Effects of Phos-Chek G75-F and Silv-Ex on red-winged blackbird (Agelaius phoeniceus) embryos

Effects of field application levels of wildfire control chemicals, Phos-Chek G75-F (PC) and Silv-Ex (SE), were examined on red-winged blackbird (Agelaius phoeniceus) embryos. Embryos were more sensitive to PC and SE when eggs were immersed for 10s at an early developmental stage (days 3-5 of incubation) than at a later stage (days 6-9 of incubation). The LC(50) (concentration causing 50% mortality) for early stage embryos exposed to PC was 213.3g/L (slope=1.6; 95% confidence interval [CI]=129.1-326.1). The no observed effect concentration (NOEC) was below 135g PC/L, which caused a significant increase in embryonic mortality and represents the lowest field coverage level of 1gal/100feet(2). The LC(50) for early stage embryos exposed to SE was 19.8g/L (slope=1.5; 95% CI=11.7-52.2). Significant mortality was observed at 10g SE/L and marginal at 7.5g SE/L with an apparent NOEC around 5g SE/L. Neither chemical resulted in apparent developmental malformations.     

浅析环境监测QC/QA过程的采样环节

对环境监测布点采样中的QC/QA以及由采样引起的误差来源做了简要分析,并对监测采样过程中QC/QA的操作提出了一些设想。     

False-negative prenatal exclusion of Wiskott-Aldrich syndrome by measurement of fetal platelet count and size

The study of the fetal platelet count and size can, according to the literature, be used for the prenatal diagnosis of the Wiskott-Aldrich syndrome (WAS). So far, no affected fetuses have been identified by this method. All pregnancies in which this method had been applied to resulted, as correctly predicted, in the birth of normal children. Here we report on a familial case of WAS where the haematological parameters failed to reveal the affected second child. Hence we assume that the platelet count and size of platelets remain normal in fetuses with WAS to the gestational age of 22 weeks and cannot be used for prenatal diagnosis.     

Effects of the mosquito larvicide GB-1111 on red-winged blackbird embryos

Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate that is used in the United States and other countries as a larvicide for mosquito suppression. As part of a multi-species evaluation of the potential effects of GB-1111 on birds, red-winged blackbird eggs were collected, artificially incubated, and treated with one of five amounts of GB-1111 varying from 0 to 10 times the expected exposure from a spray application of the maximum recommended amount (X=47 l/ha, 5 gal/ac). The application of 10 X caused a significant reduction in hatching success. A dose-related reduction of hepatic microsomal monooxygenase activity (EROD) was detected. Among body weights, skeletal measurements, and age at death, only crownrump length was different among experimental groups. Overall, the potential hazard to embryos of a representative wetland passerine appears minimal until the application rate exceeds 3 X.