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 2015 to evaluate the assessment period 2011-2015.
message figure 1: Status assessment results based evaluation of the indicator ‘PCB,
dioxin and furan'. The assessment is carried out using Scale 4 HELCOM
assessment units (defined in the HELCOM
Monitoring and Assessment Strategy Annex 4).
Good status was achieved in the majority of coastal and open sea areas. PCBs were responsible when the overall good status was not achieved. The concentrations of dioxins and furans in fish were below the threshold value in all monitored areas. However, there are areas where data are absent and thus extended monitoring is required to enable a status evaluation in the entire Baltic Sea.
Time series of PCB levels in biota show decreasing concentrations at some stations, e.g. in the Bornholm Basin, the Easter Gotland Basin and the Bothnian Bay. However, most of the stations show steady concentrations.
The confidence of the indicator assessment is moderate. It should however be noted that there has been major data reporting problems, and that the dioxin-parameter has not been fully assessed in this version of the indicator report.
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.
Concentrations of hazardous substances close to natural levels
D8 Concentrations of contaminants- D8C1 Within coastal and territorial and beyond territorial waters, the concentrations of contaminants do not exceed the threshold values
Fish safe to eat
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
Other relevant legislation: EU Water Framework Directive; EU Priority Substances Directive (2013/39/EU)
HELCOM (2017). PCB, dioxin and furan. HELCOM core indicator report. Online. [Date Viewed], [Web link].
HOLAS II component - core indicator report – web-based version July 2017 (pdf)