Atmospheric heavy metal depositions

	Author: Alexey Gusev, EMEP MSC-E

Key message

Total annual atmospheric depositions of heavy metals to the Baltic Sea have decreased in period from 1990 to 2001 by 30% for cadmium, 38% for mercury, and 69% for lead.

Assessment

The document presents computed total annual atmospheric depositions of cadmium, mercury, and lead over the Baltic Sea for 1990-2001. The atmospheric depositions of heavy metals were obtained using the latest version of MSCE-HM model developed at EMEP/MSC-E (Ilyin et al., 2003). The latest available official emission data for the HELCOM countries have been used in the model computations. Temporal variations of total annual atmospheric depositions of cadmium (Cd), mercury (Hg), and lead (Pb) to the Baltic Sea within the period 1990 – 2001 are shown in Figure 1. Time-series of total annual depositions of Cd, Hg, and Pb to the six sub-basins of the Baltic Sea are presented in Figures 2-3.

Figure 1. Computed total annual atmospheric depositions of cadmium, mercury, and lead to the Baltic Sea for the period 1990-2001, tonnes/year.

Results

Total annual atmospheric depositions of heavy metals to the Baltic Sea have substantially decreased in period 1990-2001. In particular, the decrease of cadmium depositions is amounted to 30%, of mercury depositions to 38%, and of lead depositions to 69%. On the level of individual sub-basins the most significant drop can be noted for cadmium in Kattegat (by 50%), for mercury in Belt Sea (48%) and Kattegat (48%), and for lead also in Belt Sea (77%) and Kattegat (83%). In 2001 total annual atmospheric depositions of cadmium to the Baltic Sea were about 8.3 tonnes, mercury depositions 3.2 tonnes, and lead depositions 143 tonnes. Anthropogenic sources of heavy metal emissions of HELCOM countries contributed to the deposition over the Baltic Sea in 2001 about 43% for cadmium, 36% for mercury, and 37% for lead. Among the HELCOM countries the most significant contributions to depositions over the Baltic Sea belong to Poland, Germany, and Russia. In spatial distribution of heavy metals depositions on the Baltic Sea the highest levels can be noted for the southern-western part of the Baltic Sea (Belt Sea and Baltic Proper). Significant levels of lead and cadmium depositions can also be noted for the Gulf of Riga.

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Figure 2. Time-series of computed total annual atmospheric deposition of cadmium to six sub-basins of the Baltic Sea for the period 1990-2001, tonnes/year.

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Figure 3. Time-series of computed total annual atmospheric deposition of mercury to six sub-basins of the Baltic Sea for the period 1990-2001, tonnes/year.

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Figure 4. Time-series of computed total annual atmospheric deposition of lead to six sub-basins of the Baltic Sea for the period 1990-2001, tonnes/year.
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Figure 5. Distribution of computed total annual cadmium depositions to six sub-basins of the Baltic Sea in 2001

Figure 6. Distribution of computed total annual lead depositions to six sub-basins of the Baltic Sea in 2001

Figure 7. Distribution of computed total annual mercury depositions to six sub-basins of the Baltic Sea in 2001

References

Ilyin I., O. Travnikov, W. Aas, H.Th. Uggerud 2003] Heavy metals: transboundary pollution of the environment. MSC-E and CCC. EMEP status report 2/2003. June 2003.([http://www.msceast.org/reps/SR2-2003.pdf)

Data

Table 1. Computed total annual depositions of cadmium to six Baltic Sea sub-basins for period 1990-2001. Units: tonnes/year

Table 2. Computed total annual depositions of lead to six Baltic Sea sub-basins for period 1990-2001. Units: tonnes/year

Table 3. Computed total annual depositions of mercury to six Baltic Sea sub-basins for period 1990-2001. Units: tonnes/year

	More information: Atmospheric Supply of Nitrogen, Lead, Cadmium, Mercury and Lindane to the Baltic Sea in the period 1996 - 2000

Page updated 20 November 2003