Health effects of endrin
Contents
Introduction
This toxicological profile focuses on endrin, but because of its close association to both endrin aldehyde and endrin ketone, the profile includes studies with data relevant to human exposure to these compounds when available. Endrin is a solid, white, almost odorless substance that was used as a pesticide (Health effects of endrin) to control insects, rodents, and birds. Endrin has not been produced or sold for general use in the United States since 1986. Little is known about the properties of endrin aldehyde, an impurity and breakdown product of endrin, or endrin ketone, which is a product of endrin when it is exposed to light.
Pathways for endrin in the environment
Endrin does not dissolve very well in water. It has been found in ground water and surface water, but only at very low levels. It is more likely to cling to the bottom sediments of rivers, lakes, and other bodies of water. Endrin is generally not found in the air except when it was applied to fields during agricultural applications.
The persistence of endrin in the environment depends highly on local conditions. Some estimates indicate that endrin can stay in soil for over 10 years. Endrin may also be broken down by exposure to high temperatures (230°C) or light to form primarily endrin ketone and endrin aldehyde.
It is not known what happens to endrin aldehyde or endrin ketone once they are released to the environment; however, the amount of endrin broken down to endrin aldehyde or endrin ketone is very small (less than 5%).
Exposure to endrin
Since endrin is no longer produced or used in the United States, you can probably be exposed to it only in areas where it is concentrated, such as a hazardous waste site. You may be exposed to endrin in air, water, or soil if you live near a hazardous waste site. Endrin has been detected at 120 (8.4%) such sites. Children living near hazardous waste sites could be exposed to endrin in contaminated soils, if they eat dirt. Detection of endrin in ground water or drinking water is rare. In the U.S. EPA 1989 National Pesticide in Groundwater Study, in which ground water was collected from areas with significant agricultural land uses as well as urban areas, only two wells were found with detectable levels of endrin. In wells drilled to access ground water near hazardous waste sites, 1.3% of 156 Resource Conservation and Recovery Act (RCRA) sites and 0.9% of 178 Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Superfund sites had detectable levels of endrin in the early 1980s. No information about the presence of endrin aldehyde or endrin ketone in the environment was found.
You may also be exposed to endrin by eating foods that contain endrin. Before cancellation of endrin use, reported concentrations of endrin in domestic and imported food samples ranged from 0.05 to 0.50 parts per million (ppm; where 1 ppm = 1 microgram per gram (µg/g) of food). However, no endrin was detected in food samples from a Texas survey and only 0.084% of over 13,000 food samples were found to contain endrin in 1989 after cancellation of endrin use. Endrin was found in less than 1% of all food sampled by the U.S. Food and Drug Administration (FDA) in 1991. Because endrin is no longer used in the United States, residues on imported foods are the main source of potential human exposure in food. The levels of endrin aldehyde or endrin ketone in foods are not known.
Endrin levels can build up (bioaccumulate) in the tissues of organisms that live in water. In the 1986 EPA National Study of Chemical Residues in Fish, concentrations of endrin were found in fish at 11% of 362 sites surveyed (average 1.69 parts per billion Where 1 ppb = 1 nanogram per gram (ng/g) of food; maximum 162 ppb). Endrin was also detected in 21 of 31 samples of 2 commercial shrimp species from a Gulf Coast estuary receiving both industrial discharges, and urban and agricultural runoff. The average concentration was 1,070 and the maximum concentration was 9,470 ppb. Levels of endrin have probably declined, even in such polluted areas, since using endrin was banned.
Endrin has been detected in human breast milk (0.02-6.24 milligrams endrin in each kilogram milk fat [mg/kg]); this may be a route of exposure for nursing infants. However, no studies of endrin in breast milk in United States or Canadian populations have been conducted.
Pathways for endrin in the body
Since endrin is no longer produced or used in the United States, you can probably be exposed to it only in areas where it is concentrated, such as a hazardous waste site. You may be exposed to endrin in air, water, or soil if you live near a hazardous waste site. Endrin has been detected at 120 (8.4%) such sites. Children living near hazardous waste sites could be exposed to endrin in contaminated soils, if they eat dirt. Detection of endrin in ground water or drinking water is rare. In the U.S. EPA 1989 National Pesticide in Groundwater Study, in which ground water was collected from areas with significant agricultural land uses as well as urban areas, only two wells were found with detectable levels of endrin. In wells drilled to access ground water near hazardous waste sites, 1.3% of 156 Resource Conservation and Recovery Act (RCRA) sites and 0.9% of 178 Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Superfund sites had detectable levels of endrin in the early 1980s. No information about the presence of endrin aldehyde or endrin ketone in the environment was found.
You may also be exposed to endrin by eating foods that contain endrin. Before cancellation of endrin use, reported concentrations of endrin in domestic and imported food samples ranged from 0.05 to 0.50 parts per million (ppm; where 1 ppm = 1 microgram per gram (µg/g) of food). However, no endrin was detected in food samples from a Texas survey and only 0.084% of over 13,000 food samples were found to contain endrin in 1989 after cancellation of endrin use. Endrin was found in less than 1% of all food sampled by the U.S. Food and Drug Administration (FDA) in 1991. Because endrin is no longer used in the United States, residues on imported foods are the main source of potential human exposure in food. The levels of endrin aldehyde or endrin ketone in foods are not known.
Endrin levels can build up (bioaccumulate) in the tissues of organisms that live in water. In the 1986 EPA National Study of Chemical Residues in Fish, concentrations of endrin were found in fish at 11% of 362 sites surveyed (average 1.69 parts per billion Where 1 ppb = 1 nanogram per gram (ng/g) of food; maximum 162 ppb). Endrin was also detected in 21 of 31 samples of 2 commercial shrimp species from a Gulf Coast estuary receiving both industrial discharges, and urban and agricultural runoff. The average concentration was 1,070 and the maximum concentration was 9,470 ppb. Levels of endrin have probably declined, even in such polluted areas, since using endrin was banned.
Endrin has been detected in human breast milk (0.02-6.24 milligrams endrin in each kilogram milk fat [mg/kg]); this may be a route of exposure for nursing infants. However, no studies of endrin in breast milk in United States or Canadian populations have been conducted.
Health effects of endrin
Exposure to endrin can cause various harmful effects including death and severe central nervous system (brain and spinal cord) injury. Swallowing large amounts of endrin (more than 0.2 mg/kg of body weight) may cause convulsions and kill you in a few minutes or hours.
Symptoms that may result from endrin poisoning are headache, dizziness, nervousness, confusion, nausea, vomiting, and convulsions. Some of these symptoms may continue for weeks after exposure to high doses of endrin.
No long-term health effects have been noted in workers, either in factories or during field applications, who have been exposed to endrin by breathing or touching it.
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).
Studies in animals confirm that endrin's main target is the nervous system, probably because the brain and other parts of the nervous system contain much fatty tissue, and endrin tends to stay in those tissues. Birth defects, especially abnormal bone formation, have been seen in some animal studies. While there are no human data on birth defects, evidence in rodents suggests that exposure to high doses of endrin during pregnancy could be a health risk to developing fetuses.
In studies using rats, mice, and dogs, endrin did not produce cancer. However, most of these studies did not accurately evaluate the ability of endrin to cause cancer. No significant excess of cancer has been found in exposed factory workers, although endrin metabolites have been detected in their urine. The EPA has determined that endrin is not classifiable as to its human carcinogenicity because there is not enough information to allow classification. Endrin has also not been classified for carcinogenic effects by the Department of Health and Human Services (DHHS) or the International Agency for Research on Cancer (IARC).
One study in rodents suggests that exposure to endrin aldehyde or endrin ketone may cause liver disease. No other studies were found on how endrin aldehyde or endrin ketone can affect your health.
Medical tests for exposure to endrin
If you are exposed to endrin, the chemical can be detected in your blood, breast milk, or fatty tissue. These detection methods are referred to as biomonitoring. Tests can measure endrin in the blood or fat of people recently exposed. Endrin is cleared from the blood rapidly, so samples should be taken within 1-2 weeks of exposure. Since special analytical equipment is needed, these tests are not routinely performed in doctors' offices. Although these tests can be used to confirm that a person has been exposed to endrin, it is not yet possible to use those tests to predict the type or severity of any health effects that might occur. Endrin metabolites have been found in urine (0.001-0.14 micrograms per milliliter [µg/mL]; where 1 µg/mL = 1 ppm) and feces of workers exposed to endrin.
No information is available on tests for exposure to endrin aldehyde or endrin ketone.
Further Reading
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