Two computer models, namely MOBILE2 and PAL were utilized to estimate the air pollution emissions and concentrations due to traffic to and in the Central Florida Research Park. Since the Park is under construction, there are no actual existing data. Generally accepted engineering techniques were adopted to estimate traffic flow used for the study. Sensitivity analyses were conducted on the results, and it was found that changing the number of lanes for the roads - with different volumes of traffic on each lane - does not change the results significantly . But changing the dimensions of area sources (the parking lots in this study) did change the results. Therefore, accurate dimensions of those area sources are important to an accurate model. For areas with prevailing wind directions, long rectangular parking lots can be designed with their lengths perpendicular to the wind direction to get low pollutant concentrations. The results indicate that the carbon monoxide concentrations generated by vehicles in the Research Park will be within the Ambient Air Quality Standards for all cases studied.

No / The paper presents patterns and mechanisms of light non-aqueous phase liquid (LNAPL) migration in an unsaturated/saturated sand, based on a detailed experimental investigation using a fully instrumented two-dimensional model with dimensions of 120 x 120 x 10 cm. Suction head and degree of saturation were monitored simultaneously using tensiometers and time domain reflectometry (TDR) transducers respectively. LNAPL spills into the unsaturated zone were simulated to investigate the influence of new variables of practical importance, including the spill area, volume of spill and fluctuations of groundwater table, on the patterns of LNAPL migration. The patterns are explained in terms of the relationship between matric suction and degree of saturation. Fluctuations of water level are found to have a major influence on the distribution of LNAPLs in the unsaturated/saturated sand for large volumes of LNAPL spill. Measurements of degree of saturation of water at different levels are used to explain the LNAPL migration. It was found that water suction head was not affected by migrating LNAPL if the degree of saturation of water was above the residual saturation. Results of LNAPL suction head were found to be consistent with the migration patterns. Additionally, the average suction head difference between different levels indicated accurately the direction of LNAPL migration, which was in good agreement with the patterns observed using electronic imaging.

Increased deposition of nitrogenous compounds from the atmosphere may lead to the competitive dominance of aggressive grass species and reductions in species richness. This thesis aims to investigate the effects of atmospheric deposition of ammonia on species-rich limestone grasslands in the Cotswolds, and the role that management may have in modifying these effects. A field survey investigated species composition and quantified environmental variables including atmospheric ammonia concentration. Species richness and diversity were greatest on the more heavily grazed sites on deeper soils, but these diverse grasslands were composed of a high proportion of nitrophilic, competitive and ruderal species. No relationships between atmospheric ammonia and species composition were detected. The effects of grazmg and nitrogen on species composition were investigated by transferring turves between sites with contrasting atmospheric ammonia concentrations. Although grazed plots at the high ammonia site were of slightly higher diversity than grazed plots at the low ammonia site, these differences were reversed in fenced plots. In ungrazed plots, the development of a grass dominated, species-poor community was less pronounced at the low ammonia site, although the higher level of nitrophilic/competitive species here suggested that soil depth and soil phosphorous may also be important. A controlled greenhouse experiment investigated the effect of nitrogen addition and cutting on the competition between Brachypodium pinnatum and Bromopsis erecta. Above ground growth of both species was limited by nitrogen, although growth of B. erecta appeared to be limited by another resource at high densities. There was significant niche overlap between the two species, though cutting of high density pots reduced this niche overlap. The two grasses were equally matched in competitive ability, and neither treatment had any clear effect on the outcome of competition. The tillering response to cutting was greater in B. pinnatum than in B. erecta, although nitrogen addition increased tiller production by B. erecta. The effects of nitrogen addition and cutting treatments on nine grassland species was investigated in a greenhouse experiment. Nitrogen addition had no significant effects, but cutting reduced the above ground biomass of B. erecta and B. pinnatum and increased the above ground biomass and size of most of the other species. It is concluded that atmospheric ammonia deposition appears relatively unimportant in determining the species composition of species rich grasslands. However, experimental addition of nitrogen may increase grass growth, and grass dominance in the field can lead to reductions in species richness. In grazed grasslands, grasses may become more grazing resistant under conditions of enhanced nitrogen availability. However, phosphorous may be an important factor modifying the effects of enhanced nitrogen deposition.

This work was undertaken in order to determine the extent and nature of PAH pollution In a freshwater riverine environment. An extensive survey of sediment, water and aquatic organisms was carried out to investigate sources of PAH, physicochemical relationships occurring in the water and sediment, the extent of bioaccumulation and the potential for bioconcentration through the food chain. Laboratory studies were designed to investigate the likely mode and extent of uptake of PAH by Noemacheilus barbatulus (L.), Glossiphonia complanata (L.) and Lymnaea peregra (MUller), the ability of these species to metabolise PAH compounds and the extent of depuration. All sediment PAH profiles were similar and indicative of an anthropogenic pyrolytic origin. Urban/road runoff was considered to be a major influence on sediment PAH concentrations. point sources consisted of industrial waste sewage and runoff containing used engine oil. , All sites were affected by diffuse PAH pollution. At certain sites and at times of heavy rainfall this is overlain by a greater input of PAH to the sediment from point sources. Positive linear relationships have been demonstrated between total and individual PAH content and organiC matter content in sediments throughout a range of particle sizes. A similar PAH profile was found in each sediment size fraction, thus organisms selectively removing certain sized particles are not being exposed to differing ratios of PAH compounds. The river system seems to be in a state of nearequilibrium with regard to the partitioning of PAH between bedload sediment, suspended sediment, water and interstitial water. Adsorption and desorption processes occur in two phases, the first being almost instantaneous and the second being a slower approach to equilibrium. There is no- evidence of PAH's being bioconcentrated through the food chain. Uptake by tubificid worms occurs by the ingestion of contaminated sediment. Uptake by Cottus goblo (L.), N. barbatulus, L. peregru, G. complanata and Erpobdella octoculata (t.) occurs mainly through water and was shown to be rapid. N. barbatulus, L. peregra and G. complanat~ have the capacity to metabolise PAH compounds to harmful derivatives and it is likely that C. gobio and E. octoculata also have this capability. Depuration of BaP and metabolite compounds was relatively slow. Prolonged exposure to low levels of BaP in the environment may lead to a buildup of DaP and metabolite compounds in these organisms.

Knowledge of fine sediment delivery (both timing and loading) is fundamental to the assessment of non-point source pollution in estuarine environments. This study comprised three key components that led to the development of a fine sediment and particulate associated phosphorus budget in a typical agricultural estuary. Firstly, to explore catchment inputs, turbidity and flow were monitored continuously upstream of the freshwater/saline interface on the main stem channel of the south Devon River Avon, which drains a medium sized agricultural catchment (area 340 km2), in southwest UK. Thirty-five storms were studied in detail; and the hydrological and suspended sediment load response was observed to be highly variable. Suspended sediment concentrations (SSC) reached a maximum of 804 mg L-1 and sediment load varied from 3 to 227 t per hydrological event. Most sediment load was concentrated in winter months when competent flows occur frequently. Hydrological response was also variable in terms of lag, hydrograph shape and maximum discharge wherein the response to hydrological drivers was not consistent. Analysis of key storm parameters indicated that the hydrological response of the catchment was affected by the total amount of precipitation and antecedent rainfall history but the spatial pattern in rainfall across the catchment in relation to the spatial pattern of sediment sources was the key factor influencing total load. In the second component, examination of the sediment-associated phosphorus concentrations in the surface sediment in the Avon estuary was undertaken to evaluate spatial variation in concentration as influenced by the sediment storage dynamics of key geomorphological zones i.e. saltmarshes, intertidal flats and sandy shoals. Phosphorus concentrations ranged from 1524 to 68 mg kg-1 with higher concentrations found in saltmarsh. While there was no observed relationship between key sediment properties, particle size and total organic carbon within the different geomorphic units, a clear trend in particle size and particulate phosphorus concentration was observed longitudinally between mudflat zones linked to the sedimentation dynamics of the estuary. Furthermore, the relationship of particulate phosphorus concentration to organic matter content was modified by saltmarsh vegetation inputs to the sediment column. The final component of the work drew on evidence from a GIS and field-based survey to estimate (i) the total fine sediment and associated particulate phosphorus loading of the estuary and (ii), in conjunction with river flux data and literature evidence, the total fine sediment and PP storage and the annual sediment budget (inputs, storages and output) for the study estuary. The total amount of fine sediment stored in the estuary was ca. 99000 t which equated to 40 - 100 years of the annual sediment load of the river. Approximately 50% of all fine sediment that currently enters the estuary was estimated to be retained in storage supporting the important role of estuarine sediment sink zones in the attenuation of phosphorus. The total particulate phosphorus storage in estuary fine sediment was estimated to be 20 – 40 times the measured annual catchment particulate phosphorus input. Future changes in catchment sediment supply dynamics linked to catchment restoration programmes and soil conservation initiatives could destabilise estuarine sediment sinks and this has potentially important implications for future estuarine water quality. There is a need for further work on the potential bioavailability of estuarine sediment stored phosphorus.

published_or_final_version / Nursing Studies / Master / Master of Nursing

Most countries aim to regulate and protect the state of our environment under a system of environmental standards to control the level of certain pollutants present in various media of concern. Many such standards are often set without due consideration of uncertainty and variation and based on poorly defined principles. A sound statisticallybased approach to setting environmental standards can be based on the statistically verifiable ideal standard (SVIS) of Barnett and O'Hagan (1997). The SVIS is developed and practical implications of its use considered in terms of applications to pollution situations in air, water and soil, working in co-operation with relevant bodies. Developments include a non-parametric binomial approach and quantile testing for several simple parent pollutant distributions; properties of these approaches are examined in detail. A best linear unbiased quantile estimator (BLUQE) is examined, and 5% and 1 % critical values for the 0.95 and 0.99 BLUQE tabulated for use in an approximate significance testing procedure. This work is extended to a BLUQE for ranked set sampling, demonstrating impressive efficiency gains. Assessment of the SVIS using composite sample data is also investigated, with major improvements in test perrormance over the use of the commonly accepted 'divide-by-n' rule for critical value calculation. Following Barnett and O'Hagan (1997), the problem of setting directly equivalent compatible standards at different stages of the pollutant cause-effect chain is investigated. A statistically verifiable ideal guard point standard with two levels is also developed to avoid benefit of the doubt in testing procedures for standards, and its use demonstrated for both normal and gamma parent pollutant distributions. A reference point standard is proposed for a spatially dependent pollutant variable, with a krigingbased testing procedure. Finally, a 'hotspot' identification procedure is also developed, using outlier methods and composite sampling. The work concludes with suggestions for further related research.

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