Tuesday, March 8, 2016
Flint and Elsewhere: What Aspects of Lead Poisoning Are Irreversible?
Far, far be it from me to imply that lead poisoning in infants and children is a minor problem, but I feel uneasy about the repeated declarations that children exposed to lead in the environment suffer “irreversible” effects. This I find especially worrisome when there is stress on mental retardation as a possible outcome of lead exposure—to say that mental abilities have been irreversibly affected when infants and toddlers are lead-exposed may in some cases be correct, but ignores the many factors that work together to determine an individual’s mental development. How awful it must be for parents of lead-exposed children to encounter these statements and know that people have essentially disposed of their children as beyond help!
The dramatic statements about lead exposure remind me irresistibly of the “crack baby” concept of the 1990s, when headlines regularly stated that children who had been exposed to crack cocaine prenatally were hopelessly ruined. That did not turn out to be correct, and with proper care given to lead-affected children, the present claims will probably not be true either. Naturally it would have been far better if the children had not been exposed to lead to begin with, but they can be helped to develop at normal levels or close to them. This statement applies not only to the children of Flint, whose water supply was contaminated, but also to the many children in the United States who are exposed to lead in paint, dust, and so on in their own homes.
To support this statement, I am going to refer to a document produced by the Centers for Disease Control, “Managing Elevated Blood Lead Levels Among Young Children” (www.cdc.gov/nceh/lead/casemanagement/managingEBLLs.pdf).
Where children’s blood lead levels are very high, the CDC document recommends chelation therapy, a technique that chemically removes lead from the child’s body. (Please note that while this method is necessary and effective for management of heavy metals poisoning, it is most inappropriate and should never be used for treatment of autism or related problems!) The document points out that chelation should be used with caution and that primary care providers need to seek the help of experts. “A child with a [elevated blood lead level] and signs or symptoms consistent with encephalopathy should be chelated in a center capable of providing appropriate intensive care services!” (! in original; this treatment is nothing to take casually—JM). If the treatment is done with oral chelation agents with the child as an outpatient, the dosage needs to be carefully monitored, and the treatment needs to be done in a lead-free environment.
Children with elevated blood lead levels often have inadequate nutritional intakes of iron, calcium, and vitamins, and nutritional changes have been recommended as ways to prevent absorption of lead or to combat its effects. However, it is not at all clear that nutritional factors affect blood lead levels; it may simply be that children whose families live where lead exposure is likely also have families who do not have access to healthy food or information about child nutrition. Nevertheless, improving children’s early nutrition can be an important step toward good child health and development, both physical and intellectual. Low levels of protein intake and lack of iron are associated with problems of brain and mental growth, especially when they occur in the infant, toddler, and preschool years. Giving children adequate diets is a way to fight mental retardation, even if it does not actually lower blood lead levels. The CDC recommends giving pureed meat to infants as soon as they are developmentally ready, and giving red meat to children once a day. Dairy products and fruits or fruit juices several times a day are also recommended. (Minimizing fatty snack foods is also a good idea, in that it will increase children’s appetites for nutritious foods that may be of less interest when calorie-rich snacks are available.) In order for many parents to assure good nutrition to their children, they need to have not only enrollment in WIC, but access to grocery stores that offer a variety of foods at reasonable prices.
To ensure that each child reaches the highest intellectual level he or she is capable of, high quality preschool programs are of great importance whether or not children have elevated blood lead levels, and it’s possible that such programs can make the difference between moderate retardation and fairly normal achievement for some children, if they are combined with other ways of treating lead exposure. The CDC document also suggests that developmental monitoring is needed for older children who have had elevated blood lead levels in early life. These need to continue into school age, with times of transition like first grade, fourth grade, and seventh grade getting most attention. Children who are inattentive and distractible will need help in order to have the maximum benefit from school.
To summarize, we have a number of ways to encourage good development in children who have been exposed to lead. The lead exposure may be “irreversible”, but a poor developmental outcome is not inevitable, and the worrisome trajectory present when no interventions take place can be reversed to a greater or lesser extent by help we know how to provide. What is needed, of course, is the political will and the funding to put these interventions in place. In the case of Flint, if the right decisions are made, the interventions could begin almost at once, while replacement of water pipes will take years. Similarly, when lead exposure comes from old paint, interventions can be of help now, while actually removing lead from houses can take many years—the process, indeed, can create even more dust and lead exposure than already exist.
Do I hear any candidates for president talking about this? Not really…