Mapping of toxic vapors on board of chemical tankers

During normal management of a chemical tanker, the crew will perform operations in the cargo part of the vessel, like entering tanks, cleaning lines, connecting and disconnecting of the manifold, sampling and maintenance of specific equipment. Under these circumstances there will be a higher risk of direct contact with the cargo and cargo vapors. These vapors can be taken up by ventilation intakes, bringing the cargo fumes into the accommodation and engine Radiello® passive samplers offer several advantages for this application, including no electricity use, small sizes, adjustable exposure times and especially a precise and selective measurement of air concentrations.Especially the benzene concentrations on board were relatively high. The cargo on board can explain a lot. During our stay on board benzene has been loaded in three tanks and later on these tanks have been cleaned and ventilated during our measurements. The International Maritime Organisation (IMO), recognized that chronic exposure to very low concentrations of benzene vapors in air, of the order of a few parts per million, may cause leukaemia. According to Madl, benzene exposure on board of crude oil and chemical tankers do not pose a health risk to deck crewman. interpretation of the results will soon demonstrate if we can confirm Madl’s statement on board of this type of vessels.On the other hand we measured the concentrations of toxic vapors over relatively short periods, during well specific operations on deck. Here the concentrations were measured with the ‘PAC III’ apparatus of Draeger®. The results of this investigation have to be compared with the TLV-TWA and TLV-STEL values. Conclusions here should encourage the optimization of the use of respiratory protection aids during cargo operations

Assessment of the water soluble ionic species of suspended particulate matter, collected at a coastal spot, De Haan, Belgium

Chemical characterisation of suspended particulate matter (SPM) is very useful for broadening the knowledge concerning processes which are active in the atmosphere (e.g. Lin, 2002). Continental air-masses were found to contain high levels of anthropogenic emitted species, while these levels decreased when the influence changed to an oceanic atmosphere. The high levels of NH4 +, NO3 - and non-sea-salt (NSS) SO4 2- in the fine SPM fraction of continental air-masses (0.38, 0.15μg.N.m-3 and 0.59μg.m-3, respectively) stresses the importance of secondary aerosol formation as a source for SPM. The dominant appearances of Na+, Cl-, Mg2+ and Ca2+ in coarse maritime air masses show the presence of sea-salts and soil dust in the atmosphere at the coastal region. Neutralisation ratios higher than unity (1.20-1.59) for the fine SPM fraction suggested an excess of NH4 +, which was most probably present in the form of NH4Cl due neutralisation of HCl. The latter was formed in atmospheric reactions with sea-salt particles (Kadowaki, 1977), during which HCl escapes (0.13 and 0.58% lost sea-salt chloride for winter and summer, respectively). Correlation analysis showed that warm and dry summer conditions eliminated some influence of sea-salts on atmospheric processes, that where found to be active during winter. NSS SO4 2- was the dominant S-contributor in the fine fraction (83%). During winter, a total SOR value of 0.61 was reached, while summer gave a significant lower value (0.24). These values classified the sampling-site at the Belgian coast as a combined receptor-source area, accepting pollution from the continent and its local surroundings (Shaw and Rodhe, 1982)

Atmospheric nitrogen input into the North Sea: organic nutrient detection

The levels of gaseous organic nitrogen compounds (alkyl nitrates - ANs) together with identification of the possible sources of these compounds in the air were studied. Seasonal trends were investigated by conducting the sampling campaigns during the spring, summer and winter time. The air-mass backward trajectories (BWTs) were calculated for the sampling periods by Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model (Draxler and Rolph, 2003). These BWTs were considered for the determination of the influence of the Atlantic Ocean, the North Sea and the continent as possible sources of ANs. An adapted set-up for low and high volume samplings, extraction and minimized clean-up, identification and quantification capabilities resulting from the complementary use of GC-ECD and GC-MS methods is reported. The AN levels were found to be in the range of a few to 7400 pg.m-3 in the air. The AN fraction consisted of primarily the 2C4, C5 and C6 isomers, which contribute largely to the total AN level. The N-fluxes by ANs were more pronounced for the summer periods than for the winter/spring months, organic nitrates were the most abundant in the Atlantic/Channel/UK air-masses

Major ionic species in size-segregated aerosols and associated gaseous pollutants at a coastal site on the Belgian North Sea

The chemical composition of airborne particulate matter (PM) was studied at a coastal region near De Haan, Belgium, during a winter–spring and a summer campaign in 2006. The major ionic components of size-segregated PM, i.e. NH4+, Na+, K+, Mg2+, Ca2+, Cl-, NO3-, and SO42-, and related gaseous pollutants (SO2, NO2, NH3, HNO2, and HNO3) were monitored on a daily basis. Air mass backwardtrajectories aided in evaluating the origin of the diurnal pollution load. This was characterised with high levels of fine secondary inorganic aerosols (NH4 +, NO3-, and non-sea-salt SO42-) for continental air masses, and sea-salts as the dominant species in coarse maritime aerosols. Seasonal variations in the level of major ionic species were explained by weather conditions and the release of dimethyl sulfide from marine regions. This species was responsible for an increased sea-salt Cl- depletion during summer (56%), causing elevated levels of HCl. Neutralisation ratios for the coarse fraction (0.6–0.8) suggested a depleted NH4+ level, while that for the fine fraction (1.1–1.3) had definitely an excess of NH4+, formed by the neutralisation of HCl. The results of factor analysis and the extent of SO2 oxidation indicated that the major ionic species originated from both local and remote sources, classifying the Belgian coastal region as a combined source–receptor area of air pollution

Elemental concentrations in aerosols at the Belgian coast versus seasons and air mass trajectories

Marine aerosols have extensively been monitored in the framework of a research project to investigate the inorganic and organic nutrient fluxes of the atmospheric nitrogen input into the North Sea. As a part of this project bulk analysis was also performed by energy dispersive X-ray fluorescence (EDXRF) on a total of 366 samples in order to provide detailed elemental composition. Samples have been clustered per campaign and differences were related to backward trajectories. Elements as Cl, Si, and S appeared to be the best tracers for coastal aerosols. Therefore they have been chosen to represent each campaign and to map the seasonal variations. It is clear that Cl is an excellent tracer for oceanic trajectories, while a less clear correlation between the soil dust components and the air mass trajectories is found

Atmospheric nitrogen fluxes at the Belgian coast: 2004-2006

Daily and seasonal variations in dry and wet atmospheric nitrogen fluxes have been studied during four campaigns between 2004 and 2006 at a coastal site of the Southern North Sea at De Haan (Belgium) located at coordinates of 51.1723° N and 3.0369°; E. Concentrations of inorganic N-compounds were determined in the gaseous phase, size-segregated aerosol (coarse, medium, and fine), and rainwater samples. Dissolved organic nitrogen (DON) was quantified in rainwater. The daily variations in N-fluxes of compounds were evaluated with air-mass backward trajectories, classified into the main air-masses arriving at the sampling site (i.e., continental, North Sea, and Atlantic/UK/Channel).The three, non-episodic campaigns showed broadly consistent fluxes, but during the late summer campaign exceptionally high episodic N-deposition was observed. The average dry and wet fluxes for non-episodic campaigns amounted to 2.6 and4.0mg N m-2 d-1, respectively, whereas during the episodic late summer period these fluxes were as high as 5.2 and 6.2mg N m-2 d-1, respectively. Non-episodic seasons/campaigns experienced average aerosol fluxes of 0.9-1.4 mg N m d-1. Generally, the contribution of aerosol NH4+ was more significant in the medium and fine particulate fractions than that of aerosol NO3-, whereas the latter contributed more in the coarse fraction, especially in continental air-masses. During the dry mid-summer campaign, the DON contributed considerably (~15%) to the total N-budget.Exceptionally high episodic aerosol-N inputs have been observed for the late summer campaign, with especially high deposition rates of 3.6 and 2.9 mg N m-2 d-1 for Atlantic/UK/Channel and North Sea-continental (mixed) air-masses, respectively. During this pollution episode, the flux of NH4+ was dominating in each aerosol fraction/air-mass, except for coarse continental aerosols. High deposition of gaseous-N was also observed in this campaign with an average total N-flux of 2-2.5-times higher than in other campaigns

Atmospheric nitrogen input into the North Sea: inorganic and organic nutrient fluxes. Final report EV/39

The North Sea is threatened by eutrophication. Excess supply of nutrients, especially nitrogen compounds, causes proliferation of algae, leading to pernicious oxygen depletion. The nitrogen supply is not only due to rivers, but to the atmosphere as well. Especially in summer, when nutrients are scarce and the river supply is reduced, the atmospheric contribution can become predominant. The relevant atmospheric nitrogen is emitted as nitrogen oxides (by traffic and industry) and as ammonia (by agriculture). Organic nitrogen compounds might be important but their deposition fluxes are unknown.Measurements of the concentrations of the various inorganic and organic nitrogen components and of their deposition, with rain and in the dry phase, will allow evaluating the contribution of the atmosphere to eutrophication processes, using adequate mathematical models