Showing papers by "Roy M. Harrison published in 1996"
TL;DR: In this paper, a seasonal sampling campaign was undertaken at an urban location in Birmingham, U.K., in which high-volume samplers were used to collect particulate and vapor-phase polycyclic aromatic hydrocarbons (PAHs) by means of filter papers and polyurethane foam plugs.
Abstract: Intensive seasonal sampling campaigns were undertaken at an urban location in Birmingham, U.K., in which high-volume samplers were used to collect particulate- and vapor-phase polycyclic aromatic hydrocarbons (PAHs) by means of filter papers and polyurethane foam plugs. Eighteen PAH species were determined by reversed-phase HPLC. Additionally, the suspended particle loading of the air was measured gravimetrically. Dichotomous stacked filter units (DSFUs) were run simultaneously with the high-volumes enabling the collection of particulate matter representative of fine (<2.1 μm) and coarse sized (2.1−10 μm) fractions. Filters from the DSFUs were analyzed for 19 metal species [by proton induced X-ray emission (PIXE)], ammonium, elemental carbon, and various anions. Metal and PAH concentrations were observed to be broadly in line with concentrations measured at other urban areas throughout the U.K. Chemical source apportionment studies took the form of principal component analysis (PCA) followed by multi-line...
1,243 citations
TL;DR: In this article, a simple box model was proposed to explain the atmospheric concentrations of nitrous acid in terms of a small number of basic processes in which the most important are the surface production of HONO from nitrogen dioxide, atmospheric production from the NO-OH reaction and loss of acid by photolysis and dry deposition.
Abstract: Measurements of the land surface exchange of nitrous acid over grass and sugar beet surfaces reveal both upward and downward fluxes with flux reversal occurring at an ambient concentration of nitrogen dioxide of about 10 ppb. This confirms earlier preliminary findings and strengthens the hypothesis that substantial production of nitrous acid can occur on land surfaces from reaction of nitrogen dioxide and water vapor. Detailed measurements of nitrous acid have been made in central urban, suburban, and rural environments. These measurements, in conjunction with a simple box model, indicate that the atmospheric concentrations of nitrous acid are explicable in terms of a small number of basic processes in which the most important are the surface production of nitrous acid from nitrogen dioxide, atmospheric production from the NO-OH reaction and loss of nitrous acid by photolysis and dry deposition. In the suburban atmosphere, concentrations of nitrous acid are strongly correlated with nitrogen dioxide. In the rural atmosphere a different behavior is seen, with much higher nitrous acid to nitrogen dioxide ratios occurring in more polluted air with nitrogen dioxide concentrations in excess of 10 ppb. At lower nitrogen dioxide concentrations, net deposition of nitrous acid at the ground leads to very low concentrations in advected air. The model study indicates that during daytime in the suburban atmosphere, production of HONO from the NO-OH reaction can compete with photolysis giving a HONO concentration of a few tenths of a part per billion. At the highest observed daytime concentrations of HONO, production of OH radical from its photolysis can proceed at a rate more than 10 times faster than from photolysis of ozone.
234 citations
TL;DR: In this paper, an intensive seasonal sampling campaign was conducted at an urban site in the West Midlands conurbation and simultaneously at a nearby rural location with hi-vol and medium volume samplers modified in order to collect particulate and vapour phase polycyclic aromatic hydrocarbons (PAHs) by means of filters and polyurethane foam plugs (PUFs).
177 citations
TL;DR: A comparison of Lahore yearly mean pollutant concentrations with those obtained in Birmingham, U.K., shows that airborne metal levels in the Pakistani city are greater by at least one order of magnitude.
133 citations
TL;DR: In this article, a micrometeorological method and a chamber method were used to measure ammonia exchange over a mineral-fertilised wheat crop and to monitor the seasonal variation of NH3 under a variety of environmental and soil conditions.
78 citations
TL;DR: In this article, the concentrations of dimethyl sulfide in air were obtained during a cruise between the United Kingdom and the Antarctic in the period October 1992 to January 1993 using a method of sampling and analysis optimized to avoid interferences from oxidants.
Abstract: The concentrations of dimethyl sulfide in air were obtained during a cruise between the United Kingdom and the Antarctic in the period October 1992 to January 1993 using a method of sampling and analysis optimized to avoid interferences from oxidants. In equatorial regions (30°N to 30°S) the atmospheric DMS concentration ranged from 3 to 46 ng (S) m−3, with an average of 18 ng (S) m−3. In the polar waters and regions south of the Falkland Islands, concentrations from 3 to 714 ng (S) m−3 were observed, with a mean concentration of 73 ng (S) m−3. The concentrations of a range of DMS oxidation products were also obtained. No clear relationships between reactant and product concentrations were seen. Information on particle number concentration, Fuchs surface area and the thermal volatility characteristics of the ambient aerosol was obtained, but again no clear relationships with sulfur concentrations were observed. Accumulation mode particle concentrations averaged 25 cm−3 in the clean marine and polar air masses south of 58°S while background condensation nuclei (CN) concentrations were of the order of 400–600 cm−3. Simplistic calculations suggest that a particle source strength of about 20–60 particles cm−3 d−1 is required to sustain this background CN concentration. It is not clear whether boundary layer nucleation of new CN or entrainment from the free troposphere provided the source of CN. Periods of elevated CN concentrations (>4000 cm−3) were regularly observed in the boundary layer over the Weddell Sea and were attributed to “bursts” of new particle formation. However, shortly after these nucleation events the CN concentration rapidly decayed to the background level through coagulation losses, suggesting little impact on the background CN or cloud condensation nuclei (CCN) concentration.
55 citations
TL;DR: DimDimethyl sulfide, methane sulfonate, non-sea-salt sulfate and sulfur dioxide concentrations in air were obtained during a cruise between the U.K. and the Antarctic during the period October 1992-January 1993 as discussed by the authors.
54 citations
01 Jan 1996
TL;DR: Fertilizers and Nitrate Leaching Eutrophication of Natural Waters and Toxic Algal Blooms Impact of Agricultural Pesticides on Water Quality Agricultural Nitrogen and Emissions to the Atmosphere Drugs and Dietary Additives, Their Use in Animal Production and Potential Environmental Consequences Detection, Analysis and Risk Assessment of Cyanobacterial Toxins Subject Index.
Abstract: Fertilizers and Nitrate Leaching Eutrophication of Natural Waters and Toxic Algal Blooms Impact of Agricultural Pesticides on Water Quality Agricultural Nitrogen and Emissions to the Atmosphere Drugs and Dietary Additives, Their Use in Animal Production and Potential Environmental Consequences Detection, Analysis and Risk Assessment of Cyanobacterial Toxins Subject Index.
49 citations
06 Jun 1996
TL;DR: In this article, the basic chemical concepts underlying a sound understanding of environmental science and ecology are explained and illustrated with real examples from the environment, and the role of environmental chemistry plays with respect to climate, notably global warming and ozone depletion.
Abstract: The new edition of this textbook introduces the basic chemical concepts underlying a sound understanding of environmental science and ecology. Fundamental chemical principles are explained and illustrated with real examples from the environment. From an introduction to atomic and molecular structure, the text progresses to more advanced areas within physical, inorganic, organic and analytical chemistry. Important new sections for this new edition include an introduction to the concepts of biogeochemical cycling, and the role environmental chemistry plays with respect to climate, notably global warming and ozone depletion. The case studies have been up-dated, and a section about toxic chemicals has been added. While the primary aim is to satisfy the needs of the non-chemist, the text also serves to introduce environmental precepts to chemists who wish to apply their expertise to environmental issues. This volume is especially suitable for undergraduates in environmental science, environmental chemistry and ecology at universities, colleges and technical institutes.
46 citations
TL;DR: In this article, the rate of NO + O2 reaction can be enhanced in the presence of other vehicle exhaust constituents to an extent which may account for the episodic peak concentrations of nitrogen dioxide.
27 citations
TL;DR: The organolead level in mussels is shown to be a better indicator of pollution with organic lead than that in seawater, whereas the total lead level cannot serve this purpose as it comes from other sources.
Abstract: Mussels (Mytilus galloprovincialis) and surrounding seawater were collected from various sites on the eastern Adriatic coast and examined for the presence of alkyllead compounds and the total lead content. Organoleads were quantified by gas chromatography-atomic absorption spectrometry, and total lead was quantified by differential pulse anodic stripping voltammetry. The presence of all alkyllead species in mussel tissues was established (in nanograms/gram of wet weight) : tetraalkyl (<0.2-43.6), trialkyl (<0.1-31.8), and dialkyl (<0.1-9.2), with a dominance of ethyl derivatives. The organolead level in mussels is shown to be a better indicator of pollution with organic lead than that in seawater, whereas the total lead level cannot serve this purpose as it comes from other sources. Trimethyllead amounts in mussels and seawater are highly correlated ; thus, mussels provide a good bioindicator for this chemical species. Correlation between alkyllead levels suggests the possible environmental methylation of lead. Bioconcentration factors between mussels and water for individual alkyllead compounds are, on average, lower than those for total lead, indicating less efficient bioaccumulation of organic lead.
TL;DR: In this paper, the major soluble ions, non-sea-salt (nss) sulfate, nitrate, chloride, and ammonium have been measured in aerosol samples collected at various locations and altitudes over the North Atlantic Ocean.
Abstract: Concentrations of the major soluble ions, non-sea-salt (nss) sulfate, nitrate, chloride, and ammonium have been measured in aerosol samples collected at various locations and altitudes over the North Atlantic Ocean. Concentrations of nss sulfate, nitrate, and ammonium were found to be fairly uniform within the maritime boundary layer in an air mass aged in the Azores anticyclone; average values obtained were 0.36 ± 0.11, 0.18 ± 0.03, and 0.16 ± 0.06 μg m−3, respectively. The mean cloud condensation nuclei (CCN) concentration at 1% supersaturation was 368 cm−3, corresponding to air containing the major ion concentrations above. Incursion of continental air with a travel time of about 3 days over the sea led to an increase of around fivefold in nss sulfate, nitrate, and ammonium concentrations, while CCN concentrations increased less than threefold to 1076 cm−3. Two air samples collected during the clean air period above the marine boundary layer showed much reduced concentrations of soluble ions, but a mean CCN concentration of 358 cm−3. Regression analysis of all air sample data indicates that the nss sulfate and nitrate data are correlated to the observed CCN number density. While these ions are clearly making a significant contribution to CCN activity, the degree of correlation indicates that other chemical species also play a role as CCN.
TL;DR: In this article, the authors highlight major differences between the characteristics of various urban and national emission inventories and suggest that further harmonisation of existing inventories is highly desirable, which can be achieved if each agency responsible were to present their emission inventory results, besides their own specific categorisation, also in a common emission nomenclature like CORINAIR-SNAP.
TL;DR: In this paper, the BMCAPE project conducted four field campaigns over the period November 1993 to August 1994 on the island of South Uist, off the northwest coast of Scotland as part of a project to measure the concentration and chemical composition of aerosol particles.
TL;DR: In this article, ground-level concentrations of particulate sulphate, nitrate, chloride, ammonium and iron, total particle count and gaseous nitric acid and sulphur dioxide have been measured in marine air on Santa Maria, an island in the Azores in the mid-North Atlantic Ocean.
TL;DR: In this article, the authors measured polycyclic aromatic hydrocarbons and some of their nitrated derivatives (nitro-PAHs) in atmospheric particulate matter sampled from Birmingham, UK and Damascus, Syria.
TL;DR: In this article, the determination of tetraalkyllead (TAL) and ionic alkyllead (IAL) compounds in mussel tissues is described with each step in the procedures critically evaluated.
TL;DR: In this paper, aqueous solubility, octanol-water partition coefficient (K ow ), vapour pressure and Henry's Law constant of alkyl-lead compounds have been determined.
Abstract: Physico-chemical properties of alkyl-lead compounds, namely aqueous solubility, octanol-water partition coefficient (K ow ), vapour pressure and Henry's Law constant, have been determined. Vapour pressures of trialkyl-lead salts at different temperatures were measured by a gas-saturation technique in which air was passed slowly through a glass column packed with pure solid alkyl-lead compounds. K Ow of tetra-alkyl-lead (TAL) and trialkyl-lead (TriAL) were determined under different salinity and pH conditions, and the latter were related to the species (R 3 Pb + , R 3 PbOH 0 or R 3 PbCl 0 ) dominating under a particular set of conditions. Regression calculations incorporating melting point corrections relate water solubility to K OW and provide a means of estimating either parameter for a wider range of compounds.
TL;DR: In this paper, a study was conducted to develop certified reference materials containing trimethyl-lead (TriML) in environmental matrices, and the results demonstrated that the distribution of TriML in the same material is homogeneous.
Abstract: This study was conducted to develop certified reference materials containing trimethyl-lead (TriML) in environmental matrices. A detailed description of the process to prepare candidate artificial rainwater and road dust reference materials, which includes pretreatment, homogenization and bottling procedures, is described. The homogeneity was assessed by comparing the variations within a bottle and between different bottles. The results demonstrated that the distribution of TriML in the same material is homogeneous. The stability of TriML in these materials was verified on the day of preparation and after 1, 3, 6 and 12 months. The results showed no significant difference between the initial TriML concentration and the concentration after 12 months' storage in candidate artificial rainwater kept at room temperature and in road dust stored at -20°C and 4 °C, based on a statistical analysis of the results. At 37 °C, however, TriML was shown to be unstable: this highlighted the need to store the materials in the dark, preferably at 4°C. TriML in both of the candidate reference materials was hence concluded to be stable for at least 12 months under the appropriate storage conditions.
01 Jun 1996
01 Jan 1996
TL;DR: In this paper, the authors highlighted the importance of vehicles as a major contributor to airborne particulate matter, and concluded that traffic might have only a minor influence on particulate matters.
Abstract: Previous studies have highlighted the importance of vehicles as a contributor to airborne particulate matter. For example, the Quality of Urban Air Review Group described results from a study of urban particulate matter carried out by London Scientific Services (LSS, 1990). This study showed that in central London, roadside levels of particulate matter were 2–3 times higher than at a nearby “urban background” monitoring site, indicating road vehicles as a major contributor to particulate matter. QUARG (1993a) also analysed carbon monoxide and PM10 data for the central London Enhanced Urban Network site for a part of 1992. As a correlation coefficient of only 0.3 was found it was concluded that traffic might be only a minor influence on particulate matter concentrations. It was noted that although there were large day to day variations in PM10 concentration, the variations in traffic activity were relatively small. QUARG concluded that episodes of low rainfall and high windspeed would exert a strong influence on the concentration of particulate matter, as these conditions would lead to much resuspension of deposited dusts.