climate change, air quality, and atmospheric pollution.
Christina Antonopoulou is an MSc research associate at CERTH/CPERI. She has been involved in international and national research projects and studies green energy and environment.
Georgios Zisopoulos is an MSc mechanical engineer and scientific associate at CERTH/CPERI. His focus is on computational simulations, numerical analysis and developing computational tools for the dynamic simulation of thermodynamic systems and processes.
Dr Adamantios Mitsotakis is a scientific associate at CERTH/CPERI. He focuses on the development of Liquefied Natural Gas and other alternative fuels in the Greek market.
Dr Panagiotis Grammelis is Director of Research at the Chemical Process and Energy Resources Institute of CERTH/CPERI. His research covers the exploitation of solid fuels with emphasis on thermochemical conversion technologies. Since 2011 he has been head of the Laboratory of Alternative Fuels & Technologies. He is on the editorial boards of three international scientific journals and co-author on 387 papers in scientific journals, international conferences, workshops and books.
Contact
CERTH/CPERI, 6th km Harilaou – Thermis, 57001, Thermi, Thessaloniki, Greece
E: logothetis@certh.gr
T: +30 2310 464160 T: +30 2310 464162
W: www.cperi.certh.gr/en
W: elektron-project.gr
