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.
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-------
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
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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
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* 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.
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* 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:
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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
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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.
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Figure 1-2. Relative discards .of lead and cadmium in MSW, 1986.
Cadmium 1,788 tons
14
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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&EPA
(.03-305)
United States
Environmental Protection
Agency
Washington, DC 20460
Official Business
Penalty for Private Use
S300
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