Health hazard. Where the soil is heavily contaminated, the flycatcher population has difficulty in recovering until the metal contents in the soil have fallen to levels corresponding to those in uncontaminated areas. This may take several decades, even though fallout has almost completely ceased. Photographer: Åsa Berglund.
In her work, Åsa Berglund has studied the flycatcher around the now closed lead mines with enrichment plants at Laisvall and the smelting plant at Rönnskär. At the Laisvall mine that is situated in Arjeplog Municipality, she has investigated populations of flycatcher before and after closure of the industry in 2001.
- Lead concentrations in young birds have certainly decreased at the same pace as lead fallout, but after five years there is still high mortality among young birds and their health is worse. This is shown, inter alia, by low blood values, says Åsa Berglund.
Arsenic and stress
The Rönnskär smelting plant outside Skelleftehamn has been in operation since the 1930s. Around the plant the metal concentrations in young birds are at the same level as 20 years ago, although emissions have decreased by 94-99 per cent during the same period. In the close vicinity of the smelting plant, the contents of arsenic, cadmium, mercury and lead in young birds are highly elevated. Even at the Rönnskär plant there is abnormal young bird mortality and the health effects are similar to those at the lead mine. The birds are also exhibiting signs of oxidative stress, something that can cause cell damage, Åsa Berglund has discovered.
Several decades
The flycatchers at the Rönnskär plant absorb metals chiefly from the soil which, after several decades of emissions from the industry, had very high metal contents. This may explain why the birds are subject to a high metal exposure in spite of the fact that emissions are low. The reduced metal contents in the flycatchers around the Laisvall mine are presumably due to the reduced quantity of metals in the soil. The contents are however still high enough to affect the health of birds in both areas.