Nitrate-induced photodegradation of atenolol in aqueous solution: kinetics, toxicity and degradation pathways

The extensive utilization of β-blockers worldwide led to frequent detection in natural water. In this study the photolysis behavior of atenolol (ATL) and toxicity of its photodegradation products were investigated in the presence of nitrate ions. The results showed that ATL photodegradation followed pseudo-first-order kinetics upon simulated solar irradiation. The photodegradation was found to be dependent on nitrate concentration and increasing the nitrate from 0.5 mM L⁻¹ to 10 mM L⁻¹ led to the enhancement of rate constant from 0.00101 min⁻¹ to 0.00716 min⁻¹. Hydroxyl radical was determined to play a key role in the photolysis process by using isopropanol as molecular probe. Increasing the solution pH from 4.8 to 10.4, the photodegradation rate slightly decreased from 0.00246 min⁻¹ to 0.00195 min⁻¹, probably due to pH-dependent effect of nitrate-induced OH formation. Bicarbonate decreased the photodegradation of ATL in the presence of nitrate ions mainly through pH effect, while humic substance inhibited the photodegradation via both attenuating light and competing radicals. Upon irradiation for 240 min, only 10% reduction of total organic carbon (TOC) can be achieved in spite of 72% transformation rate of ATL, implying a majority of ATL transformed into intermediate products rather than complete mineralization. The main photoproducts of ATL were identified by using solid phase extraction-liquid chromatography-mass spectrometry (SPE-LC-MS) techniques and possible nitrate-induced photodegradation pathways were proposed. The toxicity of the phototransformation products was evaluated using aquatic species Daphnia magna, and the results revealed that photodegradation was an effective mechanism for ATL toxicity reduction in natural waters.     

Exposure assessment of French women and their newborn to brominated flame retardants: determination of tri- to deca- polybromodiphenylethers (PBDE) in maternal adipose tissue, serum, breast milk and cord serum

In the frame of a French monitoring program, tri- to deca- polybromodiphenylethers (PBDE) have been measured in maternal and cord serum, adipose tissue, and breast milk samples, collected from 93 volunteer women during caesarean deliveries. The seven major tri- to heptaBDE (BDE-28, 47, 99, 100, 153, 154, and 183) were detected in adipose tissue and breast milk with cumulated median values of 2.59 and 2.51 ng g⁻¹ l w. Nine highly brominated octa- to decaBDE (BDE-196, 197, 201, 202, 203, 206, 207, 208 and 209) was performed in the same samples, with cumulated median values of 2.73 and 3.39 ng g⁻¹ l w in adipose tissue and breast milk, respectively. At this opposite, median levels of octa- to decaBDE in maternal and cord serum appeared significantly higher than the levels of tri- to heptaBDE in the same matrices, i.e. 8.85 and 12.34 versus 0.98 and 0.69 ng g⁻¹ l w, respectively.     

Nanoremediation and International Environmental Restoration Markets

Nanoscale zero‐valent iron (nZVI) is the most commonly used nanoremediation material. While there has been a reasonable level of application of nZVI technologies for in situ remediation in the United States, its utilization across Europe has been much more limited. There has been significant uncertainty about the balance between deployment risks and benefits for nanoparticles (NPs), which has affected the regulatory position in several countries. Some member states of the European Union (EU) take a strong precautionary view of the risks from the deployment of NPs into the subsurface, preventing the adoption of the technology. This article provides a risk–benefit assessment for nZVI based on published information and describes the steps that will be taken by a major European research project (NanoRem), as part of its work to provide a basis for better informed decision making in European environmental restoration markets. A key part of this process is dialogue between practitioners and researchers. NanoRem therefore has an active process of communication with different stakeholder networks (regulators, service providers, and site owners). NanoRem hopes to stimulate a consensus on appropriate use of nanoremediation and thereby stimulate effective technology transfer to the European remediation market. ©2015 The Authors     

Windsor, Ontario exposure assessment study: design and methods validation of personal, indoor, and outdoor air pollution monitoring

The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures upon asthmatic children's respiratory health was assessed. Several active and passive sampling methods were applied, or adapted, for personal, indoor, and outdoor residential monitoring of nitrogen dioxide, volatile organic compounds, particulate matter (PM; PM < or = 2.5 microm [PM2.5] and < or = 10 microm [PM10] in aerodynamic diameter), elemental carbon, ultrafine particles, ozone, air exchange rates, allergens in settled dust, and particulate-associated metals. Participants completed five consecutive days of monitoring during the winter and summer of 2005 and 2006. During 2006, in addition to undertaking the air pollution measurements, asthmatic children completed respiratory health measurements (including peak flow meter tests and exhaled breath condensate) and tracked respiratory symptoms in a diary. Extensive quality assurance and quality control steps were implemented, including the collocation of instruments at the National Air Pollution Surveillance site operated by Environment Canada and at the Michigan Department of Environmental Quality site in Allen Park, Detroit, MI. During field sampling, duplicate and blank samples were also completed and these data are reported. In total, 50 adults and 51 asthmatic children were recruited to participate, resulting in 922 participant days of data. When comparing the methods used in the study with standard reference methods, field blanks were low and bias was acceptable, with most methods being within 20% of reference methods. Duplicates were typically within less than 10% of each other, indicating that study results can be used with confidence. This paper covers study design, recruitment, methodology, time activity diary, surveys, and quality assurance and control results for the different methods used.     

Mistreatment from peers can reduce the effects of respectful treatment from bosses,and respectful peers can offset mistreatment from bosses

The present studies examine the joint influence of interpersonal fairness from peers and authorities on participants' organizational behaviors (citizenship) and attitudes (commitment). In three experimental studies, we find that mistreatment from peers, in the form of interpersonal unfairness, reduces the benefits that authorities gain from treating the same employee with high interpersonal fairness themselves. We also find that the negative effect of mistreatment from authorities can be offset by high interpersonal fairness from peers. These results come about because the interpersonal fairness shown not only by authorities but also by peers influences people's sense of standing as organization members. We discuss theoretical and practical implications, as well as limitations and suggestions, for future research.     

Second trimester two-step trisomy 18 screening using maternal serum markers

Trisomy 21 maternal serum marker screening has led to screening for other anomalies, including trisomy 18. Trisomy 18 is generally prenatally diagnosed because of major morphological defects. However, in up to 30% of cases ultrasound signs are unclear, and in most cases diagnosis is performed late in pregnancy. Of the different maternal serum markers, PAPP-A is now considered as the best for trisomy 18 screening. However, pregnancy-associated plasma protein A (PAPP-A) is of value in first trimester screening for trisomy 21, but not in the second trimester. We therefore propose a two-step screening strategy. Based on 45 trisomy 18 cases, we confirm the values of alpha-fetoprotein (AFP) (median 0.61 MoM), free β-human chorionic gonadotrophin (β-hCG) (median 0.24 MoM) and of PAPP-A (median 0.08 MoM). In the first step, a 0.5 MoM cut-off for AFP or for free β-hCG resulted in detection of 37/45 trisomy 18 cases (82%) with a 10% false-positive rate. The second step consisted of the measurement of PAPP-A for all these false-positive cases. Using a PAPP-A cut-off of 0.5 MoM, all the 37 trisomy 18 cases were detected, but now with a 0.1–0.2% false-positive rate. Amniocentesis was only offered to these few patients. This two-step second trimester screening will be of value for patients who have not been included in first trimester screening based on nuchal translucency (NT) measurement combined with the first trimester markers, PAPP-A and free β-hCG. Copyright © 2002 John Wiley & Sons, Ltd.     

NitroMAC: An instrument for the measurement of HONO and intercomparison with a long-path absorption photometer

NitroMAC (French acronym for continuous atmospheric measurements of nitrogenous compounds) is an instrument which has been developed for the semi-continuous measurement of atmospheric nitrous acid (HONO). This instrument relies on wet chemical sampling and detection using high performance liquid chromatography (HPLC)-visible absorption at 540 nm. Sampling proceeds by dissolution of gaseous HONO in a phosphate buffer solution followed by derivatization with sulfanilamide/N-(1-naphthyl)-ethylenediamine. The performance of this instrument was found to be as follows: a detection limit of around 3 ppt with measurement uncertainty of 10% over an analysis time of 10 min. Intercomparison was made between the instrument and a long-path absorption photometer (LOPAP) during two experiments in different environments. First, air was sampled in a smog chamber with concentrations up to 18 ppb of nitrous acid. NitroMAC and LOPAP measurements showed very good agreement. Then, in a second experiment, ambient air with HONO concentrations below 250 ppt was sampled. While NitroMAC showed its capability of measuring HONO in moderate and highly polluted environments, the intercomparison results in ambient air highlighted that corrections must be made for minor interferences when low concentrations are measured.     

Ectomycorrhizas impede phytoremediation of polycyclic aromatic hydrocarbons (PAHs) both within and beyond the rhizosphere

Exploitation of mycorrhizas to enhance phytoremediation of organic pollutants has received attention recently due to their positive effects on establishment of plants in polluted soils. Some evidence exist that ectomycorrhizas enhance the degradation of pollutants of low recalcitrance, while less easily degradable polyaromatic molecules have been degraded only by some of these fungi in vitro. Natural polyaromatic (humic) substances are degraded more slowly in soil where ectomycorrhizal fungi are present, thus phytoremediation of recalcitrant pollutants may not benefit from the presence of these fungi. Using a soil spiked with three polycyclic aromatic hydrocarbons (PAHs) and an industrially polluted soil (1 g kg(-1) of summation operator12 PAHs), we show that the ectomycorrhizal fungus Suillus bovinus, forming hydrophobic mycelium in soil that would easily enter into contact with hydrophobic pollutants, impedes rather than promotes PAH degradation. This result is likely to be a nutrient depletion effect caused by fungal scavenging of mineral nutrients.     

Visualization of fetal intra-abdominal organs in second-trimester severe oligohydramnios by intraperitoneal infusion

Fetal intraperitoneal infusion of saline was performed in two patients with severe oligohydramnios at 24 and 25 weeks' gestation in order to enhance visualization of intra-abdominal organs. Renal agenesis was easily diagnosed. The technique can be considered as an alternative to artificial instillation of amniotic fluid in the differential diagnosis of conditions associated with severe oligohydramnios.