Survey of inorganic trace elements and polycyclic hydrocarbons (PAH) in mussels and sediments at Grundartangi, Hvalfjörður, 2016 / Evaluation of inorganic trace elements and aromatic hydrocarbons (PAHs) in blue mussel (Mytilus edulis) and sediment at Grundartangi, Hvalfjörður, 2016




Halldór Pálmar Halldórsson, Hermann Dreki Guls, Natasa Desnica, Erna Óladóttir, Helga Gunnlaugsdóttir, Kristín Ólafsdóttir

Supported by:

Norðurál hf., Elkem Ísland ehf


Natasa Desnica

Research Group Leader

Survey of inorganic trace elements and polycyclic hydrocarbons (PAH) in mussels and sediments at Grundartangi, Hvalfjörður, 2016 / Evaluation of inorganic trace elements and aromatic hydrocarbons (PAHs) in blue mussel (Mytilus edulis) and sediment at Grundartangi, Hvalfjörður, 2016

The aim of the study is to assess the possible polluting effects of industrial plants at Grundartangi on the marine environment in Hvalfjörður. Environmental monitoring began in 2000 and was repeated in 2004, 2007, 2011 and 2013, as well as the implementation of monitoring was reviewed, including the addition of sampling points and the number of measuring factors increased. This report reports the results of monitoring measurements in samples from 2016. Mussels (Mytilus edulis) were placed in cages at seven different stations along the coast at Grundartangi, north of Hvalfjörður, including one reference point at Saurbæjarvík in the fjord. The mussel cages were then taken up and the mussels examined two months later. To assess the natural fluctuations in the concentration of substances and the growth of mussels, one control sample was taken and frozen as soon as the mussels were put out for cultivation. Mortality and growth of mussels together with the main components (water, fat, ash and salt) were measured at the end of the study. The following inorganic trace elements and organic compounds were also measured in the soft tissue of mussels; arsenic, cadmium, copper, zinc, chromium, nickel, mercury, selenium, lead, vanadium, aluminum, iron, fluorine and 16 polycyclic hydrocarbons (PAHs) but the latter were reduced by two (perylene and benzo (e) pyrene) to at the request of the buyer. PAHs were also measured in sediment samples taken at the same locations as the mussel samples. There was not much difference between stations, neither in terms of biological factors nor the main components of mussels. Mortality was low and in general the mussel seemed to be doing well. Inorganic trace elements were at a similar concentration or lower compared to previous studies and were measured at a similar concentration as in mussels from unpolluted places around the country and always at a lower concentration than the Norwegian limit for contaminated areas. Cadmium (Cd), however, was measured above the Norwegian minimum limit, but its concentration in mussels decreased at the factory sites during the growing season. It is therefore not considered that high cadmium concentrations are associated with the industrial plants at Grundartangi, but rather naturally high background concentrations in the Icelandic environment. In cases where there are maximum levels for inorganic trace elements in food (Cd, Hg, Pb), their concentration in mussels after two months at sea near the industrial plants was always well below the maximum levels for food. Only 3 PAHs were detected above the limit of detection in mussels, the same as in 2013: pyrene, phenanthrene and fluoranthene (perylene was also detected in 2013 but was omitted this time). Pyrene was at its highest concentration of the 3 PAHs detected, except in Bank 1 where fluoranthene was at its highest concentration. The concentration of PAHs in mussels was insignificant and always below the Norwegian limit for contaminated areas for mussels. All 16 PAHs were detected in all sediment samples and their total amount ranged from 209-791 µg / kg dry weight. It is likely that these PAHs in the sediment are related to industrial activities and shipping traffic in the area. Compared with Norwegian reference values, all measured sampling sites except two are classified as mild impact areas where PAH concentration is higher compared to the definition of background area. This is the second time that the concentration of PAHs is measured in sediment samples in the environmental monitoring of the industrial plants at Grundartangi and the total amount of PAH substances in the sediment was lower this year compared to 2013. The effect of the industrial plants on mussels in the vicinity of Grundartangi seems limited. substances measured in this study. The effects on the sediment's ecosystem are therefore likely to be insignificant, given the Norwegian and Canadian exposure limits of PAHs. However, it is still necessary to closely monitor and monitor the environment and the ecosystem in order to detect changes in the pollution load in this area.

The aim of this study is to estimate potential impact of organic and inorganic pollutants on the costal marine ecosystem in proximity to the industrial activities at Grundartangi in Hvalfjörður. The monitoring started in the year 2000 and has since then been revised in terms of additional sampling sites and measured elements, but the monitoring has been repeated in the years 2004, 2007, 2011 and 2013. This report summarizes the results obtained in the study performed in 2016. Caged mussels (Mytilus edulis) from a homogenous population were positioned at seven different locations along the coast close to Grundartangi industries including a reference cage at Saurbæjarvík. The mussel cages were then retrieved after a two month monitoring period. In order to enable assessment of natural changes in compound concentration and mussel size over time, a reference sample was taken from the mussel pool when the cages were initially deployed at their monitoring sites. Death rate and growth of mussels as well as their main constituents (water, fat, ash and salt) were evaluated at the end of the monitoring period. Similarly, the following trace elements and organic compounds were analyzed in the soft mussel tissue: As, Cd, Cu, Zn, Cr, Ni, Hg, Se, Pb, V, Al, Fe, F and 16 PAHs (two compounds, perylene and benzo (e) pyrene were omitted this time). PAHs were also analyzed in sediment samples taken from the same sites. Little variation was observed in main constituents and biological factors between the different sampling sites. Death rate was low and the mussels thrived well. In general, inorganic trace elements were similar or in lower concentrations compared to previous years and always below the Norwegian environmental standards, except in the case of cadmium (Cd) that exceeded the lowest Norwegian environmental limit. The Cd concentration decreased in the mussels during the monitoring period which indicates that the Cd concentration is not related to the industrial activities at Grundartangi, but rather to high natural Cd background concentration in the Icelandic environment. However, Cd as well as Hg and Pb meet the EU maximum limits for food consumption. Only 3 PAH compounds were detected above limits of quantification in the musselsamples. Pyrene was always at the highest concentration while phenanthrene and fluoranthene were at lower concentration, except at banki 1, where fluoranthene was the highest. The PAH concentrations never exceeded the Norwegian standards for total PAH concentration for mussels. All 16 PAHs were detected in all sediment samples with total PAHs ranging 209-791 /g / kg. All sites except for the reference site and S1 fall into the category slightly impacted sites due to increased PAH concentrations when compared to Norwegian reference values and below threshold effect levels compared to Canadian criteria. This is the second time that PAHs are analyzed in sediment samples to monitor the impact of the industrial activities at Grundartangi and total levels of PAH are now somewhat lower than observed in 2013. In conclusion, the effects of the industries at Grundartangi appear to be limited for the chemical compounds analyzed in the mussels. The impact on biota sediment also appears to be low. However, it is important to maintain frequent monitoring studies on the marine ecosystem near the Grundartangi industrial area in order to detect changes in pollution burden.

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