Protecting Children’s Health Preventing Children’s Exposure to Endocrine Disruptors - by Lawrence H. Keith, Ph.D. Version 1.2
Copyright 2002 by Instant Reference Sources, Inc. 2 Introduction F There are many chemicals that are present in our environment that have unknown impacts on children F One such group of chemicals are endocrine disrupting chemicals. F This is a complex and controversial topic that is still rapidly developing. F Endocrine disruptors is a new category of pollutants that do not appear to do much harm to adults - however, they may harm our children. In fact, the younger the child, the greater is the risk of harm if the child is exposed to these chemicals. The unborn child is thus at greatest risk.
Copyright 2002 by Instant Reference Sources, Inc. 3 What We Will Be Discussing F What endocrine disruptors are F What determines when a chemical is an endocrine disruptor F How endocrine disruptors can harm people F Why children are at higher risk than adults from endocrine disruptors F How children’s behavior increases their risk to chemical exposure F Public concerns and views about endocrine disruptors F Sources of endocrine disruptors
Copyright 2002 by Instant Reference Sources, Inc. 4 More of What We Will Be Discussing F EPA’s approach to regulating endocrine disruptors F Types of chemicals that are suspect endocrine disruptors F Progress (or lack of it) being made to regulate endocrine disruptors F Where to find more information about this topic F How to protect children from endocrine disruptors F How to contact the author
Copyright 2002 by Instant Reference Sources, Inc. 5 What is The Endocrine System? l The endocrine system is a system of glands that produce chemical messengers (hormones) and the receptors in tissues that respond to them. u Examples include the thyroid, pituitary and adrenal glands plus the male and female reproductive systems.
Copyright 2002 by Instant Reference Sources, Inc. 6 What are Endocrine Disrupting Chemicals (EDCs) F They are synthetic and naturally occurring chemicals that affect the balance of normal hormone functions in animals (including humans). l They may be estrogen or androgen modulators. u These are sex hormones! As “modulators” EDCs may either mimic these sex hormones or else block their activities (blocking chemicals are called anti-estrogens and anti-androgens). Either way, the effects are bad.
Copyright 2002 by Instant Reference Sources, Inc. 7 What are the Effects of Endocrine Disruptors? F The exact effects are dependent on the animal species, its age, its gender, the amount of exposure, and the timing of the exposure. l Fetuses and newborns are the most susceptible. u The reason is because sex hormones regulate sexual differentiation during fetal development. u Therefore, timing of exposure may be more important than the dose! l Sex hormones also play a role in organization of specific areas of the brain. u However, not much is known about this action yet.
Copyright 2002 by Instant Reference Sources, Inc. 8 Characteristics of Endocrine Disruptors F Thus, effects of endocrine disruptors are not focused on adults but rather on the fetus and young children. F A major complexity is that the effects in humans or other animals may not be discernable for many years after a person is born. Typically, problems arise when humans reach puberty. Source: L. H. Keith, Environmental Testing & Analysis, Vol. 8, No. 4, July/August, 1999, p.p. 27 - 28.
Copyright 2002 by Instant Reference Sources, Inc. 9 F The endocrine system appears to be similar in most animals, which means that endocrine disruptors are expected to have similar effects in most animals. l This is in contrast to the situation with carcinogens where we know that feeding studies do not necessarily mimic closely the carcinogenic effect that may occur in humans. More Characteristics of Endocrine Disruptors Source: L. H. Keith, Environmental Testing & Analysis, Vol. 8, No. 4, July/August, 1999, p.p. 27 - 28.
Copyright 2002 by Instant Reference Sources, Inc. 10 Suspected Effects in Boys and Men F Male Fertility l Reduction in sperm production. l Reduced ability of sperm’s ability to fertilize an egg. F Sexual Development Defects and Cancer l Undescended testicles in baby boys. l “Inter-sex” features (male and female organs) in baby boys. l Shorter than normal penises. l Increased incidences of cancer of the testicles in younger men. l Prostate enlargement in older men.
Copyright 2002 by Instant Reference Sources, Inc. 11 Suspected Effects in Girls and Women F Difficulty in becoming pregnant l Also difficulty in maintaining pregnancy. F Breast Cancer l This is complex and endocrine disruptors may only be one of multiple contributing factors. F Endometriosis l This is when bits of uterine lining migrate to other pelvic organs causing pain, internal bleeding, and infertility
Copyright 2002 by Instant Reference Sources, Inc. 12 Other Suspected Effects F Damage to the Immune System l This type of effects has been observed with wildlife - it is also suspected to occur with exposed humans. The classic work that brought effects of chemical pollution in wildlife to our attention was Rachel Carson’s Silent Spring in 1962. The classic work that brought effects of endocrine disruptors in wildlife to our attention was Our Stolen Future in 1996.
Copyright 2002 by Instant Reference Sources, Inc. 13 Additional Suspected Effects F Increased Incidences of Goiters l Goiters are enlargements of the thyroid gland. u They can disrupt metabolism and result in the “wasting syndrome” F Hyperactivity, Learning, & Attention Problems l These include neurological disorders such as abnormalities in behavior, difficulty in learning, distorted sensory functions, and immunological disorders that may cause susceptibility to disease, hypersensitivity and allergies. Source: American Chemical Society, “Endocrine Disruptors,” Science in Focus, 1998, Washington, DC
Copyright 2002 by Instant Reference Sources, Inc. 14 Why Children are More at Risk Than Adults from Exposure to Endocrine Disruptors F “Children are not just little adults. As a percentage of body weight, they breathe more air, drink more water, and eat more food than adults.” F “Their organ systems are undergoing rapid and sweeping development changes, and their behavior brings them into near constant contact with their physical environment.” Source: Jeff Johnson, Chemical & Engineering News, October 25, 1999, p.p. 28 - 30, American Chemical Society, Washington, DC.
Copyright 2002 by Instant Reference Sources, Inc. 15 Children’s Developing Bodies Also Differentiate Their Exposure Risks from Adults F “During the differentiation of reproductive organs, hormones, growth factors, and other endogenous chemical mediators regulate gene expression and direct differentiation.” F “One marked difference between exposure to endocrine disruptors during critical periods in development versus during adulthood is the irreversibility of an effect during development.” F Disruption of the action of estrogen (the female hormone) or androgen (the male hormone) during critical periods (for example, when the fetus is rapidly developing in the mother’s body) can lead to permanent alterations in the development of reproductive organs and other tissues with receptors for these hormones. Source: R. Bigsby, R. E. Chapin, G. P. Daston, B. J. Davis, J. Gorski, L. Earl Gray, K. L. Howdeeshell, R. T. Zoeller, and F. S. vom Saal, Environmental Health Perspectives, Vol. 107, Supplement 4, August 1999, p.p. 613 - 618.
Copyright 2002 by Instant Reference Sources, Inc. 16 In Agricultural Areas Pesticides May Drift Into Homes With Dust F In general the house dust collected from indoor carpeted areas of agricultural workers had concentrations of organophosphate pesticides 7 times higher than the house dust collected in similar areas from urban sites. l This is of concern since young children crawl around on these areas and also breathe air with stirred up dust on the floors. l The study found that children of agricultural workers have about a 4 times greater exposure to organophosphate pesticides than other children in the same community. Source: C Lu, R Fenske, J Touchstone, T Moate, G Kedan, D Knutson, and D Koch Box, Pages 131-132 in Preprints of Extended Abstracts, Vol. 39 No. 2, Symposia Papers Presented Before the Division of Environmental Chemistry American Chemical Society New Orleans, LA August 22-26, 1999. (Summary available from Dr. Keith on the Internet at http://www.acs-envchem.duq.edu/neworl.htm)
Copyright 2002 by Instant Reference Sources, Inc. 17 Children May Be Exposed at Schools and Day Care Centers F At the request of Senator Joe Lieberman (CT), the General Accounting Office (GAO) prepared a report on pesticide spraying in schools. It indicated that parents, educators, and government officials know little about the amount of pesticides being sprayed at schools or how often children are exposed. l The review documented 2,300 pesticide exposures in American schools from 1993 - 1996 and found that 329 of those individuals required some medical attention. There was no follow up information on 40% of the 2,300 exposure cases. l These figures are incomplete and unreliable because of the lack of hard data about pesticide use in the nation’s 110,000 public schools. And this doesn’t even include private schools and day care centers. Source: Senator Lieberman’s web site available January 5, 2000 at http://www.senate.gov/member/ct/lieberman/general/r010400a.html
Copyright 2002 by Instant Reference Sources, Inc. 18 Findings of the GAO Report 1. There is no comprehensive, readily-available national or state-by-state data on the amount and kinds of pesticides being used in schools. 2. Although regulations require pest control companies to keep records for two years on the amount and site of pesticide applications, only one state requires them to report the information. 3. For the cases of school exposures where follow up did occur, 329 individuals were seen at health care facilities, 15 were hospitalized, and 4 were treated in intensive care units. 4. Eight states collect information on the use of pesticides within their states, but only 2 collect information on pesticides used in schools. No state collects information on exposure patterns in schools. 5. There are no standard criteria for clearly identifying illnesses linked to pesticide exposure; misclassification of pesticide illness is common. Source: Senator Lieberman’s web site available January 5, 2000 at http://www.senate.gov/member/ct/lieberman/general/r010400b.html
Copyright 2002 by Instant Reference Sources, Inc. 19 Senator Lieberman’s Comments F The information gap on pesticide use in schools is troubling because “...children are particularly vulnerable to risks associated with pesticides, including elevated rates of leukemia and brain cancer.” F “…while we have a national framework for protecting workers from environmental and health hazards on the job, we have no such system for protecting children from toxic substances in the classroom.” F Lieberman called on EPA to take immediate steps and start by providing guidance to pest control companies and school officials on the relative risks of different application methods, and setting strong uniform guidelines for notifying parents and educators before pesticides are used on school grounds. Source: Senator Lieberman’s web site available January 5, 2000 at http://www.senate.gov/member/ct/lieberman/general/r010400a.html
Copyright 2002 by Instant Reference Sources, Inc. 20 Examples of Exposure to Pesticides at Schools F Many schools and day care centers are regularly sprayed with pesticides. Outdoors, children and wildlife are exposed to pesticides used on lawns and gardens, public parks, and playing fields. The pesticides then can be tracked indoors. Also, wooden playground structures are often treated with wood preservatives. [Source #1] F Numerous studies document that children who suffer chronic or acute exposure to pesticides experience elevated rates of childhood leukemia, soft tissue sarcoma, and brain cancer. [Source #2] l One recent study showed that after a single broadcast application in an indoor setting of chlorpyrifos, a pesticide commonly used in schools, the chemical remained on children’s toys and hard surfaces for two weeks, resulting in exposure 21 to 119 times above the current recommended safe dose. [Source #2] Source #1: WWF Canada available January 5, 2000 at http://www.wwfcanada.org/reduce-risk/c_index.html Source #2: Senator Lieberman’s web site available January 5, 2000 at http://www.senate.gov/member/ct/lieberman/general/r010400a.html
Copyright 2002 by Instant Reference Sources, Inc. 21 How to Reduce Children’s Exposure to Pesticides in Schools and Day Care Centers F When a school uses pesticides it should notify parents and teachers a day in advance. F The least toxic materials possible to do the job should be used. F People should not be allowed back into the buildings until the residue is gone. (Author’s note: as a chemist, this is not a practical statement because a specific amount per surface area should be recommended). F Only trained and licensed people should be allowed to spray pesticides. F If outside grounds and fields where children play are treated with pesticides then prior notice should be given to parents and teachers. F If a school has wooden playground products that are made from treated wood (typically using arsenic and copper compounds) then the surfaces should be painted to seal it and reduce leaching. Source: Environment and Human Health, Inc. web site available January 5, 2000 at http://www.ehhi.org/12steps.html
Copyright 2002 by Instant Reference Sources, Inc. 22 A New Congressional Initiative - School Environment Protection Act (SEPA) F Introduced by Senators Robert Torricelli (NJ) and Patty Murray (WA) on October 12, 1999 (S 1716), and by Representative Holt (NJ) on November 9, 1999 (HR 3275). Co-sponsored by Senator Robert Lieberman (CN) on December 22, 1999. l The act would require public schools to use Integrated Pest Management (IPM) approaches to pest control and identify acceptable “least toxic” pesticides. It would allow a school to use conventional pesticides only if a pest cannot be controlled after using IPM and least toxic pesticides, and provided the school staff and parents are notified 72 hours prior to application. l The act also excludes from use in schools pesticides that are determined by EPA to cause cancer, mutations, birth defects, reproductive dysfunction, neurological and immune system effects, endocrine system disruption, and those pesticides rated as acutely and moderately toxic. l Source: NCAMP, January 5, 2000 at http://www.safe2use.com/media/sepa.htm
Copyright 2002 by Instant Reference Sources, Inc. 23 S. 1716 [106th]: School Environment Protection Act of 1999 F Sponsor:Sen. Robert Torricelli [D-NJ]Sen. Robert Torricelli [D-NJ] F Cosponsors (6): Sen. John Kerry [D-MA]Sen. Paul Sarbanes [?-MD]Sen. Barbara Mikulski [D-MD]Sen. Christopher Dodd [D-CT]Sen. Joseph Lieberman [D-CT]Sen. Patty Murray [Sen. John Kerry [D-MA]Sen. Paul Sarbanes [?-MD]Sen. Barbara Mikulski [D-MD]Sen. Christopher Dodd [D-CT]Sen. Joseph Lieberman [D-CT]Sen. Patty Murray [ F Status: IntroducedOct 12, 1999 F Reported by Committee- F Voted on in Senate- F Voted on in House- F Signed by President- F This bill never became law. This bill was proposed in a previous session of Congress. Sessions of Congress last two years, and at the end of each session all proposed bills and resolutions that haven't passed are cleared from the books. F Last Action:Oct 12, 1999: Read twice and referred to the Committee on Agriculture. F This bill is identical to S. 2109 (Status: Dead).S. 2109
Copyright 2002 by Instant Reference Sources, Inc. 24 Where Can You Find More Information? F We’ve barely scratched the surface. Your library and the Internet have a wealth of additional information. Here are some more leads: F The book, Our Stolen Future (in your local bookstore, from amazon.com, etc.) F U.S. EPA endocrine disruptor page at http://www.epa.gov/scipoly/oscpendo F The author’s web page at www.instantref.com/eed.htm F Wayne Sinclair, MD, web page at www.chem-tox.com/cancerchildren/ F An excellent Japanese Web Site at http://www.nihs.go.jp/hse/environ//endocrin.html F National Coalition Against the Misuse of Pesticides at http://www.ncamp.org F Environment and Human Health, Inc. at http://ehhi.org/intro.html F World Wildlife Fund Canada at http://www.wwfcanada.org/hormone-disruptors F National Science and Technology Council - Endocrine Disruptors Research Initiative at http://www.whitehouse.gov/WH/EOP/OSTP/Environment/html/fac_endocrine.html F National Institutes of Environmental Health Sciences Environmental Health Perspectives at http://ehis.niehs.nih.gov/
Copyright 2002 by Instant Reference Sources, Inc. 25 Suspect Endocrine Disruptors Cover Many Different Kinds of Chemicals F The following list illustrates the wide variety of chemicals that may need to be monitored in the environment and food: l Biocides - chemicals that kill animals like barnacles and snails l Insecticides - chemicals that kill mosquitoes and other bugs l Herbicides - chemicals that kill weeds l Fungicides - chemicals that kill fungus l Industrial Organic Chemicals - solvents, plastics, paints, etc. l Metals - mercury, arsenic, tin, and chromium l PCBs - now are banned from commercial use l Chemicals with no commercial use - chlorinated dioxins and furans (these were impurities in Agent Orange used in the Vietnam War to defoliate the forests and they are also produced naturally in forest fires). Source: Dr. L. H. Keith at the Waste Testing and Quality Assurance Symposium, July 1997, Washington, DC
Copyright 2002 by Instant Reference Sources, Inc. 26 Where Are We Now? F EPA is less than halfway through the job of revising new limits for pesticides on food that were based on risks to adults to make them safer for risks to children. F “The Agency is mired in a regulatory battle fraught with law suits, lobbying and legislative pressure.” l “Policy papers and health studies that were supposed to guide the reassessment effort are bogged down in politicized scientific debates.” l “Proposed rule changes are slowed by technical challenges, some engineered by former EPA officials now working as consultants for pesticide concerns.” l Less than 40% of the 5,500 pesticides have new limits. l The endocrine disruptor screening program is still not launched. Source: USA Today, August 30, 1999 pages 1A - 2A
Copyright 2002 by Instant Reference Sources, Inc. 27 But There Are Two Sides to This Story F “Farmers and pesticide manufacturers say that many of the pesticides in EPA’s sights have been used for decades and that the Agency has scant scientific evidence to justify further restrictions.” F “New limits could leave crops vulnerable to pests, leading to food shortages.” Author’s Comment: Remember, EPA still doesn’t have tests that can differentiate definitively between endocrine disruptors and non-endocrine disruptors. This is a difficult test when one has to rely on the effects of chemicals on organisms to make this distinction. Source: USA Today, August 30, 1999 pages 1A - 2A
Copyright 2002 by Instant Reference Sources, Inc. 28 What Can You Do to Protect Children? F First, don’t over react. For example, don’t stop breast feeding just because of a fear of exposure of your baby to endocrine disruptors. Evaluate the situation and if, as a parent, you feel that you have a higher than average exposure to pesticides or other chemicals, then check with your doctor. Breast feeding has many health advantages. F Write to your senators and congressmen to let them know how you feel about the dead legislation.
Copyright 2002 by Instant Reference Sources, Inc. 29 What Can You Do to Protect Children? F Work with your local school boards, day care directors, parent-teachers associations, and local environmental chemists to evaluate planned pesticide applications, provide adequate prior notification to parents and teachers, make sure that trained and licensed professionals apply the chemicals, and insure that good records (i.e., what chemicals were applied, how much, where, and when) are kept by the school. F When wood treated with arsenic, copper, pentachlorophenol, and other toxic chemicals is used for playground equipment, paint its surfaces to minimize leaching of the chemicals which may result in higher exposure to children through skin absorption.
Copyright 2002 by Instant Reference Sources, Inc. 30 What Can You Do to Protect Children? F Avoid areas that have been recently sprayed with pesticides. F Wash all fruits and vegetables before preparing them for infants, children, and pregnant or nursing women. F Wash children’s hands before eating. Remember, the hand to food to mouth route is normal for a child’s eating habits. Keep tables, floors, and horizontal surfaces clean where dirt, dust, and all manner of particulate materials can concentrate. F Keep a reasonably clean, dust-free, dirt-free house. You aren’t going to be able to prevent children from crawling (nor do you want to) so make their environment as clean as possible.
Copyright 2002 by Instant Reference Sources, Inc. 31 What Can You Do to Protect Children? F When possible, select phthalate-free plastic toys for infants (these will be labeled). F If cockroaches are a problem, use an integrated approach consisting of filling gaps and cracks, keep the areas clean, and use pest baits in addition to spraying with pesticides. Be sure all foods are removed from any area sprayed with pesticides. F If fleas are a problem, use low-dose products if possible and keep treated pets away from children immediately after dipping or spraying.
Copyright 2002 by Instant Reference Sources, Inc. 32 What Can You Do to Protect Children? F Be aware of any unusually high occurrences of health problems involving symptoms from exposure to endocrine disruptors in your neighborhood. If there seem to be problems, call them to the attention of your doctor for potential referral to an epidemiologist. F Read and keep up with pending developments in this rapidly changing field. As information becomes available you’ll be seeing many more articles on endocrine disruptors in the press and on TV. There is more we don’t know than what we do know about this problem today.