Analisaram-se os riscos e danos à saúde dos agricultores causados pelos agrotóxicos, tendo como eixos centrais o processo e as relações de trabalho presentes na agricultura brasileira. Trata-se de um tema polêmico, complexo e conflituoso. Foram abordadas questões referentes à informação e às políticas públicas para o setor. Este artigo traz a contribuição e a reflexão do Grupo de Estudos de Saúde e Trabalho Rural de Minas Gerais (Gestru), que apresenta alguns resultados de seus trabalhos realizados em regiões hortifrutigranjeira, floricultora, canavieira e cafeeira de Minas Gerais. Propõe-se a incorporação de um conjunto de variáveis a serem consideradas no processo de avaliação da exposição e dos danos à saúde gerados pelos agrotóxicos. São apresentadas algumas propostas e sugestões para a construção de uma agenda de políticas e ações no campo da saúde do trabalhador agrícola brasileiro.

The immune status of peripheral blood mononuclear cells (PBMC) and sera of pregnant women infected with the helminth Schistosoma mansoni was studied during pregnancy and the cord blood mononuclear cells (CBMC) and sera from their offspring were studied at parturition. PBMC pokeweed mitogen-induced responses were maintained in gravid women, but the responses to both schistosome and non-schistosome antigenic preparations declined progressively during pregnancy. Schistosomal antigens stimulated proliferative responses by the CBMC of many neonates born of infected mothers, but not those of uninfected mothers. These specific responses by CBMC of only neonates born of infected mothers are indicative of in utero, cell-mediated sensitization of the neonates, which could be due either to circulating schistosomal antigens or to anti-idiotypic antibodies which cross the placenta during gestation. Sera from infected mothers and the cord blood sera from their babies showed the same levels of specific IgG anti-schistosomal activity. Anti-schistosomal IgM levels were maintained during pregnancy to some antigens and not to others, while such antibodies were rarely found in cord blood sera, and then only at very low levels.

Cord blood mononuclear cells (CBMC) of neonates born of mothers with Chagas' disease or schistosomiasis exhibited strong proliferative responses against idiotypes expressed on antibodies with specificity for Trypanosoma cruzi or Schistosoma mansoni antigens, respectively. These immunoaffinitypurified preparations were stimulatory if they were prepared from pools of patients' sera or from the mother's own serum, taken early during her pregnancy. These CBMC did not respond to normal immunoglobulin, and CBMC of neonates born of uninfected mothers did not respond to antibodies against either T. cruzi or S. mansoni, or normal immunoglobulin preparations.We propose that in utero exposure of a fetus to some idiotypes expressed on placentally transferred antibodies induces anti-Id T lymphocyte sensitization, which we detect as a proliferative response by CBMC exposed to immunoaffinity-purified antibodies expressing the relevant idiotypes. This is the first experimental evidence that children born of mothers with chronic infections undergo natural in utero idiotypic manipulations and are born possessing cellular anti-Id reactivity.

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