In biology, and specifically genetics, epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epigenetics. It refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence. Examples of such changes are DNA methylation and histone modification, both of which serve to regulate gene expression without altering the underlying DNA sequence.
In 2011, it was demonstrated that the methylation of mRNA has a critical role in human energy homeostasis. This opened the related field of RNA epigenetics.

A variety of compounds are considered as epigenetic carcinogens—they result in an increased incidence of tumors, but they do not show mutagen activity (toxic compounds or pathogens that cause tumors incident to increased regeneration should also be excluded). Examples include diethylstilbestrol, arsenite, hexachlorobenzene, and nickel compounds.

Diethylstilbestrol (DES, former BAN stilboestrol) is a synthetic nonsteroidal estrogen that was first synthesized in 1938. It is also classified as an endocrine disruptor.

From about 1940 to 1970, DES was given to pregnant women in the mistaken belief it would reduce the risk of pregnancy complications and losses. In 1971, DES was shown to cause a rare vaginal tumor in girls and women who had been exposed to this drug in utero

DES in food production

During the 1960s, DES was used as a growth hormone in the beef and poultry industries. It was later found to cause cancer and was "phased out in the late 1970s".[60] When DES was discovered to be harmful to humans, it was moved to veterinarian use. DES was found to cause liver failure in cats

Its white odorless crystals are toxic and very soluble in water. It occurs in nature as arsenolite and claudetite, and is also a byproduct of metal smelting. Its main use is in producing chromated copper arsenate (CCA) to treat timber. It is also used for arsenic pesticides, glass production, pharmaceuticals and non-ferrous alloys.

Hexachlorobenzene, or perchlorobenzene, is a chlorocarbon with the molecular formula C6Cl6. It is a fungicide formerly used as a seed treatment, especially on wheat to control the fungal disease bunt. It has been banned globally under the Stockholm Convention on persistent organic pollutants.

HCB is a white crystalline solid that has negligible solubility in water.

Hexachlorobenzene is an animal carcinogen and is considered to be a probable human carcinogen.[2] After its introduction as a fungicide in 1945, for crop seeds, this toxic chemical was found in all food types[citation needed]. Hexachlorobenzene was banned from use in the United States in 1966.

Human and animal studies have demonstrated that hexachlorobenzene crosses the placenta to accumulate in foetal tissues and is transferred in breast milk.

HCB is very toxic to aquatic organisms. It may cause long term adverse effects in the aquatic environment.

At the fundamental level of Gene expression is being Mutated and Corrupted and no one talks about it?

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Science Activities for Kids
Toxicology provides great examples for learning at all grade levels, and SOT provides materials and workshops for teachers. Learn more about activities for K–6 and 7–12.

Links to Fun Sites

US EPA’s Home Tour: Chemicals Around Your House
NIEHS Kids’ Pages
National Aeronautics and Space Administration
US Environmental Protection Agency
Body and Mind—Centers for Disease Control and Prevention
American Society of Human Genetics for K–12
US Food and Drug Administration
Center for Food Safety and Nutrition
Science News for Kids—Ages 9 to 14
Science Made Simple
First Gov for Kids
Howard Hughes Medical Institute Cool Science for Curious Kids
Leading Guide to Best Kids Websites