Molybden i ytvatten - En fara för laxfiskar och människor vid intag av fisken?

Sammanfattning: There are around 80, 000 polluted areas in Sweden, of which 1, 000 are classified as very high-risk areas and in need of decontamination. From the Gullspångs Elektrokemiska Fabrik AB in Sweden there is a great risk of metals, aliphatic and molybdenum spreading to the Gullspångs River. The river is a Natura 2000-area and in the river the so called Gullspång salmon is found, which is protected. Here, a literature review was conducted with the purpose to compile information about the effect molybdenum could have on the resident salmon. Results show that molybdenum can impact weight in the early life stages but has no major impact on survival. Studies could generally not conclude a high toxicity at lower concentrations. An uptake of molybdenum and accumulation is found. The obtained data shows that liver and gills contained the highest concentrations of molybdenum and muscles contained the lowest concentrations. Exposure to molybdenum did not create a stress response but had an impact on ventilation and oxygen consumption. Delayed mortality was observed in connection with exposure. No target values were found for molybdenum level in fish. In conclusion, there is currently no target value set for molybdenum in fish, but 73 μg/L is recommended for freshwater. There is an uptake of molybdenum in fish but the amount that is accumulated is minimal. An intake of 65 μg molybdenum/day should not give a negative effect on human health. Molybdenum exposure does likely not pose a high risk for the Gullspång salmon but considering the salmon is protected precautions should be taken. Keywords: molybdenum, toxicity, bioaccumulation, fish, salmo, salmo trutta