Inventories of atmospherically derived <SUP>210</SUP>Pb in soil are used to determine deposition patterns of atmospheric aerosols averaged over decades (physical half-life of <SUP>210</SUP>Pb is 22.3 years). The method has been applied to quantify the long-term average enhancement in aerosol and cloud water deposition as a consequence of aerodynamic roughness effects of forest canopies in Scotland and Sweden. Split-level sampling techniques were applied to determine the depth profiles of <SUP>210</SUP>Pb from the surface to 20-30 cm at selected locations from within the canopy as well as the adjacent open land at each site. The specific activities of <SUP>210</SUP>Pb in dried soil samples were determined by non-destructive γ-spectrometry using high resolution HPGe detectors, one of which was fitted with a Compton suppression system. Initial sampling was conducted at Dunslair Heights beneath a Norway spruce (Picea abies) canopy and in the adjacent open grassland at an elevation of 450 m asl in the Scottish Southern Uplands. The average enhancement in the <SUP>210</SUP>Pb inventory under the forest canopy of 37% is found to be consistent with deposition estimates obtained from a continuous record of cloud frequency and meteorological variables, and is also in good agreement with the UK model deposition estimates for the site. Measurement of atmospheric <SUP>210</SUP>Pb inventories at the second site, an old plantation of Scots pine (Pinus sylvestris) at 420 m asl near the summit of Dun Coillich in the Scottish Highlands, revealed an average canopy enhancement in deposition of approximately 36% relative to the open heathland in close correspondence with independent estimates of cloud droplet deposition at the site. Deposition at the exposed edge of stand, however, exceeds that in the open by approximately 56%.

VOCs are generally present in the atmosphere in the gaseous state at concentrations in the 0.1 to 10 I-1g m-3 range. In indoor environments the concentrations tend to be ten times higher. VOCs enter ambient air from industrial fugitive emissions, biogenic sources and most notably from mobile sources associated with motor vehicles. It is known that VOCs in the atmosphere can be transported into soils and ground water by infiltrating precipitation. Development of new and existing analytical tools and sampling techniques to accurately analyse and quantify these compounds in all types of media for environmental management and remediation purposes is critical. This work seeks to incorporate intrinsic valid measurements to a fast field portable soil recovery unit and therefore propose a new advanced methodology for rapid site screening of contaminated land. The production of a new intrinsic validation device using polydimethlysiloxane coupons which contain 0.09 ± 0.011Jg of acetone, 1.02 ± 0.151Jg of toluene-D8 and 10.48 ± 0.721Jg of o-xylene-D10 are described, along with its application to intrinsically valid measurements using active adsorbent sampling, where an active adsorbent method incorporating intrinsic validation protocol is suggested. The development of a new soil screening methodology is next described with the aim of incorporating and transferring the previously described intrinsic validation methodology using the PDMS validation coupons. The initial response of the internal standards when recovered using the soil recovery unit, resulted in encouraging results with RSD between 9 and 34% achieved and a maximum recovered mass of 276.85ng for toluene-D8 and 198.45ng for o-xylene-D10 at 50bars with an extraction time of 1minute. A new method of soil spiking was described, which demonstrated the reproducible toluene soil spiking at the Ug g-1 level. It was found that the recovery of toluene from soil increased with an increase in pressure and extraction time when using the proposed system, with a maximum recovery of 30.8% recorded at 50bars with an extraction time of 2minutes. This trend was also true for the internal standards.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

It is now recognised that indoor environments contribute significantly to human exposure to airborne pollutants. People spend a large amount of time in indoor environments and there are many indoor sources that are not present outdoors. Among the chemicals released in indoor environments, some of them have been identified as hormonally active or carcinogens. Indoor air pollution problems are likely to become more as stricter controls limit outdoor pollution levels. Reduction of air exchange rate and the use of new insulating materials are likely to contribute to the build-up of pollutants in indoor air. The objective of this thesis has been to develop an analytical method based on thermal desorption for the measurement of semivolatile organic compounds (S'\iO:s) to be use for indoor and personal measurements. The sampler consists of a small FMz.s impactor upstream of a sample tube filled with the adsorbent Tenax TA to collect the particulate 'and gaseous phases respectively. The analytical technique was based on thermal desorption to compensate for the low sampling volumes available with the personal sampling pump so that the entire sample can be injected on the analytical system. In addition, the current technique reduces the analytical time and cost because little sample handling is required and it is more environmental friendly because no solvents are used. The experimental work focused on the development of a vapour generation system to determine breakthrough volumes of the least volatile target compounds on the adsorbent Tenax TA, the development of the analytical method for the analysis of both the gaseous and particulate phases and the evaluation of the performance of the developed method. Finally, the applicability of the method was verified by performing a short stUdy involving indoor and personal samplings. The developed vapour generation system permitted vapours to be generated at concentrations that are representative of indoor air concentrations. The apparatus has been evaluated for a number of SIt is now recognised that indoor environments contribute significantly to human exposure to airborne pollutants. People spend a large amount of time in indoor environments and there are many indoor sources that are not present outdoors. Among the chemicals released in indoor environments, some of them have been identified as hormonally active or carcinogens. Indoor air pollution problems are likely to become more as stricter controls limit outdoor pollution levels. Reduction of air exchange rate and the use of new insulating materials are likely to contribute to the build-up of pollutants in indoor air. The objective of this thesis has been to develop an analytical method based on thermal desorption for the measurement of semivolatile organic compounds (S'\iO:s) to be use for indoor and personal measurements. The sampler consists of a small FMz.s impactor upstream of a sample tube filled with the adsorbent Tenax TA to collect the particulate 'and gaseous phases respectively. The analytical technique was based on thermal desorption to compensate for the low sampling volumes available with the personal sampling pump so that the entire sample can be injected on the analytical system. In addition, the current technique reduces the analytical time and cost because little sample handling is required and it is more environmental friendly because no solvents are used. The experimental work focused on the development of a vapour generation system to determine breakthrough volumes of the least volatile target compounds on the adsorbent Tenax TA, the development of the analytical method for the analysis of both the gaseous and particulate phases and the evaluation of the performance of the developed method. Finally, the applicability of the method was verified by performing a short stUdy involving indoor and personal samplings. The developed vapour generation system permitted vapours to be generated at concentrations that are representative of indoor air concentrations. The apparatus has been evaluated for a number of SVOCs including PAHs, phthalates, organophosphate esters and alkylphenol) with as including FW-Is, phthalates, organophosphate esters and alkylphenol) with a broad range of volatility (from naphthalene to pyrene). The breakthrough measurement study performed in the worst conditions (30 0e and 7CJllo relative humidity) demonstrated that the adsorbent Tenax TA was appropriate to quantitatively collect even the least volatile compound naphthalene over a 24 hours sampling period. The analytical method was developed for 16 R\Hs, 6 CB*is, 5 phthalates, 2 organophosphate esters, 3 alkylphenols and 5 pesticides (2 organophosphorous, 1 carbam~te, 1 pyrethro'id and 1 organochlorine). Its applicability for R\Hs measurements was verified with a standard reference material (SRM1649a, NIS1) and by comparison of indoor air filter strips analysed by the Tn method and a conventional solvent extraction method. The 10 method was shown to be quantifiable for R\Hs up to benzo(a)pyrene but less effective for less volatile At\Hs due to their incomplete desorption. A side by side comparison between the developed sampler and a low volume Filter/PUF sampler clearly demonstrate that the developed method was much more efficient than the low volume PUF sampler for the measurement of gaseous low molecular weight compounds (Mw S178 g.mol-1 ). Regarding the particulate phase, measured concentrations from both samplers were highly correlated with the exceptions of the heavy R\Hs (IP, DahA and BghiP). These results suggest that sampling artifact were limited or similar to those of the low volume sampler. The precision of the method was evaluated by the relative standard deviation from co-located measurements in an indoor environment (n=6). A number of target .compounds were detected including R\Hs, CH\Hs, phthalates, organophosphate esters and phenol. The relative standard deviation was generally less than 1CJllo indicating good reprodUcibility. A small demonstration study consisting of twenty four hours indoor and personal measurements was carried during six days. The results obtained in this demonstration study were in agreement with most previous studies reporting indoor heavy At\Hs concentrations lower or similar than outdoor R\Hs concentrations and light R\Hs concentrations higher indoors than in outdoor environments. This demonstration study also confirmed that phthalates and organophosphate esters are ubiquitous in indoor environment.

No description available.