TEXTE Environmental Impacts of Exhaust Gas Cleaning Systems for Reduction of SOx on Ships — Analysis of status quo 
Report compiled within the framework of the project ImpEx 
Other studies including chemical analyses of EGCS discharge water samples taken on board are: 
= Hansen (2012) from a hybrid system on board the RoRo Ficaria Seaways, 
USEPA (2011) from an OL system on board the cruise ship MS Zaandam, 
= Wärtsilä (2010) from a CL system on board the tanker MT Suula and 
a Hufnagl et al. (2005) from an OL system on board the RoPax Pride of Kent. 
The first study in the list was conducted on board the same ship as the above described study of 
Kjglholt et al. (2012) and was also financed by the Danish EPA. The results of the measurements 
on the discharge water are reported less extensively. The author questioned the reliability of the 
on-line monitoring for PAHypne on board, in the same way as Wärtsilä (2010). In the last three 
(older) listed studies, the samples were taken during operation of auxiliary engines. No further 
description about them is presented in this report as there are more recent and more extensive 
studies published. 
7.2 Ecotoxicological effects of EGCS discharge water 
This chapter compiles the main research work on ecotoxicological effects of EGCS discharge 
water. The approach of the studies and the main findings are presented below. Table A-5 
contains an overview of their analysis, results and tested water. 
Kathmann et al. (2019) carried out an assessment of both adverse acute (on luminescent 
bacteria and marine algae) and potentially chronic effects (dioxin-like activity and mutagenicity) 
caused by discharge water from OL and CL systems. OL discharge water tested positive for 
dioxin-like activity and mutagenicity, whereas no significant inhibition effects were shown in the 
in vivo assays. CL discharge water exerted stronger effects across all bioassays. 
An evaluation on the effects of the water treatment in CL systems showed no significant 
reduction of toxicity. The treatment step itself is pointed out as a source of toxicity; for instance, 
incomplete removal of flocculants could be a possible explanation. The analyses were performed 
with filtered samples indicating that only water soluble compounds caused the observed effects, 
which might explain the absence of biological effect reduction despite efficient PAH removal. The 
results probably underestimate the full risk potential of the samples to marine organisms. 
Toxicity could only partially be explained by the measured contaminants. This indicates that 
either mixture toxicity has to be taken into account or that toxic compounds (such as 
nitroarenes and substituted PAHs, especially nitro-PAHs) are present in the sample that were 
not captured by the applied chemical analysis. The authors concluded that further identification 
of pollutants in EGCS discharge water is required and technical measures should be re-evaluated 
to efficiently treat discharge water before its release. 
Ytrebergetal. (2019) assessed how EGCS discharge water affects microplankton species 
(laboratory experiments) as well as a natural community of pelagic microplankton originating 
from the Baltic Sea (field experiment). 
During the field experiment significant increases in chlorophyll a, particulate organic 
phosphorus (POP), carbon (POC) and nitrogen (PON) were observed when the plankton 
community was exposed to 10% EGCS discharge water for 13 days. The effects could be 
explained by stimulated algal growth due to the increased nitrate concentrations in the EGCS 
discharge water. Therefore, the authors mentioned that the additional load of nitrate from 
16