Frequently Asked Questions
Body Burden: The Pollution in Newborns: Frequently Asked Questions
Question #1: How does this study compare to the government's National Exposure Report?
In late July 2005 the Centers for Disease Control and Prevention (CDC) plans to release its third in a series of National Exposure Reports, a study that "provides an ongoing assessment of the U.S. population's exposure to chemicals," including many of the industrial chemicals EWG tested in umbilical cord blood.
Our study compares and contrasts with CDC's in the following ways:
- The CDC studies primarily adults, and tests for just a handful of chemicals in children ages one and older. EWG studied children at the moment of birth. By testing umbilical cord blood, our study defines the mixtures of chemicals that pollute a child in the womb, during the time in life of the highest sensitivity to harm from chemical exposures. CDC has not tested newborns in any of its National Exposure Report studies.
- The CDC studies individual chemicals in a multitude of people. Our study examined individual people, in this case newborns, for a multitude of chemicals.
- The CDC's work helps us assess exposure levels for each targeted contamination across the U.S. population. Our study documents instead the complex reality of the mixtures of chemicals in individual people — the human "body burden."
Although CDC's results from the Third National Exposure Report are not public as of this writing, they have published the list of chemicals that will be included in their report (CDC 2005). Our tests compare to CDC's tests in the following ways:
- EWG and CDC have tested for 62 chemicals in common (polychlorinated dibenzodioxins and dibenzofurans, mercury, organochlorine pesticides, and polychlorinated biphenyls).
- EWG has tested for 351 chemicals not included in CDC's study (polybrominated dibenzodioxins and dibenzofurans, polyaromatic hydrocarbons, perfluorochemicals, polybrominated diphenyl ethers, polychlorinated biphenyls, and polychlorinated naphthalenes).
- CDC has tested for 88 chemicals not included in EWG's study (metals, organochlorine pesticides, organophosphate insecticides, pyrethroid pesticides, herbicides, phytoestrogens, polyaromatic hydrocarbons, and tobacco smoke).
Both studies reveal disturbing gaps in our system of public health safeguards, which allows uncontrolled exposures to complex mixtures of industrial chemicals beginning even before birth.
Question #2: Why test for chemicals in people? Applications of body burden (biomonitoring) data for human health risk assessment and public health policy
Scientists and regulators use body burden data (biomonitoring studies) to estimate human health risks from exposures to industrial chemicals, to set public health policies that protect against these risks, and to track the success of these policies in reducing exposures. The applications of biomonitoring are rapidly expanding beyond its traditional use in occupational medicine and poisoning cases to new applications in measuring exposures and estimating health risks among the general population (Thornton et al. 2002, EWG 2003, Sexton et al. 2004, CDC 2003). Public health officials have recently used body burden data in assessing health risks for chemicals described below, all of which found in this study in newborn umbilical cord blood:
- Mercury. When CDC body burden studies showed high blood levels of mercury in women of childbearing age, government scientists assessed the data to show that one of every six women is exposed to mercury in excess of safe levels, through their consumption of mercury-contaminated seafood. These analyses were benchmarked back to seminal umbilical cord blood studies linking mercury to brain damage among children exposed in the womb (Grandjean et al. 1997). FDA then designed and publicized seafood consumer advisories that are intended to lower women's blood mercury levels (Carrington et al. 2004, FDA 2004). EWG's investigation identified mercury (as the form in seafood, methylmercury) in all 10 newborns tested.
- Scotchgard. Beginning in 1997 3M found the active ingredient in Scotchgard (PFOS) not only in blood from U.S. blood banks, but also in the blood of 600 children tested. Concurrently, 3M was learning that Scotchgard induces serious birth defects in laboratory studies, results that government scientists called "disturbing." EPA officials pressured 3M to take Scotchgard off the market. According to government officials, Scotchgard "combine[s] persistence, bioaccumulation, and toxicity properties to an extraordinary degree" (Auer 2000). In the past three years 3M has completely reformulated the product, although the persistent PFOS chemical will continue to pollute people, including babies in the womb, for generations to come. EWG's investigation identified PFOS in all 10 newborns tested, and represents the first reported detections of PFOS in U.S. cord blood.
- Teflon chemical PFOA. In the wake of the Scotchgard phaseout, EPA turned their attention to a closely related chemical, the Teflon ingredient PFOA. EPA conducted an assessment of human health risks benchmarked on measured levels of PFOA in the blood of the general population (EPA 2005d). This assessment, currently under review by EPA's independent Science Advisory Panel, was conducted to guide EPA in designing policies necessary to lower human exposures to PFOA. The Agency's priority review and assessment of PFOA is driven by its ubiquity in human blood — it pollutes the blood of more than 95 percent of Americans — combined with the chemicals' broad toxicity and the fact that, among all human blood pollutants, PFOA belongs to a chemical family (perfluorochemicals) that is uniquely persistent in the environment: PFOA never breaks down. EWG's investigation identified PFOA in all 10 newborns tested, the first reported detections of the chemical in cord blood from the general population.
- Dioxin. In a politically controversial series of exposure and human health risk assessments, EPA has consistently relied on body burden measurements of dioxin — in breast milk and other human tissues — to estimate exposures and health risks for the notirious family of dioxin-like chemicals (EPA 2000a). EWG's investigation identified dioxin-like chemicals in all 10 newborns tested.
Biomonitoring can fill data gaps and reduce uncertainties inherent in traditional exposure and risk assessment, leading to more fully informed public health policies. As measures of "internal dose," biomonitoring data comprise exposure estimates more direct, and with lower uncertainty, than those that scientists derive from traditional algorithms — methods that compound uncertainty by combining estimates of behavior patterns, pharmacokinetics, and external doses. When compared against measurements or estimates of internal dose from toxicology studies, biomonitoring data also providing a more direct estimate of potential hazards by reducing the need to compensate for differences in pharmacokinetics between humans and laboratory animals in exposure and risk assessments. Government scientists used this technique most recently in their risk assessment for the Teflon chemical PFOA, in which they compared measured human serum levels of PFOA to animal serum PFOA levels from laboratory studies (EPA 2005d).
In addition to the clear benefits of its use in exposure and risk assessments that shape public health policy, body burden studies are also a powerful tool for tracking the success of programs that aim to mitigate exposures. Body burden studies show, for example, that blood lead levels in children have dropped steadily since the mandatory reduction of lead in gasoline and house paint of the 1970s; the median concentration fell 85 percent between 1976 and 2000 (EPA 2003a, Pirkle et al. 1994).
Body burden data also has the capacity to uncover sensitive or highly exposed subpopulations, and the potential to elucidate distributions of exposure for individuals and across populations, including exposures to mixtures. Consideration of both of these factors — sensitive subpopulations and the nature of mixtures that comprise the human body burden — are critical components in developing effective public health policies. It is with a goal of exploring these two factors that we conducted our cord blood pollution investigation. Our study seeks specifically to measure the human body burden in an inherently sensitive in utero population, and to define in part the chemical mixtures present among the study samples.
The scientific community also uses biomonitoring such as that performed in this cord blood study to track exposure reductions that can stem from public health interventions. Biomonitoring studies have documented the success of public health interventions in dramatically reducing children's blood lead levels in the U.S. (Pirkle et al. 1994); in lowering PCB and organochlorine pesticide levels in breast milk from mothers in Germany and Sweden (Schade and Heinzow 1998, Noren and Meironyte 2000); and even in reducing exposures to second-hand smoke in the U.S. (CDC 2003).
In future biomonitoring efforts (CDC 2005) scientists from the Centers for Disease Control and Prevention plan to collect exposure data that can document the efficacy of recent public health interventions restricting the use of the Scotchgard chemical PFOS (EPA 2000d) and the popular home insecticide chlorpyrifos, or Dursban. And in the Children's Health Act of 2000 (Public Law 106-310 Sec. 1004), Congress authorized "a national longitudinal study of environmental influences (including physical, chemical, biological and psychosocial) on children's health and development." The study, as planned, aims to track exposure and health outcomes for 100,000 American children from early pregnancy to age 21 (DHHS 2004).
Question #3: Why did you test just 10 newborns?
Studies of chemicals in human tissues are expensive — in this study, laboratory costs alone were $10,000 per sample. The methods are highly specialized, few laboratories are equipped with the machines and technical expertise to run the analyses, and costs are high. Because of these constraints, a high fraction of umbilical cord blood pollution studies have tested a small number of babies. We identified 41 studies in the peer-reviewed literature that have reported on cord blood levels for some of the same pollutants we tested. Of these, 15 percent (6 studies) tested 15 or fewer babies:
- 15 subjects — Inoue K, Okada F, Ito R, Kato S, Sasaki S, Nakajima S, Uno A, Saijo Y, Sata F, Yoshimura Y, Kishi R, Nakazawa H. 2004. Perfluorooctane sulfonate (PFOS) and related perfluorinated compounds in human maternal and cord blood samples: assessment of PFOS exposure in a susceptible population during pregnancy. Environ Health Perspect. 2004 Aug;112(11):1204-7.
- 15 subjects — Guvenius DM, Aronsson A, Ekman-Ordeberg G, Bergman A, Noren K. 2003. Human prenatal and postnatal exposure to polybrominated diphenyl ethers, polychlorinated biphenyls, polychlorobiphenylols, and pentachlorophenol. Environ Health Perspect. 2003 Jul;111(9):1235-41.
- 12 subjects — Mazdai A, Dodder NG, Abernathy MP, Hites RA, Bigsby RM. 2003. Polybrominated diphenyl ethers in maternal and fetal blood samples. Environ Health Perspect. 2003 Jul;111(9):1249-52.
- 10 subjects — Sarcinelli PN, Pereira AC, Mesquita SA, Oliveira-Silva JJ, Meyer A, Menezes MA, Alves SR, Mattos RC, Moreira JC, Wolff M. 2003. Dietary and reproductive determinants of plasma organochlorine levels in pregnant women in Rio de Janeiro. Environ Res. 2003 Mar;91(3):143-50.
- 9 subjects — Cooper SP, Burau K, Sweeney A, Robison T, Smith MA, Symanski E, Colt JS, Laseter J, Zahm SH. Prenatal exposure to pesticides: a feasibility study among migrant and seasonal farmworkers. Am J Ind Med. 2001 Nov;40(5):578-85.
- 5 subjects — Schecter A, Kassis I, Papke O. 1998. Partitioning of dioxins, dibenzofurans, and coplanar PCBS in blood, milk, adipose tissue, placenta and cord blood from five American women. Chemosphere. 1998 Oct-Nov;37(9-12):1817-23.
Question #4: How do industrial chemicals get in my body?
More than 75,000 commercial chemicals are currently approved for use in the U.S. (EPA 2005c), a number that grows by 2,500 new chemicals yearly (EPA 1997). U.S. industries produce or import 3,000 of these in quantities of greater than one million pounds per year (EPA 2005c). Many pesticides banned in the U.S. for decades (PCBs and DDT, for example) persist in the environment, build up in the food chain, and continue to contribute to daily exposures. Government sources detail more than 3,000 chemicals used as food additives (FDA 2005), an estimated 10,500 ingredients in personal care products (FDA 2000), and more than 500 chemicals approved as active ingredients in pesticides (EPA 2002a,2005b). Many of these chemicals, whether used purposefully or found as unwanted impurities, can contribute to a person's body burden through exposures from food, air, water, dust and soil, and consumer products. And for many chemicals in our bodies, the health consequences are unknown. The studies aren't required under federal law, and in most cases simply haven't been done.
Question #5: How can I reduce my chemical exposures?
Some exposures to pesticides and industrial chemicals are unavoidable. Persistent pollutants, some banned for decades, still contaminate the environment and end up in the food we eat, the water we drink, and the air we breathe.
Yet even exposures to persistent pollutants can be reduced through a varied diet that contains fewer meat and high fat dairy products. Other chemical exposures, like toxic substances in household cleaners, can be avoided altogether.
Some simple tips for reducing exposures to industrial chemicals are:
- Eat fewer processed foods, which often contain chemical additives.
- Eat organic produce. It's grown without synthetic pesticides and preservative chemicals.
- Don't microwave food in plastic containers, use glass or ceramics.
- Run your tap water through a home filter before drinking. Filters can reduce levels of common tap water pollutants.
- Eat fewer meat and high fat dairy products, which contain higher levels of some pollutants.
- Reduce the number of cosmetics and other personal care products you use, which can contain harmful chemicals and can be sold with no safety testing.
- Avoid artificial fragrances.
- Don't use stain repellants on clothing, bedding or upholstery.
- Reduce the number of household cleaners you use. Try soap and water first.
- Avoid using gasoline-powered yard tools — use manual or electric tools instead.
- Avoid breathing gasoline fumes when you're filling your car.
- Eat seafood known to be low in PCB and mercury contamination, including wild Alaska salmon and canned salmon. Avoid canned tuna — it contains mercury.
Particularly if you're pregnant, try to follow the tips listed above. Is there someone in your household who can take over using household cleaners and pumping gas while you're pregnant? Eat canned salmon instead of canned tuna. Paint the baby room well before you conceive. Don't use nail polish, which contains chemicals linked to birth defects in laboratory studies.