摘要:

IntroductionThe 3rd International Passive Sampling Workshop (IPSW 2009,www.animaracio.com/ipsw2009) was held in Prague, Czech Republic between 28–30thMay, 2009 (previous events taking place in České Bude&cmb.breve;jovice, Czech Republic in 2004 and Bratislava, Slovakia in 2006). Two satellite workshops were held on the two days preceding the main event. The first concerned the setting up of an International Passive Sampling Interlaboratory Comparison (IPSIC) in water. The second was associated with the NORMAN (Network of Reference Laboratories and Related Organisations for Monitoring of Emerging Substances;www.norman-network.net) project and considered how passive samplers could be used to monitor emerging pollutants of concern. IPSW 2009 comprised 39 lectures as parallel sessions over the three days with some 33 posters being presented. The meeting attracted 89 delegates from 23 countries, the majority being drawn from the scientific community. The main workshop was organised by Tomáš Ocelka (Institute of Public Health Ostrava, Czech Republic) together with nineteen members of the international scientific committee. Although passive samplers for measuring concentrations (either equilibrium or time-weighted average (TWA)) of pollutants in both air and water have been available for over twenty years, it is only recently that their potential use in large scale regulatory monitoring programmes (e.g., The European Union's Water Framework Directive for water and the Stockholm Convention (under the auspices of the United Nations Environment Programme) for air) is being recognised. This meeting provided a forum for those involved in passive sampling to network and exchange ideas on how these devices could be used to monitor pollutants in various environmental compartments. The majority of talks concerned the use of passive samplers for monitoring the aquatic environment. Four themes were covered: theoretical aspects and calibration of devices, monitoring of water and application of samplers in monitoring programmes, eco-toxicological assessments and monitoring of air.

ISSN:0960-7919    

DOI:10.1039/b913775k

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

JEMenters its fifth year of publication, with confidence in the science it is currently publishing and optimism for even better quality material in the future. The number of articles published in 2002 was a new all time high (see below),Professor Evert Nieboer has completed his term of office as Chairman (but will continue as a member of the International Advisory Board). The Editor of the Pesticides column Dr Terry Clark has also completed his term. Both have made very substantial contributions to the successful launch and continued growth ofJEMas a truly international journal. The experience, enthusiasm, energy and wisdom each brought to theJEMBoard will be missed at future meetings. The new Chairman is Professor James Vincent of the University of Michigan (see). The “Pesticides in Perspective” column will be replaced by a “Metals in Perspective” column. The Column Editor will be Dr Adriana Oller who is the Manager, Mutagenicity and Carcinogenicity Program, NiPERA in Durham, NC, USA. I would like to express my thanks to allJEMBoard Members on both the Editorial and Advisory Boards as they play a crucial role in promotingJEMacross the globe, in supporting the journal with high quality submissions from their own groups, and in the refereeing and adjudication of articles submitted by others. There are a number of developments, some new, whichJEMreaders should be aware of as follows:Electronic publishing continues to grow in impact, andJEMcontinues to be at the forefront of such developments. Electronic files of papers can now be uploaded directly onto our web site atwww.rsc.org/submissions.Abstracts of allJEMpapers have been freely available on the web since mid-2002 and access to onlineJEMpapers is nowfree to all just two years after publication.E-mail alerts now include direct links to articles—please sign up atwww.rsc.org/is/journals/current/ej_update_form.htmto take advantage of this service.Access to the electronic form of any RSC print journal comes free with a 2003 institutional subscription, while those institutional subscribers who wish to receive just the electronic version can now subscribe and save 10%. One institutional print subscription, or online only subscription, allows site-wide access to the electronic version of that journal at no further cost.Users of RSC journals online can now benefit from a new Reference Linking facility. This citation linking backbone is a collaborative reference linking service that allows a user to click on a citation and be taken directly to the target content. Facilities include: free access to the Chemical Abstracts Service abstract for the referenceviaChemPort (www.chemport.org) and links to the full text of the reference, where available online, on the publisher's server (a subscription or pay-per-view may be required to access the article),viaCrossRef. Future enhancements will include a mechanism to purchase a printed copy of the cited articleviathe RSC Library and Information Centre's Document Delivery Service and links to other resources.Where a primary article contains chemical biology, it will be available free of charge for one month following publication in an issue through the Chemical Biology Virtual Journal (www.rsc.org/chemicalbiology). This provides an easy-to-use point of access to chemical biology literature in all RSC publications.The Contents List ofJEMwill now include 30 words of text highlighting the novel aspects of the work and its relevance/value to the environmental community. Authors are requested to provide these 30 word summaries on submission.Finally, I would like to express my sincere thanks and gratitude to everyone who has reviewed material forJEMin 2002 and responded so magnificently to allow us to maintain the fastest publication times in this sector. The reputation of the journal and, ultimately its success or failure is dependent on the reports provided by dedicated reviewers. Thus, their input cannot be underestimated. We continue to expand our database of reviewers and hope to lighten the load, a little, for many reviewers in 2003.As always, Editorial Board members and staff welcome suggestions as to how the journal might be improved or enhanced further. I wish you all every success in 2003.Harp MinhasManaging Editor

ISSN:0960-7919    

DOI:10.1039/b300298p

出版商:RSC    

年代:2003

数据来源: RSC

ISSN:0960-7919    

DOI:10.1039/b316291p

出版商:RSC    

年代:2003

数据来源: RSC

摘要:

The analytical sciences have advanced in leaps and bounds over the past 50 years, and have changed society as a result. In analytical chemistry, for instance, scientists have been driving steadily towards ever lower detection limits. Whereas in the 1950s analysts worked at the gram and microgram levels, they now operate routinely in picograms and femtograms and even, in certain kinds of analysis, in attograms (10−18).1Detection of trace metals, to take one example, has improved from parts-per-million to parts-per-trillion and even parts-per-quadrillion. And with the growth of genomics and proteomics, analysts are learning how to measure substances within living organisms at the level of attomoles—a factor of 50,000 beyond what was possible previously. Environmental monitoring is just one of the areas to benefit from these developments; others include genetic screening, forensic investigation and product safety.As in other areas of science and technology, these advances are the result of a process of technological innovation. Early work on innovation stressed a simple linear model in which scientific discoveries fed through to technological developments, which in turn fed through into economic growth. The innovation environment is now recognised as being much more complicated than this.2In place of linearity, economists now talk in terms of “systems of innovation”, with each country and each industrial or market sector being organised in a slightly different way. It is these differences in organisation and structure, and in particular the effectiveness of knowledge flows between the different actors within the system, that are the main factor linking innovation to competitiveness and economic growth.The analytical sciences are undoubtedly of major economic importance. In a UK survey, around 75% of companies in the pharmaceuticals, oil & chemicals, biomedical and food & drink industries considered that chemical and biochemical analysis was an essential business function.3As well as these industrial applications, at the molecular level analytical chemistry is playing an increasing role in areas such as biotechnology and medicine, and in material and earth sciences. Around 20% of all chemists are working as analysts, and an additional 50% are working in fields either involving some element of analysis or relying on analytical results. In the UK alone, the turnover of the analytical services business is estimated at £7 billion (US$11 billion). Hence, innovation in analysis is an important component in the performance of sectors and nations.But what, exactly, is the “innovation system” for analytical technologies? How is it structured? What are the dynamics and trends? Who is winning? And what will be the context for research and innovation in environmental analysis in the future?

ISSN:0960-7919    

DOI:10.1039/b300228b

出版商:RSC    

年代:2003

数据来源: RSC

摘要:

1.IntroductionHeavy metals can enter soil through a variety of natural processes, suchas weathering of rocks, and anthropogenic processes, such as atmospheric depositionof particles from industrial emissions and the application of fertilisers.In recent years, the utilisation of sewage sludge as a fertiliser within Europehas increased in response to changes in European Community legislation,1which has banned the dumping of sewage sludge intothe sea. In addition to valuable N, P and C, sewage sludge may contain heavymetals, even in sludge derived from non-industrial areas. When added tosoils, heavy metals may be adsorbed, form complexes or coprecipitate. Unlikeorganic pollutants, heavy metals cannot be decomposed by biological processesand tend to preferentially accumulate in the clay sized fraction because ofits large surface area. It is thus of interest to determine more about thedistribution and potential availability of metals within this fraction. Metalswhich bind strongly to the colloidal fraction can in many cases be consideredto be largely immobile. However, under certain circumstances, such as whenthe pH is increased, colloidal transport may become important.2,3This study focuses on an investigation of two biologically important metalsCu and Pb which are often found in sewage sludge. For mineral soils, a typicalcolloidal particle consists of a silica, silicate or aluminosilicate corewhich is often coated with hydrous Fe oxides, Mn oxides and natural organicmatter. These coatings are thought to have a profound effect on the bioavailabilityand cycling behaviour of trace elements.4Colloids can be separated into different sizes by sedimentation field-flowfractionation (SdFFF) with high resolution.5SdFFF is an elution technique with similarities to liquid chromatography,the main difference being that separation by SdFFF is induced by hydrodynamicprocesses (physical interactions) rather than by chemical interactionwith a stationary phase. The sample of colloidal suspension (typically50 µL containing up to 50 µg of solid) is injectedonto one end of a flat rectangular open channel, which sits within a centrifugebasket [Fig. 1(a)].Under stop flow, the centrifugal field is applied at right angles to the flatface of the channel and colloidal particles are driven towards the accumulationwall, where an equilibrium cloud is formed [Fig. 1(b)].After this relaxation period, the carrier liquid flow is turned on, and aparabolic fluid flow profile in the channel is generated. Since flow velocitiesincrease away from the accumulation wall, particles with a lower effectivemass are swept along the channel by a higher average flow velocity comparedto large particles and are eluted first [Fig. 1(c)].Schematic representationof the SdFFF-ICP-MS apparatus and the SdFFF separation mechanism occurringin the channel.The fractions eluting from SdFFF can be collected and their compositiondetermined off-line by inductively coupled plasma-mass spectrometry (ICP-MS),6inductively coupled plasma-atomic emission spectrometry (ICP-AES)7or graphite furnace atomic absorption spectrometry (GFAAS).8However, when using off-line methods with discretesamples, there is a greater likelihood of contamination problems for traceelements and it is more difficult to obtain high resolution information onchanges of chemical composition related to size. Murphyet al.9overcame this limitation by using SdFFF directlycoupled to ICP-MS. A recent improvement employed by Chenet al.10and Tadjiki7involvedusing high resolution magnetic sector mass spectrometry (HRMS).The resulting combination (SdFFF-ICP-HRMS) offers extremelypowerful particle size fractionation and multi-element analyses of majorand minor elements with low detection limits and little spectroscopic interference.For dilute suspensions (<0.2% w/v), particles withsizes <5 µm are effectively atomised by the ICP.11Direct slurry ICP-MS analysis of a range of geological materials has beenreported.12,13The eluent from SdFFFis much more dilute than the suspensions used in the previous studies, andin the normal mode of operation FFF is restricted to particles with sizes <2 µm,which makes ICP-MS a suitable method of analysis.Changes in chemical composition of the sample particles as a function ofparticle size can be displayed by plotting the appropriate eluent elementconcentration ∶ UV signal ratio (which is proportionalto the element concentration in the particles) and element atomic ratioversusparticle diameter. These data can then be used to interpret changes in mineralogyor surface coatings over the particle size distribution of the sample.The objective of our study was to identify which size fractions of thesesoil colloids contain the largest fraction of potentially bioavailable heavymetals. To achieve this, the particle size distributions and elemental compositiondistributions of the colloid phase were determined within the range 0.05–1 µm.This was performed before and after extraction with EDTA. The colloids wereanalysed for their major (Al, Fe) and minor (Mg, Ti, Mn)element compositions, including the heavy metals (Cu, Pb).EDTA is a strong complexing agent and has been used to determine extractableCu14and Pb15contents of soils. EDTA removes more than just the readily available componentand has been added to soils as an aid in phytoremediation.16

ISSN:0960-7919    

DOI:10.1039/b006633h

出版商:RSC    

年代:2000

数据来源: RSC

摘要:

1.Aim of investigationMany oxygenated volatile organic compounds (o-VOCs), including aldehydes, are known to have direct detrimental effects on human health affecting the respiratory tract and irritating the eyes, in some cases they are mutagenic and/or carcinogenic (Nishikawa and Sakai,1Keanet al.,2Sinet al.3). As such, human exposure limits to this group of highly toxic compounds requires careful attention through their long-term monitoring in the urban environment. Source profiles for the o-VOCs are particularly complex due to their emission as primary pollutants from motor vehicle exhausts and industrial processes along with theirin-situproduction as photo-oxidation products of hydrocarbons. Seasonal profiles of o-VOCs are also complex and highly dependent on the local environment and meteorological conditions. Generally concentrations of o-VOCs are greaterin winter compared with summer in urban environments (Sinet al.3), corresponding to periods of lower temperature and solar intensity, therefore reducing photo-chemistry. This highlights the importance of primary production and emissions to the atmospheric VOC burden in urban environments and also suggests the complexity of the atmospheric chemistry of the o-VOCs. Photo-oxidation of NMHCs leads to the formation of oxygenated species as secondary products. The concurrent increase in concentrations of OH, formed as intermediates in these reaction schemes and through increased photolysis of ozone during these periods of high solar intensity, may also react with and remove o-VOCs from the atmosphere and leads to complex competing reaction schemes.Formaldehyde and acetaldehyde are the main oxygenated species found in urban environments, together contributing to more than half of the oxygenated species by mass (Keanet al.,2Sinet al.3) and have been shown to be highly correlated in winter, when photo-chemistry is at a minimum. The ratio of these two compounds has been used to provide information about the origins of air masses and in general the formaldehyde/acetaldehyde ratio is greater in summer than winter. During summer months, the greater degree of photo-chemistry occurring in the atmosphere results in more conversion of alkenes to aldehydes, during this conversion formaldehyde is formed to a greater extent than acetaldehyde. Reaction rates of each of these species with OH are, however very similar (1 × 10−11and 1.4 × 10−11cm3molecule−1s−1for formaldehyde and acetaldehyde respectively) hence the ratio increases. In winter months the major sources for these compounds are from primary sources such as motor vehicles.Acetone is a key atmospheric species, known to be involved in the chemistry of the upper troposphere where its photolysis leads to the production of peroxyacetylnitrate (PAN), itself an important species, responsible for the long-range transport of nitrogen oxides to more remote regions of the globe. Sources of acetone are, however, as yet not well characterised.Isoprene, emitted into the atmosphere from plants and trees, contributes greatly to the total emission of carbon into the atmosphere (Guentheret al.4). Oxidation of isoprene in the atmosphere by the OH radical and also through ozonolysis yields formaldehyde, methylvinylketone (MVK) and methacrolein (MACR). Ratios of these species, along with their parent molecule are also useful in determining the origins of sampled air masses, although caution should be exercised in the use of MACR due to the existence of a primary, motor vehicle exhaust, source for this compound (McClarenet al.5)1.1.Existing methodsCurrent methods for the analysis of oxygenated hydrocarbons all too often rely on a chemical transformation of the target molecule into a derivatised relation containing an easily detectable functional group. For example 2,4-dinitrophenylhydrazine (2,4-DNPH) is regularly used in the detection of aldehydes (Helmig and Greenberg,6Keanet al.,2Sinet al.3) due to their reaction to form 2,4-dinitrophenylhydrozone, which can be easily analysed using chromatographic methods and are detected by a variety of techniques (including mass spectrometry and fluorescence). Derivatisation methods are not ideal for automated atmospheric chemistry applications, particularly for long-term studies. Routine manual operations are prone to error, particularly in the field and so for atmospheric science equipment automation, with as little human interaction as possible,is a key consideration.The importance of aldehydes to the chemistry of the atmosphere is clear from the particular attention aimed at this group of compounds. Nishikawaet al.7describe a system for the monitoring of formaldehyde at the sub-ppb level using derivatisation witho-pentafluorobenzyloxime (PFBO) followed by gas chromatography coupled with electron capture detection (GC-ECD). The system requires a 5 l sample which can be collected in a period of only 5 min, however, the derivatisation stage of the process requires a period of 40 min before extraction with n-hexane can occur. This system was then adapted for the analysis of low molecular mass aliphatic aldehydes (Nishikawaet al.8). Due to the lower ambient concentrations of this group of compounds compared with that of formaldehyde, a greater sample volume (up to 30 l) was required for detection of 10–67 ppb of thesecompounds. The mixture was required to stand for 80 min for complete derivatisation to occur before extraction could be performed, coupled with the long sample acquisition time (1 h) this method of aldehydes analysis loses much of the fine detail and diurnal behaviour of this group of compounds. Nishikawaet al.9,10also describe similar methods for analysis of acrolein, an irritant to eyes, skin and the nasopharyngeal membrane (Nishikawa and Sakai1), and crotonaldehyde with detection limits ranging between 0.5 and 13 ppb. All of the methods described, however require derivatisation and report recovery/collection efficiencies between 80 and 98%. Mass spectrometry has also been used in the analysis and detection of aldehydes in the atmosphere (Wedelet al.11), again such a method suffers from the inefficiency of the derivatisation stage,requiring large sample volumes and therefore reducing the frequency of analysis.Atmospheric monitoring of alcohols has received much less attention than other oxygenated species. Techniques used often give information of the combined total concentration of alcohols in each sample, due to difficulties encountered in their separation (Korenmannet al.12). Acetone, MVK and MACR are often determined in a similar way and thus it is rare that a full speciation is achieved.State of the art methods for monitoring o-VOCs include proton transfer mass spectrometry (PTR-MS) and orthogonal two-dimensional gas chromatography (2D-GC). Whilst both methods are extremely useful for oxygenated measurements, isobaric interferences are a problem with higher molecular weight PTR-MS measurements whilst the data intensive nature of 2D-GC makes it useful for only short-term focussed measurement campaigns.The work reported here indicates that an on-line carbon adsorbent-PLOT GC separation can be used with small sample volumes (1 l) and gives excellent sensitivity to on-line o-VOC analysis.

ISSN:0960-7919    

DOI:10.1039/b202798d

出版商:RSC    

年代:2002

数据来源: RSC

摘要:

Environmental impactArsenic occurrence and its toxicity have recently been subject of debate widely throughout the scientific and public community. Knowledge of its occurrence and mobilisation in pristine, high altitude sites gives the paper the novelty that would attract and benefit readers form the environmental community. This manuscript presents novel data on natural enrichment with arsenic, a hazardous contaminant, and its transportation from source areas in a high altitude environment, a subject weakly addressed in the literature. Additionally, we also present original data on potential contribution of arsenic by snow.

ISSN:0960-7919    

DOI:10.1039/b912432b

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

LegislationCommission consults on transport carbon tradingThe EU’s carbon emission trading scheme (ETS) could be extended to all major modes of transport, according to a consultation document issued by the European Commission. The idea is one of several policy options to internalise the costs of EU transport use.The inclusion of road, rail, maritime and inland waterway transport in the ETS “could be envisaged”, says the document. But practical arrangements would be different for each transport mode. For road transport in particular, “this might affect the purchase or the use of vehicles” depending on the way the scheme was adopted.Firm plans to include aviation in the ETS are already underway. Earlier this year the European Parliament demanded that shipping also be included in the scheme, but the Commission has given out mixed signals on the issue [JEM, 2007,9, 295 & 493]. Previously, a consortium of European environment agencies cautioned against emission trading for transport, arguing that the large number of small emitters would make it difficult to monitor [JEM, 2006,8, 675].Other options for internalising the environmental costs of transport outlined in the paper include taxes on carbon dioxide and other pollutants. But the document says the effectiveness of taxes is limited because they cannot differentiate between the environmental effects of emissions in different locations. As a result, the Commission pledges also to examine the feasibility and public acceptability of electronic charging for using road transport infrastructure.In a recent report, consultancy PWC warns that aircraft operators are still “far from being fully prepared” to enter the ETS. In a survey of 20 airlines, it found half expect emission trading to have a significant effect on their costs. Yet only one in four has assessed the full business impact on their organisation. The Commission has proposed including intra-EU flights in the ETS from 2011, and international flights from 2012. These dates could be brought forward by MEPs and ministers, who are currently debating the proposal [JEM, 2007,9, 493 & 643]. In their latest debate on the issue, MEPs voted for a tighter emission cap and more auctioning of allowances.The Commission will present a formal policy paper on the ETS and transport later this year, possibly with legislative proposals.In a related move, ministers have backed away from proposals to weight car taxation more heavily on the basis of carbon dioxide emissions. The proposals, which were first tabled by the Commission in 2005, would require member states to link 25% of the tax paid on cars to CO2emissions by 2008, rising to 50% by 2010. They also call for the gradual replacement of registration taxes by annual circulation taxes. Several countries expressed significant opposition to the plan at a meeting of finance ministers in Brussels. Unanimity is required to adopt tax-related measures at EU level.European Commission:http://ec.europa.eu/transport/white_paper/consultations/index_en.htm; PWC:www.pwc.deFlexibility for EU soil lawThe European Parliament has voted to give EU states more freedom to decide how to deal with areas at risk of soil degradation. The move came in a “first-reading” debate on a proposed soil protection directive [JEM, 2007,9, 296 & 907].MEPs endorsed many of the amendments tabled by its Environment Committee last October, which were designed to give member states more leeway in applying the new rules [JEM, 2007,9, 1147]. Within five years of transposing the directive, countries would have to identify “priority areas” at risk of soil degradation and draw up measures containing risk reduction targets, timetables and an estimate of implementation costs. But the choice of measures themselves would be left entirely to governments to decide.One key new amendment adopted would exempt EU countries that already have national soil protection legislation from drawing up such programmes, provided the existing rules “secure at least an equivalent level of protection”. The move is designed to reassure countries like Germany and the Netherlands, which feared the directive would force them to dismantle existing soil protection laws.The Parliament reversed certain changes made by the Committee that had watered down the draft law. It also endorsed the Committee’s demand for an EU law on biowaste within two years of the soil directive’s adoption.European Parliament:www.europarl.europa.eu/default.htmOperators fail to overturn ship pollution lawEU judges have thrown out a legal challenge to a 2005 directive on ship pollution, on the grounds that it does not breach global rules. Shipping industry trade associations had brought the case, claiming that the criminal sanctions for “intentional, reckless or seriously negligent” pollution introduced under the directive were not compatible with international law.In an opinion delivered in the European Court of Justice, Advocate-General Juliane Kokott argued that international law does not prevent the EU from imposing such sanctions. There is “no factor of such a kind as to bring into question the validity of the directive”, she said.The plaintiffs include international oil tanker association Intertanko, which represents 80% of the world’s fleet. They claim that the EU directive breaches liability rules established by the 1973 Marpol convention, which has higher legal status. A final ruling from the full court is still awaited, but in most cases the verdict reflects the advocate-general’s opinion.Meanwhile, the European Commission has announced it is to issue final written warnings to eight EU governments for failing to set out penalties for shipping pollution, as required under the directive. Cyprus, Estonia, Finland, France, Luxembourg, Malta, Portugal and the UK all failed to meet the April 2007 deadline for transposing the legislation into national law.Elsewhere, the International Maritime Organisation (IMO) has promised to accelerate work to develop a global climate policy for the shipping sector. IMO Secretary-General Efthimios Mitropoulos said he would push for an IMO report on the issue to be completed early, in time for decisions in autumn 2008. The EU has repeatedly complained of slow progress and warned that it could decide to include shipping in the EU’s cap-and-trade scheme for controlling carbon emissions [JEM, 2007,9, 493].European Court of Justice:http://curia.europa.eu/, (Case ref: C-308/06) ; International Maritime Organisation:www.imo.orgElectrowaste rules should be more focusedEU rules for the handling and treatment of electronic waste should focus on equipment with the highest environmental impact, according to a report for the European Commission.The study, by the UN University at Maastricht, is one of a series of reviews in the run-up to a revision, due later this year, of the 2003 waste electrical and electronic equipment (WEEE) directive [JEM, 2006,8, 769 & 871]. It recommends further differentiating EU collection, recycling and treatment targets according to the environmental impact of equipment types. High-impact products, such as fridges containing CFCs and mercury-based liquid crystal display monitors, should have stricter targets, it says. Other equipment unlikely to end up in domestic waste, such as large household appliances, should be excluded from the directive. No new inclusions under the law are recommended.The report points to large disparities in collection practices across Europe. The directive’s collection targets are very challenging for eastern European countries, it says. Performance in the older EU-15 is much better but rates are still only roughly half those of Switzerland and Norway.A second study, by a group of consultancies led by RPA, says the disparities between states could be reduced by harmonising registration and reporting requirements for take-back systems. The consultants also recommend harmonising requirements for financial guarantees linked to waste treatment. More should be done to ensure all producers pay for the collection of electronic waste, it says, but they should remain free to cack systems.The proposals received a mixed reaction from industry. Producer body the WEEE Forum welcomed the recommendations to differentiate waste types: “Better collection of, in particular, end-of-life refrigerators and proper extraction of CFCs is an important environmental priority”, said Secretary-General Pascal Leroy. But the AIPR, representing appliance makers and NGOs, warned policymakers not to tamper with the principle of individual producer responsibility. In a statement, the group said weakening producer responsibility would eliminate incentives for manufacturers to improve the design of products.European Commission:http://ec.europa.eu/environment/waste/weee_index.htm; Alliance for Individual Producer Responsibility:www.iprworks

ISSN:0960-7919    

DOI:10.1039/b718895c

出版商:RSC    

年代:2007

数据来源: RSC

摘要:

1.IntroductionIn environmental terms, the 19th century was the age of arsenic.1,2The uses of this element are almost too numerous to mention—embalming, cosmetics, glass and gunshot manufacture, pyrotechnics, taxidermy, weed and rodent control, and particularly in medicine, both by prescription and self-medication. Arsenic was characterized as a “therapeutic mule”.3For centuries, it was used for murder being known in France as “poudre de succession” (inheritance powder); the name arsenic is essentially synonymous with poison. However, in areas such as the Austrian province of Styria, arsenic was eaten, as the oxide or sulfide, to give freshness and beauty to the skin, to enhance sexual potency and to improve breathing and stamina in mountain climbing.4,5In 1775, Scheele discovered copper arsenite, CuHAsO3, a green pigment, known eponymously as Scheele’s Green. A related compound, copper acetoarsenite, Cu(CH3COO)2·3Cu(AsO2)2, acquired a variety of names—Schweinfurt Green, Mitis Green, Vienna Green,etc. These pigments found extensive use for coloring wallpapers, cloth and tapestries, various wrappings, children’s toys and even for foodstuffs (e.g, confectionery, blancmange).1Europeans, and to a lesser extent Americans, in the 19th century were living in a green environment, provided by green pigments based on arsenic, but in no way related to modern concepts for the adjective, green.Early in the 19th century, it appeared that there was a connection between ill health, possibly death, and habitation in rooms containing arsenic-coated wall coverings, especially if the rooms were damp. In a newspaper letter of 1839, the famous chemist, Leopold Gmelin, strongly warned against the dangers of arsenical pigments on wallpapers.6He had observed an adverse, mouse-like odor in rooms containing them, especially those facing to the North, which he attributed to a volatile arsenic compound, “alkorsin”—it is probable that he intended alkarsin, dimethylarsinoxide, (CH3)2As–O–As(CH3)2. Other authors reported the odor as leek-like. An alternative possibility was that arsenic-containing particles were flaked from the walls as a poisonous dust. Over the years an extensive dust/gas controversy developed: was the poisoning due to formation of a toxic gas or to inhalation of dust particles? The early literature has been reviewed.7–9Some of the reported events were truly bizarre. For example, in the USA, a family slept in a house where the bedrooms had been cleaned with a solution of arsenic mixed with naphtha and turpentine.10Perhaps it is not surprising that they were seized the next day with symptoms of acute arsenic poisoning. One wonders where arsenic obtained a reputation as a cleaner, and what happened to whoever did the cleaning.This article is concerned with the possible toxicity of an arsenical gas. However, the dust theory played a role in rather more recent times. The USA ambassador to Italy, Clare Booth Luce, had to resign her position in 1956 on account of arsenic poisoning. She had slept at the Embassy in a room with a ceiling decorated with arsenic-laden materials. A washing machine on the floor immediately above caused vibrations and lead arsenate particles fell as a “gray dust”. A certain irony has been noted: she and her husband, Henry Luce, had been dubbed “Arsenic and Old Luce”.11,12

ISSN:0960-7919    

DOI:10.1039/b413752n

出版商:RSC    

年代:2004

数据来源: RSC

摘要:

1.IntroductionNitrogen dioxide (NO2) is regarded as an air pollutant because of its adverse effect on human health and its contribution to the formation of low-level ozone. Consequently, in most countries, permitted concentrations of ambient NO2are subject to legislation. The UK, following the EU and the WHO, has an annual average limit for NO2of 40 µg m−3, equivalent to 21 ppb (parts per billion by volume) at ambient air pressure and temperature. Routine monitoring of NO2is therefore required to assess compliance with air quality standards. Such monitoring is particularly important for NO2because the majority of NO2in ambient air is formed from chemical oxidation of primary emissions of nitric oxide, NO. The rate of this oxidation is influenced by many factors ranging from local-scale meteorological dispersion and mixing, to regional scale transport of ozone (O3) oxidant, making it difficult to predict NO2spatial fields.Continuous analysers, such as the chemiluminescence analyser, are usually specified as the reference method for measurement of NO2, but passive diffusion samplers (particularly the Palmes-type passive diffusion tube,1PDT) remain widely used for indicative assessment of spatial variations of longer-term average NO2concentrations because of their ease of use and low cost. For example, an NO2concentration map for the entire UK is interpolated from a national network of PDTs.2The fundamental principle of PDT measurement is that NO2molecules are captured by triethanolamine (TEA) absorbent, N(CH2CH-2OH)3, coating the grids inside the closed end of the tube, with the rate of capture of NO2determined by the diffusive flux along the tube. Since TEA is extremely viscous at room temperature, it is dissolved in a solvent for application to the PDT grids. After exposure, trapped NO2is extracted into aqueous solution as nitrite ions, NO2−, and quantified.While it is accepted that NO2PDTs are not as precise as continuous analysers, considerable debate remains regarding the accuracy of NO2PDTs in the field. This debate surrounds the significance or not of specific factors giving rise to specific biases in deriving NO2concentrations. Some investigators have concluded that NO2PDTs are accurate within acceptable tolerances of precision,3whilst others have argued that specific phenomena such as wind-induced turbulence at the entrance to the tube,4or chemical production of additional NO2by co-diffusing NO and O3within the tube5,6contribute to an effective over-measurement of NO2by PDTs, or that an exposure-duration related loss of trapped NO2contributes to an effective under-measurement.7More recently, two studies8,9have suggested that the accuracy of NO2PDT measurement may also be affected by the way in which the TEA absorbent at the end of the tube is prepared. The observation has potentially major consequences for comparing NO2PDT data since there is no generally-recognised standard method of tube preparation. The variables in preparation are that the TEA absorbent may be dissolved in acetone or deionised water, in volume ratios ranging from 20%–50%, and the solution applied to the grids either by dipping the grids into the solution prior to PDT assembly, or by pipetting a known volume of solution onto the grids after assembly. The report9produced by NETCEN, the UK body currently responsible for collating and validating data from the UK national network of NO2PDTs, recommended that the preferred preparation method was to pipette an unspecified volume of a 20% TEA:water solution onto grids already assembled within the PDT cap. The recommendation was based on the observation that this preparation method yielded NO2measurements closest in value to those of a chemiluminescence analyser, whilst PDTs prepared by dipping grids into a 50% TEA:acetone solution (probably the most widespread method), or by pipetting a 50% TEA:water solution onto assembled grids, were reported to yield NO2measurements consistently higher, or lower, respectively, than the analyser. The study was conducted in a laboratory chamber. The field investigation by Kirbyet al.8also reported that tubes prepared by pipetting 50% TEA:water solution onto assembled grids yielded lower NO2measurement but that there was no difference in NO2measurement from tubes prepared using smaller volume ratios of TEA in water or using grids dipped in 50% TEA in acetone. Conversely, a recent review of routine PDT data from UK local authority networks reported no discernible effect of tube preparation method on PDT measurements.10One difficulty in trying to rationalise observations concerning the effect, or not, of absorbent preparation method is uncertainty regarding the actual mechanism of NO2complexation by TEA. A mechanism proposed by Glasiuset al.,11that yields a 1∶1 ratio between NO2in air and NO2−in solution, is shown ineqn. (1):12NO2+ N(CH2CH2OH)3+ 2OH−→ 2NO2−+−O–+N(CH2CH2OH)3+ H2OThe required hydroxyl ions are postulated to arise from the dissociation of TEA in water molecules present in the air, so the reaction will not take place in completely dry air, in accord with observations that TEA hydration is important for quantitative NO2sampling.12The OH−ions may also derive from water molecules in the absorbent solution itself (if present), and it has been suggested that the extent of this process may account for the apparent lower trapping efficiency of different molar ratio TEA:water absorbent solutions.8It is not clear from the studies cited above whether the physical process itself of coating grids (i.e.dipping or pipetting) contributes to differences in NO2measurement. It is also difficult to rationalise how different preparation methodologies may influence measurement. Given the ambiguity of the above studies and the continued importance of PDTs for ambient NO2measurement, the impetus for the current work was a detailed investigation of whether, and how, absorbent preparation method affects NO2concentrations derived from PDTs. Eight different grid preparation methods were compared in simultaneous exposures in urban air. Uniquely, this study also compared a sub-set of the PDT NO2measurements with the NO2concentration predicted to be measured by a PDT when within-tube production of NO2along the diffusion path of the tube is also taken into account.5To limit the impact on data interpretation of the further confounding issue of the loss of nitrite evident during longer exposure periods,7all exposures were of 1 week duration only.

ISSN:0960-7919    

DOI:10.1039/b311869j

出版商:RSC    

年代:2003

数据来源: RSC