Intoxicação por monofluoroacetato em animais

O monofluoroacetato (MF) ou ácido monofluoroacético é utilizado na Austrália e Nova Zelândia no controle populacional de mamíferos nativos ou exóticos. O uso desse composto é proibido no Brasil, devido ao risco de intoxicação de seres humanos e de animais, uma vez que a substância permanece estável por décadas. No Brasil casos recentes de intoxicação criminosa ou acidental têm sido registrados. MF foi identificado em diversas plantas tóxicas, cuja ingestão determina "morte súbita"; de bovinos na África do Sul, Austrália e no Brasil. O modo de ação dessa substância baseia-se na formação do fluorocitrato, seu metabólito ativo, que bloqueia competitivamente a aconitase e o ciclo de Krebs, o que reduz produção de ATP. As espécies animais têm sido classificadas nas quatro Categorias em função do efeito provocado por MF: (I) no coração, (II) no sistema nervoso central (III) sobre o coração e sistema nervoso central ou (IV) com sintomatologia atípica. Neste trabalho, apresenta-se uma revisão crítica atualizada sobre essa substância. O diagnóstico da intoxicação por MF é realizado pelo histórico de ingestão do tóxico, pelos achados clínicos e confirmado por exame toxicológico. Uma forma peculiar de degeneração hidrópico-vacuolar das células epiteliais dos túbulos uriníferos contorcidos distais tem sido considerada como característica dessa intoxicação em algumas espécies. O tratamento da intoxicação por MF é um desafio, pois ainda não se conhece um agente capaz de reverte-la de maneira eficaz; o desfecho geralmente é fata

The relationship between changes in daily air pollution and hospitalizations in Perth, Australia 1992–1998: A case-crossover study

A case-crossover study was undertaken to investigate the relationship between daily air pollutant concentrations and daily hospitalizations for selected disease categories in Perth, Western Australia. Daily measurements of particles (measured by nephelometry and PM2.5), photochemical oxidants (measured as ozone), nitrogen dioxide (NO2) and carbon monoxide (CO) concentrations were obtained from 1992 to 1998 via a metropolitan network of monitoring stations. Daily PM2.5 concentrations were estimated using monitored data, modelling and interpolation. Hospital morbidity data for respiratory, cardiovascular (CVD), gastrointestinal (GI) diseases, chronic obstructive pulmonary diseases (COPD) excluding asthma; pneumonia/influenza diseases; and asthma were obtained and categorized into all ages, less than 15 years and greater than 65 years. Gastrointestinal morbidity was used as a control disease. The data were analyzed using conditional logistic regression. The results showed a small number of significant associations for daily changes in particle concentrations, nitrogen dioxide and carbon monoxide for the respiratory diseases, CODP, pneumonia, asthma and CVD hospitalizations. Changes in ozone concentrations were not significantly associated with any disease outcomes. These data provide useful information on the potential health impacts of air pollution in an airshed with very low sulphur dioxide concentrations and lower nitrogen dioxide concentrations commonly found in many other cities

Changes in daily air pollution and mortality in Perth: A case crossover study

The monitoring of the common air pollutants in Perth has shown that concentrations exceed national standards for particles and photochemical oxidants (measured as ozone [O3]) on occasions in winter and summer respectively. By contrast, concentrations of sulphur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO) are all below national standards. In this study, a time stratified case crossover design was used to investigate the relationship between changes in daily air pollutant concentrations and mortality in Perth. The data were analysed using conditional logistic regression to produce odds ratios. Mortality data were categorised into cardiovascular disease, respiratory disease, and 'other mortality' and were obtained for the period 1992 through 1998. Network air quality data and meteorological data were obtained for the same period. The results showed significant relationships between cardiovascular mortality and NO2 and O3 concentrations. Increased odds ratios were also observed for O3 concentrations and respiratory mortality, however, only for the 8-hour O3 concentration was the increase statistically significant. A significant odds ratio was also observed for changes in CO concentrations and 'other mortality'. The data support the findings of other Australian and international studies and will assist in the evaluation of strategies designed to reduce air pollution in Perth