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Home Testing for Endocrine Disruptors

17 Oct 18:20 12,593 views | Last edited by liz almost 2 years ago


This tool is being developed to enable people to test sources of water for the presence of environmental estrogens. An increasing number of structurally diverse chemicals encountered in the environment and common household items have been identified as environmental estrogens, compounds that can mimic many of the effects of natural estrogens. Well-studied examples include DDT and several other pesticides; chemicals such as bisphenol A (BPA) and nonylphenol that leach from polycarbonate and certain other plastics; and some flame retardants, including polybrominated diphenyl ethers (PBDEs).

Human and ecological health

There is growing concern that developmental exposures to such chemicals may have significant adverse effects on human health. Endocrine disruptors act like hormones---unlike other toxins, they are biologically active even (often, especially) at low doses. This is cause for concern in light of the ubiquity of exposure to environmental estrogens at such doses. BPA, for example, is one of the highest-volume chemicals in production worldwide. In a recent review, Vandenberg et al (2010) concluded:

We believe that human biomonitoring data clearly indicate that the general population is exposed to BPA ubiquitously, including significant internal exposures to unconjugated BPA. More important, animal studies suggest that fetuses and children are particularly vulnerable to BPA exposures and, at the same time, are exposed to higher levels of unconjugated BPA.

Once studied and discussed mainly by specialists in academic labs and regulatory agencies, the past several years have seen an enormous increase in public awareness and interest in the sources, routes of exposure, and potential impacts of environmental estrogens on human health and biodiversity.

Endocrine disruptors have potentially harmful effects on non-humans as well. Wildlife is also susceptible to environmental estrogens through exposures to pesticide runoffs from farmlands, excretion of synthetic estrogens by humans and farm animals, and estrogenic surfactant by-products of many compounds used in manufacturing. Pharmaceutical estrogens used for birth control and hormone replacement therapy in humans, as well as hormones used in commercial animal feedlot operations, end up in wastewater effluents that discharge to surface waters. It is believed that environmental estrogens are contributing to the large rise in the numbers of feminized fish seen in this country and elsewhere and may be a factor in biodiversity losses worldwide.

New screening and measurement tools

Because of the magnitude of concern over potential impacts of environmental estrogens, and the lack of basic information about possible estrogenic activities of most of the 80,000+ chemicals registered for use, there have been mounting efforts to develop simple laboratory assays for estrogenic activities of individual chemicals, environmental water samples, and chemicals that migrate from consumer products such as water bottles, baby bottles, food containers, children’s toys and plastic-based resins.

One of the simplest of these new tests is the yeast-based YESassay, in which a standard lab yeast strain has been engineered to contain (i) a human ER (hER) and (ii) a gene that, when bound by activated hER, produces the enzyme β-galactocidase (β-gal). In the absence of estrogen, no β-gal is produced. When estrogen or an estrogenic chemical like BPA is added, it induces synthesis of β-gal, which is then detected by a simple colorimetric assay in which β-gal converts one chemical (yellow) into a modified form (red), a reaction that is readily detected by simple visual inspection. While more sensitive and complex yeast-based assays have since been developed, those demand more expensive chemicals and instrumentation. As described in more detail later, the original YESassay is simple, robust and inexpensive enough to make it feasible as an assay for community-based education and testing. Thus, we plan to develop materials and protocols for this assay in a version that is suitable for community-based testing for environmental estrogens.

More Information

Applications and example uses

We aim that this tool be useful in testing tap water, bottle water, water ways and other water sources for the presence of environmental estrogens. We aim to generate an archive of findings from public lab researchers around the country to help document and generate public, scientific and regulatory attention to this issue.

How to make your own

We are currently in the earliest stage of development on this tool.

How to use it

We are currently in the earliest stage of development on this tool.

Get involved!

  • This is a research project that the Public Lab Toxics and Health working group is kicking off over the next couple of months. We are collaborating with Joan Ruderman from Harvard University and Gary Wessel from Brown University and Jean Huang from Olin College. Research on the project is sited at a lab at RISD and Olin College. Active public lab researchers are Yuyu Chen, Mara Strenberg, Avery Louie and Sara Wylie. We would love to have any public laboratory people help us out in this research process, email the public lab list if you're interested in joining in!
  • short-term goals: We are currently doing background readings on the human and environmental health impacts of environmental estrogens. Here is our reading list so far.[[|Bibliography for Estrogen Screen project]]
  • and places to start contributing To Do List before January 23rd grow week!

  • read up on growing yeast--particularly home brewing kits

  • read up on how to prepare water samples for testing. --Bisphenol A samples from water bottle --water from tap --drinks bottled in plastic (ex: Coke) --human or animal urine --canned foods (can linings are a huge source of BPA exposure) --water with Phthalates --what other samples could we test?
  • develop concepts for designing home testing kits
  • develop concept for gallery show: [[|possible vessel for estrogen cultures]]

Tags: environmental-estrogen-testing tool endocrine-disruptors