Toxicity of leachate from bottom ash in a road construction

A test road constructed with municipal solid waste incineration (MSWI) bottom ash was monitored over a period of 36 months. Using chemical and toxicological characterisation, the environmental impact of leachates from bottom ash was evaluated and compared with leachates from gravel used as reference. Initial leaching of Cl, Cu, K, Na, NH4-N and TOC from bottom ash was of major concern. However, the quality of the bottom ash leachate approached that of the gravel leachate with time. Leachates from the two materials were compared regarding the concentration of pollutants using multivariate data analyses (MVDA). A standardized luminescent bacteria assay using Vibrio fischeri did not show any toxicity, most likely because saline contamination can mask the toxic response and stimulate luminescence in these marine bacteria. A mung bean assay using Phaseolus aureus revealed that the toxicity of bottom ash leachate collected at the very beginning of the experimental period (October 2001 and May 2002) might be attributed to the following components and their respective concentrations in mg l(-1): Al (34.2-39.2), Cl (2914-16,446), Cu (0.48-1.92), K (197-847), Na (766-4180), NH4-N (1.80-8.47), total-N (12.0-18.5), and TOC (34.0-99.0). The P. aureus assay was judged as a promising environmental tool in assessing the toxicity of bottom ash leachate.     

Estimation of riverine loads of nitrogen and phosphorus to the Baltic Sea, 1970–1993

This article presents the results of the first critical examination of time series of riverine nutrient-load data for the entire Baltic Sea drainage area. Water quality data collected by or for the different national environmental agencies were compiled and analysed statistically to identify and remove inconsistent or obviously incorrect observations. Moreover, sampling tours were undertaken to acquire additional information about the present nutrient concentrations in the largest rivers in the study area. Gaps in the time series of approved data were then filled in by employing statistical interpolation and extrapolation methods. Thereafter, the concentration and runoff data were combined to obtain estimates of monthly nutrient loads for the time period 1970–93. The results of the calculations showed that although there had been substantial changes in land use, atmospheric deposition and wastewater treatment in many parts of the study area, the total riverine loads of nitrogen (N) and phosphorus (P) to the Baltic Sea have been fairly constant since 1980, and most likely also since 1970. Moreover, the interannual variation was clearly correlated to the runoff. The mean annual loads for the time period 1980–93 were found to be about 825 000 tonnes N and 41 000 tonnes P, respectively. This implies that (i) several other investigators have strongly underestimated the riverine loads of nutrients, especially the nitrogen, and that (ii) the riverine loads by far exceed the input to the Baltic Sea from other sources, {i.e.} atmospheric deposition, direct emissions from cities and industries along the Baltic Sea coast and nitrogen fixation by marine algae.     

Noninvasive prenatal screening for cystic fibrosis using circulating trophoblasts: Detection of the 50 most common disease-causing variants

Objectives

Cystic fibrosis (CF) is one of the most common severe autosomal recessive disorders. Prenatal or preconception CF screening is offered in some countries. A maternal blood sample in early pregnancy can provide circulating trophoblasts and offers a DNA source for genetic analysis of both the mother and the fetus. This study aimed to develop a cell-based noninvasive prenatal test (NIPT) to screen for the 50 most common CF variants.

Methods

Blood samples were collected from 30 pregnancies undergoing invasive diagnostics and circulating trophoblasts were harvested in 27. Cystic fibrosis testing was conducted using two different methods: by fragment length analysis and by our newly developed NGS-based CF analysis.

Results

In all 27 cases, cell-based NIPT provided a result using both methods in agreement with the invasive test result.

Conclusion

This study shows that cell-based NIPT for CF screening provides a reliable result without the need for partner- and proband samples.