The history of airborne lead and other heavy metals as revealed from sediments of Lake Vähä-Pitkusta, SW Finland
Lake Vähä-Pitkusta is a small, sheltered, relative deep and undisturbed lake in SW Finland. It was cored to investigate airborne deposition of heavy metals, which is not known in detail in this area. We analysed lake sediments to detect trends in the historical load of lead, cadmium, zinc, copper, n...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Geological Society of Finland
2004-12-01
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| Series: | Bulletin of the Geological Society of Finland |
| Subjects: | |
| Online Access: | http://www.geologinenseura.fi/bulletin/Volume76/Hakala.pdf |
| Summary: | Lake Vähä-Pitkusta is a small, sheltered, relative deep and undisturbed lake in SW Finland. It was cored to investigate airborne deposition of heavy metals, which is not known in detail in this area. We analysed lake sediments to detect trends in the historical load of lead, cadmium, zinc, copper, nickel and vanadium and compared the deposition pattern described earlier from other parts of Europe. Sediments were dated using AMS radiocarbon and 137Cs-dating techniques. The results indicate that lead emissions during Roman and Medieval times reached Finland; this was detected for the first time. Medieval deposition of lead was associated with that of cadmium and zinc, suggesting their origin as long distance airborne load. Copper, nickel and vanadium deposition patterns are recent, because their strong increase of accumulation was detected only in the sediments representing the last 50 years. Most probably they originate from local pollutant sources. Overall, the results emphasize the potential value of small, sheltered headwater lakes as archives of atmospheric environmental impacts. |
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| ISSN: | 0367-5211 1799-4632 |