Mutagen

Mutagens are external factors that cause mutations or chromosomal aberrations, thus changing the genetic makeup of an organism. A distinction is physical mutagens such as radiation and high temperatures and chemical mutagens such as nitrosamines and polycyclic aromatic hydrocarbons.

The normal mutation rate (frequency with which one or more genes change ) is higher organisms at 10-5 - 10-9 per gene and generation. Mutagens cause an increase in this natural mutation rate.

Mutagens

Be mentioned here as well-known examples:

• Nitrosamines: arise, among others, when frying, roasting and grilling, and in the stomach to digest meat and cheese, which were preserved with nitrite pickling salt, but also the enjoyment of intensively fertilized plant foods. They change the chemically highly effective DNA bases.
• Base analogs: Base Similar substances are incorrectly installed during replication in the DNA and thus cause a change in the original sequence.
• Polycyclic aromatic hydrocarbons: wedged between the bases and lead to grid mutations as a variant of the gene mutations. The process of incorporation into the DNA is referred to as intercalation. A typical example is ethidium bromide, which is used in the molecular biology laboratory technique for the specific detection of nucleic acids, among others. The Ethidiumbromidmoleküle overlap to form π - stacking interactions in the base sequence of a, which can cause a shift of the reading frame.
• Many other chemical substances such as arsenic acid and its salts, asbestos, benzene, acrylamide, benzopyrene, cobalt chloride, gasoline, crude oil
• Aflatoxins: highly toxic and carcinogenic by attachment to DNA bases product of various molds.
• High-energy radiation: X-rays, ionizing and ultraviolet radiation cause mutations and chromosomal aberrations.
• Some tumor viruses: HIV virus, Epstein -Barr virus and HP viruses

The Ames test is one of the simplest and most common tests, which are used for the determination of a chemical as a mutagen.

Categories according to the Hazardous Substances Ordinance

The classification according to § 1.4.2.3 Ordinance on Hazardous Substances Appendix 1 corresponds to Directive 67/548/EEC and is thus a European setting. Where:

Category 1 substances act are known human mutagens. There is sufficient evidence for a causal association between human exposure to a substance and heritable genetic damage. Classification and labeling with hazard symbol T and R46: " May cause heritable genetic damage. ( Muta. cat 1. ) "

Substances in category 2 should be considered for humans as mutagenic. There is sufficient evidence justifying the assumption that the exposure of a human to the substance may cause heritable genetic damage. This assumption is based generally on long-term experiments and / or other relevant information. Classification and labeling with hazard symbol T and R46: " May cause heritable genetic damage. ( Muta. cat 2. ) "

Substances of category 3 owing to possible mutagenic effects in humans cause for concern. Enough information for a satisfactory assessment are not available, however. From appropriate mutagenicity There is some evidence, but this is insufficient to place the substance in Category 2. Classification and labeling with R68 " Possible risk of irreversible. "