RESEARCH

Treatment Techniques & Results

WORKSHOP ON TREATMENT PLAN FOR CHILDHOOD LEAD POISONING

Moderator: Dr. M. Markowitz; Panel: Dr. X.M. Shen, Dr. W. Rogan, Dr. D. Nag, Dr. S. Tandon, Mr. A. Perti, Dr. T. Rozema, Dr. S. Roy, Dr. M. Lahiri

The following treatment plan summary was developed for developing countries as a collective effort by the attendees of the workshop, with guidance from the panelists.

  1. Identification of Lead Poisoned Children

To initiate treatment, those affected by lead must first be identified. Health care providers must be trained to recognize lead poisoning associated symptoms. High-risk groups identified by pubic health agencies should be the subjects of targeted blood screening. Blood lead levels should be measured, instead of surrogates such as erythrocyte protoporphyrin levels.

  1. Identification and Eradication of Sources

The success of any treatment plan is dependent on the elimination of further exposure of the poisoned population and the prevention of future cases. Identifying sources of exposure in suspected high risk areas or for known cases must be a priority; and enactment and enforcement of health code aimed at eradicating those sources is the responsibility of government agencies such as the Ministries of Health, Environment, and Occupation and Safety.

  1. Education

Recognition of the problem and its interventions require an educated medical establishment and an informed public. Propagation of information relating to lead poisoning must begin with the education of an expert core of physicians who in turn can teach their peers and staff, public health nurses, community outreach workers and parents and other child caregivers. Information formats include picture pamphlet handouts, videotapes, television stories and conferences such as the current one.

4. Chelation Treatment

Any drug proposed for treatment to be used for lead poisoning should fulfill the following criteria: be safe to use, be effective at removing lead from the body, be easy to administer-- preferably orally, and be inexpensive. Currently, three drugs are available in India: CaNa2EDTA (calcium editate), D-penicillamine, and BAL (versenate). A more effective and safer alternative is succimer (DMSA) an orally administered drug in use in the US and China. This drug should be allowed for use in India and other developing countries. Care in the use of these drugs requires that they be administrated in lead free environments and under supervision to monitor for evidence of drug related toxicity.

Selection of children for chelation and specific treatment protocols may follow the US Centers for Disease Control and Prevention (CDC) guidelines that call for treatment of all children with blood lead levels > 45 ug/dL with at least one chelating agent; and two drugs for children with blood lead levels > 70 ug/dL to further increase lead excretion rapidly. Relative costs in India appears to be D-Penicillamine < CaNa2EDTA < BAL (< DMSA if bought in the US; however, the Chinese version of DMSA is 10-15% of the cost of the US version which would be competitive with D-penicillamine).

  1. Adjunctive Therapy

Although research is limited mainly to animal models, it is suggestive that there is a supportive role for other agents in the management of lead poisoned children. These agents are primarily nutritional components and include iron, calcium, zinc, B-vitamins and vitamin C. Studies of the benefits of metal (calcium and iron) supplementation to lead poisoned children are ongoing in the US. At this point, specific recommendations on the use of these agents in pharmacological quantities would be premature. However, suggesting that children receive the daily-recommended intakes of these nutrients is reasonable.

  1. Behavior Modification

The presence of lead in the environment poses the potential for toxicity. For exposure to translate into active toxicity requires a mode of entry into the body. Frequently in young children this is via hand to mouth activity resulting in ingestion of lead containing particles. Inhalation of lead fumes from car/truck exhausts or polluting factories may also contribute to lead burden in children and adults. However, airborne lead containing particles will settle and contaminate surfaces in and around homes. Teaching parents to change and limit the hand to mouth behavior of children that is not food related would decrease the amount of lead ingested; cleaning surfaces that may become repeatedly contaminated with lead may also diminish lead availability for ingestion. Thus, modifying both parental and child behavior should result in lower lead burdens in the children.

  1. Follow-up of Cases

Once identified, children receiving treatment require periodic follow-up to monitor the success of the intervention. Frequency of follow-up depends on the initial blood lead levels and the success in eradicating sources of exposure. The US Centers for Disease Control and Prevention has developed an algorithm that would be applicable to Indian children. The method of follow-up should include repeated blood lead testing.

8. Support Services

A central registry in the local, state and national Ministries of Health would gather data on number of lead tests performed, cases identified, local environmental sources of exposure and remediation efforts. Trends over time and measures of intervention success or failure could be determined from such a database. Data collection would complement environmental inspection and case management efforts by the local Ministries of Health.

For indigent members of the population, nutritional support, especially of essential metals, should be available. Since lead exposure may be due to unremediable sources outside the homes of lead poisoned children, social service support to help relocate families may be required.

9. Laboratory Support

Since case identification and monitoring of treatment intervention are dependent on the accurate measurement of lead in biological and environmental samples, a quality control program for lead testing laboratories in India should be instituted by the Ministry of Health. If commercial labs are unavailable or fail proficiency testing programs, then the Ministry of Health may assume laboratory-testing responsibilities.

10. Lead Resource Centers

Freestanding or within academic institutions, Lead Resource Centers should be established in major urban areas. These Centers would function as follows: train health care personnel and community outreach workers drawn from affected communities; provide lead related medical and environmental consultation, teaching and research information materials; run a core laboratory facility; perform basic science and clinical research. Funding for such Centers may be from a combination of public, foundations, and fee for service sources.

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