Showing papers by "Roy M. Harrison published in 1995"

Volatile organic compounds in the atmosphere

Abstract: Sources, Distributions, and Fates of VOCs in the Atmosphere Atmospheric VOCs from Natural Sources The UK Hydrocarbon Monitoring Network Source Inventories and Control Strategies for VOCs Gas Phase Tropospheric Chemistry of Organic Compounds Alternatives to CFCs and their Behaviour in the Atmosphere Volatile Organic Compounds in Indoor Air Volatile Organic Compounds: The Development of UK Policy Subject Index.

polynuclear aromatic hydrocarbon concentrations in road dust and soil samples collected in the united kingdom and pakistan

Abstract: Concentrations of polycyclic aromatic hydrocarbon (PAH) were measured in samples of soils, surface and road dusts and air from various locations in Birmingham (UK) and Lahore (Pakistan). Urban surface and road dusts were observed to decrease in PAH concentration with increasing distance from major roadways. PAH concentrations in soils in Birmingham were found to be comparable with other urban areas throughout the UK. A high correlation was found between airborne particulate matter and soil concentrations in Birmingham, which suggests that atmospheric deposition is the dominant source of PAHs in soils. A high correlation was also found between PAH concentrations in soil and road tunnel dust; this illustrates the impact of vehicle emissions as the major source of PAHs in urban areas. The high correlation between PAH species profiles distributed through soils in the UK provides evidence for either long range dispersion and deposition of particles, or similar local emission sources in all sampled areas. PAH l...

Effect of fertilizer application on NO and N2O fluxes from agricultural fields

Abstract: Losses of fertilizer as NO and N2O were studied at Broadbalk field, Rothamsted Experimental Station in England, on which subplots have been subject to differing constant levels of fertilizer application for many years. Fluxes of NO and N2O were measured using open- and closed-chamber techniques, respectively. Fluxes from unfertilized soil ranged from 0.3 to 4.8 ng N m(-2) s(-1) for NO and 0.23 to 3.0 ng N m(-2) s(-1) for N2O. The corresponding fluxes from the plot with the highest fertilizer application (92 kg N ha(-1) yr(-1) as NH4NO3) ranged from 0.5 to 64 ng N m(-2) s(-1) for NO and 0.4 to 240 ng N m(-2) s(-1) for N2O. Application of increasing amounts of fertilizer substantially enhanced emission rates of both NO and N2O. However, the amount of increase was controlled by competition between the crop and the microorganisms for the available soil nutrients, and loss of N2O to the atmosphere increased sharply at superoptimal levels of fertilizer application. The fertilizer-derived NO and N2O emissions represented approximately 90% of the total emission of these gases during the 25-day sampling period after fertilizer application. The results suggest that while increasing the amount of fertilizer increases both NO and N2O fluxes simultaneously, the NO/N2O emission ratio decreases. Results from laboratory experiments showed that the magnitude of the fertilizer loss as N2O was strongly affected by the form of the applied fertilizer.

Atmospheric chemistry of PCBs, PCDDs and PCDFs

Abstract: Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) (see Figure 1) are emitted into the atmosphere fromthe combustionof chlorine-containingmaterials.1—13Additionally, PCBs, which were used as lubricants and dielectric fluids,13 are volatilized into the atmosphere from soils and bodies of water (for example, from the Great Lakes) after their disposal or inadvertent release into, and cycling through, the environment.1,14—18 Atmospheric concentrations of PCBs, PCDDs and PCDFs have been measured at numerous locations,2,15,16,19—62 and these organochlorine

Interlaboratory programme for the quality control of trimethyllead determination in the environment

Abstract: Determinations of the trimethyllead moiety in environmental samples are carried out by a number of laboratories in Europe. To verify the quality of such determinations, the Measurements and Testing Programme (formerly BCR) of the European Commission organised an interlaboratory exercise which allowed discussion and comparison of the different techniques used so far in lead speciation analyses. In addition, this first step enabled a study of the feasibility of the preparation of candidate reference materials (CRMs) for the determination of the trimethyllead moiety in simulated rainwater to be carried out. The solutions used in this study were carefully prepared and their homogeneity and stability verified. This paper describes the organisation and the results of the intercomparison and discusses the further development of the project.

Control of PCDD and PCDF emissions from waste combustors

Abstract: From an operational and regulatory perspective, the challenge is to develop control strategies which are effective in the field, but which are also practical to implement. For example, from a knowledge of the fundamental chemical and physical mechanisms of PCDD/F formation and their relationships to the prevailing physical and chemical conditions, it is possible to identify through laboratory experiments key operational parameters or surrogate emissions

Source apportionment of atmospheric particles in the UK and Pakistan

Abstract: Intensive seasonal sampling was undertaken at urban and rural locations throughout Birmingham (UK). Dichotomous Stacked Filter Units (DSFUS) were run simultaneously with hi-vol samplers. DSFU filters were analyzed for nineteen metal species, ammonium and various anions. Hi-vol samplers were modified in order to collect particulate and vapor phase PAHs by means of filter papers and polyurethane foam plugs. Eighteen PAH species were determined by reversed-phase HPLC. Filter portions were forwarded to the University of Aveiro for analysis of elemental and organic carbon. Hi-vol air sampling equipment was run at three sites in Lahore (Pakistan) for over a year. Selected metals, anions and ammonium were quantified, along with eighteen species of particle-associated PAH. Chemical source apportionment of both the Birmingham and Lahore aerosol loads was completed using multivariate analysis. Metals and anionic data were utilized, along with organic concentrations and meteorological data. This technique typically enabled six major air pollution source categories to be identified, along with the quantitative contributions of pollutant species to each source group. The combination of measurements of PAH and inorganic pollutants proved to be a far more powerful tracer of emission sources than PAH data alone. The largest contribution to aerosol mass in the coarse sizedmore » fraction in Birmingham was observed to be soil. Whereas in the fine sized fraction major contributors are vehicular/road dust followed by secondary aerosol formation plus oil combustion. Multivariate analysis of the Lahore data revealed similar source categories to those found in Birmingham. The largest contribution to aerosol mass at all three Punjabi sites was soil. This source is followed by metallurgical processes, vehicular emissions and refuse burning.« less