Status of nanoremediation and its potential for future deployment: Risk‐benefit and benchmarking appraisals

NanoRem (Taking Nanotechnological Remediation Processes from Lab Scale to End User Applications for the Restoration of a Clean Environment) was a research project, funded through the European Commission's Seventh Framework Programme, which focuses on facilitating practical, safe, economic, and exploitable nanotechnology for in situ remediation of polluted soil and groundwater, which closed in January 2017. This article describes the status of the nanoremediation implementation and future opportunities for deployment based on risk‐benefit appraisal and benchmarking undertaken in the NanoRem Project. As of November 2016, NanoRem identified 100 deployments of nanoremediation in the field. While the majority of these are pilot‐scale deployments, there are a number of large scale deployments over the last five to 10 years. Most applications have been for plume control (i.e., pathway management in groundwater), but a number of source control measures appear to have taken place. Nanoremediation has been most frequently applied to problems of chlorinated solvents and metals (such as chromium VI). The perception of risk‐benefit balance for nanoremediation has shifted as the NanoRem Project has proceeded. Niche benefits are now more strongly recognized, and some (if not most) of the concerns, for example, relating to environmental risks of nanoremediation deployment, prevalent when the project was proposed and initiated, have been addressed. Indeed, these now appear overstated. However, it appears to remain the case that in some jurisdictions the use of nanoparticles remains less attractive owing to regulatory concerns and/or a lack of awareness, meaning that regulators may demand additional verification measures compared to technologies with which they have a greater level of comfort.     

Cocaine and metabolites in waste and surface water across Belgium

Cocaine abuse, a growing social problem, is currently estimated from population surveys, consumer interviews and crime statistics. A new approach based on the analysis of cocaine (COC) and metabolites, benzoylecgonine (BE) and ecgonine methyl ester (EME), in water samples was applied to 28 rivers and 37 waste water treatment plants in Belgium using solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry. While EME was undetectable, COC and BE were detectable with concentrations ranging from <1 to 753 ng/L and <1 to 2258 ng/L, respectively. BE concentrations were employed to calculate the local amount of abused cocaine. The highest values (up to 1.8 g/day cocaine per 1000 inhabitants) were found in large cities and during weekends. The estimation of cocaine abuse through water analysis can be executed on regular basis without cooperation of patients. It also gives clear geographical information, while prevention campaigns can easily be implemented and evaluated.     

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-2.5 pm [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.     

Effect of positional isomerism on the abiotic degradation of pesticides: Case of m- and p-imazamethabenz-methyl

The effect of positional isomerism on chemical and photochemical degradations of the Imazamethabenz-methyl (IMBM), a pesticide of the imidazolinone family, has been studied. IMBM is proposed in the form of a mixture of the two positional isomers: meta and para. The development of an effective HPLC method (resolution factor R=1.3) allows us to follow either the abiotic disappearance of the meta and para IMBM and the formation of their breakdown products. The abiotic degradation studies include the chemical hydrolysis, as well as the direct and the indirect photodecomposition. We used TiO(2), a well-known initiator of hydroxyl radicals, to highlight the role of *OH in the indirect photodegradation. This work confirms the different behaviours of positional isomers in the environment. Indeed the chemical or direct photochemical degradation is faster for the meta isomer than for the para. Whereas, concerning IMBM, there is not any prevalent influence of this type of isomerism on the indirect photochemical degradation. The degradation products were tentatively identified by LC-MS, NMR and IR and a degradation pathway was proposed.     

Phytotoxicity of nickel in a range of European soils: influence of soil properties, Ni solubility and speciation

We investigated the influence of soil properties on Ni toxicity to barley root and tomato shoot growth, using 16 European soils. The effective concentration of added Ni causing 50% inhibition (EC(50)) ranged from 52 to 1929mgkg(-1) and from 17 to 920mgkg(-1) for the barley and tomato test, respectively, representing 37- and 54-fold variation among soils. Soil cation exchange capacity was the best single predictor for the EC(50). The EC(50) based on either the Ni concentration or free Ni(2+) activity in soil solution varied less among soils (7-14 fold) than that based on the total added Ni, suggesting that solubility of Ni is a key factor influencing its toxicity to plants. The EC(50) for free Ni(2+) activity from the barley test decreased with increasing pH, indicating a protective effect of protons. The results can be used in the risk assessment of Ni in the terrestrial environment.