Download5 Hazardous Substances

Cessation target is in reach for a third of priority chemicals

The phase-out of a third of the 26 priority (groups of) chemicals which pose a risk to the marine environment is well underway in the OSPAR area. As a result, it is likely that discharges, emissions and losses of these substances will have moved towards cessation by 2020 if current efforts continue. These priority chemicals are: six pesticides (dicofol, endosulfan, lindane, methoxychlor, pentachlorophenol and trifluralin); SCCPs; nonylphenol/ethoxylates; the organotin compound TBT, and two brominated flame retardants, octa- and pentabrominated diphenyl ethers (BDEs) Table 5.1.

For many of the remaining priority chemicals, information is not available to give a complete picture, but it is often possible to judge from measures taken (e.g. use restrictions, BAT) and occurrence in the environment whether releases of those priority chemicals continue and whether further efforts are needed to move closer towards the cessation of their release by 2020. Further efforts include strengthening the implementation of existing measures Table 5.2. Better information is needed about the sources, releases and pathways for several of these priority chemicals. This includes the need for improved tracking of the releases and environmental fate of pharmaceuticals, such as clotrimazole, given that there are concerns that trace concentrations in the sea may pose a risk of disruption to ecological processes.

Heavy metal contamination is decreasing

The phase-out of old technologies and stringent pollution control measures have resulted in substantial reductions in the release of heavy metals from industrial combustion processes, metal production, transport and waste streams. Much of these reductions occurred in the 1990s as a result of technological and regulatory advances. Progress has since slowed as it becomes technically and economically more difficult for industry to reduce releases further. As a result, overall emissions to air of cadmium and mercury have been relatively constant in recent years but lead emissions have continued to fall. Progress on reducing air emissions of cadmium, mercury and lead has varied however across OSPAR countries and industries. In 2007, around 900 tonnes of lead and 40 tonnes each of cadmium and mercury were released by OSPAR countries to the atmosphere. Releases from non-regulated uses need to be further investigated and addressed.

Combustion processes in power plants and industry are major sources for emissions of heavy metals to the atmosphere and account for around two-thirds of the total amount of heavy metals entering the North-East Atlantic from the air. Changes in emission levels between 1998 and 2006 have been small. Measurements of heavy metal concentrations in rain and calculations of atmospheric inputs are consistent with trends in emissions.

Waterborne inputs show a similar pattern to atmospheric inputs, in that heavy metal loads to the sea decreased substantially between 1990 and 2006 with the greatest reductions occurring during the 1990s.

Concentrations of cadmium, mercury and lead in fish, shellfish and sediments have generally fallen since 1990, particularly in Region II, where downward trends are clear at both polluted and less polluted sites. As much of the reduction in inputs of metals occurred before 2000, changes in environmental concentrations have been relatively small since 1998 as concentrations approach, but do not reach, background levels in large parts of the OSPAR area Figure 5.2. There are still some locations in Regions II, III and IV where cadmium and mercury concentrations in fish and shellfish have risen (e.g. Dogger Bank, some UK estuaries and in the southern North Sea). In Region I, where concentrations are generally lower than in the other Regions, downward trends are only found close to pollution sources. Many of the OSPAR data series are currently too short to determine trends as – owing to the large amount of natural variation in the marine environment – trends in concentrations can only be determined using data collected systematically over relatively long periods. Continued monitoring is needed in many areas, especially in Regions III and IV, to extend these datasets so that it is possible to detect trends in future.

Concentrations of cadmium, mercury and lead exceed EU food standards in fish and shellfish at various sites, especially in Regions II and III, including on the Danish coast and in some of the heavily populated and industrialised estuaries on the UK and Norwegian coasts Figure 5.2. Concentrations in sediments are at levels that pose a risk of pollution effects for marine life in the southern North Sea, off the Dogger Bank, the German Bight, at a number of other sites around the UK and in industrialised estuaries on the Spanish and Norwegian coasts. High levels of cadmium found in fish and shellfish at sites around Iceland have been linked to natural factors (i.e. volcanic activity), but the exact source still needs to be confirmed.

PAHs are of continued regional and global concern

Polycyclic aromatic hydrocarbons (PAHs) are natural components of coal and oil and are also formed during the combustion of fossil fuels and organic material. They are one of the most widespread organic pollutants in the marine environment of the OSPAR area, entering the sea from offshore activities Chapter 7, operational and accidental oil spills from shipping Chapter 9, river discharges and the air.

Long-range atmospheric transport is an important pathway for PAHs within and to the OSPAR area and is of regional and global concern. Atmospheric emissions by OSPAR countries have been relatively constant over the past decade at about 1000 tonnes a year. However, given the expected growth in industrial activities, for example in Asia, the relative proportion of PAHs brought into the region from long-range transport is likely to increase.

Trends in PAH concentrations in fish and shellfish are predominantly downward, especially in Region III, but concentrations are still at levels which pose a risk of pollution effects in many estuaries and urbanised and industrialised locations Figure 5.2.

Progress towards the cessation of release of PAHs from human sources by 2020 will require improved use of emission control technology in combustion processes. Effective implementation of the EU IPPC Directive is particularly important. With the expected global increase in PAH emissions from combustion of fossil fuels such as coal, it is doubtful whether the cessation target can be met.

PCBs are still released to water and air

Polychlorinated biphenyls (PCBs) are a group of substances with 209 forms (congeners) which are very persistent, concentrate in fatty tissues and display a variety of toxicological properties. Production of PCBs was banned in the mid-1980s but European-wide action has not been enough to eliminate all inputs to the marine environment. Remaining sources are PCB-containing equipment, waste disposal, remobilisation from marine sediments contaminated with PCBs as a result of historic releases, and, to an unknown extent, formation as by-products in thermal and chemical processes. Large reductions in the release and phasing-out of remaining stocks were achieved in the period 1998 to 2005, but releases to air and water are still continuing.

Contamination from PCBs is widespread and there are few areas where concentrations are close to zero Figure 5.2. Concentrations are lowest along the northern coast of Norway (Region I). PCBs are however among the most prevalent pollutants in the Arctic and are widely distributed by long-range atmospheric transport. While PCB concentrations in Arctic species are decreasing, they are still found in some top predators at levels that cause concern for their health. At many locations in Regions II, III and IV, concentrations of at least one PCB congener in fish and shellfish pose a risk of causing pollution effects. Studies show that, some 25 years after their ban, PCBs may still be causing adverse biological impacts in parts of the OSPAR area.

Effects of TBT and substitute chemicals are of concern in some areas

Over the past decade, a range of national and international measures have resulted in a continuous phase-out of paints containing TBT as an anti-foulant and their use on vessels, in aquaculture and on underwater structures in the OSPAR area. A global ban on TBT in anti-fouling systems on large vessels came into effect in 2008. Together, these measures address the main TBT-related pressures on the marine environment.

Marine snails are very sensitive to the harmful effects of TBT and are thus a good indicator for TBT pollution. Since 2003, when monitoring began, the intensity of TBT-specific effects on the dogwhelk and other marine snails has clearly reduced in Region II and there are few monitoring sites in the OSPAR area where such effects are increasing. Effect levels in Region I were stable between 2003 and 2007, while data for Regions III and for parts of Region IV are mostly insufficient for trend analysis. The EcoQO set for TBT-specific effects for the North Sea and applied through consistent assessment criteria in the other OSPAR Regions, is met at most sites in northern Norway and at some sites on the UK west coast and the coasts of France and Spain.

Similarly, a number of sites in Iceland met the EcoQO in 2008. Nevertheless, TBT-specific effects are still found over large parts of the OSPAR area. There is a clear relationship with shipping, with high effect levels near some large harbours (e.g. Rotterdam, Clydeport, Vigo) and lower levels in areas with less large vessel traffic, such as along the west coast of Scotland and northern Norway. But even in these areas, harbours can have a noticeable impact, highlighting the importance of local sources and historic contamination of harbour sediments.

Copper and Irgarol (cybutryne) are the main substitutes for TBT and have been used as anti-foulants for more than a decade. Although not as detrimental as TBT they can also have adverse impacts on marine life. Rapid growth in the use of copper-based products in aquaculture over the past decade has increased the release of copper to the sea in major fish farming areas in northern Scotland and western and northern Norway.

Pesticide regulation is working

The various uses of the six OSPAR priority pesticides Table 5.1 have been phased out progressively since 1998 and have now ceased for almost all substances. The positive effect of the phase-out of lindane is confirmed by clear decreases in atmospheric deposition to the OSPAR area.

The phase-out has resulted in a general reduction in concentrations of lindane in fish and shellfish across the OSPAR area Figure 5.3. Concentrations are close to zero in some areas, for example western and northern Norway, and parts of Ireland, France and Iceland. However, concentrations in some other areas are still at levels with a risk of pollution effects. Particular examples are the Brittany coast, the German Bight, and some northern UK estuaries (Humber, Clyde, Forth, Tay). The localised nature of these hotspots, which may persist for years to come, may reflect historic use nearby.

Better regulation is needed for some brominated flame retardants

Brominated flame retardants are a large group of chemicals used in high volumes and in a vast range of consumer products. Their regulation has not been uniform, with some substances more stringently regulated than others. OctaBDE and pentaBDE, as some of the most potentially hazardous of this group of substances, have been banned and their release will essentially cease by 2020. Others, such as decaBDE and hexabromocyclododecane (HBCD) need more regulation and in anticipation of this, industry has significantly reduced releases from point sources. The priority chemical tetrabromo­bisphenol-A (TBBP-A), which is expected increasingly to replace octaBDE in specific applications, is now the most commonly used brominated flame retardant in the OSPAR area and should be kept under review.

Over the period 2000–2005, polybrominated diphenyl ethers (PBDEs) and HBCD were found in all components of the marine ecosystems in Regions I, II, III and IV. The degree of contamination by these substances is still being revealed because regular OSPAR environmental monitoring only began in 2008. Continued monitoring will be necessary to show whether actions to reduce the input of brominated flame retardants to the marine environment are effective.

Contamination from POPs requires global action

Long-range transport through air, water and biological pathways carries persistent organic pollutants (POPs), including perfluorooctane sulphonates (PFOS), SCCPs, and brominated flame retardants, to areas far from their sources. In the northern hemisphere, the prevailing air currents are towards the Arctic where many of these highly persistent contaminants end up. The tendency for these pollutants to bioaccumulate results in high concentrations in animals at or near the top of the food chain. This concerns predators such as polar bears, whales, seals and birds.

Monitoring shows that these pollutants are widely distributed through the marine environment, even in areas remote from emission sources. PFOS and related substances for example are extremely persistent and have long-term toxic effects on marine life and humans. They have been found in all environmental compartments in Regions I and II, both at polluted sites and far from direct sources.

Owing to this long-range transport, efforts to reduce emissions of POPs must occur at the global level. Recently octaBDE, pentaBDE, PFOS and lindane have been included under the UNEP Stockholm POPs Convention for global elimination. This should be followed by inclusion of SCCPs, endosulfan and HBCD. Even with a global ban coming into effect soon, these substances are so persistent that exposure and bioaccumulation will continue for many years.

Efforts on biological effects must continue

The presence of hazardous substances leads to a range of responses within marine organisms, such as the induction of specific enzymes, changes in tissue pathology and death. Contaminant-specific techniques have been developed which allow these responses to be measured, providing a means of linking the presence of contaminants and impacts. The most successful technique is the measurement of TBT-specific effects (imposex) in gastropods. Other techniques are under development to reflect the responses to multiple contaminants. For example, data on fish diseases are collected under the CEMP and combined in an index as a potential tool for assessing fish population health and to evaluate the impact of human-induced stresses on wild fish. While measurements in Region II show a worsening of fish health from the 1990s to the 2000s suggesting an overall decline in environmental conditions, this cannot be linked with observations of chemical contamination and causes still need to be investigated Figure 5.4. Recent studies of individual fish diseases have now been able to link a general decline in liver tumours in fish in the Netherlands’ waters of the North Sea since the late 1980s with a decrease in exposure to organic pollutants, such as genotoxic and carcinogenic PAHs.

It is not yet possible in most cases to link chemical monitoring with observations of effects in species in such a way that conclusions can be drawn about the impact of contaminants on the functioning of ecosystems at a regional level. OSPAR countries have made progress in standardising reference methods for monitoring biological indicators, but have not yet implemented a fully coordinated biological effects monitoring programme. This will be needed to support the regional assessment of hazardous substances. Efforts on biological effects monitoring and assessment should therefore continue and be enhanced, also in relation to combined effects on ecosystem function, for which chemical analysis is not suitable.

Understanding of endocrine disrupting effects must improve

Since the QSR 2000, there has been little improvement in knowledge about concentrations of potentially endocrine disrupting chemicals released to the marine environment. Recent work has highlighted the potential for synthetic substances to disrupt immune systems and chemical communication between organisms. Although research on these topics is expanding rapidly, the best known aspect of endocrine disruption is still the effects on sex hormone systems and reproduction in fish.

OSPAR has developed guidelines for monitoring endocrine disrupting effects in fish. These are not a formal part of the OSPAR monitoring programme, but allow surveys, for example, of feminisation of male fish through measurement of intersex and vitellogenesis (the process of yolk formation specific to the female germ cell). Endocrine disrupting effects in fish occur in many areas, although their extent, severity, and consequences are not clear. Male flounder from estuaries in Belgium, Denmark, France, Germany, the Netherlands and the UK have elevated concentrations of plasma vitellogenin (linked to reduced reproductive success in male fish), as have cod from Norwegian inshore waters, and dab from offshore waters of the North Sea. There is some limited evidence to suggest that concentrations of plasma vitellogenin in male flounder from some UK estuaries may be falling.

Emerging problems from substitute chemicals

In many cases, when a hazardous substance is phased out, its uses are filled by other chemicals. This often benefits the environment, but can lead to new and unexpected problems if properties of the replacement chemicals are not well understood. Medium-chain chlorinated paraffins (MCCPs) for example are increasingly used as substitutes for SCCPs following EU restrictions in 2002. They are less harmful than SCCPs, but are still of concern due to their persistence and accumulation in the marine environment. There is a clear need to keep environmental levels of chemicals used as substitutes under review as these could also pose environmental risks.

Market conditions affect progress towards OSPAR’s objectives

Market conditions, production methods and volumes, and technological developments have brought structural changes in some major land-based and offshore industries. Some industries have ceased, while others have emerged, and many manufacturing industries have relocated to other parts of the world, for example, Asia. Rapidly developing economies and their associated industrial development and energy demand outside the OSPAR area are causing increasing pressure on the North-East Atlantic. This is principally through long-range atmospheric transport of contaminants such as mercury and PAHs. In addition, some imported goods contain hazardous substances that can reach the sea as the product is used and following its disposal. Typical examples are lindane, nonylphenol and brominated flame retardants.

Global action is required to control the input of such substances to the marine environment. Steady growth in the use of manufactured goods and the resulting waste streams is a growing source of potential pollution that needs tackling.

Continue to "What happens next?"