The Management of Environmental Lead Exposure in the Pediatric Population : Lessons from Clitty Creek, Thailand
SURAPONG TANTANASRIKUL, M.D., M.P.H.*, BOONNUM CHAIVISUTH, M.D.*, SOMKIET SIRIRA TANAPREUK, M.D.**, CHANTA NA PADUNGTOD, M.D., D.R.P.H.**, RA TANOTHAI PLEUBREUKAN, M.D.***, TANYANAT BOONNARK, M.D.***, SARIKA WORAHAN*, PRAPAN BHUMIRA TANARAK, M.D.****, CHULA THIDA CHOMCHAI, M.D., F.A.A.P.*****,
Affiliation : * Kanchanaburi's Office of Provincial Public Health, Kanchanaburi 71000, ** Office of Occupational and Environmental Health, Ministry of Public Health, Nonthaburi 11000, *** Queen Sirikit's Child Health Institute, Bangkok 10400, **** Paholponpayuhasena Hospital, Kanchanaburi's Office of Provincial Public Health, Kanchanaburi 71000, ***** Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Method : This was a retrospective cohort study of the effects that environmental remedia tion and chelation therapy had on the blood lead levels of children residing in Lower Clitty Creek Village during the period between 1997-2001. Sixty-eight children were followed yearly for their blood lead levels and hematocrit, beginning in early 1998. Simultaneously, programs for environ mental remediation had begun. The blood lead levels (BLLs) of children were followed over a 3-year period. The BLLs during the 2 year period of environmental remediation alone were com pared. Subsequently, when chelation therapy was instituted, levels pre and post chelation therapy, as well as the efficacy of the two different chelation methods were compared using standard 2-tailed t-test.
Results : The initial average BLL was 27.75 ± 5.4 mg/dl (1998). After environmental remediation began, BLL at one year (1999) was 30.64 ± 4.49 mg/dl (p = 0.072), and at two years (2000) was 30.30 ± 5.1 mg/dl (p = 0.537). There were 18 children with BLLs > 25 who were elected to receive chelation therapy with CaNa2EDTA (11) and DMSA (7). Post chelation average BLL was 18.73 ± 7.50 mg/dl. The difference between pre and post chelation BLL was statistically significant (p < 0.001: paired t-test). The differences in average BLLs between pre and post chela tion for the EDTA group was 15.37 mg/dl and for the DMSA group it was 8.91 mg/dl. Children treated with EDTA appeared, on average, to have 6.47 mg/dl (p < 0.05: 95% CI (0.821-12.12)) lower BLL than those treated with DMSA.
Conclusion : The incident at Clitty Creek serves to illustrate the importance of environ mental remediation as a priority to treating lead poisoning in children. Only when effective environ mental deleading has taken place can medical intervention in the form of chelation therapy begin.
Keywords : Lead Poisoning, Children, Environmental Contamination
