Recent Advances in Studying Air Quality and Health Effects of Shipping Emissions

Investigation of emission characteristics of a marine cargo ship in real-world conditions

Pollution caused by ship emissions will considerably impact coastal areas. A test system that matched the actual conditions of a ship was designed based on a portable emission measurement system (PEMS), and the emission characteristic of gaseous and particle emissions and the particle size distribution of the ship's main engine were investigated under real-world operating conditions. The results showed that the emission concentrations of the main pollutants fluctuated greatly under the departure, anchoring, and docking conditions, and the peaks of CO, CO2, and NOx emissions appeared under these transient conditions. The emission concentrations of CO2, hydrocarbons, particle number (PN), and particulate mass increased with the increase in speed. The PN-based particle size distribution of the engine presented a unimodal distribution under daily operating conditions. The maximum emission factor of NOx based on the engine power was 29.53 g/kWh at the engine speed of 66 r/min. The results of the study may contribute to supplementing the emission factors of this type of ship, and provide data support for monitoring and assessment of the marine environment.

Ports and their influence on local air pollution and public health: A global analysis

Despite the skyrocketing growth in recent decades of environmental studies on ports and shipping, their local health impacts remain largely under-researched. This article tackles this gap in research by statistically analyzing data on global shipping flows across nearly 5000 ports in 35 OECD countries between 2001 and 2018. The different traffic types, from containers to bulk and passengers, are analyzed jointly with data on natural conditions, air pollution, socio-economic indicators, and public health. The principal results show that port regions pollute more than non-port regions on average, while health impacts vary according to the size and specialization of the port region. Three types of port regions are clearly differentiated: industrial, intermediate, and metropolitan port regions.

A PM10 chemically characterized nation-wide dataset for Italy. Geographical influence on urban air pollution and source apportionment

Urban textures of the Italian cities are peculiarly shaped by the local geography generating similarities among cities placed in different regions but comparable topographical districts. This suggested the following scientific question: can different topographies generate significant differences on the PM10 chemical composition at Italian urban sites that share similar geography despite being in different regions? To investigate whether such communalities can be found and are applicable at Country-scale, we propose here a novel methodological approach. A dataset comprising season-averages of PM10 mass concentration and chemical composition data was built, covering the decade 2005-2016 and referring to urban sites only (21 cities). Statistical analyses, estimation of missing data, identification of latent clusters and source apportionment modeling by Positive Matrix Factorization (PMF) were performed on this unique dataset. The first original result is the demonstration that a dataset with atypical time resolution can be successfully exploited as an input matrix for PMF obtaining Country-scale representative chemical profiles, whose physical consistency has been assessed by different tests of modeling performance. Secondly, this dataset can be considered a reference repository of season averages of chemical species over the Italian territory and the chemical profiles obtained by PMF for urban Italian agglomerations could contribute to emission repositories. These findings indicate that our approach is powerful, and it could be further employed with datasets typically available in the air pollution monitoring networks.

Emission characteristics of naphthalene from ship exhausts under global sulfur cap

The global sulfur limit regulation mandates the use of 0.5 % low sulfur fuel oil (LSFO) to reduce emissions of sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter (PM). However, the addition of naphthalene (Nap) to LSFO to stabilize its quality has led to an increase in polycyclic aromatic hydrocarbons (PAHs), with Nap being the main pollutant. This study investigates the effects of Nap in ship exhaust by analyzing the emission concentrations of volatile organic compounds (VOCs) and Nap in the exhaust of 16 ships, including 2 container ships, 6 bulk carriers, 1 tanker, 2 ferries, 3 fishing vessels, and 2 harbor crafts, based on USEPA method TO-15A. The results show that the percentage of Nap emissions in the exhaust gases of the 16 ship engines ranged from 77 % to 97 % of the total volatile organic compound (TVOC). The Nap concentration in the exhaust of fishing vessels, tanker, and harbor craft exceeded the occupational exposure limit of 50,000 μg/m3, with fishing vessels having the highest TVOC and Nap concentrations. The enhanced Nap emission in the air degrades air quality in port cities and poses an obvious potential public health risk. While the benefits of the global sulfur cap are being secured, additional efforts should be made to reduce the undetected side effects. Alternative stabilizers of LSFO should be considered, or Nap emission control should be boosted to mitigate the potential negative impact on harbor air quality.

Assessing the impact of COVID-19 on air pollutant emissions from vessels in Lianyungang Port

The COVID-19 has had a particularly significant impact on the shipping industry. Using AIS data, a "bottom-up" method was adopted to investigate whether the removal of port-imposed prevention regulations would affect ship activity and ship emissions in Lianyungang Port. The study discovered that, except for passenger ships, the total number of other ships has increased significantly, with tugs, tankers/chemical vessels, ROROs and work boats ranking among the top four. After the regulations were removed, the average normal cruising time per vessel increased from 12.23 to 20.05 h, an increase of 63.94 %, while the average operating time per vessel during slow cruising, maneuvering and hotelling decreased. Meanwhile, the total emissions of air pollutants from vessels have increased by >60 %. Relevant departments need to pay more attention to NOx and develop feasible policies to reduce emissions from especially cargo vessels, tankers and chemical vessels.

Communicating ocean and human health connections: An agenda for research and practice

The emergence of ocean and human health (OHH) science as a distinct scholarly discipline has led to increased research outputs from experts in both the natural and social sciences. Formal research on communication strategies, messaging, and campaigns related to OHH science remains limited despite its importance as part of the social processes that can make knowledge actionable. When utilized to communicate visible, local issues for targeting audiences, OHH themes hold the potential to motivate action in pursuit of solutions to environmental challenges, supplementing efforts to address large-scale, abstract, or politicized issues such as ocean acidification or climate change. Probing peer-reviewed literature from relevant areas of study, this review article outlines and reveals associations between society and the quality of coastal and marine ecosystems, as well as key themes, concepts, and findings in OHH science and environmental communication. Recommendations for future work concerning effective ocean and human health science communication are provided, creating a platform for innovative scholarship, evidence-based practice, and novel collaboration across disciplines.

Environmental assessment model for scrubbers versus alternative mitigation systems for feeder vessels in liner shipping

Implementation of the Global Sulphur Cap (GSC), in January 2020, boosted scrubber installation in vessels to fulfill the new air emission limitations. This increase in scrubbers' use has intensified concern about its environmental performance. Even though achievement of GSC requirements through this mitigation system has been widely proven, the impact of wash water discharge on the marine environment remains under discussion. In this paper, an assessment environmental model is introduced to quantify in monetary terms the performance of feeder vessels that operate with several mitigation systems. This model attempts to improve traditional air emission evaluations by including the impact of scrubbers' discharges on the marine environmental. In this way, the analysis not only allows different mitigations systems to be ranked by considering their capacity to reduce air emissions, but also provides further information about the marine eutrophication and ecotoxicity impact from scrubbers' discharge. Through the model's application to a regular shipping line between the Canary Islands and the Iberian Peninsula, it was found that, the scrubber, regardless of its operation mode (open- or closed loop), is the most efficient mitigation option after the Liquefied Natural Gas (LNG) fuel shift. The impact of scrubbers' discharge was not as significant as expected on the feeder vessel's total pollution since this provides similar relative weight to the methane emissions from a dual-engine option by operating with LNG. The results also show the need to more closely research the marine eutrophication impact of closed-loop scrubbers. Finally, this paper warns about a significant dispersion on the monetary values of marine ecotoxicity and eutrophication, due to a high dependence of the results on the frameworks' localization. Consequently, further research is needed on the homogenization of pollution monetization in the marine environment.

Possible influence of shipping emissions on metals in size-segregated particulate matter in Guanabara Bay (Rio de Janeiro, Brazil)

In the world of growing maritime fleets, ships powered by fossil fuels are being widely used that are responsible for atmospheric emissions such as particulate matter (PM). When inhaled, these can cause serious injury to the body and affect internal organs, because the particle size is on a tiny scale. The International Convention for the Prevention of Pollution from Ships (MARPOL) regulates the standards for emissions from marine diesel engines. However, although they pose risks to human health and the environment, the metals present in PM are not covered by Brazilian national current legislation. This study is based on the results of sampling of PM in the atmosphere of Guanabara Bay, Rio de Janeiro, Brazil, by means of the MOUDI cascade impactor, followed by acid opening of the collected PM and subsequent chemical analysis by ICP-MS for the determination of Ba, Ca, Cd, Co, Cu, Cr, Fe, Mg, Mn, Ni, Pb, V, and Zn. In coarse particles, the mean values ranged from 0.11 ng m^-3 for Ba to 24.9 ng m^-3 for Fe; in fine particles, from 0.07 ng m^-3 for Co to 25.0 ng m^-3 for Fe; and in ultrafine particles, from 0.11 ng m^-3 for Ba to 9.71 ng m^-3 for Fe. Finally, the nanoparticles (Ba and Ca) were not detected and the maximum value obtained was 5.32 ng m^-3 for Mn.

Influence of Adding Low Concentration of Oxygenates in Mineral Diesel Oil and Biodiesel on the Concentration of NO, NO2 and Particulate Matter in the Exhaust Gas of a One-Cylinder Diesel Generator

Air quality currently poses a major risk to human health worldwide. Transportation is one of the principal contributors to air pollution due to the quality of exhaust gases. For example, the widely used diesel fuel is a significant source of nitrogen oxides (NOx) and particulate matter (PM). To reduce the content NOx and PM, different oxygenated compounds were mixed into a mineral diesel available at the pump, and their effect on the composition of exhaust gas emissions was measured using a one-cylinder diesel generator. In this setup, adding methanol gave the best relative results. The addition of 2000 ppm of methanol decreased the content of NO by 56%, 2000 ppm of isopropanol decreased NO₂ by 50%, and 2000 ppm ethanol decreased PM by 63%. An interesting question is whether it is possible to reduce the impact of hazardous components in the exhaust gas even more by adding oxygenates to biodiesels. In this article, alcohol is added to biodiesel in order to establish the impact on PM and NOx concentrations in the exhaust gases. Adding methanol, ethanol, and isopropanol at concentrations of 2000 ppm and 4000 ppm did not improve NOx emissions. The best results were using pure RME for a low NO content, pure diesel for a low NO₂ content, and for PM there were no statistically significant differences.

On-site measured emission factors of polycyclic aromatic hydrocarbons for different types of marine vessels

A portable emission sampling system was used to perform on-site measurements of the emission factors (EFs; quantities of pollutants emitted per unit of energy consumed) of 29 polycyclic aromatic hydrocarbons (PAHs) for five types of marine vessels using light diesel in Hainan Province, China. Both gaseous- and particulate-phase PAHs from vessel emissions were sampled and measured using gas chromatography coupled with mass spectrometry (GC-MS), and the PAH EFs were calculated based on the carbon mass balance method. The average EFs of gaseous- and particulate-phase PAHs were 6.2 ± 7.8 and 17 ± 26 mg/kg, with naphthalene (NAP) and phenanthrene (PHE) dominating the gaseous- and particulate-phase PAH emissions, respectively. Among the five types of vessels, the EFs for small fishing boats were significantly higher than those for other types of vessels, and the lowest EFs were found for tug boats. Composition profiles and typical isomer ratios of PAHs were calculated for five types of vessels. Particulate-phase PAHs accounted for 63 ± 16% of the total emissions of 29 PAH species, and the particulate/gaseous-phase partitioning of PAHs was dominated by organic carbon (OC) absorption rather than black carbon (BC) adsorption. Emission factors of PAHs under different activity conditions were measured and calculated, and relatively higher EFs were found in the maneuvering mode for medium fishing boats and in the operating mode for engineering vessels. No significant differences were found among the PAH composition profiles under different activity conditions.

Environmental Analysis of the Use of Liquefied Natural Gas in Maritime Transport within the Port Environment

Sustainable transport is gaining increasing importance in the political agenda. All modes of transport are obliged to reduce their emissions by both national and international governmental bodies, this requirement being even more necessary in the case of ports due to their traffic density and proximity to the city. The objective of this research is to estimate the atmospheric emissions generated during the operational phases, which are carried out close to Spanish ports. Due to its geographical position, Spain benefits from the routes of the Atlantic corridor and Mediterranean corridor belonging to the principal European transport network. The method uses detailed information about ship movements and ship categories (ship type, engine type, fuel type, etc.). From an environmental point of view, the results show that engines powered by Liquefied Natural Gas, compared to traditional fuels, save between 28% in the case of freight ships and 31% for passenger ships in the emission of CO2 into the atmosphere (52 tons per journey). On the other hand, the saving in NOx emissions is reduced by 87%. In addition, SOx emissions are completely eliminated and PM emissions are reduced to negligible values.

Numerical Modeling of Air Pollutants and Greenhouse Gases Emissions in Intermodal Transport Chains

This paper discusses the most attractive emission compliance options (emission abatement technologies and cleaner fuels) in intermodal transport chains that include short sea shipping. Most studies on emissions-based transport chain comparisons have estimated high levels of nitrogen and sulfur oxide emissions in maritime transportation, decreasing its competitiveness. However, the consequences of regulatory and technological developments and the integration of maritime transport in intermodal transport chains have not yet been considered in detail. In order to address this research gap, a numerical model for computing emissions from different transport modes in an intermodal transport network, under the effect of these developments, is presented that is based on bottom–up emission factors that depend on the fuel type, engine type, and operational profile of each vehicle. Different emissions scenarios are chosen for specific unimodal and intermodal routes (short sea shipping-based) between Portugal and northwestern Europe. Conclusions are drawn on estimated values of air pollutant emissions and greenhouse emissions, in CO2-eq per unit of cargo, in each scenario. These results allow the identification of the most environmentally friendly transport chains, thus supporting the development of adequate transport policies.

Shipping and Air Quality in Italian Port Cities: State-of-the-Art Analysis of Available Results of Estimated Impacts

Populated coastal areas are exposed to emissions from harbour-related activities (ship traffic, loading/unloading, and internal vehicular traffic), posing public health issues and environmental pressures on climate. Due to the strategic geographical position of Italy and the high number of ports along coastlines, an increasing concern about maritime emissions from Italian harbours has been made explicit in the EU and IMO (International Maritime Organization, London, UK) agenda, also supporting the inclusion in a potential Mediterranean emission control area (MedECA). This work reviews the main available outcomes concerning shipping (and harbours’) contributions to local air quality, particularly in terms of concentration of particulate matter (PM) and gaseous pollutants (mainly nitrogen and sulphur oxides), in the main Italian hubs. Maritime emissions from literature and disaggregated emission inventories are discussed. Furthermore, estimated impacts to air quality, obtained with dispersion and receptor modeling approaches, which are the most commonly applied methodologies, are discussed. Results show a certain variability that suggests the necessity of harmonization among methods and input data in order to compare results. The analysis gives a picture of the effects of this pollution source, which could be useful for implementing effective mitigation strategies at a national level.