Health effects of endosulfan

Introduction

Endosulfan is a man-made insecticide. It is used for control of a number of insects on such food crops as grains, tea, fruits, and vegetables and on such nonfood crops as tobacco and cotton. It is also used as a wood preservative.
Endosulfan is sold as a mixture of two different forms of the same chemical (referred to as alpha- and beta-endosulfan). It is a cream-to-brown-colored solid that may appear crystalline or be in flakes. It has a distinct odor similar to turpentine. Endosulfan does not burn.
Endosulfan enters air, water, and soil when it is manufactured or used as a pesticide. Endosulfan is often applied to crops using sprayers. Some endosulfan in the air may travel long distances before it lands on crops, soil, or water. Endosulfan on crops usually breaks down within a few weeks. Endosulfan released to soil attaches to soil particles. Endosulfan found near hazardous waste sites is usually found in soil. Some endosulfan in soil evaporates into air, and some endosulfan in soil breaks down. However, it may stay in soil for several years before it all breaks down. Rain water can wash endosulfan that is attached to soil particles into surface water. Endosulfan does not dissolve easily in water. Most endosulfan in surface water is attached to soil particles floating in the water or attached to soil at the bottom. The small amounts of endosulfan that dissolve in water break down over time. Depending on the conditions in the water, endosulfan may break down within 1 day or it may take several months. Some endosulfan in surface water evaporates into air and breaks down. Because it does not dissolve easily in water, only very small amounts of endosulfan are found in groundwater (water below the soil surface; for example, well water). Animals that live in endosulfan-contaminated waters can build up endosulfan in their bodies. The amount of endosulfan in their bodies may be several times greater than in the surrounding water.

Exposure to endosulfan

The most likely way for people to be exposed to endosulfan is by eating food contaminated with it. Endosulfan has been found in some food products such as oils and fats and fruit and vegetable products. You can also be exposed to low levels of endosulfan by skin contact with contaminated soil or by smoking cigarettes made from tobacco that has endosulfan residues on it. Well water and public water supplies are not likely sources of exposure to endosulfan. Workers can breathe in the chemical when spraying the insecticide on crops. Accidental spills and releases to the environment at hazardous waste disposal sites are also possible sources of exposure to endosulfan. The most likely exposure to endosulfan for people living near hazardous waste sites is through contact with soils containing it.
Endosulfan is usually not found in the air, and it is infrequently found in soil and water. When endosulfan is found in soil and water, levels of less than 1 part of endosulfan in 1 billion parts of surface water (ppb) and less than 1 part of endosulfan in 1 million parts of soil (ppm) have been reported.

Pathways for endosulfan in the body

The most likely way for people to be exposed to endosulfan is by eating food contaminated with it. Endosulfan has been found in some food products such as oils and fats and fruit and vegetable products. You can also be exposed to low levels of endosulfan by skin contact with contaminated soil or by smoking cigarettes made from tobacco that has endosulfan residues on it. Well water and public water supplies are not likely sources of exposure to endosulfan. Workers can breathe in the chemical when spraying the insecticide on crops. Accidental spills and releases to the environment at hazardous waste disposal sites are also possible sources of exposure to endosulfan. The most likely exposure to endosulfan for people living near hazardous waste sites is through contact with soils containing it.
Endosulfan is usually not found in the air, and it is infrequently found in soil and water. When endosulfan is found in soil and water, levels of less than 1 part of endosulfan in 1 billion parts of surface water (ppb) and less than 1 part of endosulfan in 1 million parts of soil (ppm) have been reported.

Health effects of endosulfan

Symptoms of endosulfan poisoning have been seen in some people who were exposed to very large amounts of this pesticide during its manufacture. Symptoms of endosulfan poisoning have also been seen in people who intentionally or accidentally ate or drank large amounts of endosulfan. Most of these people experienced convulsions or other nervous system effects. Some people who intentionally ate or drank large amounts of endosulfan died. The health effects in people exposed to smaller amounts of endosulfan for longer periods are not known. We have no information on whether it affects the ability of people to have children or whether it causes birth defects in children. We also do not know whether endosulfan has ever affected the ability of people to fight disease or has ever caused cancer in people. The Department of Health and Human Services (National Toxicology Program), the International Agency for Research on Cancer, and EPA have not classified endosulfan as to its carcinogenicity.
You should know that one way to learn whether a chemical will harm people is to determine how the body absorbs, uses, and releases the chemical. For some chemicals, animal testing may be necessary. Animal testing may also help identify such health effects as cancer or birth defects. Without laboratory animals, scientists would lose a basic method for getting information needed to make wise decisions that protect public health. Scientists have the responsibility to treat research animals with care and compassion. Scientists must comply with strict animal care guidelines because laws today protect the welfare of research animals.
Additionally, there are vigorous national and international efforts to develop alternatives to animal testing. The efforts focus on both in vitro and in silico approaches and methods. For example, the National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences (NIEHS) created the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) in 1998. The role of NICEATM is to serve the needs of high quality, credible science by facilitating development and validation—and regulatory and public acceptance—of innovative, revised test methods that reduce, refine, and replace the use of animals in testing while strengthening protection of human health, animal health and welfare, and the environment. In Europe, similar efforts at developing alternatives to animal based testing are taking place under the aegis of the European Centre for the Validation of Alternative Methods (ECVAM).
Results from animal studies show that exposure to very large amounts of endosulfan for short periods of time can cause adverse nervous system effects (such as hyperexcitability, tremors, and convulsions) and death. Because the brain controls the activity of the lungs and heart, lethal or near lethal exposures in animals have also resulted in failure of these organs. Other effects seen in animals after short-term, high-level exposures include harmful effects on the stomach, blood, liver, and kidney. After somewhat longer exposures, the ability of animals to fight infection was also impaired. The kidney, testes, and possibly the liver are the only organs in laboratory animals affected by longer-term exposure to low levels of endosulfan. The seriousness of these effects is increased when animals are exposed to higher concentrations of endosulfan.
Studies in animals show no evidence that endosulfan causes cancer in animals. Studies in animals also show no evidence that endosulfan affects the ability of animals to have babies. Some studies show that large amounts of endosulfan damage the testes, but it is unknown whether such large amounts affect the ability of animals to reproduce. Pregnant animals given endosulfan by mouth had some offspring with low birth weight and length and some offspring with skeletal variations. In some cases, the pregnancies were terminated at an early stage. Often, these effects were seen at doses where the pregnant animals showed signs of poisoning by the endosulfan. Because these effects occurred in animals, they might also occur in humans.

Medical tests for exposure to endosulfan

Endosulfan and its breakdown products can be measured in your blood, urine, and body tissues if you have been exposed to a large amount. Tests to measure endosulfan in such bodily tissues or fluids are not usually available at a doctor's office because special equipment is needed for measuring endosulfan and its breakdown products. However, a sample taken in the doctor's office can be properly packed and shipped to a special laboratory if necessary. Because endosulfan leaves the body fairly quickly, these methods are useful only for finding exposures that have occurred within the last few days. At this time, these methods can only be used to prove that a person has been exposed to endosulfan. The test results cannot be used to predict if you will have any adverse health effects. Exposure at the same time to other chemicals at hazardous waste sites could cause some confusion in understanding these results.