When considering the impact of chemicals our planet and the life forms that live here, it is instinctive to focus on things like highly toxic or carcinogenic solvents or other industrial materials. These sorts of toxins certainly are harmful to the environment and appropriate containment and disposal is a must, however there is another group of chemicals that pose significant but much less understood risk – prescription and over the counter drugs. Human and veterinary medications have the potential to enter the environment either through inappropriate disposal of unused materials, or through patients excreting excess drug or bioactive metabolites in urine or feces. Although such medications have been demonstrated to be safe when used appropriately for their intended purpose, the effects on unintended organisms in the wider ecosystem have typically not been well studied and manufacturer’s environmental impact studies, when required, can rely on unsupportable assumptions and estimations. Furthermore, compounds of this type are generally not removed or remediated by municipal sewage treatment and can be found in surface water in a variety of ecosystems around the world.
One example of a common prescription medication that has wider impacts on the environment is levonorgestrel (LNG), a synthetic gestagen that is widely used in various kinds of hormonal contraceptives including birth control pills and implants. In the clinical setting LNG is considered to be extremely safe with few significant side effects. However, compounds of this type are generally not removed by municipal sewage treatment allowing for accumulation in local ground water and soil. LNG can now be found in surface water in a variety of ecosystems around the world and scientists are still working to understand the scope of its potential environmental impact.
Since the purpose of LNG in the clinical setting is contraception it is perhaps not surprising that several studies have reported environmental LNG exposure leading to adverse reproductive effects in fish and amphibians.1-4 However recent reports have also demonstrated that even very low levels of environmental LNG affect the thyroid system in frogs resulting in developmental delay and arrested metamorphosis.5 This poses a potentially significant danger to already threatened or endangered amphibians. As studies to understand further the mechanisms through which LNG can impact the ecosystem continue, the ability to precisely quantitate LNG in water is a key component. The Arbor Assays Levonorgestrel (LNG) EIA kit is ideal for detecting LNG in surface water samples with a sensitivity of 2.20 pg/ml, no pretreatment of the samples, and a time to answer of just 90 minutes.
SPECIAL OFFER
50% off of one LNG Kit
With Discount Code: LNGMAIL
1-plate size, limit one per customer, US customers only
Valid through June 30 2017
References
1) Zellinger et al. 2009 Effects of synthetic gestagens on fish reproduction; Environ. Toxicol. Chem. 28 2663
2) Svensson et al. 2014 Environmental concentrations of an androgenic progestin disrupts the seasonal breeding cycle in male three-spined stickleback (Gasterosteus aculeates); Aquat. Toxicol. 147 84
3) Kvarnryd et al. 2011 Early life progestin exposure causes arrested oocyte development; oviductal genesis and sterility in adult Xenopus tropical frogs; Aquat. Toxicol. 103 18
4) Safholm et al. 2012 Disrupted oogenesis in the frog Xenopus tropical after exposure to environmental progestin concentrations; Biol. Reprod. 86 126
5)Lorenz et al. 2016 The synthetic gestated levonorgestrel directly affects gene expression in thread and pituitary of Xenopus leaves tadpoles; Aquat. Toxicol. 177 63