EOM4SOIL WP 5.1: Synthesis report of current limitations of contaminants in external organic matter (EOM) regulated by law and of different monitoring studies of member countries

1 EOM4SOIL WP 5.1: Synthesis report of current limitations of contaminants in external organic matter (EOM) regulated by law and of different monitoring studies of member countries Author: Isabel Hilber, Research Group Environmental Analytics, Agroscope, Zurich, Switzerland Revisor: Thomas Bucheli, Head of Research Group Environmental Analytics, Agroscope, Zurich, Switzerland January 2023 2 Executive summary The project EOM4SOIL aims, amongst others, at proposing best management practices of organic matter (OM) for soil amendment and improving soil health. Therefore, data of contaminants such as metals, organic compounds, impurities and pathogens in OM such as compost, digestate, (sewage) sludge, etc. were gathered from ten different countries (Austria, Belgium, Italy, Finland, France, Lithuania, Spain, Sweden, Switzerland, and Turkey). The “e” of EOM defines “external” and is OM added to soil as fertilizer that did not origin from the same field as applied and/or has undergone transformations. Authors from the different countries compiled datasets of contaminants in EOM regulated by law and monitored in their countries. All data were joint in a database distinguishing between regulated and monitored contaminants in the countries and various OM. Mean values of contaminant concentrations of monitoring studies and reports were copied into the database and transformed, where possible (for instance all concentrations needed to be mg/kgdry matter (dm)), so that they could be analyzed and compared with regulated limit values. From all contaminants regulated, inorganic contaminants made three fourths, whereas from all monitored contaminants metals were half of all entries. In contrast, far more organic contaminants were monitored (46%) than regulated (4%). Additionally, regulated organic contaminants contained rather legacy compounds such as PAHs, PCBs or OCP whereas monitoring studies investigated PFOS, sulfonamides, parabens, phthalates, and flame retardants (for abbreviations see Table A 2). Obviously, regulation in most countries is “behind” environmental science investigating emerging contaminants. Organic matter covered by laws and in monitoring studies were compost, digestate, (sewage) sludge, manure, biochar, and various other organic matrices not belonging in one of the aforementioned categories. Animal by-products and nitrogen (N), phosphorous (P), and potassium (K) NPK combinations in unspecific OM were only reported in regulations but not in any monitoring study or report. Regulated and monitored means of cadmium (Cd), the sum (Σ) of the 16 polycyclic aromatic hydrocarbons (ΣPAH16) assigned priority compounds by the US environmental protection agency, and the Σ of the polychlorinated biphenyls (ΣPCB6, 7, 8) of six, seven or eight PCB congeners were compared. These contaminants monitored were, on the basis of the present data, all well below most regulated limits except for Cd in miscellaneous OM, which was only below regulated limits. This was an overall positive result. However, due to the mean (but not the extreme or single) value(s) of individual studies considered for this overall data evaluation the concentrations could well spread over a wider range than reported here. Also, monitored concentrations reported by the different authors below the limit of quantification (LoQ) could not be considered as a value because <10 mg/kgdm is not a number. Therefore, distributions of monitored concentrations could also well be lower than the reported ones here. Overall, from the available data, chemical contamination of EOM was mainly below corresponding regulated concentration values and its application in the respective context therefore not limited. However, the current data proofed to be limited (e.g. in terms of countries), hard to retrieve (e.g. often only published in grey literature not reporting for instance on LoQ, number of replicates, etc.), heterogeneous (e.g. in terms of congeners/representative compounds assessed, analytical methodologies), partly inappropriate (reported concentrations other than mg/kgdm such as g/ha, g/ha in 1, 2 or 10 years, mg/kgP2O5, %fresh weight, ng TE/kgdm, etc., could not be included here,) and scattered (e.g. in terms of EOM categories, analytes covered). 3 Table of contents 1 Introduction ..................................................................................................................................... 4 2 Material and methods ...................................................................................................................... 4 3 Contaminants .................................................................................................................................. 5 4 Regulated contaminants and major EOM categories ...................................................................... 6 4.1 Metals ...................................................................................................................................... 8 4.1.1 Cadmium (Cd) ................................................................................................................ 9 4.2 Organic contaminants ........................................................................................................... 12 4.2.1 Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) ..... 13 5 Monitored contaminants ............................................................................................................... 14 5.1 Metals .................................................................................................................................... 17 5.1.1 Cadmium (Cd) .............................................................................................................. 18 5.2 Organic contaminants ........................................................................................................... 20 5.2.1 Organic contaminants, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) .......................................................................................................................... 22 6 Results of monitored and regulated contaminants ........................................................................ 23 6.1 Monitored and regulated cadmium ....................................................................................... 23 6.2 Monitored and regulated PAHs and PCBs ............................................................................ 25 7 Discussion and conclusions .......................................................................................................... 25 8 Acknowledgements ....................................................................................................................... 26 9 References ..................................................................................................................................... 26 4 1 Introduction The project “External organic matters for climate mitigation and soil health”, EOM4SOIL, aims at proposing best management practices of external organic matter (EOM), pre-processing and application on soil to contribute to climate change mitigation and improve soil health. Examples of OMs are manure, slurry, compost, sewage sludge, digestate, etc. “External” defines the OM put on a soil as fertilizer that does not origin from the same field as applied and/or has undergone transformation(s) (pre-processing such as composting or anaerobic digestion, etc.). Sources of EOM, especially urban residues such as sewage sludge, composts and digestate contain contaminants. Restrictions and quality certificates of different European member states try to avoid deleterious effects of EOM to soil health by regulating and/or postulating limits of contaminants in organic fertilizers. The aim of this report is to provide an overview of contaminants (i) regulated/postulated in different EU member states and (ii) summarize reports and scientific articles about monitoring studies concerning contaminants in EOM. In the following, the compilation of the database underlying this report is explained in chapter 2, material and methods. All contaminants, irrespective of regulated or monitored, are presented briefly in chapter 3. Chapter 4 gives an overview of regulated contaminants followed by examples of cadmium (Cd, chapter 4.1.1) where the limit or threshold values of the different countries and OM are shown. Regulated organic contaminants are described in chapter 4.2 and concentrations ranges of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are reported in chapter 4.2.1. Chapter 5 is about monitored contaminants where the same pattern is followed as for the regulated contaminants. Chapter 6 compares regulated with monitored values and chapter 7 discusses the data and concludes. 2 Material and methods European Joint Project (EJP) SOIL/EOM4SOIL consortium members (https://ejpsoil.eu/soilresearch/eom4soil) from ten different countries (Table 1) provided data of contaminants in OM regulated in their country as well as monitored from reports published in their country and/or scientific articles. These data in different excel files were merged by the author of this report in one excel file with a sheet for regulated and one for monitored contaminants in EOM. Table 1: EOM4SOIL consortium members who provided the data this report is based on. Name Country e-mail Gerhard Soja Austria [email protected] Rebecca Hood-Nowotny [email protected] Hélène Van Der Smissen Belgium [email protected] Elina Tampio Finland [email protected] Johanna Laakso [email protected] Sabine Houot France [email protected] Tiziana Pirelli Italy [email protected] Francesca Varia francesca.v[email protected].it Assunta Amato [email protected].it Giovanni Daraguccione [email protected] Daniela Quarato daniela.qua[email protected].it Donata Drapanauskaitė Lithuania [email protected] Wiebke Mareile Heinze Sweden wiebkem[email protected] Geert Cornelis [email protected] 5 Beatriz Albero Spain [email protected] Isabel Hilber Switzerland [email protected] Ulfet Erdal Turkey [email protected] To allow for smooth data handling, thus, to search for certain names, sort, compare data, etc. an auto filter was set to the different columns in the excel database. The data sheet of regulated contaminants contained columns about the country, OM type, contaminant, unit (of the limit concentration), limit (the regulated value), and a remarks column. Monitored contaminants contained similar columns, thus, country, origin (e.g. agriculture, forestry, urban, etc.), type (e.g. compost, grass, manure, etc.) and origin specification (e.g. wood, pile I, II, …, composted sewage sludge, 74% solid fraction of digestate (SFD) + 24% wheat straw (WS) + 2% almond shell powder (ASP), etc.) of the OM, contaminant, mean, standard deviation (sd), median, number (of replicates), unit (of concentration or observation), remark, and reference (link pointing to the report online or written as is indicated in the bibliography of scientific articles). Where entries were ambiguous or unclear authors were asked to explain. Contaminants are listed in the Annex, Table A 1 (regulated inorganic contaminants), A 2 (regulated organic contaminants), A 3 (categories of regulated contaminants), and A 4 (categories of monitored contaminants). The final database is in xlsx format and available on the EOM4SOIL webpage. However, the different extracts of the database underlying this report needed to be “cleaned” for description and comparison. Therefore:  Only concentrations of the same unit could be compared. This was mg/kgdm because it was mostly mentioned  Where possible other units were transferred into mg/kgdm  Entries such as “<10” were not included in the figures because it is not a number  The points mentioned above do not hold for the pie charts about each type of contaminants regulated or monitored in the different countries  Where collaborators indicated medians, the numbers were entered as means in this report. However, medians in the original excel database were not changed and appear in the respective column  Entries ≠ replicates (n) because partners were instructed to indicate means (or medians) due to the fact that reports and publications show processed data and often raw data are not available. However, partners were asked to indicate the n that ranged from “not available” as high as over 2000  Many concentration ranges are presented in boxplots where some appear in white and some are grey shaded. This has no meaning and happened because of working with different Rversions 3 Contaminants Inorganic and organic contaminants regulated and/or monitored in Austria, Belgium, Finland, France, Italy, Lithuania, Spain, Sweden, Switzerland, and Turkey are listed in Table A 1 and Table A 2, respectively in the Annex. The tables also contain abbreviations of the contaminants. Metals are listed in Table A 1 and main categories of organic contaminants are perfluoroalkyl acids (PFAAs), aliphatic and aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), pharmaceuticals and biocides, polybrominated diphenyl ethers (PBDEs), phthalates, phenols, polychlorinated biphenyls (PCBs), parabens, alkylbenzene sulfonates, polychlorinated dibenzo-p-dioxins/-furans (PCDD/F), 6 sulphonamides, paraffins, organochlorine pesticides (OCP), halogens, and biuret (Table A 2). Furthermore, regulated and sometimes monitored impurities and pathogens are listed in Table A 3. 4 Regulated contaminants and major EOM categories Of the total 2862 contaminant entries regulated in 10 countries the majority, namely 2163 entries concerned metals (76%), 111 organic contaminants (4%), 122 impurities (4%) and 466 pathogens (16%, Figure 1). From all OM regulated (Figure 2) more than 40% entered the database as organic or organo-mineral nitrogen (N), potassium (K) and phosphorous (P) fertilizer or combinations of it (NPK combinations, Table 2). All countries except Sweden and France used these categories originating from the EU regulation 2019/1009 to characterize OM that was not processed, thus neither composted nor digestated, nor was sludge, biochar or manure. Compost is the mostly put distinct and processed OM of all organic material. In spite of the NPK combination group, the miscellaneous category was >10%. Here, countries regulated national and/or specific OM as for instance Finland, Spain and Italy peat and combinations of it, Belgium woody OM in the paper industry, Finland and Lithuania growing media, Spain olive pomace paste, humic acids and seaweed extracts, and Turkey vinasse. Figure 1: Of the 2862 entries regulating contaminants in organic matter in ten different countries four categories were formed. Over three quarters of all entries in the database concerned metal, 16% pathogens, and 4% organic contaminants and impurities, each. Category items are listed in Table A 3 of the Annex. 7 Figure 2: Almost a fifth of all organic material regulating contaminants was compost, 10% were animal by-products (ABP) without manure and about 40% concerned nitrogen, phosphorous and potassium (NPK) combinations of fertilizers that is described in Table 2. Miscellaneous was material NOT containing “ABP”, “compost”, “digestate”, “manure”, “NPK”, or “sludge” in the column OM type of the database and was material such as growing media, different peats, mixed topsoil, stillage, desiccated olive pomace paste, etc. The question is whether the contaminants categorized in Figure 1 are found equal frequently in all matrices of Figure 2. Indeed, the fraction of metals regulated was the highest in all matrices and fluctuated little, between 65 and 80% (Figure 3). While organic contaminants incl. PAHs and PCBs are regulated in a few percent in compost, digestate, and sludge and even in the permil range in the NPK combinations and the miscellaneous group (Figure 2), they are not at all regulated in manure and animal by-products (ABP). In contrast, organic contaminants are well regulated in biochar but pathogens and impurities are omitted due to obvious reasons. Table 2: Unspecific, organic material that is regulated in some countries as nitrogen, phosphorous, and potassium (NPK) fertilizer. Material State of aggregation Organic origins Class Minerals Fertilizer combinations Organic Solid Plant A Peat N Organo-mineral Liquid Animal B Leonardite NP Lignite C NK PK NPK 8 Figure 3: Fractions of contaminants regulated in different organic material (OM). Metals are listed in the Annex, Table A 1, organic compounds in Table A 2 incl. abbreviations, and impurities and pathogens in Table A 3. Contents of the miscellaneous OM is explained in Figure 2, nitrogen (N), phosphorous (P) and potassium (K) containing matrices entered the NPK combinations group and animal by-products (ABP) the respective category. 4.1 Metals As mentioned above, the majority of contaminants regulated were (heavy or trace) metals. Figure 4 shows the percentage of the individual metals of the 2163 entries. Cobalt, Cs, 137Cs, Cr VI, Se, Tl, and V are summarized in the miscellaneous group. Lead was most times regulated (312 times) in all countries followed by Cd, Cr, Cu, Hg, Ni, and Zn. Cadmium was chosen as representative heavy metal example for further analysis concerning regulated limits in OM in this report. All other metals are presented in the original excel database. 9 Figure 4: Of the 2163 entries regulating inorganic contaminants in organic matter the percentages of the eight most mentioned metals are shown in a pie chart. The miscellaneous group contains Co, Cs, 137Cs, Cr VI, Se, Tl, and V. 4.1.1 Cadmium (Cd) Of the 2163 metal entries in OM 279 concerned Cd and of these 246 entries had limit values in form of mg/kgdm. Cadmium in all OM types regulated in the 10 countries ranged from the minimum of 0.5 mg/kgdm, over the 1st quartile of 1.2, to the median of 2.0, mean of 2.4, 3rd quartile of 3.0 to the maximum of 40 mg/kgdm (Figure 5A, B). The outlier limit at 40 mg/kgdm was for sewage sludge in Spain if soil pH is >7 and the one at 20 mg/kgdm if pH is <7. A sewage sludge with 10 mg/kgdm in Belgium can be used in agriculture depending on the type of process. In Figure 5B the y-axis was cut at 6 mg/kgdm for a better overview. 16 Figure 13: Percentages of contaminant database entries (3327 in total) monitored in different external organic matter categories that were mainly (sewage) sludge, compost, digestate, manure, biochar, and the rest of material. The latter group contained for instance ashes, fall foliage, presswater, green and household waste, scum, etc. The question is whether the contaminants categorized in Figure 12 are found equal frequently in all matrices of Figure 13. The contaminants were not equally distributed in the different matrices. Metals were monitored in 50 to 86% of all contaminants in compost, digestate, manure, and miscellaneous OM but reached only a quarter in biochar and 29% in sludge (Figure 14). In the latter OM, organic compounds other than PAHs or PCBs, thus pharmaceuticals, PFOS, dioxins, etc. made up for 54% of the investigated contaminants. In biochar, PAHs were monitored in 74% of the entries. Pathogens were only monitored in compost, digestate and manure and impurities in the former two matrices. 17 Figure 14: Fractions of contaminants monitored in different organic material (OM). Metals are listed in the Annex, Table A 1, organic compounds in Table A 2 incl. abbreviations, and impurities and pathogens in Table A 4. Contents of the miscellaneous OM is explained in Figure 13. 5.1 Metals Similar to regulated metals monitored Cd, Cu, Cr, Ni, Pb and Zn contributed to 10 – 13% of all inorganic compounds (Figure 15). The miscellaneous group contained Ag, Al, B, Ba, Bi, Co, Cr III, Cr VI, Li, Sb, Se, Sn, Sr, Tl, U, V, Y. 18 Figure 15: Of the 1641 entries monitoring inorganic contaminants in organic material the percentages of the ten most mentioned metals are shown in a pie chart. The miscellaneous group contained Ag, Al, B, Ba, Bi, Co, Cr III, Cr VI, Li, Sb, Se, Sn, Sr, Tl, U, V, Y. 5.1.1 Cadmium (Cd) Of the 1641 metal entries in OM 188 concerned Cd and of these 162 entries had limit values in form of mg/kgdm and were therefore comparable. Cadmium in OM of all kinds monitored in seven countries ranged from the minimum of 0.003 mg/kgdm, over the 1st quartile of 0.2, to the median of 0.6, mean of 1.9, 3rd quartile of 1.2 to the max of 82 mg/kgdm (Figure 16A). Figure 16B shows the same graph with a cut y-axis at 10 mg/kgdm. Figure 16: Monitored cadmium (Cd) concentrations of all organic material (OM) in seven countries (Belgium, Italy, Lithuania, Spain, Sweden, Switzerland, Turkey) over the whole range (A) and zoomed on y-axis (B, ≤10 mg/kgdm). Monitored mean Cd concentrations in compost (50 entries) ranged from 0.11 to 10.0 mg/kgdm (min, max (of these means and in the following not mentioned anymore)) where the median was at 0.5 and the 3rd quartile at 0.9 mg/kgdm (Figure 17A). Cadmium in digestate was monitored in 32 samples and the concentration means were slightly lower than in compost. Mean concentrations ranged from 0.01 to 8.6 mg/kgdm (min, max) with a median of 0.23 and a 3rd quartile at 1.0 mg/kgdm (Figure 17B). 19 Figure 17: Monitored cadmium (Cd) concentrations in compost (A) and digestate (B). Monitored mean Cd in sludge (33 entries) from mainly waste water treatment plants (WWTP) and industry such as food, beverage, paper or leather and fur ranged from 0.1 to 82 mg/kgdm (min, max) where the median was at 1.1 and the 3rd quartile at 1.9 mg/kgdm (Figure 18A). Cadmium in manure (21 entries) had about 50 times lower mean concentrations than sludge and originated mainly from husbandry animals for dairy and meat production. It ranged from 0.003 to 1.8 mg/kgdm (min, max), the median was at 0.3 and the 3rd quartile at 0.5 mg/kgdm (Figure 18B). Figure 18:Monitored cadmium (Cd) concentrations in sludge (A) from food, beverage, paper and leather and fur industries as well as waste water treatment plants and manure (B). The mean Cd contents in biochars were monitored in five samples (no figure) of which only two samples were above the limit of quantification (LoQ). The observed mean values from biochar of tree barks were 1.2 mg/kgdm and the one of vine shoots 0.6 mg/kgdm. The rest of the organic material where Cd was monitored was ashes, slurry, scum for sugar factories, municipal organic waste, biogas, and presswater. The 28 observations had mean Cd concentrations from 0.18 to 9.0 mg/kgdm (min, max) with a median of 1.0 and a 3rd quartile of 1.9 mg/kgdm (Figure 19). 20 Figure 19: Monitored cadmium (Cd) concentrations in miscellaneous organic material (OM) such as ashes, slurry, scum for sugar factories, municipal organic waste, biogas, and presswater. 5.2 Organic contaminants Seven countries monitored organic contaminants (Austria and France see footnote 1) that resulted in 1518 entries. Figure 20: Countries that monitored organic contaminants. Percentages refer to a total of 1518 entries. Of monitored organic contaminants 31% concerned PAHs, 15% flame retardants, 11% pharmaceuticals, 10% PCBs, 11% miscellaneous material and the rest were fractions <10% (Figure 21 21). Similar to regulated organic contaminants PAHs made the biggest group. Therefore, PAHs and also PCBs of monitoring studies were depicted in OM categories below. Figure 21: Of the 1518 entries monitoring organic contaminants in organic matter nine categories were formed. Polycyclic aromatic hydrocarbons were the biggest group followed by flame retardants, pharmaceuticals, the group of miscellaneous organic contaminants and PCBs. The rest of the contaminants contributed to <10% of the entries. The miscellaneous group contained for instance BTEX, parabens, alkylbenzene sulfonates, etc. Abbreviations are explained in Table A 2 of the Annex. Mean concentrations, thus for instance ΣPAH16 but also individual PAH compounds such as BaP, PHE, PYR, etc. or PFT and individual PFOA and PFOS, etc. (Table A 2), of all organic contaminants in OM monitored (1383 entries) spanned over 10 orders of magnitude and ranged from 1.7e-07 to 4757 mg/kgdm (min, max) with a median of 0.02 mg/kgdm, and a 3rd quartile of 0.3 mg/kgdm (Figure 22). The minimum concentration was measured of 2,3,7,8-TCDD in Swiss digestate and the maximum of mineral oils in Belgian urban sludge. As for instance dioxins are often reported in ng/kg and PCBs in µg/kg, concentration’s span is so large and was therefore logarithmized in order to gain an overview. 22 Figure 22: Monitored, logarithmized, organic contaminants in all organic material (OM). 5.2.1 Organic contaminants, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) Similar to the few entries of regulated organic contaminants only 56 of the 473 entries (31% of 1518 entries, Figure 21) monitored ΣPAH16. The other 417 entries were single PAH compounds or fractions of the 16 PAHs. Hence, also in this chapter a categorization into different OM categories would be too much of a splitting. Mean concentrations ranged from 0.006 to 438 mg/kgdm (min, max, (log10 -2.2 mg/kgdm, log10 2.6 mg/kgdm)) with a median of 1.7 mg/kgdm (log10 0.2 mg/kgdm, Figure 23A). The highest and second highest concentration were found in two biochar samples of Spain. Nineteen entries reported ΣPCB7 and ΣPCB8 (congeners 28, 52, 101, 118, 153, 180, 138, 163 by Lithuania) mean concentrations with a minimum of 0.002 mg/kgdm, a maximum of 0.3 mg/kgdm, and a median of 0.01 mg/kgdm (Figure 23B). The two highest concentrations of 0.1 and 0.3 mg/kgdm of ΣPCB7 were recorded in sewage sludge. 23 Figure 23: Monitored, logarithmized concentrations of ΣPAH16 in all organic material (OM, A) and of ΣPCB7 and ΣPCB8 in OM. 6 Results of monitored and regulated contaminants From all contaminants regulated, inorganic contaminants made three fourths whereas monitored metals were half of all entries (Figure 1 and Figure 12). In contrast, far more organic contaminants were monitored (46%) than regulated (4%). The reason for this is that regulated organic contaminants were listed for instance as ΣPAH16 (Table A 3) while those monitored were often listed as single compounds (Table A 4 or rather Table A 2). Additionally, regulated organic contaminants contained rather legacy compounds such as PAHs, PCBs or OCP whereas monitoring studies investigated PFOS, sulfonamides, parabens, phthalates, and flame retardants (Table A 2). Obviously, regulation in most countries is “behind” environmental science investigating emerging contaminants. While OM was regulated in eight different categories (Figure 2) monitored OM could only be distributed into six classes (Figure 13). No monitoring studies did consider ABP and the generic names of NPK combinations obtained specific ones when monitored. In contrast to the fractions rather equally distributed over all matrices except biochar and ABP of the different contaminants regulated in the various OM (Figure 3), the fractions of monitored contaminants in the different matrices were not (Figure 14). Metals were monitored in the majority of compost, digestate, manure, and miscellaneous matrices, organic contaminants mostly in sludge and PAHs in biochar. Concerning inorganic contaminants, the fractions of regulated and monitored Cd entries were very similar. Thirteen percent of all heavy metals regulated concerned Cd (Figure 4) and 11% monitored (Figure 15). Cadmium, PAHs and PCBs depicted in the different matrices (above) are compared by means of violin plots. Boxand violinplots are very similar. The vertical rectangle in the violinplot corresponds to boxplots. The 1st and 3rd quartile are the lower and upper limit of the rectangle and the horizontal line is the median (e.g. Figure 24). The violinplot does not show any whiskers but the distribution of the data that gives the “body” of the violin. For instance, the peak of Cd monitored in compost (Figure 24A) is at the median, which is 0.5 mg/kgdm (also see Figure 17) meaning that the majority of the 50 entries has about this value. Outliers or single values marked as empty dots above the whiskers of the boxplots (e.g. Figure 17) are small humps in the violinplot (e.g. at 6.4 mg/kgdm and 10 mg/kgdm in Figure 24A). 6.1 Monitored and regulated cadmium Cadmium medians of all OM types monitored, thus compost, digestate, sludge, manure and miscellaneous materials, were smaller than regulated limits (Figure 24 to Figure 26). Medians, including the majority of entries, of Cd monitored in all OM types were two (miscellaneous organic material, Figure 26) to seven (manure, Figure 25B) times lower than the medians of regulated Cd. 24 First to 3rd quartiles of Cd monitored in (sewage) sludge (Figure 25A) and miscellaneous OM (Figure 26) overlapped with 1st and 3rd quartiles of Cd regulated. The regulated range of Cd in (sewage) sludge (Figure 25A) was also wide, in fact, it had the widest span for Cd in OM with more than two orders of magnitude. Cadmium contents in the rest of the OM, thus not compost, digestate, (sewage) sludge or manure, is shown in Figure 26 as miscellaneous. Please note that the y-axis was cut at 10 mg/kgdm for a better overview and the value of 40 mg/kgdm of Lithuania for organo-mineral fertilizer if total P content was >5% of P2O5-equivalent by mass was omitted (Figure 9A). In this group, the difference was smallest with a factor of two between the median monitored and regulated. Two thirds of regulated Cd belonged in this OM type (161 of 242 entries, chapter 4.1.1) but only 17% of the monitored Cd (28 of 162, chapter 5.1.1). In general, low regulated Cd concentrations belong to class A limits (Table 2) or organically managed OM, which is also true for instance for compost. Figure 24: Violinplots of Cadmium (Cd) in compost (A) and digestate (B) regulated and monitored. Figure 25: Violinplots of Cadmium (Cd) in (sewage) sludge (A) and manure (B) regulated and monitored. 25 Figure 26: Violinplots of Cadmium (Cd) in miscellaneous organic material. 6.2 Monitored and regulated PAHs and PCBs Regulated ΣPAH16 showed a narrow range in comparison to monitored (Figure 27A) and the latter spanned over four orders of magnitude. The ΣPCB6, 7, 8 monitored ranged over two orders of magnitude and the regulated values are broader than the ones of PAHs (Figure 27B). However, also the comparison of organic contaminants showed the same pattern as with Cd, namely that the majority of the monitored ΣPAH16 and ΣPCB6, 7, 8 were below the regulated limits. 7 Discussion and conclusions Contaminants regulated in the OM differed from the ones monitored, not so much with regard to the nature of the target analytes, but the frequency of investigation in the various matrices. In general, Figure 27: Violinplots of PAHs (A) and PCBs (B) regulated and monitored in all organic matter (OM). 32 Table A 4: Four categories could be classified of all monitored contaminants: organic compounds, metals, impurities, and pathogens. Abbreviations are explained in Table A 1 and Table A 2. (Please note that the author categorized the contaminants and the table has therefore no official character.) a: neither PAH compounds nor borneff specified Organic contaminants Metals Impurities Pathogens All compounds listed in Table A 2 except biuret (carbamylurea) Ag Cl Cestodes Al Impurities Clostridium perfringens As Inerts <3.33 mm, >10 mm E. coli B Inerts >10 mm Fecal coliform Ba Inerts >3.33 mm <10 mm Enterococcus Bi Microplastics Enterobacteriae Cd Plastics <3.33 mm Helminth eggs Co Plastics >10 mm Helminth eggs + larvae Cr Plastics >3.33 <10 mm Nematodes Cr III Stones Salmonella Cr VI Streptococchi faecalis Cu Teania saginata Hg Teania solium Li Trematodes Mn Mo Ni Pb Sb Se Sn Sr Tl U V Y Zn