Some types of<unk> s have significant toxicity to plants or animals, including humans. Dioxins, produced when organic matter is burned in the presence of chlorine, are persistent organic pollutants which pose dangers when they are released into the environment, as are some insecticides (such as DDT). For example, DDT, which was widely used to control insects in the mid-20th century, also accumulates in food chains, as do its metabolites DDE and DDD, and causes reproductive problems (e.g., eggshell thinning) in certain bird species. DDT also posed further issues to the environment as it is extremely mobile, traces even being found in Antarctica despite the chemical never being used there. Some<unk> s, such as sulfur mustards, nitrogen mustards, and Lewisite, are even used as chemical weapons due to their toxicity. However, the presence of chlorine in an organic compound does not ensure toxicity. Some<unk> s are considered safe enough for consumption in foods and medicines. For example, peas and broad beans contain the natural chlorinated plant hormone 4-chloroindole-3-acetic acid (4-Cl-IAA); and the sweetener sucralose (Splenda) is widely used in diet products. , at least 165<unk> s had been approved worldwide for use as pharmaceutical drugs, including the natural antibiotic vancomycin, the antihistamine loratadine (Claritin), the antidepressant sertraline (Zoloft), the anti-epileptic lamotrigine (Lamictal), and the inhalation anesthetic isoflurane. Rachel Carson brought the issue of DDT pesticide toxicity to public awareness with her 1962 book Silent Spring. While many countries have phased out the use of some types of<unk> s such as the US ban on DDT, persistent DDT, PCBs, and other<unk>  residues continue to be found in humans and mammals across the planet many years after production and use have been limited. In Arctic areas, particularly high levels are found in marine mammals. These chemicals concentrate in mammals, and are even found in human breast milk. In some species of marine mammals, particularly those that produce milk with a high fat content, males typically have far higher levels, as females reduce their concentration by transfer to their offspring through lactation.
Organochlorine compound
Persistent organic pollutant
Organobromine compound
Corrosive substance
Polycyclic aromatic hydrocarbon
Perfluorinated compound
Dioxins and dioxin-like compounds
Polychlorinated dibenzodioxins