Cadmium emissions from landfills

Cadmium releases from landfills have been evaluated by the Draft Risk Assessment Report on Cadmium (DRAR 2000). They can be evaluated at less than 0.3 tonnes/y, this representing less than 0.8% of total emissions of cadmium in water in the EU countries. The major contributors to total cadmium emissions into surface waters are zinc and lead producers, fuel combustion for electricity generation, fuel combustion for road transportation, phosphate industries and non-ferrous metallurgy (DRAR 2000). 

This fraction can lead to emissions of cadmium to the environment (atmospheric and water emissions). Today, in the EU members states these emissions need to be strictly controlled according to EU Directives on Waste (91/156/EEC), on Emissions from Municipal Solid Waste Incinerators (2000/76/EC), and from Landfills (99/31/EC). These emissions could be further reduced by an optimised collection efficiency of portable rechargeable batteries. 

Several sites may have higher concentration of cadmium emissions. These are industrial waste landfills and the origin of their cadmium emissions is not proven to be from spent batteries. 

The human health and environmental issues associated with nickel-cadmium batteries arise mainly from the ultimate disposal of the spent batteries. In general, occupational exposures to and manufacturing wastes and emissions from nickel, cadmium, cobalt and other materials in NiCd battery production are well regulated and controlled. There is virtually no danger of nickel or cadmium exposure during normal use of NiCd batteries. Even when NiCd batteries are disposed of in landfills, there is little danger of risk or exposure, at least in the short to mid-term, to nickel or cadmium from the battery s electrodes since they are always encased in at least two layers of steel or plastic or both. 

Spent NiCd batteries are, when incinerated or disposed of in landfills, a source of heavy cadmium emissions. An EU Directive, 2000/60/EC, recommended that the use of 32 chemicals should be phased out within 20 years. According to the recommendation, NiCd batteries should be banned from 2008. The recommendation of 2000 was, however, moderated in 2001. Instead of banning NiCd batteries, new take-back systems and deposit schemes should be developed in order to reduce the risk to human health and the environment. 

The second fraction of spent Ni-Cd batteries is introduced in landfills (as illustrated in Figure 22). The EC Directive on waste imposes a strict control of leachate emissions. More than 2,000 sites have been reviewed and 95% of them show cadmium concentrations in leachates below 5 micrograms per litre (Eggenberger 2000). This represents the recommended concentration of cadmium for drinking water by the World Health Organization (WHO). This low emission level from MSW landfills has been confirmed by Swedish researchers (Flyhammer 1996). 

Individual countries within the European Community handle the battery waste problem differently. For example, in Switzerland all used consumer batteries are considered hazardous waste and must be collected separately from ordinary household waste. Batteries must be recycled or stored in warehouses, not landfilled. A tax is collected on all new battery purchases to help defray the cost of recycling. In Italy, spent dry batteries are considered as hazardous waste and must be collected separately. In Sweden (10), the environmental issues relatii to waste batteries are addressed in the Control of Chemicals Bill and in the Decree on Environmentally Hazardous Batteries. All used batteries containing cadmium or mercury are collected separately under government control. The cadmium is then recycled. Regulations are in place for the manufacture of nickel/cadmium cells, limiting the exposure of workers and the emission of toxic materials. 

Consumer batteries are generally smaller and are discarded with other products in the municipal solid waste. When the waste reaches a landfill, water is leached and then nickel, cadmium, and mercury are extracted from the used and broken batteries. High concentrations of the metals are sorted out from the landfill base. When the waste reaches the incinerators, the batteries contribute high levels of metal fumes to the stack emissions and ash, which escalates the cost of environmental control. Battery producers claim that used batteries accounted for close to 1.5 million metric tons of municipal from solid waste. However, this quantity is less than 1% of the total municipal solid waste generated. This solid waste contains about 67% of the lead, 90% of the mercury, and more than 50 percent of the cadmium. In countries where county and municipal regulators mandate the removal of Pb-acid batteries from the municipal solid-waste incinerators and landfills, they require safe disposal of used batteries with appropriate certification. 

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