Polychlorinated biphenyls

from Wikipedia, the free encyclopedia
PCB congeners
(m = 0, 1, 2, 3, 4 or 5;
n = 0, 1, 2, 3, 4 or 5)

Polychlorinated biphenyls ( PCB ; polychlorinated diphenyls , polychlorobiphenyl , chlorodiphenyl ; English chlorinated diphenyls ) are poisonous and carcinogenic organic chlorine compounds. Up until the 1980s, they were mainly used in transformers , electrical capacitors , in hydraulic systems as hydraulic fluids and as plasticizers in paints , sealants , insulating materials and plastics . PCBs are now one of the twelve organic toxins known as the dirty dozen that were banned worldwide by the Stockholm Convention of May 22, 2001. PCBs have spread all over the world, they can be detected everywhere in the atmosphere, in water and in the soil.

Manufacturing

The first synthesis of polychlorinated biphenyls was described in 1881, and their large-scale production began in 1929. In industrial synthesis for the production of polychlorinated biphenyls, biphenyl is reacted with iron or iron (III) chloride as a catalyst with chlorine. Depending on the reaction conditions, different degrees of chlorinated biphenyls are formed. The hydrogen chloride formed in the substitution reaction is neutralized with sodium hydroxide solution. The mixture of polychlorinated biphenyls is then purified or separated by distillation . Commercial products were used as Askarele, for example under the name Aroclor ( Monsanto ). The chlorine content was between 21% (Aroclor 1221) and 68% (Aroclor 1268).

In the Federal Republic of Germany, the production of polychlorinated biphenyls was stopped by Bayer AG in 1983. Bayer, the only known manufacturer of PCBs in Germany, had already limited its production in 1972 and only supplied the chemical for use in closed systems.

use

PCBs were used as an industrial chemical where chemical stability was required. Further properties that determine the use were thermal stability, low water absorption and non-flammability. They were therefore used in various applications in pure form or as an admixture until the restrictions and prohibitions came into force. In Switzerland it was - typical for all countries - insulating oils in transformers , capacitors , additives to joint sealing compounds and anti-corrosion coatings , whereby the quantities used in transformers and capacitors were highest. In Germany, the main area of ​​application for PCBs was also in dielectrics and transformer oils. In joint sealing compounds, especially in building construction , PCBs were used as plasticizers . Other areas of application besides those mentioned were hydraulic oils in mining and carrier fluids for insecticides. Since the early 1930s, PCBs were first used in the USA in large capacitors and as transformer oils and as a lubricant. Germany and France became the second and third largest producers after the war. In 1972 Switzerland, Sweden and Japan banned its use in open uses (plasticizers) in 1978. The production was discontinued in 1977 in the USA and 1983 in Germany. A total of at least 1.3 million tons of PCB were produced worldwide, Bayer AG alone produced 159,000 tons.

properties

PCBs have a biphenyl backbone (two benzene rings linked by a single bond ) on which one or more hydrogen atoms have been replaced by chlorine atoms . The general formula is therefore C 12 H 10 − x Cl x .

In their pure form, PCBs are almost odorless liquids or solids; technical products can be yellowish. Polychlorinated biphenyls are thermally and chemically stable , flame- retardant , electrically non-conductive and super-hydrophobic . They have a relatively high density of 1.4 g / ml. In the case of highly chlorinated PCBs, biodegradation takes place under anaerobic conditions by using the chlorine atoms as electron acceptors, a so-called chlorine respiration . Low chlorinated PCBs can be degraded aerobically or anaerobically. Since PCB-degrading organisms cannot live on PCBs alone due to a lack of nitrogen and, in most cases, important nutrients can also be found elsewhere, PCBs are hardly biodegraded. The bacteria do not benefit from breaking them down, and there are only a few strains that have the genes for the corresponding enzymes.

After mass poisoning with PCB-contaminated food in 1968 in Japan ( Yushō disease ), the production and use of PCBs in Germany were banned in 1978, first in open systems and in 1989 generally. Since the end of the transition period in 1999, contaminated PCBs have to be reported and disposed of as hazardous waste. In Germany this takes place e.g. B. in the underground landfill Herfa-Neurode instead.

PCB was used as an insulating oil (chlorodiphenyl, askarele ) in capacitors , etc. a. in fluorescent lamp lights, washing machines , spin dryers and other older devices with capacitor motors , in industrial systems for reactive current compensation and in the magnetic voltage stabilizers previously used in households for operating tube devices . Decisive for the use instead of other insulating oils were the excellent insulating properties, the long-term stability and the non-flammability. The capacitors were hermetically sealed designs made of metal with glass or ceramic feedthroughs. Chlorodiphenyl-containing capacitors were marked as such in the GDR from a certain point in time (imprinted “chlorodiphenyl”). Compared to other insulating oils, chlorodiphenyl smells intensely fruity even in the smallest quantities and can be absorbed by the body when it comes into contact with the skin.

Typical PCB-containing capacitor from a capacitor motor ( spin dryer , GDR , year of construction approx. 1979)

Building joint sealants can also be the cause of PCB contamination in indoor air and ultimately by people. This mainly affects concrete skeleton structures built between 1955 and 1975.

Another area of ​​application are plasticizers or components of varnishes and paints. PCB can penetrate plastic materials, making them pasty and eventually starting to flow.

Congeners of the PCB

Polychlorinated biphenyls (PCB) are a group of 209 congeners that differ in the number and position of the chlorine atoms on the biphenyl:

Overview of the congeners
PCB homolog CAS number Cl substituents Number of isomers
Monochlorobiphenyl 27323-18-8 1 3
Dichlorobiphenyl 25512-42-9 2 12
Trichlorobiphenyl 25323-68-6 3 24
Tetrachlorobiphenyl 26914-33-0 4th 42
Pentachlorobiphenyl 25429-29-2 5 46
Hexachlorobiphenyl 26601-64-9 6th 42
Heptachlorobiphenyl 28655-71-2 7th 24
Octachlorobiphenyl 55722-26-4 8th 12
Nonachlorobiphenyl 53742-07-7 9 3
Decachlorobiphenyl 2051-24-3 10 1

A numbering of the PCB has been in use since 1980 in order to name the individual congeners briefly and clearly. Technical mixtures contain only around 80 to 100 congeners.

Environmental impact

As a result of accidents, improper waste management and diffuse inputs, PCBs have spread into the environment, accumulate as persistent and bioaccumulative substances in the food chain and can now even be found in fish in the Antarctic , in deep-sea creatures, in breast milk and in human beings Adipose tissue can be detected.

Between 1950 and 1990 a lot of PCB was used in the construction of apartment blocks and other concrete buildings (" prefabricated buildings ") as joint seals between the concrete slabs: demolition and renovation require proper and proper disposal in order to avoid further large PCB sources. Even today, PCB is one of the most important building pollutants in existing buildings .

In 1984, the biggest environmental scandal in this regard in what was then Yugoslavia was uncovered: The Slovenian river Krupa and the karst landscape there have been contaminated with PCBs for decades by improperly stored waste from the company Iskra Kondenzatorji from Semič . The pollution was discovered purely by chance by scientists from the health department in Maribor and later also in Ljubljana , when the source of the Krupa was examined in order to investigate it for drinking water production for the Bela krajina (see also PCB pollution of the Krupa ). The fact that this is a karst landscape is particularly problematic: Even today, PCB contamination is high and can be detected in soil samples, fish, in water, in domestic animals, etc.

In August 2003, a settlement was reached to compensate residents of the city of Anniston , Alabama , who were known to Monsanto for years of exposure to harmful by-products of PCB production. Production was prohibited by law as early as 1976, but the process dragged on for decades: Monsanto paid $ 390 million, insurance 160 million and Solutia 50 million. Other costs such as disposal are said to have amounted to 100 million that the total was $ 700 million.

In June 2011, the Dortmund public prosecutor brought charges against the management and operations of Envio Recycling GmbH & Co. KG : They are said to have deliberately violated official requirements from May 2006 to May 2010 and, among other things, accepted PCB contamination of their employees. PCB-contaminated transformers and capacitors were improperly dismantled on the premises of Envio AG. The charges were made on four counts, including assault.

In 2014, researchers caught amphipods at the bottom of the Mariana Trench in the Sirenatief and in the Kermadecgraben at depths of more than 10,000 m . When examining these cancers, the researchers found greatly increased levels of both PCBs and polybrominated diphenyl ethers (PBDE) .

Human health

Structures of the twelve dioxin-like PCBs

The acute toxicity of PCBs is low, whereas a chronic toxicity can be determined even with small quantities: Typical effects of PCB poisoning are the occurrence of chloracne , hair loss , hyperpigmentation , liver damage, teratogenicity and damage to the immune system ( immunotoxicity ). PCBs bioaccumulate in the food chain and are suspected of being carcinogenic . In addition, physical and mental development can be delayed by PCBs: They are suspected of being endocrine disruptors that have a hormonal effect and could be responsible for sterility in men and male animals, undescended testicles and other hormone-related diseases. An EU study has found that phthalates , parabens and PCBs disrupt the hormonal balance of male fetuses and children, and thus lead to feminization . In addition, dietary PCBs have been linked to an increased risk of high blood pressure . In humans, 90–95% of PCBs and dioxins are absorbed through food, especially through fatty animal foods. In Switzerland, almost two thirds of this intake is obtained through the consumption of dairy products and meat.

The chronic toxicity makes PCB as building pollutants such. B. from old, mechanically destroyed capacitors , joint sealing compounds (especially in concrete buildings from the 60s and 70s) or acoustic ceilings , especially dangerous, because usually the length of time people with weak immune systems (i.e. children, sick and old people) stay indoors is particularly long . Due to the accumulation in adipose tissue, even the smallest continuously ingested amounts are harmful. The poison accumulates in organisms at the end of the food chain . Against this background, the evaluations of one-off contaminations should be seen (e.g. the feed or pork contamination case in Ireland at the beginning of December 2008): a one-off consumption of food with a hundred times higher content of PCBs than the limit value allows questionable, but does not lead to any acute symptoms of intoxication, as the limit value for daily, lifelong intake was met taking into account the accumulation.

Due to their fat solubility , PCBs are absorbed by the body even when they come into contact with the skin. Buildings contaminated with PCBs can lead to increased indoor pollution with PCBs. In the case of people who are in these polluted rooms, sometimes elevated PCB levels can be detected in the blood.

Defective capacitors or other relevant contamination can be identified by the fruity smell: oils based on hydrocarbons hardly smell.

Wildlife

Despite the ban on the manufacture of PCBs in the USA in the late 1970s and in the EU in the 1980s, the substances continue to accumulate at the top of the food pyramids ("at the end of the food chain") due to their longevity : in marine mammals such as killer whales z. B. hinder or prevent reproduction. The concentration of PCBs found in the tissues of killer whales affects the reproduction and immune system of the animals and threatens over half of the killer whale populations worldwide. Most affected are populations that live in the vicinity of industrial regions .

In the case of meat products , contamination can occur e.g. B. from paints containing PCBs in stables. In 2016, for example, the Federal Office for Agriculture in Switzerland set up the “National Strategy on PCBs in Food from Farm Animals” . The Federal Office of Public Health surprisingly found dioxin-like PCBs in veal samples. Two of 53 suckler cow farms examined were contaminated with PCBs. The amount exceeded the legally stipulated maximum level in some cases by almost five times. Even milk samples were above the maximum level. In one case, the sources of pollution were a paint in the barn containing PCBs, in the other, the ingestion of contaminated grass and soil.

Fire exposure

In the event of heat or fire (building fires, improper disposal or contaminated metal scrap), polychlorinated biphenyls are produced, among other things, from polychlorinated dibenzodioxins and dibenzofurans (commonly known as dioxins). For this reason, among other things, a guideline on handling PCB-containing capacitors from 1987 pointed out that special fire protection measures must be taken for the installation locations of PCB capacitors, that heating must be counteracted during fire fighting and that access should be allowed if there is a fire is only possible with full body protection and air-independent self-contained breathing apparatus.

It must be avoided that PCBs end up in waste incineration plants that are not equipped for this purpose (i.e. without reheating of the exhaust gases) or in metal scrap ( see also TCDD as a toxic substance ) .

Control, prevention and prohibitions

Germany

On February 14, 1989, production, marketing and use were banned in the Federal Republic of Germany. The bans on capacitors and transformers came into effect at different times.

The German PCB directive knows two limit values: the precautionary value and the limit value (300 or 3000 ng / m³ indoor air ):

  • Rooms with over 3000 ng / m³ must be renovated immediately,
  • in rooms with more than 300 ng / m³, the cause of the pollution must be removed if possible; the room should be ventilated as well as possible in order to keep the concentration as low as possible.

There are also maximum levels for the occurrence of PCBs in food :

  • At the European level, the maximum limits for PCBs in various foods and their intermediate products such as B. Animals set out in the Commission Regulation setting maximum levels for certain contaminants.
  • If the EU regulation does not regulate these, they are listed in German law in Section 4 of the Annex to the Contaminants Regulation .

disposal

Until the EU-wide ban, the underground final storage of contaminated components and devices was used. This is no longer permitted since 2007. Until then, z. B. PCB-filled transformers and capacitors emptied, filled with a binding granulate, resealed and taken to the underground dump. Even today, the transformers are drained, but then rinsed, dismantled and rinsed again until a PCB concentration below 50 ppm is reached and the metals can be recycled . Organic PCB-contaminated substances as well as the remains of capacitors are incinerated in a controlled manner.

Transformer oils with PCB admixtures below 0.2% were replaced on site.

Only a few hazardous waste incineration plants fulfill the prerequisite for the complete destruction of the PCB: heating to over 1000 ° C with a supply of oxygen .

In a ZVEI leaflet there are disposal instructions for electrotechnical components and in particular a table with typical labels on capacitors broken down by manufacturer.

Recognizability

Widespread ignorance led and still leads to the first environmental contamination and health risks. Cases have been documented in which, for example, building rubble, paint residues or the burning of contaminated wood resulted in ingestion by livestock and subsequently poisoned food. A potential source of danger are oil-filled or soaked transformers and capacitors that are permanently installed or, in the case of capacitors, were or are part of devices. If the devices and installations remain intact, there is no danger. In the event of demolition and disposal, the hermetically sealed housings were and will be destroyed in ignorance and contamination occurs on site, during transport or in the recycling facility (people, buildings, work equipment, soil). Capacitors, in particular, are a long-term risk because they are also used in small designs in many places. Components with filling quantities <100 ml may continue to be operated until the end of their use, whereas installations with larger filling quantities may not continue to be operated and must be disposed of. Areas of application for PCB as an impregnating and insulating material can be electrical devices and electrical installations manufactured in the period from around 1960 to the 1980s:

Since PCBs are not retained by plastic materials, the following identifying features of capacitors can be summarized:

Capacitors that could contain PCB (often recognizable by the print)
  • Housing made of (painted) sheet steel, insulating bushings made of glass or ceramic
Capacitors that do not contain a PCB
  • Housing made of (unpainted) aluminum, plastic cover with crimped connections or connections in resin closure
  • Housing made of plastic or synthetic resin

The letter designations / types of the capacitors MP, MKK, MKP, MPP, MKV, MFV, MPK as well as LK and LP can be assumed that they do not contain a PCB. In cases of doubt, capacitors with illegible or incomplete labeling can be identified by calculating the volume weight after weighing and measuring. From the date of manufacture in 1988, one can assume PCB-free capacitors.

Since chlorodiphenyl has a characteristically fruity smell, destroyed housings and impurities as well as heavily contaminated places can often be recognized for decades.

Limit values

Area Limit values source
toxicologically justified hazard value 200 ng / m³ for stays of less than 7 hours
70 ng / m³ for stays of more than 7 hours
toxicologically based room air precautionary value 20 ng / m³ for stays of less than 7 hours
10 ng / m³ for stays of more than 7 hours
currently valid indoor air intervention values ​​for interiors 3000 ng / m³ In some federal states this value is converted to the length of stay, i. H. 9000 ng / m³ for schools and workplaces
currently valid room air precautionary values ​​for interiors 300 ng / m³ In some federal states this value is converted to the length of stay, i. H. 900 ng / m³ for schools and workplaces
currently valid air limit value for workplaces with known pollutant handling A MAK value (maximum workplace concentration) and since 2016 an AGW (workplace limit value) of 3 µg / m³ in the inhalable fraction has been in force since 2015. The value is calculated as the sum of the indicator congeners (PCB 28 + PCB 52 + PCB 101 + PCB 138 + PCB 153 + PCB 180) × 5.

Air limit value for pregnant women In 2002 the regional committee for occupational safety and security technology (LASI) recommended that pregnant workers adhere to the precautionary value of 300 ng / m³ (based on 24 hours).
Limit value for substances, preparations and products Materials that contain more than 50 mg PCB / kg may only be disposed of in an approved facility.
Maximum content in muscle meat of fish and fishery products and their processed products (excluding wild eel) 6.5 pg / g fresh weight WHO-PCDD / F-PCB-TEQ
75 ng / g fresh weight (sum of congeners 28, 52, 101, 138, 153, 180)
Maximum content in lean meat from wild eel ( Anguilla anguilla ) and its products 10 pg / g fresh weight WHO-PCDD / F-PCB-TEQ
300 ng / g fresh weight (sum of congeners 28, 52, 101, 138, 153, 180)

To determine PCB concentrations, the theoretical concentrations of all congeners would have to be determined and added up, which is not possible for practical reasons. Therefore, simplified methods are used. In the Contaminated Sites Ordinance , the PCB concentration is defined as the sum of the congeners PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180, multiplied by a factor of 4.3.

Stockholm Convention

Most states - exceptions are the United States and Italy - have ratified the Stockholm Convention on Persistent Organic Pollutants of 2001 ( POP or Stockholm Convention ): it came into force in 2004 and bans the production of PCBs and prescribes the destruction of them PCB-containing substances by 2028.

Analytics

Initially, the analysis of PCBs in environmental samples caused difficulties, which also led to a late discovery of PCBs in the environment because chemically similar pesticides and insecticides to DDT made detection more difficult. For the determination, the sample is first extracted with an organic solvent (e.g. hexane ) and then the PCB is enriched using column chromatographic methods. The subsequent quantitative analysis of PCBs is then carried out using gas chromatographic methods. Because of the great effort required to measure all 209 congeners, a method was implemented that only records six congeners (28, 52, 101, 138, 153 and 180) as characteristic indicators. In rivers suitable PDMS - passive samplers for representative sampling.

See also

literature

  • Hans Drexler, Thomas Kraus: Biomonitoring of polychlorinated biphenyls . In: Hazardous substances - keeping the air clean , Volume 71, Issue 1/2 (2011), pp. 20–24.
  • Peter Kredel: Manufacture and use of PCB in the chemical industry . In: Hazardous substances - keeping the air clean , Volume 71, Issue 1/2 (2011), pp. 7–9.
  • AM Ruder, MJ Hein, NB Hopf, MA Waters: Mortality among 24,865 workers exposed to polychlorinated biphenyls (PCBs) in three electrical capacitor manufacturing plants: A ten-year update. In: International Journal of Hygiene and Environmental Health . Volume 217, number 2–3, March 2014, pp. 176–187, doi: 10.1016 / j.ijheh.2013.04.006 , PMID 23707056 , PMC 4557692 (free full text).

Movies

Web links

Individual evidence

  1. ^ A b c Peter Kredel: Manufacture and use of PCB in the chemical industry. In: Hazardous substances - cleanliness. Air . 71, No. 1/2, 2011, pp. 7-9.
  2. a b Werner Müller, Friedhelm Korte : Polychlorinated Biphenyls - Successors of the DDT? In: Chemistry in Our Time . tape 7 , no. 4 , 1973, p. 112–119 , doi : 10.1002 / ciuz.19730070404 .
  3. Larry W. Robertson, Gabriele Ludewig: Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs. In: Hazardous substances - cleanliness. Air. 71, No. 1/2, 2011, pp. 25-32.
  4. a b c d PCB management: homework completed and unfinished , speech by Jochen Flasbarth , President of the Federal Environment Agency , at the event "30 years of PCB management - what is (still) to be done?" On August 20, 2013, p. 3ff
  5. J. Gluge, C. Steinlin, S. Schalles, L. Wegmann, J. Tremp, K. Breivik, K. Hungerbühler, C. Bogdal: Import, use, and emissions of PCBs in Switzerland from 1930 to 2100. In: PLOS ONE . 12, 2017, p. E0183768, doi: 10.1371 / journal.pone.0183768 .
  6. ^ Lutz Bonk, Margret Böckler, Frank Göller, Werner Jasny, Eduard Tigges: Use, disposal and recycling of components and components in electrical engineering containing PCBs . In: Hazardous substances - cleanliness. Air. 71, No. 1/2, 2011, pp. 15-19.
  7. a b c d e Hansjörg Kieper, Heinz-Dieter Neumann, Rita Rachor-Ebbinghaus: Polychlorinated biphenyls in building construction. In: Hazardous substances - cleanliness. Air. 71, No. 1/2, 2011, pp. 10-14.
  8. M. Zennegg, E. Vermeirssen, P. Schmid: Measurement of PCB and dioxins in rivers. Evaluation of the practicability of sediment analyzes and measurements by means of passive collectors in the water phase to localize emission sources . Federal Office for the Environment , Bern. Umwelt-Wissen No. 1639, 2016, p. 17.
  9. ^ K. Breivik, A. Sweetman, JM Pacyna, KC Jones: Towards a global historical emission inventory for selected PCB congeners - a mass balance approach1. Global production and consumption . In: Science of The Total Environment . tape 290 , no. 1–3 , 2002, pp. 181-198 , doi : 10.1016 / S0048-9697 (01) 01075-0 , PMID 12083709 .
  10. Chang, Oh, Haddock: 4-Chlorobiphenyl Pathway Map , as of August 15, 2011.
  11. Dr. Birgit Zimmermann Bavarian State Office for Health and Food Safety, Dr. Michael Albrecht Bavarian State Office for Health and Food Safety: Food: Polychlorinated Biphenyls (PCB) - Internet offer. In: www.lgl.bayern.de. Retrieved January 3, 2017 .
  12. Federal Office of Public Health - PCB (polychlorinated biphenyls). (No longer available online.) In: bag.admin.ch. Archived from the original on March 20, 2016 ; accessed on March 23, 2016 .
  13. VDI 2464 sheet 1: 2009-09 Measurement of immissions; Measuring indoor air; Measuring polychlorinated biphenyls (PCB); GC / MS method for PCB 28, 52, 101,138, 153, 180 (Ambient air measurement; Indoor air measurement; Measurement of polychlorinated biphynyls (PCBs); GC / MS method for PCB 28, 52, 101,138, 153, 180). Beuth Verlag, Berlin, p. 4.
  14. a b c d Deutschlandfunk.de , Forschungs aktuell , June 17, 2016, Monika Seynsche : PCB has catastrophic consequences for marine mammals (June 19, 2016).
  15. ^ M. Kohler, J. Tremp, M. Zennegg, C. Seiler, S. Minder-Kohler, M. Beck, P. Lienemann, L. Wegmann, P. Schmid: Joint sealants: an overlooked diffuse source of polychlorinated biphenyls in buildings. In: Environmental Science & Technology . Volume 39, number 7, 2005, pp. 1967-1973, doi: 10.1021 / es048632z , PMID 15871225 .
  16. S. Polič, H. Leskošek, M. Horvat; PCB Pollution of the Karstic Environment (Krupa River, Slovenia) (PDF; 114 kB), in Acta Carsologica 29/1, 10, Ljubljana 2000, pp. 141–152.
  17. Damir Kundić: Somovi iz Kupe godinama zatrovali smrtonosnim spojem , German catfish from the Kolpa are poisoned with lethal substances for years , online edition of the Croatian newspaper Novi list (Rijeka) from November 11, 2012, accessed on February 19, 2013
  18. "Monsanto Hid Decades Of Pollution. PCB Drenched Ala. Town, But No One Ever Told What " , Washington Post , January 1st 2002 (to Anniston process)
  19. Article on the Anniston process on the website of the Organic Consumers Association ( Memento from May 11, 2006 in the Internet Archive )
  20. DerWesten , June 24, 2011, derwesten.de: Public prosecutor's office is bringing charges in the Envio case
  21. Alan J. Jamieson, Tamas Malkocs, Stuart B. Piertney, Toyonobu Fujii, Zulin Zhang: Bioaccumulation of persistent organic pollutants in the deepest ocean fauna . Nature Ecology & Evolution 1, Article 0051, 2017, doi : 10.1038 / s41559-016-0051 .
  22. Unknown author: Environmental toxins even in the deep sea trench Surprisingly high PCB values ​​in supposedly untouched deep sea . scinexx das Wissensmagazin, February 14, 2017, German-language article about the high PCB concentrations in the amphipods
  23. M. Van den Berg et al. : The 2005 World Health Organization Reevaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins and Dioxin-Like Compounds . In: Toxicological Sciences . 93, No. 2, 2006, pp. 223-241. PMC 2290740 (free full text). doi : 10.1093 / toxsci / kfl055 . PMID 16829543 .
  24. ^ The Guardian: Two-year-olds at risk from 'gender-bending' chemicals, report says (English) November 6, 2009.
  25. ^ The Telegraph , October 23, 2009, telegraph.co.uk: Why boys are turning into girls .
  26. Carolina Donat-Vargas, Alfredo Gea, Carmen Sayon-Orea, Carmen de la Fuente-Arrillaga, Miguel Angel Martinez-Gonzalez: Association Between Dietary Intake of Polychlorinated Biphenyls and the Incidence of Hypertension in a Spanish CohortNovelty and Significance: The Seguimiento Universidad de Navarra Project . In: Hypertension . tape 65 , no. 4 , April 1, 2015, p. 714-721 , doi : 10.1161 / HYPERTENSIONAHA.114.04435 , PMID 25646299 ( ahajournals.org [accessed January 9, 2018]).
  27. Federal Office for Agriculture: PCBs and dioxins in food from farm animals . (PDF; 1.9 MB).
  28. Federal Institute for Risk Assessment : Dioxin-like PCBs in pork from Ireland , December 7, 2008.
  29. Gerhard Volland, Bernd Schilling, Thomas Gabrio, Bernhard Link, Iris Zöllner: Dioxin-like polychlorinated biphenyls (PCB) in indoor air. Hazardous substances - keeping air clean 69 (3), pp. 83–89 (2009).
  30. ^ Jean-Pierre Desforges, Ailsa Hall, Bernie McConnell, Aqqalu Rosing-Asvid, Jonathan L. Barber: Predicting global killer whale population collapse from PCB pollution . In: Science . tape 361 , no. 6409 , September 28, 2018, p. 1373-1376 , doi : 10.1126 / science.aat1953 , PMID 30262502 .
  31. Stefanie Hablützel: PCB: The poison that you want to forget . In: observer.ch , March 28, 2018, accessed on April 12, 2018.
  32. PCB residues in beef: Report on the follow-up investigations , April 2014.
  33. EU Commission: Grazing cows may pick up persistent organic pollutants from soil or surroundings , News Alert "Science for Environmental Policy" from January 10, 2019. '
  34. C. Bogdal, S. Züst, P. Schmid, T. Gyalpo, A. Zeberli, K. Hungerbühler, M. Zennegg: Dynamic Transgenerational Fate of Polychlorinated Biphenyls and Dioxins / Furans in Lactating Cows and Their Offspring . Environmental Science & Technology , 2017, 51 (18): 10536-10545. doi: 10.1021 / acs.est.7b02968 .
  35. Guideline for dealing with PCB power capacitors , (GDR) Ministry of Electrical Engineering and Electronics, 9 pages, Berlin on October 31, 1987, accessed on October 23, 2019.
  36. DIBt (1995): Guideline for the assessment and remediation of PCB-contaminated building materials in buildings . DIBt-Mitteilungen 2: 50–59. German Institute for Building Technology, Berlin.
  37. Regulation (EC) No. 1881/2006 of the Commission of December 19, 2006 setting the maximum levels for certain contaminants in food . (OJ L 364 of December 20, 2006, p. 5)
  38. Text of the contaminants ordinance
  39. Regulation (EC) No. 850/2004 of the European Parliament and of the Council of April 29, 2004 on persistent organic pollutants and amending Directive 79/117 / EEC , ABl. EG (2004) No. L 158, pp. 7-49.
  40. a b c ZVEI: Information sheet on the disposal of high-voltage capacitors containing PCBs - power, fluorescent lamp and motor capacitors , Appendix 2 from page 7, accessed on July 24, 2018.
  41. a b c https://www.umweltbundesamt.de/sites/default/files/medien/1410/publikationen/2018_10_uba_hg_dioxine_bf_neu.pdf Background information from the Federal Environment Agency 2018: Dioxins and dioxin-like PCBs in the environment and food chains , accessed on May 31, 2019
  42. ^ RK Bauer, M. Barghoorn, P. Gössele: Final report on the research project PCB small capacitors at the Technical University of Berlin 1988, p. 55.
  43. a b Toxicological assessment of polychlorinated biphenyls (PCB) after inhalation , study by the State Environment Agency NRW, 2002.
  44. a b PCB Directive North Rhine-Westphalia as of July 3, 1996.
  45. Technical rules for hazardous substances (TRGS 900) "Air limit values" p. 8, p. 22.
  46. https://onlinelibrary.wiley.com/doi/full/10.1002/3527600418.am5346921d0018
  47. a b Text of the PCB / PCT waste ordinance
  48. a b Regulation (EU) No. 1259/2011 of the Commission of December 2, 2011 amending Regulation (EC) No. 1881/2006 with regard to the maximum levels for dioxins, dioxin-like PCBs and non-dioxin-like PCBs in food
  49. SR 814.680: Ordinance on the remediation of contaminated sites (Contaminated Sites Ordinance, AltlV) .
  50. Hans-Ulrich Maier: Analysis of environmental samples - Qualitative and quantitative analyzes of PVBs and PBDEs , LABO, May 2010, 8–9.
  51. VDI 2464 sheet 1: 2009-09 Measurement of immissions; Measuring indoor air; Measuring polychlorinated biphenyls (PCB); GC / MS method for PCB 28, 52, 101,138, 153, 180 (Ambient air measurement; Indoor air measurement; Measurement of polychlorinated biphynyls (PCBs); GC / MS method for PCB 28, 52, 101,138, 153, 180). Beuth Verlag, Berlin, p. 5.
  52. M. Zennegg, E. Vermeirssen, P. Schmid: Measurement of PCB and dioxins in rivers. Evaluation of the practicability of sediment analyzes and measurements by means of passive collectors in the water phase to localize emission sources . Federal Office for the Environment , Bern. Environmental Knowledge No. 1639, 2016, p. 46.