or ionizing radiation
Carcinogen means "cancer generator" or "cancer pathogen" and comes from ancient Greek καρκίνος karkínos "cancer" and γένος génos "descent", while the front part of carcinogens is derived from the Latin word cancer (also "cancer"). The term is often used adjectivally (a substance has a carcinogenic effect , including carcinogenic , carcinogenic or carcinogenic , ie carcinogenic ).
Should it lead to the triggering of cancer, one speaks of a cancer induction (from the Latin: inducere "to trigger, to initiate").
In 1775 it was recognized by the English doctor Percivall Pott that chimney sweeps caused so-called chimney sweepers through contact with soot, due to aromatic hydrocarbons in soot. In the early 19th century, skin cancer was reported among workers in copper smelters and tin foundries in Cornwall. Here arsenic compounds were the cause. Jonathan Hutchinson diagnosed skin cancer in patients in 1888 as a result of using ointments containing arsenic. From around 1925, arsenic compounds were used in pesticides in viticulture and fruit growing. Later, an accumulation of types of cancer typical for arsenic compounds was observed among winemakers, so that these preparations were banned. In 1895, the surgeon Ludwig Rehn established the increased incidence of bladder cancer among workers in aniline factories, due to various aromatic amines . From the beginning of the plastic production of PVC in the 1930s, workers developed certain forms of liver cancer , which resulted in the MAK value of vinyl chloride being drastically reduced several times. Different types of cancer also occurred in workers in factories in which beryllium , cobalt and nickel compounds , chromates or asbestos were processed, as well as in tar and paint factories.
Carcinogens can be divided into two groups:
- Initiating carcinogens are substances that can cause cancer.
- Carcinogens undergoing doctoral studies, on the other hand, promote the (further) development of the cancer.
Furthermore, it is called co-carcinogens when a substance itself is not carcinogenic, but can cause cancer in certain combinations with other substances, which are also not a carcinogen.
Many carcinogens are only effective after being metabolized in the body. For example, 3,4- benzopyrene is only carcinogenic after enzymatic conversion into epoxybenzpyrene. The same applies to nitrosamines , which are metabolized into the corresponding aldehydes and reactive carbenium ions . Nitrosamines can not only be absorbed from the environment (e.g. cigarette smoke), but can also be formed in the stomach from amines and nitrites . The effect of the carcinogens is essentially based on genotoxic changes in the DNA and thus leads to the degeneration of the cell.
Before the introduction of the global harmonized system for the classification and labeling of chemicals (GHS), carcinogens were classified in the European Union in accordance with Directive 67/548 / EEC - implemented in Germany in accordance with Section 22.214.171.124 GefStoffV Annex 1. The following table shows the classifications across from:
|Directive 67/548 / EEC||GHS|
|Carc. Cat. 1; R45 May cause cancer||Carc. 1A - H350 May cause cancer|
|Carc. Cat. 2; R45 May cause cancer||Carc. 1B - H350 May cause cancer|
|Carc. Cat. 1; R49 May cause cancer if inhaled||Carc. 1A - H350i May cause cancer if inhaled|
|Carc. Cat. 2; R49 May cause cancer if inhaled||Carc. 1B - H350i May cause cancer if inhaled|
|Carc. Cat. 3; R40 Limited evidence of a carcinogenic effect||Carc. 2 - H351 Suspected of causing cancer|
Classification according to GHS
The GHS is a United Nations initiative to adapt the various systems of chemical classification that have existed around the world. Two categories have been created here, the first of which can be further subdivided if the relevant authority so orders:
- Category 1: Known or likely to be carcinogenic in humans
- Category 1A: Category 1A for substances known to be carcinogenic to humans; the classification is mainly based on evidence in humans;
- Category 1B: Category 1B, for substances likely to be carcinogenic in humans; the classification is mainly based on evidence in animals.
Confirmed human epidemiological and / or animal test data result in classification in category 1. A further differentiation into categories 1A and 1B is based on the informative value of the evidence in conjunction with additional information. In individual cases, it is possible, on the basis of a scientific assessment, to base a probable carcinogenic effect in humans on studies which have only produced limited evidence of a carcinogenic effect in humans in connection with limited evidence in experimental animals.
- Category 2: Suspected carcinogenic effects in humans
In the case of insufficiently reliable data for classification in category 1, a substance can be classified in category 2 if studies in humans give rise to a suspicion of carcinogenic effects or animal studies reveal a suspicion of carcinogenic effects.
Classification according to Directive 67/548 / EEC
Before the introduction of the GHS, Directive 67/548 / EEC regulated the classifications in Europe. The categories meant:
Substances were classified in category 1, of which the carcinogenic effect in humans is known and there is sufficient evidence for a causal relationship between exposure of a person to the substance and the development of cancer. The classification and labeling is carried out with the hazard symbol T and R45: "Can cause cancer (canc. Cat. 1)" or R 49: "Can cause cancer if inhaled (canc. Cat. 1)". (Only if they are very toxic for other reasons are they marked with T +).
- Arsenic acid and its salts
- Dimethyl sulfate
- soluble nickel salts
- Diesel exhaust
Substances that are considered to be carcinogenic for humans were assigned to category 2, i.e. if there are sufficient indications for the justified assumption that exposure of a person to the substance can cause cancer. This assumption is generally based on long-term tests and / or other relevant information. The classification and labeling is carried out with the hazard symbol T and R45: "Can cause cancer (canc. Cat. 2)" or R 49: "Can cause cancer if inhaled (canc. Cat. 2)". (Only if they are very toxic for other reasons are they marked with T +). Examples:
Substances are classified in category 3 if they give cause for concern because of their possible carcinogenic effects in humans, but insufficient information is available for a satisfactory assessment, e.g. For example, there are indications from suitable animal experiments, but they are not sufficient to classify the substance in Category 2. The classification and labeling is done with R40: "Suspected carcinogenic effect". Examples:
Classification according to IARC
The International Agency for Cancer Research (IARC) regularly publishes test results in extensive monographs and divides 1017 substances and mixtures into 4 groups based on the data known so far (as of April 2020):
Group 1: carcinogenic to humans
So far (as of April 2020) 120 substances / groups of substances have been classified in Group 1, including acetaldehyde in connection with the consumption of alcoholic beverages, alcoholic beverages , busulfan , benzene , diesel engine emissions , processed meat ( sausage , ham ), formaldehyde , Helicobacter pylori (infection), wood dust , leather dust , plutonium , tobacco smoke (direct and indirect, and smokeless tobacco use), vinyl chloride
Group 2A: probably carcinogenic
Up to now (as of April 2020) 83 substances / groups of substances have been classified in group 2A, including acrylamide , chloral , diazinon , red meat (e.g. meat from beef, pork or sheep), very hot drinks (more than 65 ° C) ), Glyphosate , open chimneys , malathion , shift work ( night work ), titanium dioxide
Group 2B: possibly carcinogenic
314 substance groups of substances have been (April 2020) classified in Group 2B, including benzofuran , lead , carbazole , Diesel fuel (marine applications), furan , melamine , radiofrequency radiation , parathion , pyridine , tetrachlorvinphos ,
Group 3: not classified
Group 3 includes all substances that do not fall into one of the other three groups. Currently (as of April 2020) there are 500 substances in group 3, including amaranth (coloring), azobenzene , caprolactam , fluoride (inorganic, used in drinking water), drinking coffee , phenol , saccharin and its salts, sulfites , tea . The originally existing group 4: Probably not carcinogenic , in which caprolactam was classified, is no longer used.
Criticism of hazard-based classification systems
Classification systems based on the identification of hazards (such as those of the IARC or GHS) are, according to Boobis et al. (2016) are out of date and therefore serve neither science nor the public. Such systems led to the classification of substances with different potency and mode of action in the same category, for example the consumption of meat products and mustard gas . A characterization of hazards and risks, on the other hand, would provide a balanced picture of hazards, dose-response curves and exposure , and thus enable better-informed risk management decisions . On the other hand, systems designed to identify hazards would, in their opinion, encourage scaremongering, unnecessary economic costs, the loss of useful products, higher health care costs and the promotion of unnecessary research.
Alan Boobis is said to be lobbying. Its close association with the International Life Sciences Institute (ILSI) and simultaneous membership in the Joint FAO / WHO Meeting on Pesticide Residues (JMPR) has been criticized. In particular, the JMPR's announcement of the harmlessness of glyphosate is to be questioned critically insofar as ILSI received donations in the millions from Monsanto . Because of its proximity to industry, Boobis was excluded from the European Food Safety Authority (EFSA).
Numerous carcinogens occur naturally. For example, aflatoxin B1 , one of the most potent carcinogenic compounds of all, is produced by the Aspergillus flavus mold . This often affects fatty and starchy seeds such as nuts, grains, corn or pistachios.
Tumor viruses , e.g. B .:
Electromagnetic and particle radiation can be carcinogenic from energies of around 4 electron volts - which corresponds to the binding energy of the nucleotides in the DNA strand . Radioactivity is also included , since high-energy radiation is also emitted. UV-C radiation is at the risk limit and therefore already carcinogenic. Visible light is harmless due to the low electromagnetic energy.
- Category: Carcinogenic substance (List of substances available in Wikipedia, classified as H350 or H350i)
- Category: Substance suspected of having a carcinogenic effect (substances classified with H351)
- Paul Rademacher: Chemical Carcinogens . In: Chemistry in Our Time . tape 9 , no. 3 , 1975, p. 79-84 , doi : 10.1002 / ciuz.19750090303 .
- Erik Petersen: The International Cancer Research Agency ( IARC ): Cancer is largely an environmental disease and is preventable . In: environment · medicine · society . tape 28 , no. 1 , 2015, p. 7–9 ( PDF ).
- List of carcinogenic, mutagenic or toxic substances for reproduction from the IFA
- The Carcinogenic Potency Database - Assessment of 1451 chemicals for their carcinogenic potency after evaluating over 6000 experiments
- National Institute of Environmental Health Sciences: 13th Report on Carcinogens
- IARC Monographs Program on the Evaluation of Carcinogenic Risks to Humans
- IARC and NTP carcinogen list
- Legal texts on CLP
- CLP regulation of December 16, 2008 (PDF)
- Reach Compliance: Globally Harmonized System (GHS) - ANNEX VII: Translation table from classification under Directive 67/548 / EEC to classification under this Regulation. (No longer available online.) In: reach-compliance.eu. Archived from the original on March 4, 2016 ; accessed on November 10, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- IARC Monographs - Monographs available in PDF format. (No longer available online.) In: monographs.iarc.fr. Archived from the original on March 4, 2016 ; accessed on November 10, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- IARC Monographs - Classifications. In: monographs.iarc.fr. October 26, 2015, accessed November 10, 2015 .
- Agents Classified by the IARC Monographs, Volumes 1–124. In: monographs.iarc.fr. October 26, 2015, accessed September 30, 2019 .
- WHO study on meat and cancer: Shall we stop eating sausage now? , Stiftung Warentest, October 29, 2015
- IARC Monographs evaluate consumption of red meat and processed meat , World Health Organization (WHO), October 26, 2015
- IARC: Cell Phone Radiation Is a Possible Human Carcinogen , Microwave News, June 3, 2011
- The IARC Monographs: Updated Procedures for Modern and Transparent Evidence Synthesis in Cancer Hazard Identification. (pdf) In: J Natl Cancer Inst. September 9, 2019, p. 36 , accessed on April 10, 2020 ( doi : 10.1093 / jnci / djz169 ).
- Alan R. Boobis, Samuel M. Cohen, Vicki L. Dellarco, John E. Doe, Penelope A. Fenner-Crisp, Angelo Moretto, Timothy P. Pastoor, Rita S. Schoeny, Jennifer G. Seed, Douglas C. Wolf : Classification schemes for carcinogenicity based on hazard identification have become outmoded and serve neither science nor society . In: Regulatory Toxicology and Pharmacology . October 22, 2016, p. 1-9 , doi : 10.1016 / j.yrtph.2016.10.014 .
- International Life Sciences Institute - Lobbypedia. Retrieved March 16, 2019 .
- Glyphosate: Science as the plaything of industry. May 31, 2016, accessed March 16, 2019 .