Century Perspective of Heavy Metal Use in Urban Areas. A Case Study in Stockholm

The inflow and stock (amount in use) of heavy metals (cadmium(Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni) and zinc (Zn)) in goods in 1995 have been quantifiedin the anthroposphere of Stockholm, Sweden. Statistics on national, regional and local level were used. Contacts were established with representatives from production and constructionin the industrial sector and with authorities. The results show that the stock of Cd is 0,2 kg per capita. For the other heavymetals the corresponding result per capita is: Cr 8, Cu 170, Hg 0,01, Ni 4, Pb 73 and Zn 40 kg. The inflow varies between2–8%of the stock indicating the importance of the stock. The lowestlevels are for Cu and Pb. Heavy metal levels in solid waste are high, between 15–45% of the amount in the inflow (Hg excluded), the lowest values were for Cu and Pb. Thus, recyclingis incomplete. Long life expectancy goods form the majority of the stock but there is a tendency that short life expectancy goods increase their importance in the inflow. Concealedgoods are also more frequent in inflow than in the stock.     

Goods in the Anthroposphere as a Metal Emission Source A Case Study of Stockholm,Sweden

The aim of this study was to quantify the diffuse emissionsduring use of metal containing goods in the capital of Sweden,Stockholm. The following metals were studied: Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni) and Zinc (Zn).A major part of the metals are found in a protected environmentwhere degrading processes like corrosion are most limited. However, during the lifetime of some goods the metal release to the environment is significant. The quantitatively most dominant emissions were found for Cu and Zn. The tap water system and roofs/fronts (Cu) represent goods with large exposedareas but with relatively small release rates per unit. In contrast, brake linings, aerial lines and electrical grounding (Cu) and tyres, brake linings and chemicals (Zn) are allgoods with high release rates but mostly limited exposed stocks.High yearly emissions are also found for Pb, ammunition andsinkers dominate the calculated emissions totally. For Cr and Ni, stainless steel represent the major part of the stocks, butcorrosion was estimated to give only a minor contribution to the emissions. Potential emission sources, i.e. stabilisers,pigments and plated goods dominate the exposed Cd stock. Theseemissions were not quantified due to lack of data. Hg is currently phased out, but one major source of emission, i.e. the use of amalgam, will be continuously significant for several decades. The importance of the traffic sector is obvious. The emissionsfrom brake linings (Cu, Zn and Pb), tyres (Zn, Pb, Cr and Ni)and asphalt wear (Cu, Zn, Cr, Ni and Pb) are all of large importance for the total emission from respectively metal.     

Copper Emissions from Fuel Combustion Consumption and Industry in Two Urban Areas 1900–1980

The type of energy system andindustrial structure of urban areas is veryimportant for the total amounts of Cu emitted.The total per capita emission for the New Yorkarea is estimated to be approximately 4 timeslarger than Stockholm municipality between 1900–1980. The latter was mainly the result of largedifferences in energy systems and industrialstructure. Hydro-electric power and non fossilfuels were important energy sources for Stockholmwhile coal was a much more significant fuel forthe New York area. Metal processing hascharacterised the industries of Stockholm whilethe New York area was a national centre forcopper and petroleum refining as well as thechemical industry. In both cases the estimated Cuemissions from fuel combustion and industrydecreased from 1900–1980. But in the case ofconsumption related emissions the time trendsdiffer between the two urban areas. In Stockholmend use was the largest category of Cu emissionsduring the whole time period studied. In the NewYork area consumption related emissions becamethe largest source of Cu emission in the 1950s.