Society is increasingly faced with the challenge of addressing the burden of disease arising from environmental exposures. Physical hazards (air pollution, for example), chemical hazards (neurotoxins, for example), and biological hazards (algal blooms, for example) significantly affect health; in fact, environmental risk factors are believed to “play a role in more than 80% of the diseases regularly reported by the World Health Organization.”1 Chemicals are particularly troublesome because they are pervasive. They are found in health care supplies and equipment, the food we eat, the water we drink, the air we breathe, and the cosmetics and personal products (such as shampoos, baby bottles, toys, and thousands of other consumer products) we use.
Throughout the years, nurses have been critical to advocacy efforts, particularly in regard to lobbying for reform of the Toxic Substances Control Act (TSCA), passed by Congress in 1976, which is the primary chemicals management law in the United States.2 One national nursing organization dedicated to the intersection of nursing, the environment, and health, the Alliance of Nurses for Healthy Environments (ANHE), has provided leadership in this effort (for more information, see http://envirn.org).
Toxic chemicals continue to present a significant burden to public health. According to one analysis, almost all pregnant women were found to have detectable levels of certain chemicals in their bodies, including polycyclic aromatic hydrocarbons, phthalates, perfluorinated compounds, polychlorinated biphenyls (PCBs), perchlorate, lead, and mercury.3 Many of these chemicals are regularly detected in cord blood or other fetal tissue.4, 5 Such widespread exposure to toxic chemicals can increase the risk of cognitive, behavioral, and social impairment in children, as well as specific neurodevelopmental disorders, such as autism and attention deficit–hyperactivity disorder (ADHD).6-9
Among the multiple causes of disability, exposure to chemicals deserves special scrutiny, because this is a preventable cause of harm. The importance of these exposures and of their impact on pediatric health outcomes was underscored last year when the National Institutes of Health launched the Environmental Influences on Child Health Outcomes (ECHO) program, a seven-year initiative that supports the investigation of environmental exposure on key pediatric health outcomes, including neurodevelopment.10
CHEMICALS AND CHILDREN
The environment affects a child's health very differently than that of an adult. Contaminants affect children disproportionately because their bodies are not fully developed and their rapidly growing systems (the neurological system, for example) can be more easily harmed.11 Children are often exposed to these contaminants through their behavior—when they crawl on the floor or explore their environment by touching and tasting objects indiscriminately. In addition, because they are young, there is the potential for environmental exposures to negatively impact their health for a long time.
Trends in neurodevelopmental disorders. Data indicate a growing trend in the prevalence of neurodevelopmental disorders in the United States: from 1997 to 2008, there was a 17% increase in the prevalence of developmental disabilities, including learning disabilities, ADHD, autism, and other cognitive disorders.12 In 2013, the U.S. Environmental Protection Agency (EPA) released the third edition of America's Children and the Environment, a report that details the impact of air pollutants, lead, mercury, drinking water contaminants, climate change, and a variety of chemicals on the health of children, particularly in regard to cancer, obesity, respiratory diseases such as asthma, and neurodevelopmental disorders.11 Since the first edition was published in 2000, this report has highlighted research findings that show stronger and more consistent associations between environmental exposures and pediatric health outcomes. For example, trends indicate an increase in the proportion of children five to 17 years old who have been diagnosed with ADHD, from 6.3% in 1997 to 9.5% in 2010.11 The National Toxicology Program has linked attention-related behavior, along with other neurodevelopmental health issues, to lead exposure.13
Many toxic chemicals can interfere with healthy brain development, even at low levels of exposure and particularly during critical windows of vulnerability, such as prenatally and during early childhood.14-16 Chemicals of concern based on epidemiologic study findings include lead, methylmercury, PCBs, arsenic, toluene, manganese, fluoride, and chlorpyrifos, among many others.17 The health effects can last a lifetime and include emotional impacts as well as economic consequences. It has been estimated that it costs approximately twice as much in the United States to educate a child who has a learning or developmental disability as a child who does not have a disability.18
A growing number of scientists, health professionals, and children's advocates are raising concerns about current U.S. chemical policies, including the TSCA, that are not fully protecting the public's health—in particular the health of children.
THE TOXIC SUBSTANCES CONTROL ACT
In 1976, Congress enacted the TSCA, empowering the EPA to collect data on and regulate chemicals that are toxic to human health. According to the EPA, about 85,000 chemicals are currently listed on its chemical substance inventory—only nine of which are regulated under the TSCA because of substantial limitations in the law.19 These chemicals include PCBs, halogenated chlorofluoroalkanes, dioxin, asbestos, hexavalent chromium, tricarboxylic acid, triethanolamine salts of a substituted organic acid, mixed mono and diamides of an organic acid, and triethanolamine salt of tricarboxylic acid.19
After decades of Congressional discussion and debate, President Barack Obama signed into law the Frank R. Lautenberg Chemical Safety for the 21st Century Act on June 22, 2016, which amends the TSCA.20 These reforms include (1) a requirement that the EPA evaluate existing chemicals with clear and enforceable deadlines, (2) a risk-based safety standard, (3) increased public transparency for chemical information, and (4) a consistent source of funding for the EPA to carry out these responsibilities.20
Despite this progress, many health care providers are concerned that gaps in the law continue to place children at risk for neurodevelopmental health issues. The ANHE's past efforts to address these concerns were recognized when the leaders of Project TENDR (Targeting Environmental Neuro-Developmental Risks), a collaborative initiative of leading scientists, health professionals, and children's health advocates, invited ANHE members to join them in a consensus-building process that led to the publication last July of a national call to action, “Project TENDR: Targeting Environmental Neuro-Developmental Risks. The TENDR Consensus Statement.”21 This consensus statement promotes the reform of national policies based on the mounting evidence of chemical-associated health issues in children.
Project TENDR's mission is to reduce chemical exposures in children that contribute to neurodevelopmental disorders, and to ultimately reduce the prevalence of these disorders. Formed in 2015, Project TENDR has sought to raise awareness about the evidence linking chemicals and neurodevelopmental disorders and to set priorities for action.21 For examples of these links, which are also highlighted in Project TENDR's consensus statement,21 see Table 1.9, 17, 22-28
A call to action. In the consensus statement, Project TENDR members call for the reduction of widespread exposures to chemicals that interfere with brain development. The following statements were endorsed by Project TENDR after an extensive review of the literature and an analysis of current laws, and with the intent of protecting children's health21:
* The growing body of scientific evidence on toxic chemicals points to their clear association with brain and cognitive disorders.
* A reduction in the production and use of identified neurotoxins is needed owing to their widespread use and large-scale impact.
* Children's risks of developing learning and developmental disorders are particularly high prenatally and during early childhood.
* There is still uncertainty about many other chemicals and their impact on a child's brain because of a lack of testing and data, but the potential for associations is high.
* Current national policies and systems for making decisions about chemicals based on the evidence are inadequate, to the detriment of children's health.
Looking forward. The TSCA reforms included in the Frank R. Lautenberg Chemical Safety for the 21st Century Act address several recommendations made in a National Academy of Sciences report, Science and Decisions: Advancing Risk Assessment,29 such as using science-based assumptions that protect health when data are missing, rather than waiting for more data. If fully enforced, these reforms will ultimately lead to a reduction in chemical exposures and an improvement in children's health.
Despite the promise of health protective policies as a result of the new TSCA reforms, the pace of chemical reviews and action will be slow, especially given the sheer number of chemicals that need to be tested and regulated. In addition, these reforms do not address the critical need to update nursing, medical, and public health curricula, examinations, and certification criteria to include knowledge about chemicals and their impact on health outcomes. The nursing profession must advance the nursing curriculum to include this content, and nurses must become informed about the evidence linking chemical exposures to health; integrate this knowledge into our standards of practice; educate the public; and advocate for a cleaner, healthier world.
2. U.S. Congress. Summary of the Toxic Substances Control Act (15 U.S.C. §2601 et seq). Washington, DC; 1976.
3. Woodruff TJ, et al Environmental chemicals in pregnant women in the United States: NHANES 2003-2004 Environ Health Perspect 2011 119 6 878–85
4. Chen A, et al Hydroxylated polybrominated diphenyl ethers in paired maternal and cord sera Environ Sci Technol 2013 47 8 3902–8
5. Lien GW, et al Analysis of perfluorinated chemicals in umbilical cord blood by ultra-high performance liquid chromatography/tandem mass spectrometry J Chromatogr B Analyt Technol Biomed Life Sci 2011 879 9-10 641–6
6. Council on Environmental Health. Chemical-management policy: prioritizing children's health Pediatrics 2011 127 5 983–90
7. Di Renzo GC, et al International Federation of Gynecology and Obstetrics opinion on reproductive health impacts of exposure to toxic environmental chemicals Int J Gynaecol Obstet 2015 131 3 219–25
8. Gore AC, et al Executive summary to EDC-2: The Endocrine Society's second scientific statement on endocrine-disrupting chemicals Endocr Rev 2015 36 6 593–602
9. Lanphear BP, et al Low-level environmental lead exposure and children's intellectual function: an international pooled analysis Environ Health Perspect 2005 113 7 894–9
10. National Institutes of Health. Environmental influences on child health outcomes (ECHO) program
. n.d. https://www.nih.gov/echo
12. Boyle CA, et al Trends in the prevalence of developmental disabilities in US children, 1997-2008 Pediatrics 2011 127 6 1034–42
13. National Toxicology Program. NTP monograph on health effects of low-level lead
. Research Triangle Park, NC: National Institute of Environmental Health Sciences, National Institutes of Health, U.S. Department of Health and Human Services; 2012 Jun. https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html
14. Abt E, et al Science and decisions: advancing risk assessment Risk Anal 2010 30 7 1028–36
15. Lyall K, et al Maternal lifestyle and environmental risk factors for autism spectrum disorders Int J Epidemiol 2014 43 2 443–64
16. Zoeller RT, et al Endocrine-disrupting chemicals and public health protection: a statement of principles from the Endocrine Society Endocrinology 2012 153 9 4097–110
17. Grandjean P, Landrigan PJ Neurobehavioural effects of developmental toxicity Lancet Neurol 2014 13 3 330–8
19. U.S. Government Accountability Office. Chemical regulation: options exist to improve EPA's ability to assess health risks and manage its chemical review program
; 2005 Jun. GAO-05-458. Report to Congressional requesters; http://www.gao.gov/assets/250/246667.pdf
20. U.S. Congress. Frank R. Lautenberg chemical safety for the 21st century act. Washington, DC. 2016.
21. Bennett D, et al Project TENDR: Targeting Environmental Neuro-Developmental Risks: the TENDR consensus statement Environ Health Perspect 2016 124 7 A118–A122
22. Fortenberry GZ, et al Urinary 3,5,6-trichloro-2-pyridinol (TCPY) in pregnant women from Mexico City: distribution, temporal variability, and relationship with child attention and hyperactivity Int J Hyg Environ Health 2014 217 2-3 405–12
23. Cowell WJ, et al Prenatal exposure to polybrominated diphenyl ethers and child attention problems at 3-7 years Neurotoxicol Teratol 2015 52 Pt B 143–50
24. Jedrychowski WA, et al Prenatal exposure to polycyclic aromatic hydrocarbons and cognitive dysfunction in children Environ Sci Pollut Res Int 2015 22 5 3631–9
25. Liu J, et al Blood lead concentrations and children's behavioral and emotional problems: a cohort study JAMA Pediatr 2014 168 8 737–45
26. Karagas MR, et al Evidence on the human health effects of low-level methylmercury exposure Environ Health Perspect 2012 120 6 799–806
27. Harada M Congenital Minamata disease: intrauterine methylmercury poisoning Teratology 1978 18 2 285–8
28. Eubig PA, et al Lead and PCBs as risk factors for attention deficit/hyperactivity disorder Environ Health Perspect 2010 118 12 1654–67