This core indicator evaluates the status of the marine environment based on concentrations of dioxin and dioxin like compounds in Baltic Sea fish, crustacean and molluscs as well as on concentrations of non-dioxin like PCB in Baltic Sea fish. Good status is achieved when the concentrations of PCBs, dioxins and furans are below the threshold values. The current evaluation is based on data up to 2016 to evaluate the assessment period 2011-2016.
Key message figure 1. Status assessment results based evaluation of the indicator 'PCBs, dioxins and furans'. One-Out-All-Out (OOAO) method (main figure), dioxin-like PCBs, dioxins and furans in biota (upper insert) and non-dioxin-like PCBs in biota (lower insert). The assessment is carried out using Scale 4 HELCOM assessment units (defined in the HELCOM Monitoring and Assessment Strategy Annex 4). Click here to access interactive maps at the HELCOM Map and Data Service: PCBs, dioxin and furan.
Good status was achieved in the majority of coastal and open sea areas. PCBs as well as dioxins and furans were responsible when the overall good status was not achieved. However, there are areas where dioxins and furans data are absent, or of low abundance and often short time series (i.e. initial data) and thus extended monitoring is required to enable an improved status evaluation in the entire Baltic Sea. A good example of this is the fail status in the One-Out-All-Out (OOAO) method map (Key figure message 1) that is driven by the status of dioxin-like PCBs, dioxins and furans, the assessment if which is based on limited data availability and a precautionary 'initial' data handling approach (see assessment protocol and Results figure 2. Time series of PCB levels in biota show decreasing concentrations at some stations, e.g. in the Bornholm Basin, the Eastern Gotland Basin and the Bothnian Bay. However, most of the stations show no significant trends. The confidence of the indicator assessment is moderate. The indicator is applicable in the waters of all countries bordering the Baltic Sea.
PCBs are synthetic chemicals which do not occur naturally in the environment. Due to their properties, PCBs have been used in a wide variety of applications and manufacturing processes, especially as plasticizers, insulators and flame-retardants. They are widely distributed in the environment through, for example, inappropriate handling of waste material or leakage from transformers, condensers and hydraulic systems. Long-term effects of PCBs include increased risk of cancer, infections, reduced cognitive function accompanied by adverse behavioural effects, as well as giving birth to infants of lower than normal birth weight (Carpenter 1998, Carpenter 2006). There are also indications that PCBs are associated with reproductive disorders in marine top predators.
Dioxins (PCDD/Fs) were never produced intentionally, but they are minor impurities in several chlorinated chemicals (e.g., PCBs, chlorophenols, hexachlorophene, etc.) and are formed in several industrial processes and from most combustion processes, such as municipal waste incineration and small-scale burning under poorly controlled conditions. The most relevant toxic effects of PCDD/Fs are developmental toxicity, carcinogenity and immunotoxicity.
D8 Concentrations of contaminants
- D8C1 Within coastal and territorial and beyond territorial waters, the concentrations of contaminants do not exceed the threshold values
D9 Contaminants in fish and other seafood
- D9C1 The level of contaminants in edible tissues (muscle, liver, roe, flesh or other soft parts as appropriate) of seafood (including fish, crustaceans, molluscs, echinoderms, seaweed and other marine plants) caught or harvested in the wild does not exceed the threshold.
HELCOM (2018). PCBs, dioxins and furans. HELCOM core indicator report. Online. [Date Viewed], [Web link].
Polychlorinated biphenyls PCBs, dioxin and furan HELCOM core indicator 2018 (pdf)