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Lars Håkanson

Bio: Lars Håkanson is an academic researcher. The author has contributed to research in topics: Trophic state index & Loss on ignition. The author has an hindex of 3, co-authored 3 publications receiving 4642 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a sedimentological risk index for toxic substances in limnic systems should at least, account for the following four requirements: the following: the quality of the sediment, the water quality, the sediment quality, and the sediment diversity.

6,177 citations

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TL;DR: In this article, the relationship between lake trophic type and sediment type, as expressed by determinations of simple chemical data on nitrogen, phosphorus, carbon and loss on ignition, was studied.

53 citations

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TL;DR: A conceptual model concerning the causal relationships determining the “road between dose and response” of toxic substances in aquatic environments is introduced and utilizes mercury as a type element.

51 citations


Cited by
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Journal ArticleDOI
TL;DR: Investigation of the middle and lower reaches of the Yangtze River in China found that heavy metals may be mainly derived from metal processing, electroplating industries, industrial wastewater, and domestic sewage, and Hg may also originate from coal combustion.

1,116 citations

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TL;DR: Comparative data for normalized enrichment factors and the modified degree of contamination show that Tamaki Estuary sediments have suffered significant systematic heavy metal contamination following catchment urbanization.
Abstract: Eight sediment cores recovered from Tamaki Estuary were analysed for Cu, Pb, Zn, and Cd using downward cored sub-samples. The results indicate a significant upward enrichment in heavy metals with the highest concentrations found in the uppermost 0–10 cm layer. Assessment of heavy metal pollution in marine sediments requires knowledge of pre-anthropogenic metal concentrations to act as a reference against which measured values can be compared. Pristine values for the cored sediments were determined from flat “base-line” metal trends evident in lower core samples. Various methods for calculating metal enrichment and contamination factors are reviewed in detail and a modified and more robust version of the procedure for calculating the degree of contamination is proposed. The revised procedure allows the incorporation of a flexible range of pollutants, including various organic species, and the degree of contamination is expressed as an average ratio rather than an absolute summation number. Comparative data for normalized enrichment factors and the modified degree of contamination show that Tamaki Estuary sediments have suffered significant systematic heavy metal contamination following catchment urbanization. Compared to baseline values the uppermost sediment layers show four-fold enrichment averaged across eight cores and four analysed metals.

1,039 citations

Journal ArticleDOI
TL;DR: In the last decade, a new pattern of Hg pollution has been discerned, mostly in Scandinavia and North America, mostly due to more widespread air pollution and long-range transport of pollutants.
Abstract: During the last decade a new pattern of Hg pollution has been discerned, mostly in Scandinavia and North America. Fish from low productive lakes, even in remote areas, have been found to have a high Hg content. This pollution problem cannot be connected to single Hg discharges but is due to more widespread air pollution and long-range transport of pollutants. A large number of waters are affected and the problem is of a regional character. The national limits for Hg in fish are exceeded in a large number of lakes. In Sweden alone, it has been estimated that the total number of lakes exceeding the blacklisting limit of 1 mg Hg kg-1 in 1-kg pike is about 10 000.

894 citations

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TL;DR: Tests revealed elevated contents of cadmium, lead, arsenic, antimony and mercury in farming soils of Suszec commune, which pointed to metal depletion in the soil.

767 citations

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TL;DR: PCA/FA and cluster analysis suggest that As, Cd, Co,Cr, Cr, Cu, Mn, Ni and Zn are derived from the anthropogenic sources, particularly metallic discharges of the copper mine plant.

752 citations