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Data Set #054

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    Lead is widespread in municipal solid waste throughout the United States.  The sources for the lead are numerous, although lead-acid storage batteries are the biggest culprit by far.  According to the EPA, in 1995 lead acid storage batteries accounted for 64.7% (by weight) of the lead in the waste stream.  The second biggest source of lead in municipal solid waste is from Cathode Ray Tubes (CRTs), which accounted for 28.56% of the waste stream lead in 1995.  CRT waste contribution was expected to increase to 30% by the the year 2000, due to the rapidly escalating number of consumer electronic devices that are thrown away each year.

    CRTs are the major component of television screens and computer monitors, with the lead confined predominantly to the neck and funnel of the CRT.  When CRTs are disposed of in landfills, lead and other heavy metals can leach into groundwater.  When CRTs are incinerated, the ash can become contaminated with the heavy metals causing further disposal problems.  The leachability of lead in CRTs is determined by the Toxicity Characteristics Leaching Procedure (TCLP), a general method to examine whether a solid leaches hazardous pollutants.  The regulatory limit for for TCLP lead is 5.0 mg/L.

    Over 10 weeks, televisions and computer monitors were collected from individual donations, electronics repair facilities, an electronics manufacturer, and institutional electronics disposal.  A total of 36 models of CRTs were obtained and tested, with 15 of these exceeding the regulatory limit of lead.  In the study, researchers used the TCLP to identify the leachable concentration of lead in the neck, funnel and face.  In this data set we list the weighted average that was obtained (weighted by fractional mass).  Several models of CRTs had a (weighted) leachable lead concentration reported as <1.0 mg/L; we converted these figures to 1.0 mg/L for data analysis purposes.
 

Source:   "Characterization of Lead Leachability from Cathode Ray Tubes Using the Toxicity Characteristic Leaching Procedure", Townsend, T.G., 1999, University of Florida and the Florida Center for Solid and Hazardous Waste Management.

     
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Leachable Lead Concentrations in CRTs    
source: FLORIDA CENTER FOR SOLID AND HAZARDOUS WASTE MANAGEMENT
           
TV/Computer Maker Year manufactured CRT maker Leachable Lead Concentration (mg/l) Bin Freq.
Acer 93 Panasonic 57.2 0-10 19
Digital 90 Clinton 1.0* 10-20 4
Elite 92 Chunghwa 19.3 20-30 4
Emerson 84 Goldstar 1.5 30-40 2
Gateway 93 Toshiba 3.2 40-50 2
Gateway 92 Toshiba 54.1 50-60 3
Hp 84 Matsushita 1.0* 60-70 1
Hp 85 Matsushita 1.0* 70-80 0
IBM 87 Matsushita 1.0* 80-90 1
IBM 89 Panasonic 9.4    
IBM 92 Phillips 41.5    
Imtec 89 Samsung 60.8    
Imtec 89 Hitachi 85.6    
Memorex 97 Toshiba 2.2    
Memorex 97 Kch 2.3    
Memorex 98 Samsung 6.1    
Memorex 98 Chunghwa 9.1    
Memorex 97 Toshiba 10.6    
Memorex 98 Samsung 15.4    
Memorex 97 Chunghwa 21.3    
NEC 87 NEC 10.7    
Orion 96 Orion 33.1    
Panasonic 84 Matsushita 3.5    
Quasar 84 Quasar 43.5    
Samsung 89 Samsung 1.0*    
Seiko 87 NEC 26.6    
Sharp 94 Sharp 1.5    
Sharp 84 Sharp 4.4    
Tandy 85 Sharp 35.2    
Techmedia 95 Samsung 6.9    
Teknika 86 Phillips 1.0*    
Ttx 91 Chunghwa 2.8    
Zenith 94 Zenith 1.6    
Zenith 94 Zenith 21.5    
Zenith 77 Zenith 21.9    
Zenith 85 Toshiba 54.5    
      * listed as <1.0 in study    
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