Heavy metal
content of
newspapers
47
Environmental Management and Health, Vol. 11 No. 1, 2000, pp. 47-66.#MCB University Press, 0956-6163
P. Tucker, P. Douglas, A. Durrant and A.S. Hursthouse
Department of Chemistry and Chemical Engineering,University of Paisley, Paisley, Scotland, UK
Keywords Newspaper, Heavy metals, Copper, Ink, Colour
Abstract Examines whether there are any environmental or health implications associated with the increased use of colour in newspapers, if the newspapers are reused or recycled. New heavy metal analyses of UK daily newspapers from 1992, 1996 and 1998 are reported. Lead, mercury and cadmium were found to be below their measurement detection limits (4ppm, 5ppm and 1ppm respectively) in nearly all samples. Barium and total chromium levels were highest in supplements printed on ``glossy'' paper. Copper was present at levels around 20-30ppm in the standard newsprint sections and at levels of 80ppm or more in the supplements. Copper concentrations increased by 33-40 per cent between 1992 and 1998 which correlated well with the increased colour content. A scientific appraisal and review showed that the heavy metal contents of newspapers are highly unlikely to pose any environmental risk or to have any health implications.
Introduction
Old newspapers are a major target of strategies for recycling or reusing greater percentages of the domestic waste stream. Its uses in applications such as animal bedding and home composting are being explored increasingly, and increased recovery for recycling into new paper is being advocated. Recycling printed paper, however, generates a de-inking sludge as a waste or by-product. One of the options for disposal of the by-product is through land-spreading. In considering all these applications, it is important to ascertain whether there are any potential health or environmental implications associated with returning old newspapers (or their residues) back into the environment. In the past, concern was expressed about the levels of heavy metals in printers' inks, though nowadays both industry and environmental organisations agree that these may no longer be a problem (e.g.Caractere, 1991; Endriss, 1993; Grund, 1994; Friends of the Earth, 1997).
There are, however, relatively few published scientific analyses of the heavy metal contents of actual newspaper which can be cited to fully substantiate these claims. Major analyses of the newspaper components of the domestic waste stream were undertaken in the UK in 1992 and 1993, though as far as the authors are aware, these have not been repeated in the UK since. The period
The research register for this journal is available at http://www.mcbup.com/research_registers/emh.asp
The current issue and full text archive of this journal is available at http://www.emerald-library.com
EMH
11,1
48
1992 to 1998, however, has seen significant increases in the amount of coloured inks used in newspaper publishing. The environmental and health implications of this change have not yet been addressed in the UK and it is important, if only for reassurance, to consider any possible issues that may be raised. This paper reports a recent scientific study of the heavy metal contents of UK newspapers undertaken from 1992, 1996 and 1998 and examines the longitudinal trends in these data, and the implications resulting from the increasing use of colour.
Heavy metal concentrations and possible sources
Previously published analyses of the heavy metals content of newspapers and magazines are summarised in Table I. These data were measured variously between 1977 and 1995 (see Table I footnote for reference list). Because of the different sample bases, the data are not directly comparable, but nevertheless provide indications of the most significant metal species present in the printed papers. Lead and chromium levels above 20ppm have not been detected since 1992. This results from the now almost universal replacement of lead and chromium pigments from news and magazine inks. Mercury and cadmium levels have remained very low throughout, rarely exceeding 1ppm. Zinc concentrations show much wider variations with no obvious trend or degree of consistency between analyses. Copper concentrations also show significant concentration ranges amongst the analyses, ranging from around 2ppm (for black and white sections of newspaper) to over 140ppm (for ``blue'' printed extracts). Whole newspapers, unsorted by colour, variously returned copper concentrations between 14 and 50ppm.
Heavy
metal
content
of
newspapers
49
Table
I.
Published
metal
contents
of
newspapers
and
magazines
(1977-1995)
Concentrations (ppm)
Ref. Material Fraction Country Year Ag Ba Cd Cr Cu Hg Mn Ni Pb Sn Zn
1 Newspaper and mags Coloured US 1977 333 0.05 94 20 7.8 3.0 514 240 100
2 Newsprint ± Canada 1982 0.18 14 0.015 0.65 37
3 Newsprint ± Germany 1988 15 24
Magazines ± 37 69
4 Daily newspaper Colour headlines US 1989-91 0.1 0 101 0 1 4 1
Black and white 0 0 2 0 1 4 0
5 Centre Daily Times Glossy ad (mixed) 0.1 1 114 0 5 10 14
Glossy ad (blue) 0.2 1 141 0 7 10 14
Centre Daily Times Blue headlines 0.1 0 101 0 1 4 1
Black and white 0.0 0 2 0 1 4 0
Collegian Black pictures 0.2 1 3 0 2 5 3
Black and white 0.1 1 2 0 1 4 8
USA Today Mixed colours 0.3 1 53 0 1 3 9
Blue 0.4 1 132 0 2 2 12
Black and white 0.4 1 2 0 1.5 3 19
6 Detroit News ± US 1991 54 33.6 183
7 Newspaper Primarily black and white
US 1992 0.68 17.2 ND 2.1
8 Newsprint Glued Canada 1992? 9.3 0.1 1.3 10 0.3 19.5 4.3 2.4 18 8
Black and white 18.4 0.1 3.8 13 2.9 45.0 6.2 7.2 24 19
Colour 23.2 0.1 215 36 0.3 81.9 106 5.7 25 29
Magazines Glued 24.2 0.001 16.6 26 0.3 50.9 17.6 0.4 36 36
Not glued 36.9 0.3 5.8 37 0.3 50.9 8.2 5.9 31 18
10 Newspaper ± #1 UK 1992 3.79 0.3 25.6 17.25 0.03 40.9 10.9 89.4 23.1
Magazines ± #2 2.3 0.39 30.3 55.8 0.02 37.2 22.6 15.6 74.4
Newspaper ± #3 1993 0.15 0.33 4.12 17.7 0.05 55.5 2.13 7.88 18.2
Magazines ± #4 0.38 1.83 21.5 56.7 0.06 35.3 11.5 11.7 66.0
9 National newspapers ± Eire 1995 ND 1.35 1.954 ND 1.35 0.48 11.9
Notes:ND = Not detected; # ``as received'' moisture contents = 25.67 per cent (1), 12.76 per cent (2), 25.46 per cent (3), 9.93 per cent (4); other results refer to dry weight or moisture content not stated
EMH
11,1
50
Table
II.
Metal
contents
of
newspapers
and
magazines
(1996)
Concentrations (ppm)
Material Fraction Country Year Ag Ba Cd Cr Cu Hg Mn Ni Pb Sn Zn
Unprinted newsprint
(5 samples) ± Various 1996 <0.2 24.9 <0.2 1.4 1.3 <5 47.2 <0.7 <4 <3 8.3
56national newspapers
(printed on same paper)
Standard newsprint
fraction only UK 1995-96 <0.2 14.8 <0.2 2.3 21.3 <5 59.1 1.5 <4 <3 19.5
Unprinted magazine
paper (9 samples) ± Various 1996 1.2 35.0 <0.2 11.7 3.4 <5 11.2 2.5 <4 5.7 10.5
96periodicals (printed
on same paper) ± UK 1995-96 1.0 33.7 <0.2 10.9 36.6 <5 10.5 2.5 <4 5.0 16.0
276periodicals ± UK 1996 0.7 59.2 <0.2 16.2 46.3 <5 23.5 5.9 <4 7.4 44.8
156national
newspapers (1 week average)
Including
colour supps UK 1996 <0.2 10.3 <0.2 1.2 40.3 <5 44.6 3.3 <4 <3 21.8
Junk mail (3 months
Heavy metal
content of
newspapers
51
Other metals showed very much less pronounced trends and, in some cases,marginally higher levels in the unprinted paper. Such anomalies are thought to be due to natural sample variability.
Attempts have been made to trace the sources of heavy metals in newspapers back to the individual material components. Copper is well known to be a design component of the blue pigments used in news inks. The levels of other heavy metals in inks are very low in comparison; however, it is difficult to determine these levels accurately. Analyses of Pb, Hg, Cd, Cr(VI) in printing inks by some commercial laboratories have proved to be very inaccurate (DaRochaet al., 1995). Primary sources of the heavy metals are thought likely to be from additives to paper making (Simonet al., 1997; Hammet al., 1986), impurities in pigments from some manufacturers (Grund, 1994), from the wood (Nye, 1992) or from corrosion in the paper mill (McCrady, 1996). Hamm et al. (1986) found levels of copper, chromium, lead and cadmium to be typically less than 1ppm in spruce wood, with comparable levels in both mechanical and chemical pulps. Jokinen and Siren (1995) attribute trace chromium levels to coatings and filler material and lead to the fillers. Hamm et al. (1986) also considered fillers to be a major source of lead and chromium and have recorded levels from 27ppm to 332ppm lead and 5.6 to 1993ppm chromium in samples of kaolin. Other authors (e.g. Caractere, 1991) confirm that low levels of heavy metal impurities can be found in the primary materials used as extenders in inks; illustrative values being 30ppm barium in silica, < 20ppm barium in calcium carbonate; 5ppm lead in silica and < 5ppm lead in calcium carbonate; 3ppm chromium in calcium carbonate and 2ppm cadmium in silica.
From the above results, it appears that copper is now the only principal metal which is attributable to the inks. Copper is known to be present within the blue (and green) inks based on the copper phthalocyanine pigment. Zinc is not a design component of any ink currently used in the news industry. The link between blue printing and high copper concentrations is readily hypothesised, though it has not yet been quantified. It is conjectured that, with the escalating use of colour over recent years (and with possible further increases in the future), copper concentrations of newspapers are rising and are likely to rise further. To judge if the resulting environmental impact could become significant, projections of the likely scale of such rises need to be made. To make these projections, it is necessary to quantify the relationship between copper levels and colour usage more fully, and to examine the current trends in these parameters in detail. Quantified trends cannot be elicited from the data presented above as ``like with like'' comparisons cannot be made. Details of studies to quantify the trends are now given.
Longitudinal study methodology
Elemental analyses
EMH
11,1
52
concentrations between the horizons and to correlate identified differences with colour content. In designing the study, it was recognised that there could be large variations in elemental concentrations among individual titles, and significant variations in colour content on a daily basis and possibly seasonally as well. In order to minimise the effects of these variabilities, each sample analysed was homogenised from a whole week's run of newspapers. The weeks chosen for the analyses were the last weeks in February, in 1992 and 1998. Four individual national newspaper titles were included in the study: two tabloids and two broadsheets. The 1992 editions were purchased from a supplier of historic newspapers.
Each week's run of newspapers was shredded into 4mm622mm strips. These were thoroughly mixed and progressively sub-sampled by coning and quartering to produce a representative sample of approximately 100 grams. These samples were then homogenised and mixed in a laboratory pulper at a consistency of 3.3 per cent using de-ionised water. Aliquots of approximately 100ml were extracted from the mixed pulp and dried. Three spot samples were taken from each aliquot and microwave digested in aqua regia. The digested samples were analysed using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Results were computed from the average of the three spot samples.
Colour contents
While it is well known that colour usage in newspapers has escalated significantly over recent years, it proved very difficult to get a fully quantitative and objective measure of the magnitude of this rise. Representative statistics could not be found in the public domain. Consequently, proxy statistics had to be adopted to estimate these data. These statistics comprised:
. The compiled amount of colour display advertising. (Industry average statistics were published until 1996);
. The numbers of pages containing some colour, through direct counting of these pages.
. Direct measurements of percentage area bounding all coloured display and editorial (which is still an incomplete measure because of the variable amount of contained white space).
Heavy metal
content of
newspapers
53
Longitudinal study results
Elemental analyses
The measured elemental concentrations of the four newspaper samples are given in Tables III-VI. From our source, 1992 colour supplements were only supplied with newspaper A. Colour supplements and standard newsprint sections were analysed separately.
In general, changes in metal concentrations between the two time horizons were relatively small. The most significant trend was a mean increase in copper by 32 per cent relative between 1992 and 1998. It should be noted however that copper in one of the samples (newspaper A), actually decreased over that period. Zinc contents decreased between the two time horizons on average by 10 per cent relative, or by about 2-3ppm. Most of the changes did not exceed the expected inter-sample variabilities expected at a single time horizon. Such variabilities were quantified in the 1996 analyses (Table VII).
Table III. Metal concentrations (Newspaper A)
Standard newsprint Supplements
Element 1992 (ppm) 1998 (ppm) 1992 (ppm) 1998 (ppm)
Ag <1 <1 <1 <1
Ba 29.3 10.7 61.7 73.0
Cd <1 1.6 <1 3.0
Cr 1 1.3 5.3 1.3
Cu 39.3 23.3 53.7 54.7
Hg <5 <5 <5 <5
Mn 55.3 43.7 42.3 54.7
Ni <2 <4 <1 <1
Pb <4 <4 10 <4
Sn 7.3 7.3 53.0 56.3
Ti 8.3 4.7 28.7 17.0
Zn 28.3 16.0 67.7 30.7
Table IV. Metal concentrations (Newspaper B)
Standard newsprint Supplements
Element 1992 (ppm) 1998 (ppm) 1998 (ppm)
Ag <1 <1 <1
Ba 4 8.3 28
Cd <1 <1 <1
Cr <1 <1.3 6.7
Cu 12.3 30.0 68.7
Hg <5 <5 <5
Mn 47 46 15.7
Ni 1.3 <1 <1
Pb <4 <4 <5
Sn 2.7 8.3 41.0
Ti 1.3 3.7 28.0
EMH
11,1
54
Overall, chromium, tin, titanium and barium concentrations all tended to be higher, though not consistently so, in the magazine supplements compared to the standard newsprint sections. The changes in metal concentrations between the 1992 and 1998 supplements appear to be slight, although a fall in lead levels
Table V.
Metal concentrations (Newspaper C)
Standard newsprint Supplements
Element 1992 (ppm) 1998 (ppm) 1998 (ppm)
Ag <1 <1 <1
Ba 5.3 6.7 10.3
Cd <1 <1 <1
Cr <1 1.6 1
Cu 17.3 33.0 111.7
Hg <5 <5 <5
Mn 36.6 29.0 41.0
Ni <1 <1 <1
Pb <4 <4 <4
Sn 4.3 11.3 7.7
Ti 2.3 19.3 15.3
Zn 18.7 24.0 13.7
Table VI.
Metal concentrations (Newspaper D)
Standard newsprint Supplements
Element 1992 (ppm) 1998 (ppm) 1998 (ppm)
Ag <1 <1 <1
Ba 9.7 10.3 10.7
Cd <1 2.3 <1
Cr 1 <1 <1
Cu 18.0 28.7 71.3
Hg <5 <5 <5
Mn 38.3 52.3 74.0
Ni <1 1.3 <1
Pb <4 <4 <4
Sn 8.3 7.7 7.3
Ti 8.3 4.7 14.0
Zn 16.7 17.7 22.0
Table VII. Variability among individual editions
15 Newspapers 27 Periodicals
Element Mean (ppm) Std Dev. (ppm) Mean (ppm) Std Dev. (ppm)
Ba 10.3 2.1 59.2 50.8
Cr 1.2 0.5 16.2 15.7
Cu 40.3 14.2 46.3 30.3
Mn 44.6 14.1 23.5 17.5
Ni 3.3 4.0 5.9 4.4
Heavy metal
content of
newspapers
55
from 10ppm to < 4ppm is noted. There was no apparent difference in copperlevels between the two time horizons. The results however must be treated with caution as they are based on just one supplement from 1992.
Colour contents
The percentage of colour display, averaged over 11 national titles, is summarised in Figure 1 for the period 1992-1995. Results are monthly averages. The general trend shows a rise from about 15 per cent to around 30 per cent colour display over the four year period. Month-to-month fluctuations are of order+2.5 per cent. The phase and magnitude of the fluctuations were not consistent among individual titles.
Table VIII compares the average percentages of colour pages (of standard newsprint) over a week's run of individual titles (including the associated
1992 1993 1994 1995
Year
% Colour Diaplay
35
30
25
20
15
10
5
0
Source: Media Week Oct 6 1995 and other editions
Figure 1. Percentage of colour display
Table VIII. Percentage of colour pages (1992 and 1998) Percentage pages with some colour Ratio
Newspaper February 1992 February 1998 1998/1992
A 36 31 0.86
B 15 32 2.13
C 4 20 5.00
D 16 28 1.75
X 24 61 2.54
Y 13 16 1.23
EMH
11,1
56
Sunday editions) for the last weeks in February 1992 and 1998 respectively. Newspapers A-D correspond to the titles analysed in the longitudinal compositional study. Newspapers X-Z are other titles for which 1992 data could be obtained. These data were collected by counting pages in library archives. The data set is small as few 1992 editions remained openly accessible.
Again there is much variation among titles, with one title (newspaper A) actually showing a drop in colour between the two horizons. On average, over all seven titles, the percentage of colour printed pages approximately doubled between 1992 and 1998.
The range of day-to-day changes were measured for 13 national titles over the last two weeks of February 1998 (Table IX). Variations up to+40 per cent are evident.
The third estimate of the long-term and weekly variations in the percentage of colour was derived from a random sub-sample of 43 editions of a single Sunday newspaper title spanning a 117 week period from October 1995 to December 1997 (Figure 2). No significant long-term change in the area of colour was detected. The average area of colour was 14.4 per cent with a standard deviation of +1.5 per cent. For this particular title, colour pages averaged around 30 per cent, which by implication means that around 40 per cent of an average colour-printed page is actually coloured (although 40 per cent is an over-estimate due to white space within some of the coloured blocks).
The conclusions from these studies are not definite, though it is estimated that colour usage in the standard newsprint sections of national newspapers approximately doubled between 1992 and 1998. The change was not smooth, having both substantial daily and monthly fluctuations. Changes were not consistent between individual titles. Clearly this raises the question of sample representativity in one-off spot measurements. If copper contents map directly to colour contents, copper levels might be expected to vary by a factor of 2 between individual days and perhaps around+10 per cent (relative) between
Table IX.
Colour contents of 13 national newspapers
Newspaper
Percentage pages with some colour (range over 2 weeks in 1998)
A 23 ± 43
B 26 ± 44
C 14 ± 28
D 20 ± 31
E 29 ± 50
F 38 ± 51
G 31 ± 50
H 17 ± 26
I 24 ± 50
J 28 ± 70
K 21 ± 50
L 31 ± 46
Heavy metal
content of
newspapers
57
weekly or monthly composite samples. Such inferences would appear consistent with the measured elemental variabilities (Table VII).
Correlation between copper concentrations and colour
Results are shown in Figure 3.
While there are absolute differences between individual newspapers, it is noted that for any given newspaper, the copper concentration increases directly with its percentage of colour pages. It is also noted that this still holds true for newspaper A, for which the copper concentrations and the colour pagination were both lower in 1988 than in 1992.
20
15
10
5
0
% Colour (Editorial + Display)
0 10 20 30 40 50 60 70 80 90
100 110 120
Week
Figure 2. Variation in coloured area (October 1995-December 1997)
Newspaper A
Newspaper B
Newspaper C
Newspaper D
0 10 20 30 40
% of Pages with Some Colour
45
40
35
30
25
20
15
10
5
0
Copper content (ppm)
EMH
11,1
58
Environmental burden of the total newspaper package
In considering the heavy metal content of newspapers, it is important to consider the overall package rather than just the standard newsprint sections. Metal concentrations in the overall package (which includes colour supplements) will generally be higher than for the newsprint section alone. Typically, in 1998, the supplements comprised around 10-20 per cent (by weight) of the total weekly newspaper package. The total metal concentrations for the whole packages of newspapers A-D (in 1998) are calculated in Table X.
On average, around 35 per cent of the copper was associated with the supplements which, for these samples, comprised 16 per cent of the weight of the total package. Similar levels of enrichment within the supplements were found for barium, tin and titanium. There was no preferential enrichment of zinc or manganese within the supplements.
The 1996 results for newspapers A-D, extracted from the 1996 data set, provide another comparison with the 1998 data. Results for these two time horizons are broadly similar for copper (42.6 to 39ppm), zinc (21 to 19ppm), barium, and manganese. Possible temporal changes in tin and titanium are noted, with average changes of +8ppm and ±19ppm for these elements respectively. By comparing Tables II and XIII, it is also noted that measured concentrations in the four-newspaper 1996 sub-sample correspond reasonably well with the average concentrations of the parent sample. Thus, newspapers A-D together appear to be quite a reasonable indicator for the whole national picture.
In order to complete the longitudinal analyses, data for the missing 1992 supplements need to be estimated. In making these estimates, it had to be assumed that their elemental compositions had not changed significantly
Table X.
Hg <10 <10 <10 <10 n/m n/m <5
Mn 45 40 31 54 15 41 43.7
Heavy metal
content of
newspapers
59
between 1992 and 1998. The main source of variation was assumed to be thedifferent numbers of supplements issued at each horizon. Newspapers A-D together issued four supplements in 1992 and seven supplements in 1998. These statistics correspond reasonably well (pro-rata) to the overall picture. In total, 15 supplements were issued by UK national newspapers in 1992 and 30 in 1998. Analyses results are given in Figure 4.
The results indicate that copper concentrations may have increased by around 33 per cent (relative), 7 per cent (absolute) post 1992 for the standard newsprint sections and 40 per cent (relative), 12 per cent (absolute) for the total package. These increases have been attributed both to the general rise in colour content in the standard newsprint sections and to the increased number of colour supplements now being issued. There has been little change since December 1996.
Future projections
The current (1998) figures show around 33 per cent colour pages (on average) in the standard newsprint sections. In projecting further increases in colour content in these sections, and assuming no changes to the number or size of supplements or paginations, projected average copper levels for the whole package of national newspapers could become of order 50ppm (for 50 per cent colour pages), 60ppm (for 67 per cent colour pages) and 80ppm (for 100 per cent colour pages). Such estimates are based on per-newspaper averages and do not consider the different circulation figures of individual titles. A general rule of thumb can be derived that there may be a rise of about 0.75ppm copper for each 1 per cent increase in colour pagination.
50
45
40
35
30
25
20
15
10
5
0
Copper Concentration (ppm)
Feb-92 Dec-96 Feb-98
Standard Newsprint Whole Package
EMH
11,1
60
Future concentrations will also be influenced by the relative numbers and paginations of the supplements. They may be influenced further by the mix of papers and inks used for those supplements. Metal analyses were undertaken separately for the major generic categories of ink and paper used for supplements.
. Improved (or high brightness) newsprint/Heat set web offset ink (HSWO);
. Improved (or high brightness) newsprint/Cold set web offset ink (CSWO);
. Super calendered paper/Gravure ink;
. Coated mechanical paper grades/Heat set web offset ink (HSWO).
Samples were aggregated according to type from a week's run of 15 daily newspapers (the first week of March 1998). Results are listed in Table XI. Barium, chromium, lead and titanium concentrations were all higher with the coated mechanical and super calendered papers. The elevated levels are most likely to be associated with the fillers and coatings used in these grades. Copper levels were highest with the improved newsprint/heatset ink combination. This may be due, in part, to a higher level blue-coloured printing in the improved newsprint/HSWO titles than in other titles on that particular week. Different copper loadings among the different printed inks may also be likely. These aspects were not investigated further.
If the recent movement towards printing more supplements using the improved newsprint/ heat set combination continues, this could further aggravate the burden of copper in the total package.
Environmental and health implications
While some ``heavy'' metals have been detected in newspaper samples, the overall concentrations of those metals were low. To evaluate whether there
Heavy metal
content of
newspapers
61
may be potential environmental concern, it is instructive to compare the resultswith analyses of other materials and waste streams having potentially similar end uses, and with the legislative and guideline values for their use.
Studies of the ingestion of newspapers by livestock, either fed as part of the diet or used as bedding (e.g. O'Connell and Meaney, 1997; Comerford, 1992) have shown that metal concentrations may be lower in newspapers than in animal feeds such as beet pulp and molasses, though higher than those found in sawdust bedding. It should also be noted that these, and similar studies by Temple (1990), Comerford and Spencer (1993), Grieveet al. (1982), Heffronet al. (1977) and Shaneet al. (1993) all concluded that newspapers are relatively safe for ingestion by cattle and sheep. Abnormal or elevated levels of either copper or zinc were not found, in the short term, in the blood and liver of newspaper-fed specimens compared to those in the control groups.
Comparative compositional data for newspapers and other components of the domestic waste stream were presented by DoE (1995). Selected results have been extracted to illustrate specific comparisons of interest. The source data themselves give separate analyses for 32 individual categories of household waste. In presenting the data here, the published figures have been adjusted to reduce all concentrations to a dry weight basis (Table XII).
The respective metal concentrations in newspapers sampled in that study were, in nearly every case, lower than the equivalent concentrations in the other potentially compostable waste streams. Even at current newspaper copper levels of around 40ppm, copper concentrations appear no higher than those historically recorded for kitchen wastes (DoE, 1995). Whilst comparative studies of newspapers against other green wastes have not been undertaken since 1993 (as far as the authors are aware), the newspaper fraction would not appear to present a potential major input of heavy metals to household composting schemes.
Cr 5.53 18.60 17.20 12.78
Cu 23.75 31.00 45.73 70.80
Hg 0.06 0.16 0.15 0.21
Mn 74.52 70.93 208.40 158.51
Ni 2.86 13.10 16.16 120.18
Pb 10.55 30.20 75.88 31.83
Zn 24.45 186.14 146.24 119.96
EMH
11,1
62
In considering the potential uses of newspaper in gardening and agriculture applications, either applied directly or after composting, and in considering the potential impacts of returning de-inking sludge residues (from newspaper recycling) to the soil, reference is made to the UK and EC limits for sludge amended soils and to the ICRCL trigger levels for soil (below which remediation is not considered necessary) (Table XIII).
Of the metals investigated, copper would appear the most sensitive substance to deal with in complying with these limits, if returning old newspapers or their residues to the land. In this context it must further be borne in mind that the de-inking process for recycling newspapers preferentially concentrates metals into the de-inking sludge, with sludge concentrations typically >5 times those of the newspaper feed stock. Neither current levels nor the projected increases pose a problem with the general principle of applying these sludges as soil conditioners. The levels do, however, affect the application rates that can be used. Procedures may have to adapt to any future increases in copper.
Copper in newspapers is predominantly associated with the pigment copper phthalocyanine ``Blue 15'', the commonest blue pigment in news inks. Typically
Table XIII.
Cu 2-250 50-140 135 130c
2-60
Hg 0.01-0.3 1-1.5 1 1d
0.008-0.19 20e
Ni 2-1,000 30-75 75 70c
2-100
Pb 2-300 50-300 300 500d
10-150 2,000e
Zn 10-300 150-300 300 300c
25-200
Notes: All concentrations mg/kg dry solids. Source: Royal Commission on Environmental Pollution (1996)
* Directive 86/278/EEC (1986)
** SI 1989 No. 1263 (1989) and DoE (1989)
Heavy metal
content of
newspapers
63
copper phthalocyanines contain 5-10 per cent copper. It is generally reportedthat these pigments are stable, insoluble in water and practically non-biodegradable (e.g. Maret, 1995; Rusterholtz, 1987). Toxicity tests on the copper phthalocyanines Blue 15 and Green 7 are summarised by Webb (1984). An eight-week study injecting mice weekly with Pigment Blue 15 produced no tumours. Three month pre-chronic feeding studies using Pigments Blue 15:3 and Green 7 evidenced no toxic effects. The Ames Bioassay Test (which is a bacterial mutagenesis assay) was negative and acute toxicity tests demonstrated high lethal dose levels (LD50; Oral, Rat >10g/kg). In 1991 three copper phthalocyanine pigments (Blue 15, Green 7 and Green 36) were delisted from reporting requirements under section 313 of the US ``Emergency Planning and Community Right to Know Act'' also referred to as Title II of the Superfund Amendments and Reauthorization Act (SARA) of 1986. However, despite being delisted as a source of copper for reporting under SARA III Section 313, local municipalities have begun to severely restrict the amount of total copper allowed in waste streams (daPonte, 1992). This, perhaps, forms the main stimulus for concern (as discussed above).
In granting the delisting, EPA carried out a technical review. The following extracts are taken from the commentary reported in the Federal Register (May 23, 1991).
. . .have very low solubilities in water (estimates are 8610 -7± 3
610-4Mg/L for pigment blue 15) and do not disassociate or hydrolyze in water under environmental conditions.
. . .it appears that photolysis of these pigments with the resultant release of copper will not occur.
Data indicate that under environmental conditions, abiotic oxidation of these copper pigments does not occur.
No data on the anaerobic or aerobic biodegradability of the copper pigments were found. However based on their extremely low solubility in water, their large cross sectional diameter, these pigments are expected to be very resistant to degradation processes.
On the basis of molecular weight, extremely low solubility in water, and data from sub-chronic toxicity tests, the three phthalocyanine pigments are not expected to be appreciably absorbed by any route of exposure or metabolized to yield copper ion.
Because copper does not appear to be available from phthalocyanine pigments, bioaccumulation of copper is not a concern.
Summary and conclusions
EMH
11,1
64
amongst individual issues and titles due to variations in the amount of blue printing. In considering overall copper concentrations, standard newsprint and colour supplements must be considered together. The 1998 copper concentrations in the overall package averaged around 40ppm. Concentrations in the standard newsprint sections may have increased by around 33 per cent (relative) between 1992 and 1998. Concentrations in the overall package may have risen more (about 40 per cent relative) between these time horizons. Increases are attributed to a rise in the average number of colour pages and to a doubling of the number of colour supplements issued.
Lead, mercury and cadmium were found to be below their measurement detection limits in nearly all samples. Total chromium levels were highest in the coated and super calendered papers. Apart from copper, only minor trace levels of other heavy metals could be conclusively identified as being attributable to the inks, although the sources of zinc remain unclear. Measured levels of zinc varied between 8ppm and 21ppm. There was no obvious relationship between zinc levels and any parameter in the measured samples. The possibility of contamination from non-paper/ink sources of zinc (e.g. contamination in the household, or from transport and handling) cannot be discounted.
The copper in newspapers is bound into the copper phthalocyanine pigment, which according to informed professionals, including the US EPA, is inert under environmental conditions, non-water soluble, not biodegradable and not bioavailable. Because of its low solubility and other factors, it is concentrated in the sludge rather than the water effluent in de-inking operations. Regulations relating to the disposal of this sludge, however, tend to impose limits on the total copper content. Future increases in newspaper colour pagination may propagate problems in meeting such regulations.
Health studies have found that the common pigments used in news inks have low acute toxicity, and are not carcinogenic or mutagenic. No abnormal accumulations of heavy metals were found in the liver, blood or milk of cows fed on newspaper. Composting newspapers may cause less of a copper burden than other household sources of compostable material.
Future trends in the copper content of newspapers need to be monitored. While it is considered highly unlikely that a future increase would have any health implications, there may be some environmental management implications relating to the reuse and recycling of newspapers, if total copper levels continue as a regulatory control. The implications will be largely procedural.
While the results of the experimental study refer specifically to UK newspapers, it is considered that the main conclusions on copper content should apply generally to other countries as well. Inks are supplied for an international market and the use of the copper phthalocyanine pigment is quite ubiquitous.
References
Heavy metal
content of
newspapers
65
Comerford, J.W. (1992), ``Heavy metal and hydrocarbon residues in tissue and blood of beef steersbedded on waste newspapers'', Bull. Environ. Contamination and Toxicology, Vol. 49, pp. 18-22.
Comerford, J.W. and Spencer, S.W. (1993), ``Waste newspaper as a bedding material for beef and dairy cattle'', Proceedings of the 4th International Livestock Environment Symposium, pp. 1212-19.
daPonte, E. (1992), ``Environmental alternatives to PCN blues and DCB yellows'',American Ink Maker, Vol. 71 No. 1, pp. 24-8.
DaRocha, M. and DiPiazza, J.et al. (1995), ``Analyzing for CONEG heavy metal in printing inks'', American Ink Maker, Vol. 73 No. 4, pp. 65-8.
Directive 66/278/EEC (1986),Official Journal of the European Communities, L181, pp. 6-12. DoE (1989),Code of Practice for Agricultural Use of Sewage Sludge, HMSO, London.
DoE (1995), The National Household Waste Analysis Project, Phase 2 ± Volume 3, Chemical Analysis Data, Report CWM/087/94, Department of the Environment, London.
Endriss (1993), ``Paints and plastics colorants free of heavy metals?'',Proceedings of the ISCC/ CPMA Symposium on Colour Pigments, Regulations and the Environment, Newport, April. EPA (1995), 2.600R95047, Analysis of Potential Effects of Toxics on Municipal Solid Waste
Management Options, http://www.epa.gov/cgi-bin/claritgw Federal Register(1991), Vol. 56 No. 100, 23 May, 23650-23652.
Fitzgerald, M. (1992), ``Are newspapers hazardous to your health?'',Editor and Publisher, Vol. 125 No. 9, p. 9.
Friends of the Earth (1997),Paper Recycling ± Exposing the Myths, Briefing Paper, Friends of the Earth, London.
Greive, D.G., Burton, J.H., Braun, H.E. and Frank, R. (1982), ``Voluntary intake of shredded newsprint by dairy cows'',Canadian Journal of Animal Science, Vol. 62, pp. 799-806. Grund, N. (1994), ``Ecological parameters in pigment printing'', Melliand Textilber/Melliand
English, Vol. 75 No. 7-8, pp. 157-9.
Grunewald, H., Hogrebe, B. and Von der Geest, C. (1988), ``Environmentally relevant content of liquid and solid waste from Deinking plants'' (in German), Wochenblatt fur Papierfabrikation, Vol. 116 No. 7, pp. 263-5.
Hamm, U., Geller, A. and Gottsching, L. (1986), ``Heavy metals in wood, virgin pulps, waste paper and paper'' (in German),Das Papier, Vol. 40 No. 10A, pp. 37-46.
Heffron, C.L. Reid, J.T. and Furr, A.K.et al. (1977), ``Lead and other elements in sheep fed colored magazines and newsprint'',Journal of Agricultural and Food Chemistry, Vol. 28, pp. 657-60. Inter-departmental Committee on the Redevelopment of Contaminated Land (1987), ICRCL
Guidance Note 59/83 2nd Edition, Department of the Environment, London.
Jokinen, K. and Siren, K. (1995), ``Harmful residues in recycled fibre ± metals and compounds'', Paperi Ja Puu ± Paper and Timber, Vol. 77 No. 3, pp. 106-10.
Maret, J.P. (1995), ``The impact of printing inks on the environment'',Packing India, Vol. 28 No. 2, pp. 25-31.
McCrady, E. (1996), ``Effect of metals on paper: a literature review'',Alkaline Paper Advocate, Vol. 9 No. 1, pp. 8-9.
Media Week(1995), 6 October.
EMH
11,1
66
O'Connell, J.M. and Meaney, W.J. (1997), ``Short-term fate of heavy metals/trace elements, naphthalene and polychlorinated biphenyls in lactating cows fed newspaper'',Irish Vet Journal, Vol. 50 No. 3, pp. 171-3.
Royal Commission on Environmental Pollution Nineteenth Report (1996),Sustainable Use of Soils, Cm 3165, HMSO, London.
Rusterholtz, W.E. (1987), ``Inks and the environment: an update for boxmakers'', Boxboard Containers, Vol. 95 No. 2, pp. 27-8.
Shane, B.S. and Metosh-Dickey, C.A. et al. (1993), ``Toxicological evaluation of milk from lactating dairy cows following consumption of newsprint'', Journal of Agricultural and Food Chemistry, Vol. 41 No. 2, pp. 240-5.
SI 1989 No. 1263 (1989),The Sludge (Use in Agriculture) Regulations, HMSO, London.
Simon, P.J., Giesson, B.C. and Copeland, T.R. (1997), ``Categorization of papers by trace metal content using atomic absorption spectrometric and pattern recognition techniques'', Analytical Chemistry, Vol. 49 No. 14, pp. 2285-8.
Temple, G. (1990), ``Newsprint gets farmer ± and livestock ± okay'',Biocycle, Vol. 31, September, pp. 60-3.
