Assessment of uncertainty of NO2 measurements by the chemiluminescence method and discussion of the quality objective of the NO2 European Directive

Hereafter, an assessment of the ability of the chemiluminescence method to measure ambient NO2 with an accuracy within 15%, as requested by the data quality objective of European directive 1999/30/CE, is presented. In general, uncertainty is evaluated using the response to reference materials or by means of inter-comparisons used to determine some statistics like repeatability, reproducibility and calibration bias. These are incomplete approaches and the method of the Guide to the Expression of Uncertainty in Measurement, advised by the Directive, should be preferred. In fact, even if it requires a large data set, it allows the relative influence of all possible sources of uncertainty to be studied. The extent of NO2 uncertainty is mainly dependent on the level of NO. It is decreased by NOx and the correlation between NOx and NO. Furthermore, the uncertainty budget reveals that the contribution of accuracy of calibration standard, linearity, converter efficiency and drift of the analyser between calibration checks to the overall uncertainty is less important than the contribution of interference, mainly humidity and PAN in rural areas. The relative expanded uncertainty of the NO2 hourly average exceeds 30% for NO2 concentrations lower than 40 microg m(-3). Nevertheless, the data quality objective of 15% is reached for 200 microg m(-3), the hourly limit value of the European directive. On the contrary, at the limit value on the annual average, 40 microg m(-3), the data quality objective is not met if NO is higher than 100 microg m(-3). However, the data quality objective could be reached by correcting the measurements with the bias due to interference.     

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency by steroid analysis in the amniotic fluid of mid-pregnancy: Comparison with HLA typing in 17 pregnancies at risk for CAH

Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies.     

Report on the fifth meeting of INRA’s national network of ecotoxicologists,ECOTOX

The fifth meeting of INRA’s national network of ecotoxicologists took place on 25 to 27 November 2014 in Biarritz, France. The main aim of the meeting was to bring together ecotoxicologists from INRA and associated partners, providing them ample opportunity to share and discuss their latest scientific results as well as the national policy of research in ecotoxicology and to precise perspectives for the network.     

Academic expertise in assisting private companies in the fields of environment and environmental toxicology: the role of individual expertise

Environmental Science and Pollution Research - The scientific knowledge produced by academic research can be valued in all sectors of human activity, including private sector. The ROVALTAIN...     

Feasibility study of preparation and certification of reference materials for nitrogen dioxide and sulfur dioxide in diffusive samplers

This paper presents the results of a feasability study for the preparation and certification of reference materials (RMs) for nitrogen dioxide (NO(2)) and sulfur dioxide (SO(2)) in diffusive samplers. RMs for NO(2) were prepared by exposure to gas mixtures in a chamber while the RMs for SO(2) were prepared by liquid spiking. Certification of RMs for NO(2) was found feasible with a certified uncertainty of 5.8% and a proposed shelf life of 5 years. The uncertainty was calculated with contribution from the homogeneity of preparation, stability and transport of the CRMs and from an external verification of the certified value. To reach 5.8% of uncertainty, the contribution of the differences between the results of analysis by ion chromatography and colorimetry must be eliminated. It is proposed to solve this by pre-extracting the samplers with water before analysis. The results of this study indicate that the samplers are stable for at least two years before and after exposure when stored in a refrigerator. By contrast, the certification of RMs for SO(2) was found to not be feasible due to instability problems. This instability was attributed to reaction of sulfate on the walls of the samplers. Alternatively, the preparation of RMs by simultaneous exposure to SO(2) and NO(2) has been tested. Satisfying homogeneities has been reached both for NO(2) and SO(2).     

Potential of <Emphasis Type="Italic">Ranunculus acris</Emphasis> L. for biomonitoring trace element contamination of riverbank soils: photosystem II activity and phenotypic responses for two soil series

Foliar ionome, photosystem II activity, and leaf growth parameters of Ranunculus acris L., a potential biomonitor of trace element (TE) contamination and phytoavailability, were assessed using two riverbank soil series. R. acris was cultivated on two potted soil series obtained by mixing a TE (Cd, Cu, Pb, and Zn)-contaminated technosol with either an uncontaminated sandy riverbank soil (A) or a silty clay one slightly contaminated by TE (B). Trace elements concentrations in the soil-pore water and the leaves, leaf dry weight (DW) yield, total leaf area (TLA), specific leaf area (SLA), and photosystem II activity were measured for both soil series after a 50-day growth period. As soil contamination increased, changes in soluble TE concentrations depended on soil texture. Increase in total soil TE did not affect the leaf DW yield, the TLA, the SLA, and the photosystem II activity of R. acris over the 50-day exposure. The foliar ionome did not reflect the total and soluble TE concentrations in both soil series. Foliar ionome of R. acris was only effective to biomonitor total and soluble soil Na concentrations in both soil series and total and soluble soil Mo concentrations in the soil series B.     

Organochlorine and heavy metals in newborns: Results from the Flemish Environment and Health Survey (FLEHS 2002–2006)

To collect regional information on internal levels of pollutants in humans in Flanders, 1196 mother–child pairs were systematically recruited in 2002–2003 via 25 maternities across Flanders. Cd, Pb, PCB congeners 118, 170, 138, 153 and 180, p,p′-DDE — a key metabolite of DDT- and hexachlorobenzene (HCB) were measured in cord blood or plasma. Cd was detected in 64% of the samples (geometric mean 0.21 µg/L cord blood). p,p′-DDE (110 ng/g plasma lipids) and Pb (14.7 µg/L blood), were measurable in nearly all samples. The individual PCB congeners could be detected in 40 to 81% of the newborns (138 + 153 + 180 = 64.4 ng/g plasma lipids). HCB (18.9 ng/g plasma lipids) and dioxin-like compounds measured by DR-CALUX® (23 pg CALUX-TEQ/g lipids) were above detection limit in more than 75% of the samples. Age and smoking habits of the mothers, did not influence the cord blood Pb and Cd levels. The organochlorines increased 4 to 9% per year of the mother's age (partial R² = 0.05 to 0.22). Mothers had 2.6% less PCBs in cord blood (partial R² = 0.02) for each unit increase in pre-pregnancy BMI. Season of delivery, breastfeeding previous children or consumption of local dairy products, were minor determinants. Up to 20% of the variability in organochlorine concentrations was explained by residence area. It was concluded that the place of birth in Flanders is an important determinant of the load of pollutants measured at the start of life. This underlines the validity of human biomonitoring on (relatively) small geographical scale.     

Hg concentrations and related risk assessment in coral reef crustaceans, molluscs and fish from New Caledonia

There is a dramatic lack of data on Hg levels in marine organisms from tropical areas, and in particular from New Caledonia. For the first time, this study reports the total Hg concentrations in the tissues of several marine taxa from the New Caledonian lagoon. Seafood from both wild and farmed populations was considered. Hg concentrations varied over three orders of magnitudes according to factors including species, age (size/weight), trophic level, lifestyle and geographical origin. Taking into account the edible tissues, estimations of the amount of flesh that should be consumed by a 60-kg person to reach the Hg Provisional Tolerable Weekly Intake (PTWI) reveal acceptable risk for Human health in general. However, a risk was clearly identified in one site of the lagoon (i.e. Grande Rade) where high Hg concentrations were measured. These concentrations were higher than values reported in the current literature.