Persistent Organic Pollutants in the Environment

EMEP Status Report 3/2005

A.Gusev, E.Mantseva, O.Rozovskaya, V.Shatalov, N.Vulykh W.Aas, K.Breivik

ABSTRACT

In accordance with the 2005 Work-plan for Implementation of the Convention (ECE/EB.AIR/83/add2, item 2.7) Meteorological Synthesizing Centre East (MSC-E) and Chemical Coordinating Centre (CCC) continued the investigations of the environmental pollution by polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB). The outcome of the studies is summarized in this Status Report.

At present the measurements of POP concentrations in the atmosphere and precipitation are performed by 12 EMEP monitoring sites. Most of the sites are located in Northern and Central Europe, and no sites in southern and eastern parts of Europe. The adopted EMEP monitoring strategy for 2004-2009 (EB.AIR/GE.1/2004/5) aims to improve the distribution of monitoring sites over European region.

The official data on POP emissions (PAHs, PCDD/Fs, PCBs, HCB) for the period from 1990 to 2003 (at least for one year) were submitted by 36 Parties to the Convention. It should be noted that the number of countries reporting official information on POP emissions and their spatial distribution is gradually increasing. According to the official data and expert estimates the emissions of all the pollutants of concern tend to decrease from 1990 to 2003. In particular, emissions of four indicator PAHs (benzo[a]pyrene (B[a]P), benzo[b]fluoranthene (B[b]F), benzo[k]fluoranthene (B[k]F), indeno[1,2,3-cd]pyrene (I_P)) have decreased by 18 - 33% depending on particular PAH, and emissions of PCDD/Fs by 63%.

In course of preparation for the review of MSCE-POP regional model MSC-E has summarized the information on model sensitivity to variations of pollutant-specific and environmental parameters in the EMEP/MSC-E Technical Report 5/2005 [Gusev et al., 2005a]. The report provides also a detailed description of MSCE-POP regional model along with the input data required for modeling of POPs. This information was presented at the sixth TFMM meeting in Zagreb, Croatia in April 2005. During the meeting it was recommended that the continuation of MSCE-POP model review at the forthcoming Workshop in Moscow in October 2005 will be focused on the comparison of model results with measurements and POP model intercomparison study.

Model evaluation of the environmental pollution levels in the current year was performed out for the four indicator PAHs, PCDD/Fs, PCBs, and HCB for the period 1990-2003. The evaluation of trends in European region contamination by PAHs and PCDD/Fs is carried out at the regional scale. Transboundary transport was estimated for B[a]P and PCDD/Fs. For PCBs and HCB evaluation of pollution levels was performed on the hemispheric scale.

Annual mean B[a]P deposition flux over Europe has decreased by 20% on average during the period 1990-2003 and its value for 2003 is amounted to 16 g/km2/y. Average value of B[a]P annual air concentrations over Europe amounts to 0.2 ng/m3. At the same time in central and eastern parts of the Europe contamination levels exceed 1 ng/m3. Total annual depositions of B[b]F, B[k]F, and I_P in European countries in period 1990-2003 have decreased by 21%, 28%, and 15%, correspondingly. The most pronounced changes in deposition levels can be noted for countries of western and southeastern parts of Europe.

Evaluation of environmental pollution by dioxins and furans (PCDD/Fs) was made for the indicator congener 2,3,4,7,8-PeCDF. Following the reduction of emission PCDD/F annual total depositions over Europe have decreased by 47% in period 1990-2003. The decrease of annual mean air concentration of PCDD/F is accounted for 41% during this period. Mean value of PCDD/F annual air concentration over Europe in 2003 is accounted for 2.6 fg TEQ/m3 varying from 0.02 to 15 fg TEQ/m3 for most of European countries. Mean level of annual PCDD/F deposition fluxes is about 0.6 ng TEQ/m2/y.

The transboundary transport of B[a]P and PCDD/Fs between European countries was assessed. The contribution of the external sources to air concentrations of B[a]P and PCDD/Fs is essential and varies typically from 30 to 70%. In case of PCDD/Fs noticeable contribution to air concentrations and depositions over Europe belongs also to the re-emission from underlying surface.

The POP intercontinental transport was investigated by the example of HCB and PCB-153 using the hemispheric version of MSCE-POP model. HCB and PCBs are the pollutants with significant long-range transport potential therefore evaluation of pollution of European region and remote regions like the Arctic by these POPs requires consideration of the influence of remote emission sources. In the framework of co-operation with national experts MSC-E participated in German Canadian Project "Quality of measuring data on atmospheric inputs of POPs" where it contributed with the study of pollution levels of B[a]P and g-HCH within the OSPAR region, over Europe, and on the hemispheric scale.

The development of the hemispheric MSCE-POP model was continued during this year with the refinement of its ocean block, in particular, the descriptions of the processes of diffusion, partitioning to particulate organic matter, and sedimentation within the seawater for POPs were refined.

Monitoring and model assessment of POP pollution in the EMEP region has been carried out by the EMEP Centres in co-operation with the subsidiary bodies to the Convention (WGE, WGSR), international organizations (AMAP, EU, HELCOM, UNEP, WMO), as well as with national experts.

In the framework of POP model intercomparison study the third expert meeting was organized in Moscow in February 2005. Fulfillment of the II and III Stages of intercomparison programme were discussed. Results of Stage II are presented in the EMEP/MSC-E Technical Report 4/2005 [Shatalov et al., 2005a].