Pollution Control Monitoring FAQs

What environmental quality standards are set in the UK / EU and how are these monitored?

Aarhus University, identifies 4 EU countries that have set EQSs for at least one PCB.

The Environment Agency in accordance with OSPAR measure 7 PCBs in sediment and biota in the marine environment and for inland waters (under the WFD) the same 7 dioxin-like PCBs in biota. No PCBs are monitoring in water.

UK Marine Strategy

Environment Agency assessments for the UK Marine Strategy follow reporting requirements to OSPAR.

PCBs

The polychlorinated biphenyls considered are CB28, CB52, CB101, CB118, CB138, CB153 and CB180. Risk-based monitoring and assessment of the status and trends of polychlorinated biphenyl concentrations in biota and sediment are conducted within the annual UK Clean Seas Environmental Monitoring Programme (carried out by Cefas) using methods and principles set out in the OSPAR Coordinated Environmental Monitoring Programme. The most toxic are the so-called ‘dioxin-like’ polychlorinated biphenyls: the four non-ortho (CB77, 81, 126 and 169) and eight mono-ortho (CB105, 114, 118, 123, 156, 157, 167 and 189). Of these only CB118 is monitored.

EAC

Environmental Assessment Criteria were developed by OSPAR and the ICES for assessing the ecological significance of sediment and biota concentrations. Some Environmental Assessment Criteria values were specifically compiled for the assessment of monitoring data on hazardous substances from the Co-ordinated Environmental Monitoring Programme contributing to OSPAR’s Quality Status Report 2010 (OSPAR Commission, 2010). The Environmental Assessment Criteria do not represent target values or legal standards under the OSPAR Convention and should not be used as such. The values were set so that hazardous substance concentrations in sediment and biota below the Environmental Assessment Criteria should not cause chronic effects in sensitive marine species, including the most sensitive species, nor should concentrations present an unacceptable risk to the environment and its living resources.

The monitoring data are used to investigate trends in polychlorinated biphenyl concentrations and to compare concentrations against two sets of OSPAR assessment criteria: Background Assessment Concentrations and the Environmental Assessment Criteria. Environmental Assessment Criteria are analogous to the Environmental Quality Standards used to assess contaminant concentrations in water (European Commission, 2008b), for example under the Water Framework Directive (European Commission, 2010). Background Assessment Concentrations are used to assess whether concentrations are near background values for naturally occurring substances and close to zero for man-made substances, the ultimate aim of the OSPAR Hazardous Substances Strategy.

OSPAR has a long term ultimate objective to achieve concentrations of close to zero for man-made substances in the marine environment

Monitoring

Owing to their persistence, potential to bioaccumulate and toxicity they have been included on the OSPAR List of Chemicals for Priority Action (OSPAR, 2007). Six PCB congeners were recommended for monitoring by the European Commission (2001). As the most toxic PCB, CB118 is also monitored. As per the OSPAR Coordinated Environmental Monitoring Programme (CEMP) (OSPAR, 2016), Contracting Parties are required to monitor the seven PCB congeners CB28, CB52, CB101, CB118, CB138, CB153, and CB180 (OSPAR, 1997) on a mandatory basis in biota (fish and mussels) and sediments for temporal trends and spatial distribution. Marine sediments, in particular those with a high organic carbon content, may accumulate hydrophobic compounds like PCBs to considerably higher concentrations than surrounding waters.

There is no monitoring of PCBs in water due to the low concentrations and therefore the difficulty to carry out measurements with any confidence. PCBs partition quickly from the water into sediment or are taken up by biota.

(Cefas measure 25 PCBs in total including the seven used for UKMS)

Sampling

The sampling strategy is defined by the purpose of the monitoring programme and the natural conditions of the region to be monitored (OSPAR, 1997). Typically sampling approaches include fixed-monitoring site sampling, stratified random sampling, or stratified fixed sampling. Muddy sediments, namely those containing a high proportion of fine material, are preferable for organic contaminant monitoring, although sieving of sediments may be an alternative (OSPAR, 2002).

Polychlorinated biphenyl (PCB) concentrations are measured in fish liver and shellfish – for the UK Marine Strategy biota assessments PCBs are measured in common dab, flounder, plaice, pacific oyster and blue mussels.

Other than for ease of sampling/trawling and their sustainability, dab, flounder & plaice are sea bed (bottom) feeding fish. Concentrations of the likes of PCBs which can bioaccumulate in their tissues (the edible filets which we eat) and more so in their livers (fat depots) will reflect their local habitats such muddy environments where such chemicals can be deposited and accumulate in their diet (benthic worms, etc).

For the target bivalves which are found in estuaries and coastal (intertidal and subtidal) zones and muddy and sandy habitats, their feeding mechanism involves filtering volumes of sea water and contaminants in the water column which are attached to small suspended particles (organic or fine sediment materials) can accumulate in the tissues of the shellfish via this filtering process. Levels of contaminants measured in the bivalve tissues (again which we eat) can be a proxy for levels associated with suspended matter in the water.

All these species are commercial and are eaten by humans thus food safety regulations listing acceptable levels of contaminants in edible species can be referred to in assessing risks to human health via consumption.

Useful links (and further details about our monitoring/assessments):

Water Framework Directive

The Environment Agency include the following dioxin-like PCBs in their blue mussel and fish monitoring programmes. An initial monitoring of the full dioxin suite was carried out to check there were no issues.

PCB - 028 : Wet Wt
PCB - 052 : Wet Wt
PCB - 101 : Wet Wt
PCB - 118 : Wet Wt
PCB - 138 : Wet Wt
PCB - 153 : Wet Wt
PCB - 180 : Wet Wt

The Environment Agency does not routinely monitor sediment contamination although they currently have a project looking at the mobilisation of sediment contaminants (POPs). They don’t monitor for dioxins in water.

The threshold value for dioxin-like PCBs is defined based on Ecological Quality Standards (EQS) derived for the purposes of the EU Water Framework Directive and is 0.0065 μg/kg Toxic Equivalency (TEQ) for fish, crustaceans or molluscs.

Are all such discharges of PCBs in the UK licensed?

The ENDs monthly Report article – ‘A poisonous legacy: PCB and the killer whale apocalypse’ 23 Oct 2020 references a Natural Resources Wales (NRW) permit in place to allow the discharge of PCBs into the environment from Monsanto’s old chemical works site at Newport. However, It is inevitable that there are many discharges of PCBs to controlled waters in the UK, from some of the over 21,000 historic landfills, however we understand from the UK Environment Agency that PCBs simply are not monitored in water in the UK. Furthermore, based on the UK Environment Agency’s Guidance on monitoring of landfill, leachate, groundwater and surface watereven if they were monitored the levels in discharge from historic landfills could be well below the reporting limits of the method used, as with the Raggatt and Kewaigue landfills in the Isle of Man, thus not even raising awareness of the presence of PCBs.

The EQS for PCBs in inland waters is based on the UK EA’s latest minimum reporting value for PCBs, lower than that in the aforementioned published guidance on monitoring, as recommended by consultants APEM Ltd. The EQSs for PCBs in sediment and biota in coastal waters are based on the Environmental Assessment Criteria (EAC) set by OSPAR (EACs were developed by OSPAR for assessing the ecological significance of sediment and biota concentrations and are analogous to the Environmental Quality Standards used to assess contaminant concentrations in water (European Commission, 2008b):

The main OSPAR measure on PCBs is PARCOM Decision 92/3 on the phasing out of PCBs, which also requires the destruction of all identifiable PCBs.

What is the Department doing about existing historic discharges of PCBs?

Whilst OSPAR has a long term ultimate objective to achieve concentrations of close to zero for man-made substances in the marine environment, it recognises that diffuse emissions continue and through its Co-ordinated Environmental Monitoring Programme publishes currently monitored levels on an interactive map on the OSPAR website (Home Page - ICES.OHAT). The Department is also committed to achieving this, and is working towards a regular monitoring programme of hazardous pollutants in sediment and shellfish in our coastal waters to be reported on the OSPAR website.

The Department continues to work with Manx Utilities and the Department of Infrastructure to find a solution to minimise discharge of PCBs from The Raggatt through the Regional Sewage Treatment Programme.

As an example, the diagram below shows the current status of discharges of a specific PCB (118) for the UK and France, with the red dots indicating levels assessed as above Environmental Assessment Criteria.