The concentrations were generally Low or Moderate for HCB and lindane, Moderate for cadmium, mercury and lead, and Moderate or High for PCB and DDT. A general downward trend was found in the Northeast Atlantic for lead, lindane, PCB and DDT and also in the Baltic Sea and Mediterranean Sea for lindane. A general upward trend was found in the Mediterranean Sea for mercury and lead.
EEA-32 emissions of a number of compounds categorised as persistent organic pollutants (POPs) have decreased between 1990 and 2010, including hexachlorobenzene (HCB) by 91%, hexachlorocyclohexane (HCH) by 93%, polychlorinated biphenyls (PCBs) by 74%, dioxins & furans by 83%, and poly-aromatic hydrocarbons (PAHs) by 52%. While the majority of individual countries report that POP emissions have fallen during this period, a number report that increases in emissions of one or more pollutants have occurred.
In 2010, the most significant sources of emissions for these POPs included the sectors 'Commercial, institutional and households' (11% of HCB, 37% of dioxins and furans, 18% of PCB emissions) and 'Industrial processes' (70% of HCB, 66% of HCH, 28% of PCBs).
Important emission sources of PAH include residential combustion processes (open fires, coal and wood burning for heating purposes etc.), industrial metal production processes, and the road transport sector. Emissions from these sources have all declined since 1990 as a result of decreased residential use of coal, improvements in abatement technologies for metal refining and smelting, and stricter regulations on emissions from the road transport sector.
Environmental context: Persistent organic pollutants (POPs) are chemical substances that persist in the environment, have potential for biomagnification through the food web, and pose a risk of causing adverse effects to human health and the environment. This group of substances includes unintentional by-products of industrial processes (such as PAHs, dioxins and furans) pesticides (such as DDT) and industrial chemicals such as polychlorinated biphenyls (PCBs). All share the property of being progressively accumulated higher up the food chain, such that bioaccumulation in lower organisms to relatively low concentrations can expose higher consumer organisms, including humans, to potentially harmful concentrations. In humans they are also of concern for human health because of their toxicity, their potential to cause cancer and their ability to cause harmful effects at low concentrations. Their relative toxic/carcinogenic potencies are compound specific, but in general the major concerns are centred on their possible role in causing cancer, neurobehavioral, immunological and reproductive disorders. More recently concern has also been expressed over their possible harmful effects on human development.
Across the EEA-32 countries, emissions of lead have decreased by 89%, mercury by 63% and cadmium by 60% between 1990 and 2010. For each substance, the most significant sources in 2010 are from energy-related fuel combustion, particularly from public power and heat generating facilities, and from industrial facilities.
Much progress has been made since the early 1990s in reducing point source emissions of cadmium and lead (e.g. emissions from industrial facilities). This has been achieved through improvements in, for example, abatement technologies for wastewater treatment, incinerators and in metal refining and smelting industries, and in some countries by the closure of older industrial facilities as a consequence of economic re-structuring.
In the case of mercury, the observed decrease in emissions may be largely attributed to improved controls on mercury cells used in industrial processes (e.g. in the chlor-alkali process) including the replacement of old mercury cells by diaphragm or membrane cells, and the general decline of coal use across Europe as a result of fuel switching.
The promotion of unleaded petrol within the EU and in other EEA member countries through a combination of fiscal and regulatory measures has been a particular success story. EU Member States have completely phased out the use of leaded petrol, a goal that was regulated by Directive 98/70/EC. From being the largest source of lead emissions in 1990, when it contributed around 75% of the EEA-32 total for lead, emissions from the road transport sector have decreased by nearly 99%. Nevertheless, the road transport sector still remains an important source of lead, contributing around 10% of total lead emissions in the EEA-32 region. However since 2002 little progress has been made in reducing emissions further; 98% of the total reduction from 1990 emissions of lead had been achieved by 2002.
Environmental context: Heavy metals (such as cadmium, lead and mercury) are recognised as being toxic to biota. All are prone to biomagnification, i.e. being progressively accumulated higher up the food chain, such that bioaccumulation in lower organisms at relatively low concentrations can expose higher consumer organisms, including humans, to potentially harmful concentrations. In humans they are also of direct concern because of their toxicity, their potential to cause cancer and their potential ability to cause harmful effects at low concentrations.
The relative toxic/carcinogenic potencies of heavy metals are compound specific, but exposure to heavy metals has been linked with developmental retardation, various cancers and kidney damage. Metals are persistent throughout the environment, and cadmium, lead and mercury are among those heavy metals that are already a focus of international and EU action. These substances tend not just to be confined to a given geographical region, and thus are not always open to effective local control. For example, in the case of cadmium, much is found in fine particles which do not readily dry-deposit, and therefore have long residence times in the atmosphere and are subject to long-range transport processes.
Soil contamination requiring clean up is present at approximately 250000 sites in the EEA member countries, according to recent estimates. And this number is expected to grow. Potentially polluting activities are estimated to have occurred at nearly 3 million sites (including the 250000 sites already mentioned) and investigation is needed to establish whether remediation is required. If current investigation trends continue, the number of sites needing remediation will increase by 50% by 2025. By contrast, more than 80000 sites have been cleaned up in the last 30 years in the countries where data on remediation is available. Although the range of polluting activities (and their relative importance as localised sources of soil contamination) may vary considerably across Europe, industrial and commercial activities as well as the treatment and disposal of waste are reported to be the most important sources. National reports indicate that heavy metals and mineral oil are the most frequent soil contaminants at investigated sites, while mineral oil and chlorinated hydrocarbons are the most frequent contaminants found in groundwater. A considerable share of remediation expenditure, about 35% on average, comes from public budgets. Although considerable efforts have been made already, it will take decades to clean up a legacy of contamination.