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RESEARCH
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National Policy, Standards, Legislation & Enforcement
The workshop focussed on assewering the following key questions
It was pointed out that screening children is not the preferred prevention method, because it will only find affected children after they have been exposed. It is preferable to focus on removing sources of exposure and on behavior modification that could decrease exposure. A question was raised about the utility of screening. If children are found to have high lead levels, what can be done to help them? This group did not focus on which children should receive treatment because that was the task of another panel. Rather, we assumed that children with very high lead levels should receive treatment but noted that the high cost of treatment may be prohibitive for most individuals. Usually, screening is indicated if identifying an asymptomatic, exposed individual can lead to individual intervention. The group did not think it feasible to perform individual environmental interventions. However, it was thought possible that screening would provide an avenue by which physicians could advise parents about the need to keep children’s hands clean, avoid lead-containing cosmetics, etc. In addition, it was noted that implementation of a screening program can lead to lower lead levels for an entire community, perhaps by raising awareness of the issue among both parents and physicians. Screening high-risk children will serve to publicize the issue and galvanize prevention efforts. We next turned our attention to where screening should be done if it will be done. Little research has been done in India to tell us what the most important lead sources are. Therefore, we don’t know what age children are at highest risk for exposure. However, we do know the age of highest risk for cognitive health effects in early childhood. Therefore, we thought it best to screen children around age 2 years. We also recommend screening children of occupationally exposed workers, as these adults may bring lead into the home environment that could affect their children. Initially, screening should occur in the larger cities, both because these are higher-risk areas and because some infrastructure exists there to perform the work. Later, universal screening might be done if it seems indicated. The initial screening program will provide information on which children are at high-risk. Existing mechanisms should be used to accomplish screening most effectively. Children can be screened when they present themselves at immunization clinics. Children of workers can be screened during special programs at the workers’ factories. Screening should be included as part of larger health exams both because it is cost-effective and because parents will not be interested in lead screening alone. The group’s preference was for point-of-care testing so that follow-up can be performed immediately if lead levels are high. This obviates the need for re-contacting parents and bringing children in again for a repeat test. Immunization clinics do not have laboratory equipment for lead testing, so this plan implies use of a portable blood lead analyzer. Lead testing using the portable analyzer now on the market (ESA LeadCare) is now too costly for routine screening in India. However, the cost of supplies is expected to drop so that Lead Care tests will become as cheap as tests done on graphite furnace atomic absorption spectrophotometers (GFAA) and on anodic stripping voltammetry (ASV) desktop instruments. The tests could eventually be done for as little as $1 U.S. but this will still be prohibitively costly for poor families. For the present, lead testing must be performed in centralized laboratories. It will be most cost-effective to use existing equipment (GFAA and ASV) in existing laboratories. The National Institute of Occupational Health (NIOH) recently surveyed Indian laboratories to determine which had the capacity to perform accurate lead tests. Only 8 of 70 with GFAA instruments were found to have them up and running. An advantage to using centralized laboratories is that they can maintain statistics on a large scale, providing valuable information to program planners. A disadvantage is that there may be logistical problems in sending blood samples to the central labs in a timely manner. The mail system would not be timely enough so couriers would be needed. It was unclear as to how many tests can be handled by the eight central laboratories. Their capacity may be a limiting factor in determining how large an initial screening program can be. Capacity clearly does not exist for implementing universal screening. For example, it was noted that approximately 12 million immunizations are performed in India each year. If each lab can perform 50,000 tests in a year, it would take 300 labs to do 15 million blood tests. Follow-up testing should also be done at centralized laboratories. Centralized laboratories can continue to provide follow-up testing even after clinics achieve the capacity to perform point-of-care testing. It was agreed that the testing method does not matter as long as the lab technician is well trained. Each of these methods (GFAA, ASV, portable) can perform adequately well. It was also noted that the type of lab (e.g. government, academic, etc) does not determine its quality. However, it was noted that filter paper is not a suitable testing method for India because filter paper is easily contaminated by atmospheric lead dust. Another option is in using ZPP testing rather than blood lead testing. ZPP tests can be used to identify children with very high blood lead levels requiring treatment. Children with moderately elevated blood lead levels would not be detected. This is a far cheaper option than direct lead testing. Laboratory standards must be implemented to ensure quality. The same standards are required for screening as for testing performed for other reasons (e.g. for diagnostic tests on symptomatic individuals, etc.) It is very important to require certification based on mandatory proficiency testing, including blinds, and inspection of labs to ensure their quality. The focus of these efforts should be collegial rather than punitive, i.e. if a lab is failing, the response should be help to identify and correct the source of the problem(s). Proficiency testing and quality control standards should probably be implemented from one top lab, such as the lab at the National Institute of Occupational Health (NIOH) which is currently developing capacity to serve as a national reference laboratory. Training of the individual drawing the blood is also important for obtaining uncontaminated samples. This training should be included for all medical students and physicians. The group was also asked to consider methods of educating physicians and parents in conjunction with a screening program. It was thought that physicians and parents are presently relatively unaware of lead hazards. Outreach to parents can occur through movie trailers, television spots, the Integrated Child Development System (ICDS) angawadi network (which provides one health and nutrition outreach worker for every 1500 individuals), and through schools (schoolchildren will bring the message home to their parents, who can then use the information to protect their younger children). Incentives for parents to obtain tests for their children could include coupons given to pregnant women, or a requirement for a lead test on school enrollment. Physicians will be reached best through the Indian Medical Society and through local teaching association seminars. It was noted that education of both parents and physicians must be an ongoing process, not a one-time effort. |