In an earlier blog post ‘titanic pollution’, I talked about pollution from cruise ships, including grey water, emissions, and black carbon. This is a follow-up post of sorts, focusing specifically on black carbon, its sources, transformation, and effects on the environment and human health.
The journal article ‘Black Carbon and Other Air Pollutants in Italian Ports and Coastal Areas: Problems, Solutions and Implications for Policies’ takes a regional look at black carbon pollution in Italy and examines the consequences it has on human health and agricultural production in Italian ports and surrounding coastal areas [1]. The article notes that ports and coastal areas in Italy are particularly appropriate subjects for researching black carbon as it is a hub for cruise ships and the rising concern about the public effects of such entertainment behemoths
Figure 1. Black carbon emissions by ship type [2]
The article notes that black carbon (BC) is extremely small particles that result from the burning of fossil fuels and biofuels, often from diesel engines and coal-fired power plants. Figure 1. shows how cruise ships are disproportionately producing BC, as they account for 6% of global BC emissions despite only making up 1% of the global shipping fleet, releasing the highest amount of BC per ship of any vessel.
The article then describes BC as an aerosol that can either float through the air thousands of miles, or it can land on a surface within a few meters of the source. As they float in the air, BC particles absorb solar energy and contribute to global warming.
In fact, BC is the second largest contributor to global warming, causing a net positive radiative forcing of 1 to 1.2 Wm–2 (± 0.4 Wm–2) in 4 ways [3]:
1. Absorbing and intercepting direct sunlight (negative forcing) of direct sunlight in (negative forcing)
2. Absorbing reflected solar radiation by the earth/clouds (positive radiative forcing)
3. Deposition on sea ice and snow which increases the absorption of sunlight
4. Evaporation of low clouds aided by BC caused warming (positive forcing)
Figure 2. Black Carbon warming potential in the Arctic [4]
Figure 2 better illustrates how black carbon contributes to warming, in the Arctic environment where its warming potential is the greatest due to its ability to accelerate ice melt in the region. The effects of black carbon on global warming are already being felt, as scientists have estimated that the black carbon produced by vessels, planes, and diesel generators results in 23 mm of additional snowmelt each summer in the most frequently visited areas of the ice-covered landmass [5].
Another scary aspect of black carbon is its ability to serve as a bed for other toxic chemicals. Evidence has suggested that the carbon core of BC can act as a universal carrier of various combustion-derived chemical constituents like semi-volatile organic fractions and transition metals [6]. This has huge ramifications on the associated health impacts of BC pollution. The article notes that health effects depend on the particle size and the substances sorbed on their surface, with soot BC, which can vary in size from ultrafine (less than 0.1 µm) to fine (less than 2.5 µm) being more detrimental to health than larger ones. A WHO report found that BC exposure was linked to cardiopulmonary morbidity and mortalities [7]. Also, as a universal carrier of other pollutants, a wide variety of chemicals of varying toxicity to the lungs, the body’s immune system, and potentially even blood circulation is introduced to the human body [8].
In the reference article, Italy’s food production is also noted to have been affected by BC. Wheat, maize, rice, and soybean crops have all been found to have been damaged by BC, caused by pollution of water supplies by deposition of emissions and BC deposition on plant leaves. Given Italy’s 7500km coastline is filled with important agricultural areas, the emissions from nearby cruise ships are noted as an important issue that needs to be addressed.
Figure 3. Cartoon on cruise ship pollution [9]
While providing recommendations to the Italian authorities to slow steaming within their waters and gradually increase limits on black carbon emission in regional waters, the reference article does highlight a problem that extends far beyond Italy. Given the massive impacts of black carbon, authorities globally should increase efforts to weed out black carbon emissions, especially from sources like incomplete combustion in diesel engines. Even if the problem is not directly in our faces, we as consumers of entertainment should be more aware of the impact of our activities unlike those seen in Figure 3.
– Lucian Taft Kimbrell
References
[1] Brewer, T. L. (2020, November 29). Black Carbon and other air pollutants in Italian ports and coastal areas: Problems, solutions and implications for policies. MDPI. Retrieved March 5, 2023, from https://doi.org/10.3390/app10238544
[2] Fleck, A. (2022, May 2). Infographic: Cruise ships are the biggest black carbon polluters. Statista Infographics. Retrieved March 5, 2023, from https://www.statista.com/chart/27353/worst-black-carbon-polluters/
[3] Shrestha, G., Traina, S. J., & Swanston, C. W. (2010, January 15). Black Carbon’s properties and role in the environment: A comprehensive review. MDPI. Retrieved March 5, 2023, from https://doi.org/10.3390/su2010294
[4] Clear Seas . (2022, February 22). Black Carbon in the Arctic: What you need to know. Clear Seas. Retrieved March 5, 2023, from https://clearseas.org/en/blog/black-carbon-in-the-arctic-what-you-need-to-know/
[5] Lu, D. (2022, February 22). Black Carbon Pollution from tourism and research increasing Antarctic snowmelt, study says. The Guardian. Retrieved March 5, 2023, from https://www.theguardian.com/world/2022/feb/22/black-carbon-pollution-from-tourism-and-research-increasing-antarctic-snowmelt-study-says
[6] Cassee, F. R., Héroux, M.-E., Gerlofs-Nijland, M. E., & Kelly, F. J. (2013). Particulate matter beyond mass: Recent health evidence on the role of fractions, chemical constituents and sources of emission. Inhalation Toxicology, 25(14), 802–812. https://doi.org/10.3109/08958378.2013.850127
[7] Ågren, C. (2012, June). Health effects of black carbon. Airclim. Retrieved March 5, 2023, from https://www.airclim.org/acidnews/health-effects-black-carbon
[8] EEA. (2013, December 13). Status of black carbon monitoring in ambient air in Europe. European Environment Agency. Retrieved March 5, 2023, from https://www.eea.europa.eu/publications/status-of-black-carbon-monitoring[9] Hallatt, A. (2019, April 20). Arctic Circle cartoons and the environmental cost of cruise ships in Lyttelton, New Zealand. Alex Hallatt. Retrieved March 5, 2023, from https://www.alexhallatt.com/blog/arctic-circle-cartoon-cruise-ships-are-very-polluting-and-damage-the-environment
[9] Hallatt, A. (2019, April 20). Arctic Circle cartoons and the environmental cost of cruise ships in Lyttelton, New Zealand. Alex Hallatt. Retrieved March 5, 2023, from https://www.alexhallatt.com/blog/arctic-circle-cartoon-cruise-ships-are-very-polluting-and-damage-the-environment
