Hazardous Substances Thematic Assessment

The state of the environment is poor in areas with high population and industrialisation levels, particularly because of mercury and PBDE, when current concentration levels are compared with assessment criteria for areas where no harm to the environment is expected.

The comparison of hazardous substances with assessment criteria indicates a low impact by hazardous substances in the sparsely populated areas of Regions I and III (Table S.1), whereas the more densely populated and industrial areas of Regions II and IV are at levels where impact from hazardous substances cannot be excluded.

Table S.1: Status of Regions based on OHAT model and confidence for the number of stations/time trends for each Region; this is a fair estimate of the confidence for each assessment

Integrated assessment using CHASE (State)

A mathematical method, CHASE, was used to make an integrated assessment of sediment and biota based on several indicators. Following this analysis, the status was classified as either good (contaminant concentrations well below EQS thresholds) or poor (one contaminant has concentrations above EQS, or several contaminants are very close to EQS). Time trends were also assessed. (For more details on method and results, refer to the CHASE Assessment .)

For sediment, about half of the Regions have a good status using this method (Table S.2). Among the Regions with poor status, the Irish Sea may possibly progress from poor to good environmental status during the next 10-20 years, while in the others, either no significant improvement can be detected or improvement is too slow to lead to a change in status in the foreseeable future. No Regions with currently good status are in danger of taking on poor status. The main substances that lead to overall poor contamination status are mercury, lead and, in one case, CB118.

For biota, only two out of twelve Regions have good status (Table S.2). Again, the Irish Sea may possibly progress from poor to good environmental status during the next 10 years; for most other Regions, there is no evidence of improving status. The main culprits causing poor status in most parts of the Regions are mercury and CB118. Also, mercury is the main reason for the lack of improvement, as mercury concentrations, with few exceptions, are either increasing (Southern North Sea, English Channel) or stable. 

Table S.2: Summary of CHASE integrated analyses of status in 2020, as well as predicted status in 2030 if current trends continue. A hyphen indicates that there were not enough data for the analysis. The sub-regions Barents Sea, Norwegian Sea, Norwegian Trench and Gulf of Cadiz did not present enough data for any integrated analysis. For more details, see "Other assessment – CHASE"

* The point estimate indicates “good” status, but "poor" is not outside the 95% confidence limits

Individual indicator assessments (State):

• PCBs

Polychlorinated biphenyls (PCBs) were banned in many countries in the mid-1980s. Although local problems remain, PCB concentrations in sediment and biota have decreased in most OSPAR assessment areas. Except for the most toxic congener (CB118), concentrations are below the level at which they could present an unacceptable risk to the environment.

The high bioaccumulation rate leads to very high concentrations in marine mammals and birds. The PCB concentration ranges found in the tissues of marine mammals generally show decreasing trends between the 1970s and 2010s. However, small toothed whales and pinnipeds still present PCB levels surpassing the proposed toxicity thresholds.

• PAHs

Although mean concentrations of polycyclic aromatic hydrocarbons (PAHs) in shellfish and sediment, and of PAH bile metabolites in fish are above background concentrations in most assessed areas, they are below levels likely to harm marine species. Concentrations are decreasing or stable in all but one (Irish and Scottish West Coast sediment) of the areas assessed.

• PBDEs

Biota sites have good geographical coverage, sediment sites are more limited. PBDEs in sediment and biota have been stable (54% of assessed areas) or declining (46%) for the past 20 years. Concentrations are below thresholds (FEQGs) for all assessment areas and congeners, except BDE209 in Irish Sea sediment, and should not cause adverse effects to marine wildlife.

• Metals

In most areas, concentrations of lead and mercury in fish and shellfish are above background levels and mercury is above the environmental threshold. Despite bans, concentrations in biota are mostly increasing, particularly in Region II. Concentrations in sediments are often above the environmental thresholds but decreasing in most sub-regions.

• Organotins

Following the bans on the use of tributyltin in antifouling paints there has been a marked improvement in the reproductive condition of marine snails since QSR 2010 over the assessment period 2008–2020. Mean concentrations in sediment have measurably reduced, at the rate of approximately -10% per year, in the Southern North Sea, but no monitoring station is yet significantly below the EQS value proposed by Sweden of 0,8 µg kg-1 at 2,5% OC (see: Background document on Tributlytin (TBT)
in sediment, Swedish Quality Standard) assessment criteria, which in many cases are below the detection limits of the methods used for analysis. Normalisation is not employed all over the OSPAR Region. The need for follow-up of the situation is still apparent.