Children's Environmental Health Initiative Health Article

CHILDREN'S ENVIRONMENTAL HEALTH INITIATIVE

It is well known that children are different from adults when it comes to susceptibility to environmental exposures. The studies of Japanese exposed to A-bomb radiation showed that children, especially those with in utero exposures, had more and earlier cancers than did adults who were exposed. The hormone DES and the sedative thalidomide caused birth defects and (in the case of DES) cancer in offspring of women who were given the drugs during pregnancy, with no such effects found in exposed adults. Successively, lead, PCBs, and methylmercury have been shown to cause subtle impacts on IQ and cognition in children at levels much lower than those which cause effects in adults. More recently, questions have been raised about endocrine effects of chemicals on children exposed during critical periods of development, as well as about the causes of developmental disabilities in children.

Children also have different exposure patterns. Their intake rates of food, water, and air are higher, per body weight, because they have higher rates of metabolism. They eat different arrays of foods than adults and their proximity to the ground, their play behaviors, and their mouthing habits result in a greater exposure to contaminants in dust and soil.

In the United States, "children's environmental health," as a field of study, resulted from the work of a small technical committee of the American Academy of Pediatrics that was established in 1957 as the Committee on Radiation Hazards and Epidemiology of Malformation. As is evident from this title, initial concerns were over the hazards of radiation (diagnostic and fallout-related) and the causes of birth defects. However, the committee soon became involved in other issues, such as the safety of drinking water, and in 1962 it was renamed the Committee on Environmental Hazards (it is now called the Committee on Environmental Health). It published its first statement on environmental risks to children, The Hazards of Radioactive Fallout, in 1962. Over time, the committee has formulated positions for the pediatric community on numerous environmental hazards for children including environmental tobacco smoke, air pollution, lead poisoning prevention, child labor, and noise levels in newborn nurseries.

In the early 1990s, two important advocacy organizations were created that did much to further the initiative: the Alliance to End Childhood Lead Poisoning and the Children's Environmental Health Network (CEHN). These two advocacy organizations brought various environmental and public health scientists and advocates together to catalyze their efforts into a much larger movement. By 1992 the major federal agencies (Centers for Disease Control and Prevention [CDC], Housing and Urban Development [HUD], and the Environmental Protection Agency [EPA]) had completed strategic plans to eliminate lead poisoning, a bolder goal than had ever previously been put forward. Congress had enacted the Lead-Based Parent Hazard Reduction (1992), Title XI of the Housing and Community Development Act, which directed all three agencies to put in place a regulatory and assistance framework to address the abatement of lead in housing. In 1991, CEHN developed the first training curriculum for pediatric environmental health for health care providers, and in 1993, in partnership with the National Institute of Environmental Health Sciences (NIEHS) held the first scientific meeting on this topic. CEHN promoted consideration of children's unique exposures, physiology, and susceptibility based on developmental stages.

In 1993 the National Academy of Sciences (NAS) published the report Pesticides in the Diets of Infants and Children, in which the expert committee concluded that the EPA risk-assessment process for pesticides was inadequate for ensuring that children's health would be protected because the EPA was not considering the dietary patterns of young children (which are very different than adults) nor their susceptibilities (testing did not assess a number of child health endpoints such as developmental neurotoxicity.) The report concluded that the risk-assessment procedures that were used by the EPA, which considered that two tenfold "uncertainty factors" would be sufficient for extrapolating from high-dose testing of laboratory animals to lower dose exposures of people, were inadequate, and suggested that the EPA should apply an additional factor of ten to account for the susceptibility of children.

In 1993, numerous administrative reforms were undertaken, including improvement of dietary surveys, pesticide residue monitoring, and food intake models to better assess dietary patterns of children. Additionally, EPA moved to add child health endpoints to pesticide studies required of manufacturers for approval of pesticides. In 1996 the U.S. Congress enacted the Food Quality Protection Act (FQPA). This act included a requirement for an additional tenfold "margin of safety" to protect children. There were other innovative provisions (also recommended by the NAS) including the requirement for aggregate (all routes of exposure) and cumulative (all pesticides that share a common mode of action) assessment of pesticide risks to children. In the case of the EPA, the pesticide reassessments required by the FQPA have already resulted in cancellations of many of the household uses of organophosphate pesticides (for example, chlorpyrifos and diazinon), which were particularly risky for children because of the greater potential for exposure and the likelihood of cumulative impacts from all of the organophosphates. Likewise, uses on foods that children eat (e.g., apples) have been sharply curtailed (e.g., chlorpyrifos and methyl parathion). However, cumulative assessments have yet to be completed, and it is difficult to predict what the total impact of FQPA will be by the time of the completion of required reviews of all food pesticide standards in 2006. FQPA contained an additional provision requiring screening and testing of pesticides for potential to disrupt the endocrine system.

Meanwhile, progress was made on other fronts. The EPA, in 1996, published a white paper on children's environmental health that established a number of goals, most of which were eventually realized. Following on this, the EPA, NIEHS, and CDC joined together in 1998 in the Children's Environmental Initiative that funded the first Centers for Children's Environmental Health and Disease Prevention Research at academic medical and public health centers across the country. The EPA also established an Office of Children's Health Protection, which coordinates policies across all environmental areas and issues reports on the state of children's health and the environment. To guide its efforts and assist with establishing priorities, EPA created a Children's Health Protection Advisory Committee.

In 1997, President Clinton issued an executive order on children's environment, health, and safety requiring that all federal agencies consider the risks to children in their actions. The executive order also established the Council on Children's Environmental Health, co-chaired by the secretary of health and human services and the Environmental Protection Agency administrator. The executive order required that all agencies incorporate knowledge about exposures and susceptibilities to children in their decisions. This resulted in policy changes in a number of areas, most notably the Food and Drug Administration's policy on pediatric testing of drugs. The council soon established a focus on four areas: childhood cancer, developmental disabilities, asthma, and injuries. By 2000 it had brought about a number of changes, including the creation of a national childhood cancer registry, the development of an integrated federal strategy to eliminate lead poisoning, and a national plan of action to address the asthma epidemic. It also developed the vision and plans for a children's environmental prospective study, a study that would enroll large numbers of children as infants and track them in an effort to understand the impacts of environmental exposures early in life on developmental and health outcomes.

Between 1998 and 2000 the federal Agency for Toxic Substances and Disease Registries and the EPA established so-called Pediatric Environmental Health Specialty Units (PEHSUs) in medical institutions in each of the ten federal regions in the United States. The PEHSUs provide clinical consultation and referral services for evaluation of individual pediatric patients with suspected environmental health problems. In 1999 the American Academy of Pediatrics published the Handbook of Pediatric Environmental Health, a manual that provides a definitive guide to this area for clinicians and broad coverage of the field. Children's environmental health is now established as an area of study in pediatrics. Moreover, consideration of children's risks is becoming a routine part of health, environment, and safety assessments. Thus, the expansion of scientific capability in these areas will go hand in hand with being able to provide health protection for children.

LYNN R. GOLDMAN

(SEE ALSO: Agency for Toxic Substances and Disease Registry; Environmental Determinants of Health; Environmental Protection Agency; Food and Drug Administration; Lead; Maternal and Child Health; Pesticides; Risk Assessment, Risk Management; Uncertainty Analysis)