Dimethoate 40% organosphosphorous pesticide toxicity in Prochilodus lineatus (Prochilodontidae, Characiformes) eggs and larvae.

Toxicity tests using early life stages of fish are of great importance in assessing risks to growth, reproduction and survival in polluted environments and are important tools for good environmental monitoring. However, a small number of standard bioassays of this type have been developed in Brazil. Curimbatá (Prochilodus lineatus) is an abundant South American characid fish of great commercial interest. It was chosen for testing different concentrations of 40% dimethoate, an organophosphate insecticide and acetylcholinesterase enzyme (AChE) inhibitor used widely in Brazil. The 48-h LC50 for eggs is higher than 16.0 microg.L-1, whereas for recently hatched larvae it was found to be significantly lower (11.81 microg.L-1, ranging between 10.23 microg.L-1 - 13.65 microg.L-1) and also significantly lower than that for eggs by a Student t-test for independent samples (p = 0.03). The 96-h LC50 for 3-day old larvae was 10.44 microg.L-1 (8.03 microg.L-1 - 13.57 microg.L-1), similar to that of recently-hatched larvae (p = 0.76). Larval mobility was also found to be reduced by this insecticide.

Dimethoate 40 percent organosphosphorous pesticide toxicity in Prochilodus lineatus (Prochilodontidae, Characiformes) eggs and larvae

Os testes de toxicidade com os primeiros estágios de vida de peixes são de elevada importância no que se refere ao comprometimento das fases de crescimento, reprodução e sobrevivência dos organismos em ambientes poluídos, constituindo uma ferramenta importante para um adequado monitoramento ambiental. Entretanto, um pequeno número de bioensaios desta natureza tem sido desenvolvido no Brasil. O curimbatá (Prochilodus linetaus) é um peixe da ordem Characidae de grande interesse comercial e muito abundante na América do Sul. A espécie foi utilizada para testar diferentes concentrações de dimetoato 40%, um pesticida organofosforado inibidor da enzima acetilcolinesterase (AChE) utilizado em grande escala no Brasil. A CL50 (48h) para ovos é superior a 16,0 µg.L-1; entretanto para larvas recém-eclodidas foi significativamente mais baixa (11,81 µg.L-1 , variando de 10.23 a 13,65) de acordo com o teste-t para amostras independentes (p = 0.03). A CL50 para larvas com 3 dias de vida foi de 10,44 µg.L-1 (8,03-13,57), apresentando-se similar ao resultado encontrado para larvas recém-eclodidas (p = 0.76). A mobilidade das larvas foi reduzida na presença deste pesticida.

Diarrhoea and garbage disposal in Salvador, Brazil.

The association of infantile diarrhoea with the presence of garbage in the environment was investigated in Canabrava, a peripheral neighbourhood of Salvador, northeast of Brazil. A cross-sectional study was conducted with all the 184 children aged less than two years residing in Canabrava, which is located close to the city garbage dump. Variables selected for study included the method used for the disposal of excrement, type of floor, mother's education, unemployment of the head of the family, regularity of the water supply, presence of toilet, storage of garbage inside the house, age, gender, duration of breastfeeding, and the number of people per room. The estimated prevalence of diarrhoea was 21.2%. Exposure to garbage in the environment was found to be the most important factor associated with diarrhoea (adjusted odds ratio [AOR] = 3.98, 95% CI 1.56-10.13). Other important variables were the mother's education (AOR = 2.79, 95% CI 1.09-7.13), maternal breastfeeding (AOR = 2.30, 95% CI 1.05-5.04), and unemployment of the head of the family (AOR = 2.09, 95% CI 0.93-4.69). These findings indicate the necessity of adopting solutions in the public domain and of intersectorial policies for the reduction of diarrhoea.