United States Environmental Protection Agency Office of Solid Waste Washington, DC 20460 January 1989 EPA/530-SW-89-015B Office of Solid Waste Characterization of Products Containing Lead and Cadmium in Municipal Solid Waste in the United States, 1970 to 2000 Final Report Executive Summary and Chapter 1, Lead and Cadmium in Municipal Solid Waste: Overview and Summary Original editions of this document are printed on recycled paper with ink free of lead and cadmium. ------- ------- EXECUTIVE SUMMARY As disposal of municipal solid waste (MSW) has become an issue of increasing importance in the United States, combustion of wastes has been recognized as one of several alternative management approaches. A'concern associated with municipal waste combustion, however, is that heavy metals (lead and cadmium in particular) have been found in analytical tests of the ash from these facilities. This report characterizes the sources of lead and cadmium in products disposed in MSW over the time period 1970 to 1986, with projections to the year 2000. LEAD IN MUNICIPAL SOLID WASTE Lead is widespread in the municipal waste stream; it is in both the combustible and,noncombustible portions of MSW. Discards of lead in MSW are overwhelmingly greater than discards of cadmium (Figure 1). Lead-acid batteries (primarily batteries for automobiles) rank first, by a wide margin, of the products containing lead that enter ^the waste stream. Trends in quantities of lead discarded in products in MSW (ranked by tonnage discarded in 1986) are shown in Table 1. The last two columns on the table indicate whether the total tonnage of lead in a product is generally increasing or decreasing, and whether the percentage of total MSW lead contained in a product is increasing or decreasing. Changing trends in discards of lead are illustrated in Figure 2. Lead discards in batteries are shown to be growing steadily, as are discards in consumer electronics. Discards of leaded solder in cans and lead in pigments, however, virtually "disappear" from the graphic between 1970 and 1986. Lead discards in other products are shown to be relatively small. Findings about the individual products in MSW that contain lead are: * Lead-acid Batteries contributed 65 percent of the lead.in MSW in 1986; this percentage has ranged between 50 and 85 percent during the 1970 to 1986 period studied. The tonnages in Table 1 represent discards after recycling, but of all the products considered, only lead-acid batteries are recycled to a significant extent. Recycling rates, which have ranged from 52 to 80 percent, have a major effect on the^ tonnage: of lead-acid batteries discarded. : ..r "-'-_. V^ * Consumer Electronics (television sets, radios, and video Cassette recorders) accounted for 27 percent of lead discards in MSW in 1986. They contribute lead from soldered circuit boards, leaded glass in television sets, and plated steel chassis. Leaded glass accounts for most of the lead in these products. .-.'."' ; ~ * Glass and Ceramics. as reported here, include lead in products such as glass containers, tableware and cookware, and other items such as -'"'. , - V ' " ,"" 7 - , . J- ------- Figure 1. Relative discards of lead and cadmium in MSW, 1986. Cadmium 1,788 tons ------- Table 1 LEAD IN PRODUCTS DISCARDED IN MSW. 1970 TO 2000 (In short tons) Products 1970 Lead-acid batteries 83,825 Consumer electronics 12,233 1986 2000 Tonnage 138,043 181,546 Increasing 58,536 85,032 Increasing Percentage Variable Increasing Glass and ceramics Plastics Soldered cans Pigments All others Totals 3,465 1,613 24,117 27,020 12.567 164,840 7,956 3,577 2,052 1,131 2.537 213,652 8,910 3,228 787 682 1.701 281,887 Increasing Increasing; decreasing after 1986 Decreasing Decreasing Decreasing Increasing; s after 1986 Fairly stable Decreasing Decreasing Decreasing ------- Year 2000 1986 1970 Figure 2. Lead in discards of products in MSW, 1970, 1986, anc . 2000. 50,000 100,000 150,000 200,000 250,000 300,000 Tons 01 All others Glass EZJ m Pigments Electronics D m Cans Batteries ^ Plastics ------- optical glass. These contributed 4 percent of lead discards in 1986. (Leaded glass in light bulbs is included in the "All Other" category in Table 1.)- * Plastics use lead in two ways: As a heat stabilizer (primarily in polyvinyl chloride resins) and as a component of pigments in many resins. This category, which includes products such as nonfood packaging, clothing and. footwear, housewares, records, furniture, appliances, and other miscellaneous products, accounted for about 2 percent of lead discards in 1986. Plastics in consumer electronics products are counted under that category. * Soldered Cans have experienced a large decline in usage since 1970, when they contributed 14 percent of the lead in MSW. Leaded solder is currently used in steel food cans, general purpose cans (like aerosols), and shipping containers. * Pigments containing lead compounds have declined greatly since 1970, dropping from 18 percent of total lead discards to less than one percent. This category includes pigments used in paints, printing inks, textile dyes, etc. Pigments used in plastics, glass and ceramics, and rubber products are accounted for In those categories. * All Others include brass and bronze products, light bulbs (which contain lead in solder and in glass), rubber products, used oil, collapsible tubes, and lead foil wine bottle wrappers. Collapsible.tubes contributed over 5 percent of total lead discards in 1970, but their use has declined dramatically since then. None of the other items has exceeded one percent of the total since 1970. CADMIUM IN MUNICIPAL SOLID WASTE Like lead, cadmium is widespread in products discarded into MSW, although it occurs in much smaller quantities overall. Since 1980, nickel- cadmium household batteries have been the Number 1 contributor of cadmium in MSW. ' Trends in quantities of cadmium discarded in products in MSW (ranked by tonnage discarded in 1986) are shown in Table 2. Trends in discards of cadmium in products in MSW are illustrated in Figure 3. Discards of cadmium in household batteries were small in 1970, but then increased dramatically. Cadmium discards in plastics are relatively stable. Discards of cadmium in consumer electronics are shown to decrease over time, while the other categories are relatively small. Findings about cadmium discards in individual products in MSW are: * Household Batteries (rechargeable nickel-cadmium batteries) have accounted for more than half of cadmium discards in the U.S. since 1980. This growth is projected to continue unless they are replaced by another type of battery. ------- Year 2000 1986 197*0. Figure 3. Cadmium in discards of products in MSW, 1970, 1986, and 2000. 500 1,000 1,500 2,,p:flO 2,500 All others E] Pigments E3 Appliances Electronics E Plastics M Batteries 3,000 Tons ------- * Plastics continue to be an important source of cadmium in MSW, contributing 28 percent of discards in 1986. Cadmium is used in .stabilizers in polyvinyl chloride resins and in pigments in a wide variety of plastic resins. Cadmium is found in nonfood packaging, footwear, housewares, records, furniture, and other plastic products. Table 2 CADMIUM IN PRODUCTS DTSfi/lRDED IN MSW. 1970 TO 2000 (In short tons) Products Household batteries Plastics Consumer electronics Appliances Pigments Glass and ceramics All others Totals 1970 1986 2000 Tonnage 53 342 930 502 2,035 380 571 107 79 32 12 1,196 Consumer 161 88 70 29 1 1,788 2 Electronics 67 57 93 37 11 ,684 (tel Increasing Variable Decreasing Decreasing Variable Variable Variable Percentage Increasing Variable; decreasing after 1986 Decreasing Decreasing Variable Variable Variable 1 ' 111 - iniTM x - »» u V VM b»*.*v*> J. CAV*^\XI^ j ^\J JLI11C JL J- y LlCLU cadmium-plated steel chassis in many cases. These chassis have been replaced by circuit boards, so cadmium discards in consumer electronics are declining as the older units are replaced. They contributed 9 percent of the total in 1986. * Appliances (dishwashers and washing machines) formerly had cadmium-plated parts to resist corrosion. This source of cadmium is declining as cadmium-plated parts are replaced by plastics, which are themselves another source of cadmium discards in appliances. Cadmium discards from appliances accounted for about 5 percent of total in 1986. * Pigments used in printing inks, textile dyes, and paints may contain cadmium compounds, although this is not a large source of cadmium in MSW (about 4 percent of total). * Glass and Ceramics may contain cadmium as a pigment, as a glaze, or as a phosphor. This is a relatively small source of cadmium in MSW. ------- * All other sources of cadmium include rubber products, used oil, and electric blankets and heating pads. These contribute very small amounts of cadmium to MSW. LEAD AND CADMIUM IN COMBUSTIBLE AND NONCOMBUSTIBLE PRODUCTS Removal of the noncombustible products containing lead and cadmium before municipal solid waste is incinerated has been suggested as a way to manage the heavy metal content of incinerator ash. Using data developed in this study, the lead and cadmium content of the combustible and noncombustible fractions of MSW was examined. Almost 98 percent of the lead in MSW is found in noncombustible products, mostly in lead-acid batteries (Figure 4). If all the noncombustible products containing lead were removed, most of the remaining lead would be in plastics (71 percent) and other pigments (24 percent). Noncombustible products also contribute the majority (64 percent) of cadmium in MSW, with nickel-cadmium batteries being the primary source (Figure 5). If all of the noncombustible products containing cadmium were removed, plastics would contribute most of the remainder (88 percent), with other pigments accounting for 11 percent. POTENTIAL EFFECTS OF RECYCLING Recycling of lead-acid batteries to recover lead has a very significant influence on the amount of lead discarded. A previous study for EPA estimated the recycling rate of these batteries to be 80 percent in 1986; if there were no recycling of batteries, up to 700,000 additional tons of lead would have been discarded. The battery recycling rate has been as low as 52 percent in the early 1980s. The rate is affected by several factors, including the price of lead and regulatory requirements. No other recycling of lead or cadmium was identified, although small amounts of nickel-cadmium batteries may be exported for recycling. There are, however, several products that are recovered for recycling in which lead or cadmium is an incidental constituent. The lead or cadmium is thus removed from the waste stream entering an incinerator by the recycling process. The recycled products identified are: paper products that are deinked for recycling purposes, soldered cans, rubber tires, appliances, glass containers, and plastics. LIMITATIONS OF THIS REPORT While this report contains useful data on discards of lead and cadmium in municipal solid waste, there are some limitations in its application to the issue of lead and cadmium in municipal waste combustor ash. These limitations are: ------- Figure 4. Relative discards of lead in combustible and noncombustible products, 1986. Combustibles 2.3% Figure 5. Relative discards of cadmium in combustible and noncombustible products, 1986. ------- * This characterization identifies the sources of lead and cadmium in MSW; it does not tell us whether these are the major sources of leachable lead and cadmium in MWC ash. * The MSW characterization presented here may not correlate well with the waste input at any particular MWC facility. * The identified compounds of lead and cadmium may recombine with other materials in the combustion chamber to form new compounds; this issue is beyond the scope of this study. * In addition to MSW, other nonhazardous wastes contain lead and cadmium; these wastes may in some instances be incinerated along with MSW. These wastes, which were identified but not characterized in this study, include: municipal sludge, construction and demolition wastes, industrial and military wastes,.and automotive and other transportation equipment wastes. 10 ------- Chapter 1 LEAD AND CADMIUM IN MUNICIPAL SOLID WASTE: OVERVIEW AND SUMMARY In the past few years, environmentally-sound disposal of municipal solid waste (MSW) has become a major issue for the United States, especially at the local and state levels. As more and more landfills are closed and new landfills become increasingly difficult to site, communities are seeking methods of disposal. Recovery and recycling of materials and combustion (incineration) of MSW are two important alternatives that are being considered and imp1emented. Municipal waste combustion (MWC) is attractive to many communities because combustion reduces the volume of waste by up to 90 percent and the weight of waste by up to 80 percent. In addition, sales of recovered energy products (e.g., steam or electricity) help to offset the costs of disposal. Combustion of municipal solid waste does present some problems, however, and one of these is the disposal of the ash remaining after the combustion process is complete. Analytical tests have detected heavy metals (lead and cadmium in particular) in the ash remaining after municipal waste combustion (1). This report addresses one of many unanswered questions about MWC ash: What are the sources of lead and cadmium in municipal solid waste? OVERVIEW OF THIS REPORT This report characterizes lead and cadmium in products disposed in municipal solid waste over the time period 1970 to 1986, with projections of disposal to the year 2000. A summary of the findings is included in this chapter, with more detailed discussions on lead in Chapter 2, and cadmium in Chapter 3. Wastes Included in This Report Municipal solid waste is defined in EPA's Subtitle D* reports (2) as wastes coming from household, institutional, and commercial sources. Examples of institutional sources include hospitals (except for infectious wastes), schools, and prisons. Examples of commercial sources include retail stores, office buildings, and warehouses. Some wastes from industrial sources are also included, for example: corrugated boxes and other packaging, cafeteria and washroom wastes, and office wastes. * Subtitle D of the Resource Conservation and Recovery Act (RCRA) regulates those wastes generally classified as nonhazardous, while Subtitle C deals with hazardous wastes. 11 ------- Wastes Not Included in this Report A number of wastes* regulated under Subtitle D are not characterized in this study, including: - Municipal sludge - Industrial nonhazardous process waste - Small quantity generator waste '- Construction and demolition waste. While these wastes are not characterized for lead and cadmium content in this report, they may contain those metals and if incinerated along with MSW, they could contribute to lead and cadmium in the ash. METHODOLOGY The general methodology for this study is called the materials flow methodology; it is based on a methodology for estimating municipal solid waste that was developed at EPA in the mid-1970s (3) and that has been used periodically for EPA reports ever since. The materials flow methodology applies to the United States as a whole; it is not tailored to any specific locality. Data series on production of the products and materials in the waste stream are used as a basis. Adjustments are then made for imports and exports of the products, for diversions away from the waste stream, for the lifetimes of the products, and for materials recovery. Application of the methodology to discards of lead and cadmium required some additional steps. Numerous assumptions were required to determine end uses of products (like lead-containing solder) that would enter the municipal waste stream rather than others, such as demolition wastes. Also, lead and cadmium occur in many intermediate products, such as pigments, that enter the waste stream as part of another product. All assumptions were documented. The methodology is summarized in Figure 1-1, and a more detailed description is included in Appendix A of this report. RELATIVE DISCARDS OF LEAD AND CADMIUM Both lead and cadmium have been detected in analyses of ash from municipal waste combustors (MWC). Discards of lead in products classified as MSW are, however, very much greater than discards of cadmium.** As Figure 1-2 demonstrates, nearly 100 times more lead than cadmium was discarded in 1986; this relationship has been relatively constant since 1970. * See Reference .2 for definitions and discussion of these wastes. ** Later in this chapter, relative discards of lead and cadmium in the .combustible and noncombustible fractions of MSW are discussed. 12 ------- Consumpti of Lead or Cadmium Intermediate Products Manufacturing or Converting Losses Imports Diversions Exports ImP,orts Diversions Products Entering MSW Discards to Incineration or Landfill T Exports Manufacturing or Converting Losses Figure 1-1. Materials flow methodology for estimating lead and cadmium in MSW discards. ------- Figure 1-2. Relative discards .of lead and cadmium in MSW, 1986. Cadmium 1,788 tons 14 ------- TRENDS IN DISCARDS* OF LEAD AND CADMIUM Lead in MSW Discards of lead in products in MSW from 1970 to 2000 are summarized in Tables 1-1 and 1-2. Some perspective on the discards of various. products can be gained from Tables 1-3 and 1-4 and Figure 1-3. The products are discussed below in order of their relative rankings in 1986 (Table 1-3). (Each of these products is discussed in more detail in Chapter 2.) Lead-Acid Batteries. By any measure, lead discarded in lead-acid storage batteries overwhelms all other sources. These batteries, which primarily provide starting, lighting, and ignition (SLI) for automotive products, rank Number 1 in discards for all years from 1970 to 2000 (Table 1-4 and Figure 1-3). Table 1-2 demonstrates the high percentage of lead discarded in these batteries. They were 50 percent of the total lead discards in 1970, 76 percent in 1980, and 65 percent in 1986, a percentage that is projected to remain about constant to 2000. The figures show that discards of lead from batteries peaked in 1982 at about 409,000 tons. Several factors contributed to this: sales and imports of automotive vehicles were high in 1978 (there is a four-year lag between battery purchases and discards); the estimated pounds of lead per battery peaked at that time; and recycling of lead from batteries was declining. (Recycling is discussed in more detail later in this chapter.) An estimated 138,000 tons of lead in batteries were discarded in 1986. These discards are projected to increase gradually to about 182,000 tons in 2000 under stable conditions (Table 1-1 and Figure 1-3). Consumer Electronics. This category of products includes primarily television sets, radios, and more recently, video cassette recorders (VCRs). Consumer electronics were the Number 4 contributor of lead in MSW in 1970, but by 1975 they were Number 2, a position they continue to hold (Table 1-4). The sources of lead in these electronics products include soldered circuit boards, leaded glass in television sets, and plated steel chassis. Discards of lead in consumer electronics amounted to about 12,000 tons in 1970, or 7 percent of total lead discards. By 1986, this has grown to 58,500 tons, or 27 percent of total. By 2000, discards of lead in consumer electronics is projected to be 85,000 tons, or 30 percent of total. (See Figure 1-3.) Solder containing lead is commonly used in circuit boards in consumer electronic products. This has been an increasing source of lead discards, but the amount discarded is projected to decline in the future (Table 1-1). . This reflects a general decline in the use of lead in solder in * "Discards" in this section refers to discards after recycling; in other words, the products shown in these tables and figures would be incinerated unless otherwise disposed. . 15 ------- Table 1-1 DISCARDS* OF LEAD IS PRODUCTS IH THE MUNICIPAL WASTE STREAM. 1970 TO 2000 BRASS AMD BRONZE PRODUCTS CANS AHD OTHER SHIPPING CONTAINERS Solder in food cans Solder in beverage cans Solder general cans Solder In shipping concainers Subtoeal cans and shipping concainers CONSUMER ELECTRONICS Circuit boards Plascics TV piccure cubes TV and radio chassis Subcocal consumer eleccron. CLASS AND CERAMIC PRODUCTS** LEAD-ACID STORAGE BATTERIES Starting- lighting-ignition Portable Subcocal - lead-acid bacceries LIGHT BULBS Glass Solder Subcocal - light bulbs PIGMENTS* Princing inks All other produces Subcocal - pigments PLASTICS-H- Honfood packaging Clothing Footwear Miscellaneous nondurables Subtotal nondurables Housewares Toys Records Luggage Furniture Appliances Miscellaneous durables Subcocal - durables Subtotal - plascics RUBBER PRODUCTS Tires and rubber produces All other rubber products Subcocal - rubber products USED OIL MISCELLANEOUS PRODUCTS Collapsible cubes Foil wine wrappers Subcocal raise, p'roduccs 1970 410 11,995 9,227 2,307 588 24,117 1,417 0 10,430 386 12,233 3,465 83,823 2 83,825 491 156 647 19,192 7,828 27,020 775 116 152 56 1,099 80 130 97 3 84 88 32 514 1,513 36 16 52 1,557 9,310 591 9.901 (In short 1975 474 10,291 7,260 1,911 660 20,122 1,759 0 17,935 499 20,193 4,122 206,420 7 206,427 507 161 668 13,819 3,198 17,017 689 182 342 89 1,302 227 354 166 4 155 74 61 1,041 2,343 38 15 53 1,230 2,360 356 3,216 tons) 1980 404 6,882 1,077 1,257 459 9,675 3,441 0 17,690 683 31,814 5,396 205,641 18 205,659 623 197 820 8,222 1,642 9,864 968 67 264 371 1,670 189 222 304 8 426 113 80 1,342 3,012 70 33 103 810 1,477 383 1,360 1985 267 1.898 0 911 198 3,007 5,883 0 40,818 310 47,011 6,911 221,913 41 221,954 706 224 930 1,414 954 2,368 916 31 372 377 1,696 166 183 209 4 368 98 742 1,770 3,466 42 18 60 314 607 243 850 1986 321 1,139 0 778 135 2,052 6,092 0 52,165 279 58,536 7,956 137,996 47 138,043 709 225 934 265 866 1,131 934 29 324 391 1,678 177 219 242 5 416 92 748 1,899 3,577 48 21 69 192 639 202 841 1990 310 642 0 439 52 1,133 3,568 46 48,230 0 51,844 8,415 167,236 71 167,307 727 230 957 220 718 938 1,007 30 290 390 1,717 137 176 215 7 362 148 758 1,803 3,520 55 24 79 61 240 100 340 1995 181 594 0 406 46 1,046 2,714 26 76,280 0 79,020 8,663 172,639 91 172,730 787 249 1,036 179 630 809 1,003 30 290 390 1,713 145 183 95 5 160 139 731 1,458 3,171 57 24 81 48 220 80 300 2000 207 443 0 303 41 787 990 42 84,000 0 85,032 8,910 181,445 101 181,546 847 268 1,115 140 542 682 1,003 30. 290 390 1,713 145 183 120 6 177 153 731 1,515 3,228 59 24 83 36 200 60 260 GRAND TOTAL 164,84.0 275,865 269,417 287,138 213,652 234,904 267,086 281,887 * Discards after recycling. ** Except for glass in light bulbs and television sets. + Except for pigments in glass, plascics, and rubber. H- Except for plastics in consumer electronics. L6 ------- Table 1-2 (In percent of total lead Products BRASS AND BRONZE PRODUCTS CANS AND OTHER SHIPPING CONTAINERS Solder in food cans Solder in beverage cans Solder in general cans Solder in shipping containers Subtotal - cans and shipping containers CONSUMER ELECTRONICS Circuit boards Plastics TV picture tubes TV and radio chassis Subtotal - consumer electronics GLASS AND CERAMIC PRODUCTS** LEAD-ACID STORAGE BATTERIES Starting-lighting-ignition Portable Subtotal - lead-acid batteries LfCIIT BULBS Glass Solder Subtotal - light bulbs PIGMENTS* Printing inks All other products Subtotal - pigments PLASTICS-H- Nonfood packaging Clothing Footwear Miscellaneous nondurables Subtotal - nondurables Housewares Toys Records Luggage Furniture Appliances Miscellaneous durables Subtotal - durables Subtotal - plastics RUBBER PRODUCTS Tires and tire products All other rubber products Subtotal - rubber products USED OIL MISCELLANEOUS PRODUCTS Collapsible tubes Foil wine wrappers Subtotal - misc. products 1970 0.2 7.3 5.6 1.4 0.3 14.6 0.9 0.0 6.3 0.2 7.4 2.1 50.8 0.0 50.9 0.3 0.1 0.4 11.6 4.8 16.4 0.5 0.1 0.1 0.0 0.7 0.0 O.I 0.1 0.0 0.0 0.1 0.0 0.3 1.0 0.02 0.01 0.03 0.9 5.6 0.4 6.0 1975 0.2 3.7 2.6 0.7 0.2 7.3 0.6 0.0 6.5 0.2 7.3 1.5 74.8 0.0 74.8 0.2 0.1 0.2 5.0 1.2 6.2 0.3 0.1 0.1 0.0 0.5 0.1 0.1 0.1 0.0 0.1 0.0 0.0 0.4 0.9 0.01 0.01 0.02 0.4 1.0 0.1 1.2 1980 0.1 2.5 0.4 0.5 0.2 3.6 1.3 0.0 10.3 0.3 11.8 2.0 76.3 0.0 76.3 0.2 0.1 0.3 3.1 0.6 3.7 0.4 0.0 0.1 0.1 0.6 0.1 0.1 0.1 0.0 0.2 0.0 0.0 0.5 1.1 0.03 0.01 0.04 0.3 0.6 0.1 0.7 discards) ' 1985 0.1 0.7 0.0 0.3 0.1 1.1 2.1 0.0 14.2 0.1 16.4 2.4 77.3 0.0 77.3 0.2 0.1 0.3 0.5 0.3 0.8 0.3 0.0 o.i 0.1 0.6 0.1 0.1 0.1 0.0 0.1 0.0 0.3 0.6 1.2 0.01 0.01 0.02 0.1 0.2 0.1 0.3 1986 0.2 0.5 0.0 0.4 0.1 1.0 2.9 0.0 24.4 0.1 27.4 3.7 64.6 0.0 64.6 0.3 0.1 0.4 0.1 0.4 0.5 0.4 0.0 0.2 0.2 0.8 0.1 0.1 0.1 0.0 0.2 0.0 0.3 0.9 1.7 0.02 0.01 0.03 0.1 0.3 0.1 ' 0.4 1990 0.1 0.3 O.-O 0.2 ' 0.0 0.5 1.5 0.0 20.5 0.0 22.1 3.6 71.2 0.0 71.2 0.3 0.1 0.4 0.1 0.3 0.4 0.4 0.0 0.1 0.2 '.0.7 0.1 0.1 0.1 0.0 0.2 0.1 0.3 0.8 1.5 0.02 0.01 . 0.03 0.03- 0.1 0.0 0.1 1995 0.1 0.2 0.0 0.2 0.0 0.4 1.0 0.0 28.6 0.0 29.6 3.2 64.6 0.0 64.7 0.3 0.1 0.4 0.1 0.3 0.3 0.4 0.0 0.1 0.1 0.6 0.1 0.1 0.6 0.0 0.1 o.-i ' 0.3 0.5 1.2 0.02 :- 0.01 0.03 0;02 0.1 0.0 0.1 2000 0.1 0.2 0.0 - 0.1 0.0 0.3 0.4 0.0 29.8 0.0 30.2 3.2 64.4 0.0 64.4 0.3 0.1 0.4 0.1 0.2 0.3 0.4 0.0 0.1 0.1 0.6 0.1 0.1 0.0 0.0 0.1 0.1 0.3 0.5 1.1 0.02 0.01 0.03 0.01 0.1 0.0 0.1 GRAND TOTAL 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 * Discards after recycling. ** Except for glass in light bulbs and television sets. + Except for pigments in glass, plastics, and rubber. H- Except for plastics in consumer electronics. 17 ------- Table 1-3 DISCARDS* OF LEAD IN PRODUCTS IN THE MUNICIPAL WASTE STREAM. 1986 RANKED IN ORDER OF WEIGHT OF LEAD (In shore cons and percent of cocal) Produces Short Tons Percent LEAD-ACID STORAGE BATTERIES Starcing-lighting-ignition 137,996 Portable 47 Subtotal - lead, batteries 138,043 CONSUMER ELECTRONICS ' Circuit boards 6,092 TV picture tubes 52,165 TV and radio chassis 279 Subtotal-consumer electronics 58,536 GLASS AND CERAMIC PRODUCTS''* 7,956 PLASTICS* Nonfood packaging 934 Clothing 29 Footwear 324 Miscellaneous nondurables 391 Subtocal-oondurables - 1,678 Housewares 177 Toys 219 Records 242 Luggage < 5 Furniture 416 Appliances ,92 Miscellaneous durables 748 Subtotal-durables 1,899 Subtotal-plastics 3,577 CANS AND OTHER SHIPPING CONTAINERS Solder in food: cans 1,139 Solder in general cans 778 Solder in shipping containers 135 Subtotal-cans and shipping containers 2,052 FTaiENTS-H- Printing inks 265 All other products , 866 Subtotal -pigments 1,131 LIGHT BULBS Clas* 709 Solder 225 Subtocal-lighc bulbs . 934 COLLAPSIBLE TUBES 639 BRASS AND BRONZE PRODUCTS 321 FOIL WINE WRAPPERS 202 USED OIL ... 192 RUBBER PRODUCTS _ Tires and cire products 48 All other rubber products 21 Subtotal-rubber products 69 GRAND TOTAL 213,653 64.6 0.0 64.6 2.9 24.4 0.1 27.4 3.7 0.4 0.0- 0.2 0.2 0.8 0.1 0.1 0.1 0.0 0.2 0.0 0.3 0.9 1.7 0.5 0.4 0.1 1.0 0.1 0.4 0.5 0.3 0.1 . 0.4 0.3 0.2 0.1 0.1 0.02 0.01 0.03 100.0 it Discards 'after recycling. ** Except for glass in light bulbs and television sets. + Except for plastics in consumer electronics. . H- Except for pigments in glass, plastics, and rubber 18 ------- VD Table 1-4 SOURCES OF LEAD IN MSW, RANKED BY TONNAGE. 1970 TO 2000 RANK^-^" -"-"'YEAR No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 1970 Lead-Acid Batteries Pigments Soldered Cans Consumer Electronics Collapsible Tubes Glass Products 1975 Lead-Acid Batteries Consumer Electronics Soldered Cans Pigments Glass Products Collapsible Tubes 1980 Lead-Acid Batteries Consumer Electronics Pigments Soldered Cans Glass Products Plastics 1966 Lead-Acid Batteries Consumer Electronics Glass Products Plastics Soldered Cans Pigments 1990 Lead-Acid Batteries Consumer Electronics Glass Products Plastics Soldered Cans Pigments 1995 Lead-Acid Batteries Consumer Electronics Glass Products Plastics Soldered Cans Light Bulbs 2000 Lead-Acid Batteries Consumer Electronics Glass Products Plastics Light Bulbs Soldered Cans Lead-Acid Batteries are primarily automotive batteries. Pigments Include pigments in paints, inks and dyes, but not those in glass, plastics, and rubber Soldered Cans Include food, beverage, and other cans Consumer Electronics include circuit boards, picture tubes, TV and radio chassis, and plastics Collapsible Tubes are tubes of the type used for artists'paints. Glass Products include all uses except light bulbs and TV picture tubes ------- Figure 1-3. Lead in discards of products in MSW, 1970, 1986, and 2000. Year 2000 1986 1970 50,000 100,000 150,000 200.000 250,000 300,000 All others El Pigments D Cans Glass M Electronics S Batteries Plastics Tons 20 ------- electronic components as reported by the Bureau of Mines, and reflects changes in the manufacturing processes. Discards of lead from solder in consumer electronics were about 1,400 tons in 1970 (less than one percent of the total), and were about 76,000 tons in 1986 (about 3 percent of total). .These discards of lead are projected to decline to less than 1,000 tons and less than one percent of total discards by 2000. Leaded glass in television picture tubes is the major source of lead in consumer electronic products. (According to the Bureau of Mines, 75 percent of lead used in glass is used in picture tubes.) Lead in the glass provides shielding from X-rays and otherwise enhances the qualities of the glass. This source of lead in MSW has increased steadily since 1970, and is projected to continue to do so (Table 1-1). Discards of lead from glass in TVs were about 10,000 tons in 1970 (6 percent of total), and were about 52,000 tons in 1986, or 24 percent of total lead. These discards are projected to be 84,000 tons, or 30 percent of total, in 2000 if present trends continue. Finally, many steel chassis in television sets and radios were coated with terne metal (a lead and tin,alloy) up until 1980. This has never been a major source of lead in MSW (less than one percent), and is projected to disappear as old television sets are phased out. It is of interest to note that in 1986, lead-acid batteries and lead in consumer electronics together accounted for 92 percent of lead discards in MSW. Glass and Ceramic Products. It was possible to quantify lead in glass in television picture tubes and light bulbs separately (Chapter 2). Lead discards in the remaining products in MSW were quantified in total, but it was not possible to determine separate end uses of the lead. This category of discarded products includes glass containers for food, beverages, and miscellaneous products such as cosmetics; glass and ceramic tableware and cookware; mirrors; optical glasses; electronic products; enamels for appliances and other uses; and miscellaneous decorative and other uses. The major uses of leaded glass are in television picture tubes and light bulbs, as described elsewhere. Other uses of leaded glass include tableware and bifocal lenses in reading glasses. Lead is a component in glazes and enamels used on glass containers, tableware, and cookware. Enamels used in silk screening designs on glass typically contain 40 to 50 percent lead monoxide. Lead is also used as a colorant in some of these designs. These discards ranked Number 3 in 1986 at almost 8,000 tons and almost 4 percent ,of total lead discards. In 1970 lead use in these glass products ranked Number 6 at 3,500 tons and 2 percent of total. This use is projected to grow to 9,000 tons in 2000, or 3 percent of the total. 21 ------- Plastics.* Discards of lead in plastic products did not rank in the top six sources in 1970, but in 1986 plastics ranked fourth, and this is projected to continue (Table 1-4). Lead is used in two ways in plastics: as a component in compounds designed to act as heat stabilizers, primarily in polyvinyl resins, and as a component in pigments used in a variety of plastic resins. Discards of lead in plastic products has been growing, but this source contributes a small portion of the total (Figure 1-3). In 1970 lead in plastic discards contributed 1,600 tons, about one percent of the total. In 1986 lead in plastics comprised about 3,500 tons, less than 2 percent of total. Projections to 2000 show about 3,200 tons of lead in plastics being discarded, slightly more than one percent of total. The projected decline is attributed to regulations on lead in certain products, such as toys and furniture. Discards of lead in products made of plastics ranked as follows in 1986: nonfood packaging (highest tonnage), miscellaneous durables, furniture, miscellaneous nondurables, footwear, records, toys, housewares, appliances, and others. Soldered Cans. In 1970, lead in solder .in cans and shipping containers represented the Number 3 discard into MSW, but by 1986 this was the Number 5 source of discards (Table 1-4). The use of leaded solder in steel food cans has declined dramatically, and soldered steel beverage cans have virtually disappeared. Use of leaded solder in general purpose cans, such as aerosols, and in shipping containers has also declined. Figure 1-3 illustrates this decline. Discards of lead in soldered cans were 24,000 tons, or over 14 percent of total discards, in 1970. In 1986, only 2,000 tons of lead were discarded in soldered cans, representing less than one percent of total. These discards are projected to be about 800 tons, much less than one percent of total, in 2000. Pigments. Discards of pigments in plastics, glass, and rubber are discussed in other sections. The remaining pigments--those used in paints, printing inks, textile dyes, and miscellaneous uses--are included in this section. These pigments ranked second in discards of lead into MSW in 1970, but they are ranked Number 6 in 1986 (Table 1-4). As illustrated in Figure 1- 3, use of lead in pigments has been in decline, in large part due to concerns about toxicity. Discards of lead in printing inks, once an important source of lead, have declined dramatically, from 19,000 tons in 1970 to less than 300 tons' in 1986.' -Use of lead in many kinds of paint has been regulated, also leading to a decline in consumption. * Plastics in consumer electronics are counted in that category. 22 ------- Total discards of lead in these pigments was 30,000 tons in 1970, or 16 percent of total lead discards. This had declined to about 1,200 tons in 1986--less than one percent of total. The decline is projected to continue, to about 700 tons in 2000, much less than one percent of the total. Light Bulbs. Light bulbs are not a large source of lead in MSW, but are of interest because they contain two sources of lead: solder and leaded glass. While not ranked in the top six sources of lead in MSW in 1986, light bulbs are projected to be the Number 5 source in 2000 (Table 1-4). In 1970 lead discarded into MSW from light bulbs was estimated to be about 600 tons, less than one percent of the total. By 1986 these discards were over 900 tons; by 2000, over 1,000 tons. The percentage of total is not projected to be over one percent in any case. Collapsible Tubes. Collapsible tubes made of lead are used for products such as artists' paints. These tubes represented the Number 5 source of lead in MSW in 1970 (Table 1-4), at over 9,000 tons and over 5 percent of total discards. By 1986, however, collapsible tubes contributed only about 600 tons, less than one percent of the total. The decline is projected to continue, to only 200 tons in 2000. Brass and Bronze Products. Lead is a component of some brass and bronze products, although most of these applications are not discarded into MSW. Brass and bronze items that may be discarded into MSW include locks, keys, and miscellaneous products such as clock and watch parts, musical instruments, etc. Discards of lead in brass and bronze products are a very small part of total lead discards, estimated to be less than 500 tons per year since 1970 and declining. Foil Wine Wrappers. Lead foil wine wrappers are used to cover the corks on some wine bottles, although aluminum foil is replacing lead in many instances. Discards of. lead from this source are estimated to have declined from about 600 tons in 1970 to about 200 tons in 1986, with a continued decline to about 60 tons in 2000. Used Oil. Gasoline additives were formerly an important use of lead before the phase-out due to regulatory action began. Some of the lead from the additives enters used automotive oil, as does some lead from other sources such as engine wear. It was estimated that about 1,500 tons of lead in used oil entered MSW in 1970, almost one percent of total discards. By 1986 this had decreased to less than 200 tons, and by 2000, lead in used oil is proj ected to be only 36 .tons. Rubber Products. Most of the lead consumed by the rubber industry is used in products like lead-sheathed hose that do not enter MSW. It was estimated that 100 tons or less of lead enters MSW in rubber products each year. About 50 tons Of lead in rubber were discarded in 1970; about 70 tons in 1986; and a projected 80 tons in 2000. 23 ------- Cadmium in MSW Discards of cadmium in products in MSW from 1970 to 2000 are summarized in Tables 1-5 and 1-6. Tables 1-7 and 1-8 show how products discarded into MSW rank in their contributions of cadmium. A perspective on the changing importance of the various sources of cadmium is shown in Figure 1-4. Products containing cadmium in MSW are discussed below in order of the relative rankings in 1986 (Table 1-7). (More details on these products are contained in Chapter 3.) Household Batteries. Household batteries (primarily rechargeable nickel-cadmium batteries) have been the Number 1 source of cadmium in MSW since 1980 (Table 1-8). Their growth has been rapid--they were the Number 5 source of cadmium in 1970. Nickel-cadmium (Ni-Cd) batteries have become very popular for uses such as portable hand tools, small appliances such as vacuum cleaners and mixers, portable television sets, cameras, etc. In 1970 discards of cadmium in household batteries were estimated at 53 tons, or 4 percent of total cadmium discards. By 1986 this number was 930 tons, or 52 percent of the total. If this growth continues as projected, discards in 2000 will be over 2,000 tons, or 76 percent of total (Figure 1-4). Plastics. Plastics have ranked second only to household batteries as a source of cadmium in MSW since 1980 (Table 1-8). Like lead, cadmium is used as a stabilizer in polyvinyl chloride resin and as a pigment in a variety of resins. Discards of cadmium in plastics were 342 tons in 1970, or almost 29 percent of the total cadmium discards. Cadmium in plastics peaked at 595 tons in 1978 (38 percent of total discards), then generally declined to 502 tons in 1986 (28 percent of total discards). Projected discards are 384 tons in 2000, or 14 percent of total (Figure 1-4). The decline is generally attributed to concern over toxicity and regulations on the use of cadmium in products like toys and furniture. In 1986, plastic products containing cadmium in discards ranked as follows: nonfood packaging (highest tonnage), miscellaneous durables, miscellaneous nondurables, furniture, toys, records, footwear, and others. It is of interest to note that household batteries and plastics combined accounted for 80 percent of cadmium discards into MSW in 1986. Consumer Electronics. Discards of cadmium-plated chassis in radios and television sets gave consumer electronics the Number 3 ranking in cadmium discards in 1986. This is a declining source of cadmium discards, however, ranking Number 1 in 1970 and Number 4 in 2000 (Table 1-8 and Figure 1-3). Cadmium was formerly used to plate the chassis or steel sheet that holds electronic parts of the radio or TV together. By 1980 this technology has been replaced by printed circuit boards, so this source of cadmium is declining as older equipment is replaced. 24 ------- Produces 1970 Table 1-5 DISCARDS* OF CADMIUM IN PRODUCTS IN THE MUNICIPAL WASTE STREAM. 1970 to 2000 " "~~~(In short tons) 1975 1980 1985 1986 1990 1995 2000 to Ul APPLIANCES Cadmium plating Plastics Subtotal - appliances CONSUMER ELECTRONICS Cadmium plating Plastics Subtotal - consumer Icctronlcs GLASS AND CERAMIC PROOUGTS HOUSEHOLD BATTERIES Nickel-cadmium batteries Dry cell casings c.,|,( gen I-lioiisuliold bnttorles PIGMENTS** PLASTICS* Nonfood packaging Clothing Footwear Miscellaneous nondurables " Subtotal-nondurable? Houseuares Toys Records Luggage Furniture Miscellaneous durables Subtotal-durables Subtotal-plastics RUBBER PRODUCTS** USED OIL MISCELLANEOUS PRODUCTS Electric blankets and heating pads 47 60 107 571 0 571 32 51 2 51 79 209 15 19 11 254 19 34 12 5 10 8 88 342 10 1 39 52 91 330 0 330 27 209 2 211 65 133 36 70 13 252 56 109 21 6 18 21 231 483 13 1 32 77 109 176 0 176 23 996 2 998 56 128 8 31 37 204 33 53 65 9 77 15 252 456 8 1 25 54 79 158 0 158 25 996 3 999 59 139 2 27 43 211 21 32 22 5 35 73 188 399 24 64 88 161 0 161 29 927 3 930 70 166 2 21 51 240 31 44 29 9 46 103 262 502 6 1 GRAND TOTAL 1.196 1,222 1.828 1 1.727 1,788 19 38 57 101 36 137 32 1,305 3 1,300 78 150 2 21 46 219 20 34 12 7 23 78 174 393 8 1 1 2,015 12 46 58 67 41 108 34 1,709 3 85 150 2 21 46 219 22 3} 7 6 11 82 161 380 9 1 1 2,388 9 48 57 20 47 67 37 2.032 3 2,035 93 ISO 2 21 46 219 22 33 a 7 1) 82 16! 384 9 I 1 2.634 * Discards after recycling. ** Except for pigments in glass, plastics, and rubber. + Except for plastics in appliances and consumer electronics. ** Assumed to be all nontire products. ------- Table 1-6 DISCARDS* OF CADHIIIH IH PRODUCTS TH TIIE HUDTCIPAt WASTE STREAK. (In percent of total cudalun discards) 1970 TO 2000 to APPLIANCES Cadnlun placing Plastics Subtotal-appliances CONSUMER ELECTRONICS Cadmium placing Plastics Subtotal-consumer electronics CLASS AND CERAMIC PRODUCTS HOUSEHOLD BATTERIES Nickel-cadmium baccerles Dry cell casings Subtotal-household baccerlea PIGMENTS** PLASTICS+ Nonfood packaging Clothing Footwear Miscellaneous nondurables Subcotal-nondurables Houseuares Toys Records Luggage Furniture Miscellaneous durables Subtotal-durables Subtotal-plastics RUBBER PRODUCTS-H- USED OIL MISCELLANEOUS PRODUCTS Electric blankets and heating pads GRAND TOTAL 1970 3.9 5.0 S.9 47.7 0.0 47.7 2.7 4.3 0.2 4.4 6.6 17.5 1.3 1.6 0.9 21.2 1.6 2.8 1.0 0.4 0.8 0.7 7.4 28.6 0.8 0.1 0.1 100,0 1975 3.2 4.3 7.4 27.0 0.0 27.0 2.2 17.1 0.2 17.3 5.3 10.9 2.9 5.7 1.1 20.6 4.6 8.9 1.7 0.5 1.5 1.7 18.9 39.5 1.1 0.1 0.1 100.0 1980 1.8 4.2 6.0 9.6 0.0 9.6 1.3 54.5 0.1 54.6 3.1 7.0 0.4 1.7 2.0 11.2 1.8 2.9 3.6 0.5 4.2 0.8 13.8 24.9 0.4 0.1 0.1 100.0 1985 1.4 3.1 4.6 9.1 0.0 9.1 1.4 57.7 0.2 57.8 3.4 8.0 0.1 1.6 2.5 12.2 1.2 1.9 1.3 0.3 2.0 4.2 10.9 23.1 0.3 0.1 0.1 100.0 1986 1 J 3.6 4.9 9.0 0.0 9.0 1.6 51.8 0.2 52.0 3.9 9.3 0.1 1.2 2.9 13.4 1.7 2.5 1.6 0.5 2.6 5J8 14.7 28.1 0.3 0.1 0.1 100.0 1990 0.9 1.9 2.8 5.0 1.8 6.8 1.6 64.8 0.1 64.9 3.9 7.4 0.1 1.0 2.3 10.9 1.0 1.7 0.6 0.3 1.1 3.9 8.6 19.5 0.4 0.0 0.0 100.0 1995 0.3 1.8 2.1 0.7 1.8 2.5 1.4 75.7 0.1 75.8 3.5 5.6 0.1 0.8 1.7 8.2 0.8 1.2 0.3 0.3 0.5 3.1 6.1 14.3 0.3 0.0 0.0 100.0 2000 0.3 i.a 2.1 0.7 1.8 2.5 1.4 75.7 0.1 75.8 3.5 5.6 0.1 0.8 1.7 8.2 0.8 1.2 0.3 0.3 0.5 3.1 6.1 14.3 0.3 0.0 0.0 100.0 * Discards afcer recycling. ** Except for pigments in glass, plastics and rubber. + Except for plastics in appliances and consumer electronics. H- Assumed to be all non-tire products. ------- Table 1-7 DISCARDS* OF CADMIUM -IN PRODUCTS IN THE MUNICIPAL WASTE STREAM. 1986 RANKED IN ORDER OF- WEIGHT OF CADMIUM (in short tons and percent of total) Products Short Tons HOUSEHOLD BATTERIES Nickel-cadmium batteries ' 927 Drycell casings 3 Subtotal-household bcrteries 930 PLASTICS** Nonfood packaging 166 Clothing 2 Footwear , 21 Miscellaneous nondurables 51 Subtotal-nondurables . 240 Housewares 31 Toys 44 Records 29 Luggage 9 Furniture 46 Miscellaneous durables - 103 Subtotal-durables 262 Subtotal-plastics 502 CONSUMER ELECTRONICS Cadmium plating 161 APPLIANCES ; Cadmium plating 24 Plastics 64 Subtotal-appliances 88 PIGMENTS+ . 70 GLASS AND CERAMIC PRODUCTS 29 RUBBER PRODUCTS-H- ," 6 USED OIL 1, MISCELLANEOUS PRODUCTS ' , Electric blankets and heating pads 1 GRAND TOTAL 1,788 Percent 51.8 0.2 52.0 9.3 0.1 . 1.2 2.9 13.4> 1.7 2.5 1.6 0.5 2.6 5.8 14.7 28.1 9.0 1.3 3.6. 4.9 3.9 1.6 0.3 0.1 0..1 100.0 * Discards after recycling. ** Except for plastics in appliances. + Except for pigments in glass, plastics, -H- Assumed to be all non-tire products. and rubber. 27 ------- Table 1-8 SOURCES OF CADMIUM IN MSW. RANKED BYTONNAGE, 1970TO 2000 RANK^^ ^x^YEAR No. 1 No. 2 No. 3 No. 4 No. 5 1970 Consumer Electronics Plastics Appliances Pigments Household Batteries 1975 Plastics Consumer Electronics Household Batteries Appliances Pigments 1960 Household Batteries Plastics Consumer Electronics Appliances Pigments 1966 Household Batteries Plastics Consumer Electronics Appliances Pigments 1990 Household Batteries Plastics Consumer Electronics Pigments Appliances 1995 Household Batteries Plastics Consumer Electronics Pigments Appliances 2000 Household Batteries Plastics Pigments Consumer . Electronics Appliances 1-0 00 Consumer Electronics primarily Includes cadmium plating on televisions and radios, plus some plastics In later years. Plastics include all plastic uses except for appliances and consumer electronics. Appliances primarily include cadmium plating in.dishwashers and washing machines and plastics. Pigments includes pigments in paints. Inks, and dyes, but not those in glass, plastics and rubber. Household Batteries are primarily rechargeable nickel-cadmium household batteries. ------- Figure 1-4. Cadmium in discards of products in MSW, 1970, 1986 and 2000. Year 1986 IS 1 500 1,000 1,500 2,000 2,500 All others D Pigments E2 Appliances Electronics E3 Plastics M Batteries 3,000 Tons 29 ------- In 1970, cadmium discards in consumer electronics were estimated at 571 tons, or 48 percent of total discards. By 1986, these discards were 161 tons, or 9 percent of total; projected 2000 discards are 67 tons, or 2.5 percent of total. Appliances. There are two potential sources of cadmium in discarded appliances: cadmium plating and plastics. Appliances ranked Number 4 in cadmium discards in 1986, but are projected to drop to Number 5 by 1990 (Table 1-8). Cadmium was formerly used to plate nuts, bolts, and screws in dishwashers and washing machines because of cadmium's corrosion-resistant properties. As more appliance parts are made of plastic, however, the use of cadmium plating has been phased out. Appliances contributed an estimated 107 tons of cadmium to MSW in 1970, or 9 percent of the total. By 1986, these discards had declined to 88 tons, 5 percent of total. A continued decline is projected, to 57 tons, or 2 percent, in 2000. Pigments. Cadmium in pigments in glass, plastics, and rubber is discussed in other sections. It was not possible to quantify the amounts of cadmium in other individual uses such as printing inks, textile dyes, and paints; these categories are discussed collectively in this section. These pigments ranked Number 5 in discards in 1986 (Table 1-8). Discards of cadmium in pigments have been relatively constant over the study period (Figure 1-4). In 1970, discards were an estimated 79 tons, or about 7 percent of total discards of cadmium. In 1986, discards were 70 tons, or 4 percent of total. By 2000, projected discards will be 93 tons, or just over 3 percent of total. Glass and Ceramic Products. There are three uses for cadmium in glass and ceramic products: as a pigment in the glass, as a glaze for glass or ceramic products, and as a phosphor, e.g., in fluorescent tubes. Glass and ceramic products account for a relatively minor portion of cadmium discards in MSW. In 1970, 32 tons, or less than 3 percent of total, were discarded. In 1986, 29 tons, or less than 2 percent of total, were discarded. In 2000, it is estimated that 37 tons, or less than 2 percent of total, will be discarded. Rubber Products. Small amounts of cadmium are used in non-tire rubber products such as hose and hot water bottles. This is a very minor source of cadmium in MSW. An estimated 10 tons of cadmium were discarded in rubber products in 1970, less than one percent of the total. In 1986, an estimated 6 tons were discarded, again less than one percent. In 2000, discards of 9 tons of cadmium in rubber products are projected, less than one percent of the total. 30 ------- Used Oil. Studies have shown that small amounts of cadmium are detected in used automotive oil. It was therefore estimated that one ton of cadmium per year is discarded into MSW with used oil. This may overstate these discards. Miscellaneous Uses. Cadmium is used in very minor amounts in the controls of electric blankets and heating pads. It was estimated that one ton of cadmium is discarded in these products each year. This may overstate these discards. PRODUCTS CONTAINING BOTH LEAD AND CADMIUM Throughout this report, estimates of lead and cadmium discards in products have been made separately. There are a number of products, however, that may often contain both metals in varying amounts. Table 1-9 presents a listing of these products in 1986. Those quantified include consumer electronics, glass and ceramic products, plastics, pigments, rubber products, and used oil. In addition, there are other products not quantified in Table 1-9 that may contain both lead and cadmium. It is projected, for example, that some consumer electronics discarded after 1986 will include plastics 'that may- contain lead or cadmium. Appliances are not listed here, but they may contain pigments formulated with cadmium or lead. Many products, especially packaging, are made of composite materials, e.g., paper, plastic, and foil, that could contain lead or cadmium in pigments. It is very difficult, therefore, to predict whether some products do or do not contain lead and/or cadmium. LEAD AND CADMIUM IN COMBUSTIBLE AND NONCOMBUSTIBLE PRODUCTS There has been considerable speculation as to whether the heavy metals in municipal waste combustor ash come from combustible or noncombustible materials (or both) in the incoming waste. While this'study was not designed to address this issue directly, some interesting observations can be derived from the data series developed. Lead in Combustible and Noncombustible Products The relative tonnages of lead in combustible and noncombustible products in MSW are shown in Figure 1-5. The noncombustible products overwhelmingly predominate at almost 98 percent of the total weight of lead. The reasons for this are illustrated in Figure 1-6: lead-acid batteries and consumer electronics, two relatively heavy products, contribute most of the lead in MSW. Glass products and all other sources, e.g., light bulbs and soldered cans, account for the rest of the lead. Sources of lead in combustible products in MSW are illustrated in Figure 1-7. If all of the noncombustible products were removed from the incoming waste at an .incinerator (by deposits, preprocessing, or other management methods), most of the remaining lead (71 percent) would be 31 ------- Table 1-9 PRODUCTS CONTAINING BOTH LEAD AND CADMIUM. 1986 (In short tons) Products CONSUMER ELECTRONICS Circuit boards TV picture tubes TV and radio chassis Cadmium plating Subtotal - consumer electronics GLASS AND CERAMIC PRODUCTS PLASTICS Nondurables Durables Subtotal - plastics PIGMENTS RUBBER PRODUCTS Tires Non-tire products Subtotal - rubber products USED OIL Lead 6,092 52,165 279 58,536 7,956 1,678 1.899 3,577 1,131 48 21 69 192 Cadmium _24 24 29 240 262 502 70 _6 6 1 32 ------- Figure 1-5. Relative discards of lead in combustible and noncombustible products, 1986. Combustibles 2.4% V^ "% <.-. ff > < % Noncombustiblesli"" '" 33 ------- Figure 1-6. Sources of lead in noncombustible products, 1986 Glass 3.8% . ^ All Other 2.0% Consumer Electronics Figure 1-7. Sources of lead in combustible products, 1986. Used Oil 3.85% Rubber 1.4% 34 ------- contained in plastic products. , Other pigments in painted products or products such as printed paper and dyed textiles would account for most of the rest (24 percent). Other small contributors of lead include used oil and rubber products. Cadmium in Combustible and Noncombustible Products Noncombustible products also contribute the majority of cadmium in MSW (64 percent), but not in such overwhelming amounts as is the case for lead (Figure 1-8). The primary source of cadmium in noncombustible products is household (nickel-cadmium) batteries (81 percent). Figure 1-9 also illustrates that consumer electronics contribute the second highest amount of cadmium in noncombustible products (14 percent). The remainder is contributed by appliances and other products (e.g., electric blankets and heating pads). If all the cadmium in noncombustible sources, were removed from MSW entering an incinerator, the cadmium in plastics would provide most of the remainder (88 percent). This is illustrated in Figure 1-10. Pigments in painted products, printed paper, and dyed textiles would contribute most of the remainder of the cadmium (11 percent). Very small amounts would come from rubber products and used oil in MSW. Lead and Cadmium in Combustible and Noncombustible Products The data reported above can be combined in another way to show the relative discards of lead and cadmium in combustible and noncombustible products. Combined discards of lead and cadmium in noncombustible products come overwhelmingly from the lead in products (Figure 1-11). For both, metals the primary source in this instance is batteries. For combined discards of lead and cadmium in combustible products, lead still predominates, but not by such an overwhelming margin (Figure 1-12). Lead contributes almost 89 percent of these discards; cadmium, 11 percent. For both lead and cadmium, plastic products contribute the highest tonnage in combustible products, while pigments in other products are the second largest contributor. THE .POTENTIAL EFFECTS OF RECYCLING Lead-acid Batteries Recycling has been suggested as a way to reduce the amounts of . lead and cadmium entering municipal waste combustors. Only one of the lead or cadmium-containing products currently identified is recycled in significant amounts: lead-acid SLI batteries. This one product is extremely significant. As noted earlier, lead-acid batteries contributed 65 percent of the lead discards in MSW in 1986--138,000 tons. If these batteries were not recovered for recycling at significant rates (80 percent in 1986), up to 700,000 35 ------- Figure 1-8. Relative discards of cadmium in combustible and noncombustible products, 1986. 36 ------- Figure 1-9. Sources of cadmium in noncombustible products, 1986. Appliances 2.5% All Others 2.2% Consumer Electronics 14.1% Figure 1-10. Sources of cadmium in combustible products, 1986. Rubber and Oil 1.1% 37 ------- Figure 1-11. Relative discards of lead and cadmium in noncombustible products in MSW, 1986. Cadmium 0.5% Figure 1-12. Relative discards of lead and cadmium in combustible products in MSW, 1986. 38 ------- additional tons of lead from lead-acid batteries would have been discarded in 1986. Historic discards and recycling of lead-acid batteries are illustrated in Figure 1-13. Recycling rates dropped as low as 52 percent in the early 1980s (apparently due to low prices for lead and increased regulations), and the figure illustrates that net quantities of batteries to be disposed increased at that time. Recycling obviously plays an important role in management of these batteries. Other Products No other recycling of lead or cadmium in products in MSW was identified, although there may be some small exports of nickel-cadmium batteries for recycling abroad. Some recycling of products in MSW that removes lead and cadmium from disposal in a landfill or incinerator as a by- product rather than as a goal of the recycling activity was identified.* These activities are discussed briefly in this section. (More information can be found in Chapters 2 and 3.) Paper Products. A number of paper products are recovered for recycling, including some that are printed with inks that could contain lead or cadmium in the pigments. In many cases, such as newspapers made into boxboard or magazines made into roofing felt, the' inks tend to remain in the recycled product. Some paper products are, however, deinked before being recycled into new products. These include recovered newspapers that are deinked before being made into new newsprint, and high grade recovered papers like computer printout that are deinked before being made into a product like paper towels. It was estimated that up to 49 tons of lead in printing inks could have been removed by recjrcling of deinked papers in 1986. Since use of lead in printing inks was shown to be declining, removal of lead would also be declining. Data were not available to make similar estimates for cadmium in printing inks. Solder in Cans. The lead in soldered steel cans is removed from the municipal waste stream when the cans are recovered for recycling, though the lead itself is not recycled, but would become an industrial waste. It was estimated that 85 tons of lead were removed through recovery and recycling of steel cans in 1986. Since the use of leaded solder in steel cans is declining, removal of lead in this manner is also declining. Rubber Products. Although rubber is not recovered for recycling in large quantities, some recycling of rubber tires does occur. This has the potential to remove from the waste stream any lead pigments or other chemicals present in the rubber. It was estimated that 3 tons of lead were removed from * Lead or cadmium in these recycled products would either be incorporated into the new products or would become industrial waste, e.g., sludges from deinking papers. .39 ------- Figure 1-13. Discards of lead in SLI lead-acid batteries, 1970 to 2000. Tons 1,000,000 900,000- 800,000- 700,000- 600,000- 500,000- 400,000 300,000 200,000 100,000 0 1970 1975 1980 1985 1990 1995 2000 40 ------- the waste stream in this manner in 1986. Since all cadmium in rubber was assumed to be in non-tire products, no recovery of cadmium was estimated. Appliances. There is cadmium plating in older model dishwashers and washing machines. If the ferrous metal in these appliances is recovered for recycling, the cadmium is removed from the waste stream as well. It was estimated that 2 tons of cadmium were removed in this way in 1986. This is a declining source of cadmium in the waste stream. Glass Products. Although it was not possible to quantify, there are silk-screened designs that may contain lead and/or cadmium on many glass containers. Many glass containers are recycled, so some lead and cadmium is removed from the waste stream in this manner. Plastics. Recycling of plastics in the United States has been minimal; it was estimated to be one percent in 1986. Further, most of the plastic products recycled under existing programs have been polyethylene terephthalate (PET) beverage bottles or high-density polyethylene (HOPE) milk jugs. Since lead and cadmium are not approved for use in food-contact packaging, the metals would not be affected by this recycling. There is an increasing amount of recycling of other plastic products, however, so some lead and cadmium may be removed from the waste stream in this manner, now or in the future. Summary. Although precise estimates are not possible, probably not more than one to 2 percent of lead in MSW (exclusive of lead in batteries) is currently removed by recycling activities. The amount of cadmium affected by recycling is even smaller. LIMITATIONS OF THIS REPORT While this report contains useful data on discards of lead and cadmium in municipal solid waste, there are a number of limitations in its application to the issue of lead and cadmium in municipal waste combustor ash. Some of these limitations are discussed in this section. Correlation of Characterization Data with Leachable Metals in Ash The purpose of this report was to characterize the sources of lead and cadmium in municipal solid waste. It is beyond the scope of this study to identify the sources of leachable lead and cadmium in municipal waste combustor ash. Correlation of Characterization Data with Individual Samples of Ash This report contains data characterizing the lead and cadmium content of products defined as constituents of municipal solid waste. This characterization may not correlate well with the input into any particular combustion facility at the time ash samples were taken. Management practices vary widely at municipal waste combustor (MWC) facilities depending on many factors. If the waste was pre-processed 41 ------- before combustion, then many of the noncombustible materials that may contain lead or cadmium were probably removed. Facility management also varies as to whether large items such as appliances and furniture are excluded, and these items are likely sources of heavy metals. If a facility has a small capacity and small quantities of waste are handled at any given time, then the opportunity to remove large noncombustible products is more frequent. There are also differences among facilities as to the mixtures of residential and commercial wastes handled, with some facilities processing almost exclusively one or the other. Effects of the Combustion Process on Ash Characteristics This report characterized lead and cadmium in products that may enter an incinerator. Whether the metals leave the incinerator in the same form that they enter is unknown. For example, lead monoxide (PbO) is a very common compound used in many products--glass, batteries, pigments, etc. The melting point of lead monoxide is 1,630 degrees Fahrenheit, well within the range of most municipal waste combustors. It is not known whether the PbO would recombine with other elements in the MWC to form new lead compounds, but it seems highly likely. Lead and Cadmium in Other Wastes This study was specifically designed to characterize lead and cadmium in municipal solid waste. There are instances, however, when incinerators that burn primarily MSW may receive and burn other wastes that may contain these metals. While it was not possible in this report to quantify the amounts of those wastes, nor to characterize them in terms of lead and cadmium content, some data were gathered in the course of this study that indicate where lead and cadmium may occur in some other wastes (Table 1- 10). This partial listing illustrates the problems involved in identifying the sources of lead and cadmium in the ash from municipal waste combustors. 42 ------- Table 1-10 WASTES OTHER THAN MSW THAT MAY CONTAIN LEAD AND CADMIUM Nonhazardous Wastes Possible Sources of Lead and Cadmium Municipal sludge Construction and demolition wastes Industrial and military wastes Automotive and other transportation wastes Lead pipes, lead solder Siding Wall and ceiling tile Structural steel Polyvinyl chloride (PVC) pipe Wire and cable coverings Gutters and downspouts. Conduit Wallcoverings Plumbing fittings and hardware Pipes and solder Light fixtures Neon tubing Some window glass Enameled building panels Flooring materials Paint (especially older houses) Caulking Conveyor belts Industrial and military batteries Industrial and military electronics Communications equipment Electrical machinery Storage tanks Hosing Automotive finishes * Upholstery and trim Auto tops Mufflers 43 ------- Chapter 1 REFERENCES 1. U.S. EPA, Office of Solid Waste. Characterization of Municipal Waste Combustor Ashes and Leachates from Municipal Solid Waste Landfills. Monofills and Co-disposal Sites. .November 1987. , . . 2. U.S. EPA, Office of Solid Waste., Subtitle D Study. Phase I Report. (EPA/530-SW-86-054). October 1986. 3. Smith, F. L., Jr. A Solid Waste Estimation Procedure: Material Flows Approach. U.S. EPA, Office of Solid Waste. (SW-147). May 1975. 44 ------- ------- &EPA (.03-305) United States Environmental Protection Agency Washington, DC 20460 Official Business Penalty for Private Use S300 ------- |