Heavy metals are well-known for toxic effects on organisms. Due to human activities such as mining and smelting processes the bio-available amounts of heavy metals have increased in nature. The emission of toxic metals into the environment has become much reduced during the last decades, following increased environmental concern, and improved handling of metals and cleaning techniques at metal processing industries. However, little is known about the recovery rate of metal contaminated environments at the actual lower levels of metal deposition rate. The aim of this project is to monitor environmental effects of decreased metal deposition in study areas in the surroundings of metal industries in northern Sweden. The study was initiated in the 1980s, using the insectivorous bird pied flycatcher (Ficedula hypoleuca) as model organism, where we focus on metal accumulation in tissues of nestlings, the transfer routes for metals to the birds, the health effects of the nestlings, and the breeding performance.