Lead poisoning among children of Santo Amaro, Bahia, Brazil in 1980, 1985, and 1992

A cross-sectional epidemiologic survey conducted at the beginning of 1992 evaluated the status of lead intoxication among children from 1 to 5 years of age living within 500 meters of a primary smelter in the Brazilian city of Santo Amaro, Bahia. A total of 103 children in this age group were initially enrolled in the study; however, 2 were later excluded because they could not be located, and 1 was excluded from the statistical analyses for reasons noted bellow. The results were compared with those from similar surveys made in 1980 and 1985 in the same area with children of the same age. A blood sample was obtained from each child, the child's hematocrit and zinc protoporphyrin (ZPP) level were determined, and an interview questionnaire was used to collect information of clinical or epidemiologic interes from the child's mother or guardian. The geometric average ZPP was 65.5 ug/100 mL (geometric standard deviation = 1.7), a level far exceeding the upper limit of normality established by the U.S. Center for Disease Control and Prevention of 3o ug/100mL. One child was excluded from the statistical analyses because it exhibited an extremely high ZPP level (789 ug/100 mL). Higher average ZPP levels were found for girls, children with darker-skinned racial backgrounds, children from homes where smelter slag was commonly used around the house, children presenting pica, and children of smelter workers. Of the symptoms of lead poisoning investigated, only nervousness and easy irritability exhibited high frequencies among the children studied. However, the prevalence of above-normal ZPP levels suggestive of lead poisoning was 92.2 percent in 1980, 98.4 percent in 1985, and 97.0 percent in 1992. Hence, the apparent prevalence of lead poisoning continued very high in 1992, indicating that the control measures adopted were ineffective or that other unidentified and uncontrolled risk factors were playing an important role. Overall, however, the proportion of children with very high ZPP levels fell sharply, and that of children with moderately high levels also declined notably, indicating that the severity of the problem had been reduced even though new cases of intoxication continued to occurr. The Santo Amaro smelter closed its doors in December 1993 (AU)

Evoluçao da intoxicaçao por chumbo em crianças de Santo Amaro, Bahia 1980, 1985 e 1992 / Evolution of lead poisoning among children living in Santo Amaro, Bahia- 1980, 1985 and 1992

Um estudo epidemiológico de corte transversal, realizado no início de 1992, avaliou a situaçao da intoxicaçao por chumbo em 101 crianças de 1 a 5 anos de idade residentes num raio de 500 m de uma fundiçao primária de chumbo, localizada na cidade de Santo Amaro, Bahia. Estudaram-se todas as crianças dentro dessa faixa etária. Os resultados foram comparados com os de outros estudos efectuados em 1980 e em 1985, na mesma área, em crianças da mesma idade. Para cada criança, determinou-se hematócrito, concentraçao de zincoprotoporfirina (ZPP), e aplicou-se um questionário para a coleta de informaçoes de interesse clínico-epidemiológico, respondido pela mae ou responsável pela criança. A média geométrica de ZPP foi de 65,5/ug/100 mL (desvio padrao geométrico= 1,7) muito acima, portanto, do limite de normalidade establecido pelo CDC-EUA (30 ug/mL). Encontraram-se médias mais elevadas de ZPP para as crianças de raça escura, do género feminino, residentes em domicílios onde, con frequencia, usou-se escória da fundiçao; que comiam objetos estranhos; e que eram filhos de trabalhadores da fundiçao. Entre os sintomas de intoxicaçao por chumbo pesquisados, apenas o nervosismo e a irritabilidade fácil apresentaram frequencias elevadas na population infantil. A prevalencia de intoxicaçao por chumbo (níveis de ZPP acima do valor normal) foi de 9.2,2 percentagem em 1980, de 98,4 percentagem em 1985 e de 9,70 percentagem em 1992. A intoxicaçao por chumbo continua a apresentar uma prevalencia muito elevada, indicando uma ineficácia das medidas de controle utilizadas e/ou a influencia de fatores de risco nao identificados nem controlados. Contudo, a proporçao de crianças com ZPP extremadamente elevada diminuiu acentuadamente, assim como a proporçao dquelas com niveis moderadamente elevados, embora menos destacadamente, a gravidade do problema foi reduzida, mas novos casos de intoxicaçao continuam ocorrendo (AU)