Dieldrin and Aldrin
At a Glance
Aldrin and dieldrin are toxic pesticides now banned due to concerns about their impact on human health.
They have been linked to both an increased risk of breast cancer and higher rates of mortality from breast cancer.
What are dieldrin and aldrin?
Aldrin and its active ingredient, dieldrin, are pesticides that were used on crops from the 1950s until they were banned for agricultural use in 1975.[1] Dieldrin continued to be used for termite control until being completely banned by the EPA in 1987.[2]
Where are dieldrin and aldrin found?
Aldrin and dieldrin are still being used in developing countries such as Kenya and Cameroon.[3],[4] Although no longer used in the United States, dieldrin is still found in the environment at very low levels due to historical use.[5] It has been detected in a variety of foods, especially those coming in contact with soil previously treated with the pesticide.[6] It can also be found in the air, water and soil around toxic waste sites.[7]
What evidence links dieldrin and aldrin to breast cancer?
Although levels in the environment are low, dieldrin builds up in the body over time.[8] Dieldrin is stored in fatty tissues such as breast tissue. High levels of dieldrin in the body have been linked to higher rates of breast cancer mortality.[9] Dieldrin is an endocrine disruptor, meaning that it interferes with hormones like estrogen and androgen in the human body and may impact risk of breast cancer.[10]
- Blood samples from healthy women were collected and analyzed 20 years apart for levels of dieldrin. Researchers found that women with higher levels of dieldrin had two to seven times the risk of developing breast cancer compared to women with lower levels.[11],[12] There was also a higher breast cancer mortality among women with the highest levels of dieldrin.[13]
- Studies using breast cancer cells found that dieldrin significantly increased cell reproduction.[14],[15]
- When exposed to dieldrin, normal human breast cells begin to act like cancer cells. The researchers propose that long-term exposure may cause the cells to completely transform into cancer cells.[16]
- Dieldrin increased the number and size of breast tumors in mice.[17] The chemical also affected the ability of female mice to get pregnant.[18]
What about effects of exposures to dieldrin in women who have been diagnosed with breast cancer?
Higher levels of blood dieldrin measured at the time of diagnosis are associated with both higher all-cause mortality and higher breast cancer specific mortality when women are followed for 5 or 15-plus years following diagnosis. The relationships are particularly strong for women diagnosed with ER+ tumors.[19]
Who is most likely to be exposed to dieldrin and aldrin?
Dieldrin sticks to soil and degrades very slowly.[20] Therefore, many people are exposed to low levels of dieldrin through contaminated soil and food.[21] Agricultural and termite control workers who used it in the past were exposed to the pesticides in higher concentrations. People living or working near where dieldrin was used may have also been exposed.[22] Dieldrin can also be passed from exposed mothers to fetuses and infants by crossing the placenta and accumulating in breast milk.[23]
Who is most vulnerable to the health effects?
The health effects associated with dieldrin depend on the level to which a person is exposed and the length of time in which the exposure occurs.[24]
What are the top tips to avoid exposure?
- Check to see if your home was once treated with dieldrin.[25]
- Avoid going near hazardous waste sites.[26]
Other Resources:
- ATSDR toxic substances portal https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=56
Updated 2019
[2] Snedeker, S M. “Pesticides and breast cancer risk: a review of DDT, DDE, and dieldrin.” Environmental Health Perspectives 109, 1 (2001): 35-47. doi:10.1289/ehp.01109s135.
[3] Wesseling, C et al. “Agricultural pesticide use in developing countries: health effects and research needs.” International Journal of Health Services 27, 2 (1997): 273-308. doi:10.2190/E259-N3AH-TA1Y-H591.
[4] Colopy, James. “Poisoning the developing world: the exportation of unregistered and severely restricted pesticides from the United States.” UCLA Journal of Environmental Law and Policy 13, 2 (1995): 177-178. Accessed October 28, 2020. https://escholarship.org/uc/item/7c287495.
[5] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[6] Høyer, A P et al. “Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study.” BMC Cancer 1 (2001): 8. doi:10.1186/1471-2407-1-8.
[7] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[8] Wesseling, C et al. “Agricultural pesticide use in developing countries: health effects and research needs.” International Journal of Health Services 27, 2 (1997): 273-308. doi:10.2190/E259-N3AH-TA1Y-H591.
[9] Snedeker, S M. “Pesticides and breast cancer risk: a review of DDT, DDE, and dieldrin.” Environmental Health Perspectives 109, 1 (2001): 35-47. doi:10.1289/ehp.01109s135.
[10] Høyer, A P et al. “Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study.” BMC Cancer 1 (2001): 8. doi:10.1186/1471-2407-1-8.
[11] Snedeker, S M. “Pesticides and breast cancer risk: a review of DDT, DDE, and dieldrin.” Environmental Health Perspectives 109, 1 (2001): 35-47. doi:10.1289/ehp.01109s135.
[12] Høyer, A P et al. “Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study.” BMC Cancer 1 (2001): 8. doi:10.1186/1471-2407-1-8.
[13] Høyer, A P et al. “Organochlorine exposures influence on breast cancer risk and survival according to estrogen receptor status: a Danish cohort-nested case-control study.” BMC Cancer 1 (2001): 8. doi:10.1186/1471-2407-1-8.
[14] Andersen, Helle Raun et al. “Effects of currently used pesticides in assays for estrogenicity, androgenicity, and aromatase activity in vitro.” Toxicology and Applied Pharmacology 179, 1 (2002): 1-12. doi:10.1006/taap.2001.9347.
[15] Soto, A M et al. “The pesticides endosulfan, toxaphene, and dieldrin have estrogenic effects on human estrogen-sensitive cells.” Environmental Health Perspectives 102, 4 (1994): 380-3. doi:10.1289/ehp.94102380.
[16] Valerón, Pilar F et al. “Differential effects exerted on human mammary epithelial cells by environmentally relevant organochlorine pesticides either individually or in combination.” Chemico-Biological Interactions 180, 3 (2009): 485-91. doi:10.1016/j.cbi.2009.04.010.
[17] Cameron, Heather L and Warren G. Foster. “Developmental and lactational exposure to dieldrin alters mammary tumorigenesis in her2/neu transgenic mice.” Plos One 4 (2009): 4303. doi:10.1371/journal.pone.0004303.
[18] Cameron, Heather L and Warren G. Foster. “Developmental and lactational exposure to dieldrin alters mammary tumorigenesis in her2/neu transgenic mice.” Plos One 4 (2009): 4303. doi:10.1371/journal.pone.0004303.
[19] Roswall, Nina et al. “Organochlorine concentrations in adipose tissue and survival in postmenopausal, Danish breast cancer patients.” Environmental Research 163 (2018): 237-248. doi:10.1016/j.envres.2018.02.003.
[20] ToxGuide for Aldrin/Dieldrin. (2002). http://www.atsdr.cdc.gov/toxguides/toxguide-1.pdf. Retrieved July 6, 2016.
[21] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[22] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[23] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[24] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
[25] Wesseling, C et al. “Agricultural pesticide use in developing countries: health effects and research needs.” International Journal of Health Services 27, 2 (1997): 273-308. doi:10.2190/E259-N3AH-TA1Y-H591.
[26] Agency for Toxic Substances and Disease Registry. “Toxic Substances Portal: Aldrin/Dieldrin.” Last modified September 2002. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=316&tid=56.
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