Since the 1930s, synthetic pesticide production has exponentially increased and at that time many experts predicted correctly that cancer rates would also rise.
Since then billions of tons of toxic substances that didn’t previously
exist have been released into the environment, yet only about 3% of the 75,000 chemicals used today have been tested for safety. A large body of scientific evidence suggests that exposure to synthetic toxic chemicals in the environment is contributing to high cancer rates and degenerative diseases. One of the most hazardous and pervasive of the environmental toxic chemicals found in our water, air, and soil is organochlorines.
The cheap availability of chlorine gas, together with the development of industrial chlorinating procedures in the 20th century, led to the production of a wide range of organochlorine compounds. Many utilized for a variety of commercial applications including insecticides, defoliants and polychlorinated biphenyls, (PCBs) whicha are used as coolants in electricity supply transformers. However, it was soon found that many of these chemicals suffered from a major disadvantage in that they resisted biodegradation, and that the continued use of these compounds would lead to their persistence and accumulation in the environment, thus entering the human food chain. As with all xenobiotics, the toxicity of the organochlorines is related to their absorption, distribution, metabolism and elimination.
Most organochlorines have been delivered to the world as chlorinated insecticides.
Organochlorine insecticides are classified into three subgroups:
dichlorodiphenylethanes (DDT, dicofol, methoxychlor, and perthane)
chlorinated cyclodienes (aldrin, dieldrin, endrin, chlordane, endosulfan, and heptachlor
hexachlorocyclohexanes (BHC, chlordane, lindane, mirex, and toxaphene)
Some of the more extensively used organochlorine insecticides are DDT (dichlorodiphenyltrichloroethane), polychlorinated biphenols (PCBs), and the polyvinylchlorides (PCVs) – dioxin, aldrin, dieldrin, and atrazine. Polychlorinated biphenyls were also once commonly used electrical insulators and heat transfer agents. Their use has generally been phased out due to health concerns. PCBs were replaced by polybrominated diphenyl ethers (PBDEs), which bring similar toxicity and bioaccumulation concerns.
These chlorinated insecticides are used for the control of a wide range of insects. Organochlorines are not only used extensively as insecticides, but also as detergents, spermicidal foam, paper, lubricants, and plastics. In general, organochlorine insecticides are neurotoxicants and act as nervous system disruptors leading to convulsions and paralysis of the insect and its eventual death. Because of their known environmental toxicity and potential carcinogenicity, the countries that still use organochlorine insecticides are under tremendous pressure to cease use completely.
For several decades, science has reported that organochlorines become concentrated in animal and human fat tissue. Thus, they can be absorbed orally and topically, with absorption being rapid due to the lipid solubility of these compounds. In terms of human health, organochlorines present in the environment have been shown to cause a range of complications, including birth defects, cognitive and neurological impairment and cancer. Among the several hundred organochlorines that have undergone toxicological testing to date, all have been found to cause one or more of a wide variety of adverse health effects, often at very low doses. Many organochlorines are endocrine disrupters that can mimic or otherwise interfere with hormone action, raising the possibility of severe long-term effects on reproduction, development and behavior.
Organochlorines are compounds that contain carbon, chlorine, and hydrogen. Their chlorine-carbon bonds are very strong which means that they do not break down easily. They are highly insoluble in water, but are attracted to fats. They have a long-term residual effect in the environment since they are resistant to most chemical and microbial degradations. Because organochlorines are very stable compounds that are easily solubilized in fats,and insoluble in water, they remain in the environment creating a prolonged and continuous threat to the ecosystem. The chemical chemical half-life is 7-30 years, resulting in long-term persistence in the body.
As environmental pollutants, organochlorines are now prevalent. According to Greenpeace, thirteen tons of chlorine is produced in North America every year. 1% is used to chlorinate drinking water, while the rest is used to produce plastics, to bleach paper products, and serve other functions in the industrial and agricultural industries.
Another major threat to the environment is the contamination of surface water due to organochlorine insecticide sprays. This surface water not only seeps through the ground, but is also dispersed, eventually reaching reservoirs such as lakes, rivers and oceans. Organochlorines can spread far from their originating point. Some studies have reported organochlorine contamination in the Arctic and Antarctic at very high levels. They easily bioaccumulate in biota. Passing through the food chain levels, they increase their concentrations (biomagnifying). With this long-term environmental contamination, organochlorine insecticides affect animals such as marine life, beneficial insects, and birds. Contaminated food and water from organochlorines are the primary way they enter the human body. Generally, they display their effects after a relatively long period of exposure. Organochlorines have been found in human tissue due to their inefficient metabolism and their solubility in lipids, which lead to lifelong sequestration in adipose tissue, such as the breast.
Their massive introduction into the international chemical industry began after World War II. DDT, for example, was introduced in 1943 by the U.S. as a pesticide for the military’s anti-malarial campaigns, and widespread civilian use began two years later after the end of the war. DDT is an insecticide because it inhibits neuronal repolarization. Manifestations of DDT poisoning in humans arise by the same mechanism. Symptoms of poisoning include perioral and lingual paresthesia, apprehension, hypersensitivity to stimuli, irritability, dizziness, vertigo, tremor, and convulsions.
Dioxins are formed by the incineration of products containing PVC, PCBs, and other chlorinated compounds by industrial processes that use chlorine and by the combustion of diesel and gasoline. Dioxins are known human carcinogens and endocrine disruptors. One of the dioxins (2,3,7,8-tetra chlorodibenzo-para-dioxin—TCDD) has been classified by the International Agency for Research on Cancer as a known human carcinogen. In 2000, the U.S. Environmental Protection Agency officially declared TCDD to be a known carcinogen. What dioxins have in common is that they collect in the body fat of humans and other animals and stay there for a very long time. The most recent data in studies of a cross-section of Americans indicate that over 95 percent have measurable levels of dioxins in their bodies, and that older people have statistically higher body burdens of the chemicals than younger people. Even worse, they are directly toxic to the brain even at low levels of exposure and have been linked to cognitive decline and Alzheimer’s disease.
From the 1950s until 1970, the pesticides dieldrin and aldrin (which breaks down to dieldrin, the active ingredient) were widely used on crops, including corn and cotton. Dieldrin has been shown to be an endocrine disruptor, both by stimulating estrogen-regulated systems and by interfering with androgen-regulated pathways. In 1975, the U.S. EPA banned all uses of aldrin and dieldrin except for termite control, because of the concerns about damage to the environment and human health. Later, in 1987, the EPA banned these pesticides altogether. However, many are still being used in other countries today. Despite regulatory bands or strict limits on usage being imposed on organochlorine pesticides in most countries since the 1970s, residues persist in soil and rivers resulting in a widespread contamination of the eco-system including marine life.
It is an unfortunate fact that much of the cancer research currently going on is funded by the very same chemical companies that are filling the world environment with organochlorine pollution.