Reconstruction of historical cadmium and lead emissions from a Swedish alumworks, 1726–1840

Cadmium and lead emissions from historical alum production were estimated from element analysis of shale and data on the use of shale and other raw materials. The total cadmium and lead content in the shale was ∼ 2.6 and 10 tonnes, respectively. The works constructed their own lead pans and purchased ∼ 260 tonnes of lead to do so. It is assumed that a minor part of the metals in the shale were emitted to the air and the bulk was deposited in bings of used shale, whereas the share of air emissions from the construction of the lead pans was high. The resulting immission pattern for cadmium is thus characterized by a dispersion < 500 m while substantial amounts of lead were deposited at least 2 km away. Assuming a uniform dispersion within 5 and 20 km, respectively, the cadmium and sulphur deposition rates around the works were similar to pre-industrial rates (Cd 0.1 mg/m2/year and S 100 mg/m2/year) while the lead deposition reached a value of 150 mg/m2/year, if dispersed within 2 km.