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Anna McLean

NRDC: Endocrine Disruptors - 0 views

www.nrdc.org/...qendoc.asp

shared by Anna McLean on 11 Jun 10 - Cached
  • 5. Should humans be concerned for their health based on evidence that fish, birds and alligators have been affected? Yes. All vertebrates (fish, amphibians, reptiles, birds, and mammals, including humans) are fundamentally similar during early embryonic development. Scientists can therefore use the evidence acquired on other species to make predictions about endocrine disrupting effects on humans.
  • 6. Is there direct evidence that humans are susceptible to endocrine disruption?
  • 8. These days don't chemicals have to be safe to be allowed on the market? No.
  • Anna McLean on 11 Jun 10
     
    Frequently asked-type questions
  • Anna McLean on 11 Jun 10
     
    Obviously, this site is for the general public. But, it could be a useful link for your webpages if you want some basic background information to persuade people that this IS relevant to them and their families.
suwhitte

Environmental Health Perspectives - 0 views

ehp03.niehs.nih.gov/home.action

EED general

shared by suwhitte on 14 May 10 - Cached
  • suwhitte on 14 May 10
     
    Environmental Health Perspectives (EHP) is a monthly journal of peer-reviewed research and news published by the U.S. National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services. EHP's mission is to serve as a forum for the discussion of the interrelationships between the environment and human health by publishing in a balanced and objective manner the best peer-reviewed research and most current and credible news of the field. With an impact factor of 6.12, EHP is the top monthly journal in public, environmental, and occupational health and the second-ranked monthly journal in environmental sciences. The environmental health sciences include many fields of study and increasingly comprise a multidisciplinary research area. EHP publishes articles from a wide range of scientific disciplines encompassing basic research; epidemiologic studies; risk assessment; relevant ethical, legal, social, environmental justice, and policy topics; longitudinal human studies; in vitro and in vivo animal research with a clear relationship to human health; and environmental medicine case reports. Because children are uniquely sensitive to their environments, EHP devotes a research section specifically to issues surrounding children's environmental health. Search current issue and archives for journal articles related to your topic.
Vanessa Ward

San Francisco Medical Society | The Weight of Evidence - 0 views

www.sfms.org/...Template.cfm

SFMS Blumberg Grun obesity epidemic endocrine disruption EDCs obesity

shared by Vanessa Ward on 11 Jun 10 - Cached
  • “leading to neglect of other plausible mechanisms and well-intentioned but potentially ill-founded proposals for reducing obesity rates”
  • Since publication of that review, substantial evidence has emerged that increases the plausibility of one of the alternative mechanisms suggested by Keith et al: disruption of weight regulation by endocrine-disrupting chemicals (EDCs) in the environment.
  • Concerns about the potential contribution of EDCs to childhood obesity build from two considerations, one out of human biology and the other from animal experiments
  • ...7 more annotations...
  • Prior
  • toxicologists were concerned more with weight loss, which was seen as an adverse outcome.
  • Many of these chemicals alter the behavior of specific genes that are involved in determining the number of fat cells (adipocytes) an individual will have as an adult.
  • he list of contaminants implicated by animal studies is substantial, including several estrogenic EDCs such as DES, bisphenol A, soy phytoestrogens
  • Almost no human data are available to test the obesogen hypothesis in people. No epidemiological evidence exists, because the hypothesis is so new
  • One in vitro experiment, however, has demonstrated that exposure to obesogens increases the rate of conversion of human stem cells to adipocytes (Kirchner et al 2010), confirming the validity of the basic mechanism and the relevance of the animal studies to people.
  • That would be a big win for medicine and public health.
  • Vanessa Ward on 11 Jun 10
     
    San Francisco Medical Society discusses the possible relationship between chemical exposure and the obesity epidemic.
suwhitte

Environment and health: 6. Endocrine disruption and potential human health implications... - 0 views

www.cmaj.ca/...1471

shared by suwhitte on 20 May 10 - Cached
  • suwhitte on 20 May 10
     
    link to a pdf of a review article on endocrine disruptors and human health. A nice overview of the field.
Anna McLean

Human Health: Fish consumption -- Critical contaminants - 1 views

www.great-lakes.net/...critical.html

shared by Anna McLean on 24 May 10 - Cached
  • DDT and DDE are probable human carcinogens and endocrine disrupters.
  • Mercury is not known to be a carcinogen, but it is toxic to the fetuses of humans and animals.
  • ercury in Lake Huron fish has caused fish consumption advisories and has been detected in Lake Huron water, sediment and wildlife.
  • Anna McLean on 24 May 10
     
    Although the use of DDT was banned a long time ago, it is still negatively affecting wild life. This page adds more detail to what we saw in the film, "The Estrogen Effect: Assault on the Male."
  • Anna McLean on 24 May 10
     
    Under the metals section, there is a short description of heavy metals. These metals are known to damage organisms, and as shown in some of our mini-presentations, can act as EEDs. For example, erythropoietin's functions are inhibited by lead as an EED.
Liz Richardson

Global assessment of the state-of-the-science of endocrine disruptors - 0 views

www.who.int/...index.html

general EED wildlife humans

shared by Liz Richardson on 21 May 10 - Cached
  • Liz Richardson on 21 May 10
     
    This is just the index, but the WHO has attempted to pinpoint which hormone compounds are most effective EEDs, and which hormones are most often mimicked. Discusses EED effects on wildlife as well as humans. Criteria for assessment of endocrine disruptors proposed for future studies.
suwhitte

Gordon Research Conferences - 2010 Program (Environmental Endocrine Disruptors) - 0 views

www.grc.org/programs.aspx

shared by suwhitte on 20 May 10 - Cached
  • suwhitte on 20 May 10
     
    At this upcoming conference and past conferences (see conference history), top scientists, studying endocrine disruption effects on humans and wildlife, meet to share the latest findings. Look over the program for topics and scientists - may be useful in identifying a topic for your project. I have attended two of these conferences and they were excellent and very current.
Vanessa Ward

Epigenetics, Evolution, Endocrine Disruption, Health, and Disease -- Crews and McLachla... - 1 views

endo.endojournals.org/...s4

shared by Vanessa Ward on 22 May 10 - Cached
  • Endocrine-disrupting chemicals (EDCs) in the environment have been linked to human health and disease. This is particularly evident in compounds that mimic the effects of estrogens.
  • information recently uncovered, regarding mechanisms of endocrine and environmental signaling, to explore the role of the environment in health and disease.
  • Vanessa Ward on 22 May 10
     
    This a good article that gives a general overview of EDC's and the role they play in the compromise of physical and mental health. One particularly interesting thing is how a discussion of EDC's and evolution is presented.
srom88

Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimatin... - 1 views

www.ncbi.nlm.nih.gov/...PMC1874187

shared by srom88 on 24 May 10 - Cached
  • In addition to having highly permeable skin (which makes amphibians particularly vulnerable to chemical contaminants), amphibians also typically reproduce and pass through critical hormone-regulated developmental stages while in the aquatic environment
    • srom88
      srom88 on 24 May 10
       
      What about human skin and its permeability to these pesticides?
  • atrazine is of special concern because it is a ubiquitous, persistent contaminant of ground-water and surface water that is active at low, ecologically relevant concentrations
    • srom88
      srom88 on 24 May 10
       
      Atrazine is common pesticide used; definite possibility for a focus.
  • realistic pesticide mixture composed of chemicals applied to cornfields in York County, Nebraska.
    • srom88
      srom88 on 24 May 10
       
      Can also find different experiments in different locations in the US or even out of the country.
  • ...32 more annotations...
  • Radioimmunoassay
    • srom88
      srom88 on 24 May 10
       
      very sensitive technique used to measure concentrations of antigens (for example, hormone levels in the blood) without the need to use a bioassay.
  • With the exception of metalaxyl, no single compound affected mortality
  • mortality was 4% for animals exposed to single pesticides (range = 0–7.8%), with the highest mortality (7.8%)
  • Propiconizole significantly delayed time to initiate metamorphosis (FLE; F = 2.72, df = 10, p = 0.003) and time to complete metamorphosis (TR; F = 2.81, df = 10, p = 0.002) relative to controls (Figure 1).
  • Animals exposed to pesticide mixtures at 0.1 ppb had significantly longer larval periods: initiation of metamorphosis (days to FLE) was delayed
  • there was a significant effect on SVL at metamorphosis (F = 2.1, df = 10, p < 0.05; Figure 3). The smallest animals to metamorphose were those exposed to cyfluthrin, tebupirimphos, or atrazine
  • All the mixtures (0.1 ppb each pesticide) retarded growth
  • For the pesticide mixtures, 0.1 and 10 ppb atrazine + S-metolachlor resulted in a negative but nonsignificant relationship between TR and SVL, whereas 0.1 and 10 ppb Bicep II Magnum exposure resulted in maintenance of the positive relationship between TR and SVL, but the relationship was significant for the 0.1 ppb concentration only
    • srom88
      srom88 on 24 May 10
       
      Different combinations of pesticides will affect the organism differently.
  • Histologically, presumptive males maintained both a cortex and a medulla separated by connective tissue without clear formation of testicular lobules (e.g., undifferentiated), whereas females showed regression of the gonadal medulla and an ovarian vesicle but lacked significant numbers of developing oocytes in the cortical regions of the gonad
  • Seventy percent of the animals exposed to the nine-compound mixture were unable to sit upright. Exposure to the nine-compound pesticide mixture was associated with meningitis, otitis interna, and septicemia due to the gram-negative, water-borne bacteria Chryseobacterium (Flavobacterium) menigosepticum
  • Morbidity and mortality rates in animals treated with the nine-pesticide mixture were significant (G = 100.12, df = 4, p < 0.001) compared with those in controls or the other mixtures (all of which showed a 0% incidence) and reached 70% of the 59 animals that survived to complete metamorphosis in animals exposed to the pesticide mixture.
  • After noting that animals exposed to the nine-compound mixture contracted flavobacterial meningitis (see above “Flavobacterial response”), we examined the condition of the thymus as an estimate of immune function.
  • Although a sizable database examining the toxicological effects of pesticides on amphibians exists (Pauli 2004), most of these studies examine acute toxicity, morbidity, and mortality only
  • We demonstrated that a realistic pesticide mixture (based on a mixture applied to an actual field) at low ecologically relevant concentrations can have dramatic effects on amphibian development and growth, and ultimately (we predict) survivorship
  • one of these compounds (propiconizole) retards larval development and delays metamorphosis, and two others (tebupirimphos and cyfluthrin) retard larval growth. In addition to these new data, the present study confirms the retardation of amphibian development
  • Atrazine has a number of well-documented adverse effects on amphibian larvae. It is a potent endocrine disruptor that both chemically castrates and feminizes exposed male amphibian larvae and also retards larval development and growth
  • It also induces edema (Carr et al. 2003), erratic swimming (Carr et al. 2003), and irregular behavioral activity (Rohr and Palmer 2005) and is an immunosuppressant (Christin et al. 2003; Gendron et al. 2003; Kiesecker 2002) in amphibians.
  • As one of the world’s most commonly applied pesticides, it is the most common contaminant of groundwater and surface water
  • effects of atrazine on the gonads were not detectable because individuals from the present population do not complete sexual differentiation of the gonads before metamorphosis
  • retardation of growth and development was more severe when atrazine was combined with other pesticides (e.g., S-metolachlor), and the nine-pesticide mixture had the most severe impact.
  • amphibians (including leopard frogs) often breed in temporary water sources
  • Retardation of growth is also detrimental. Smaller size at metamorphosis limits food availability for newly metamorphosed frogs, which are gape-limited predators (Figure 12A). Further, smaller individuals are more susceptible to predators, which may also themselves be gape-limited predators
  • esticide mixtures retard growth and size at metamorphosis, exposed amphibians are less likely to find food and more likely to be preyed upon. Also, decreased size at metamorphosis combined with subsequent decreased postmetamorphic growth decreases the chances that amphibians will survive overwintering
  • alteration of the relationship between time to metamorphosis and size at metamorphosis is even more significant than either measured alone. In amphibians, the larval stage is a period of growth. A
  • pesticides that produce no effects alone may act as “enhancers” that worsen the effects of pesticides that act as “effectors” when the two groups of chemicals are combined.
  • characterize pesticide interactions as concentration additive or response additive
  • Pesticide-induced declines in populations as a result of decreased prey availability and increased susceptibility to predators (as a result of decreased size and the negation or reversal of the relationship between time to metamorphosis and size at metamorphosis) may be difficult to discern in the wild. Perhaps more important, emergent diseases caused by agents such as ranavirus
  • and chytrid
  • are considered major contributors to amphibian declines
  • the effects of atrazine on sex differentiation can negatively affect amphibian population
  • trazine has been shown to increase disease rates and parasite loads in amphibians by several pathogens
  • including the trematode associated with development of limb deformities
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