Chlorinated solvents, such as tetrachloroethene (PCE), trichloroethene (TCE), and carbon tetrachloride (CT), are primary contaminants of concern for a vast majority of federal and state Superfund sites in the US due to their prior widespread use as solvents for numerous industrial and commercial applications. Source-zones containing large quantities of contaminant are typically present at sites contaminated by chlorinated solvents. Particularly in regions such as the SW US, these source zones reside, at least in part, in the extensive vadose zones typical of these regions. There are two primary concerns associated with sites that contain vadose-zone contaminant sources. First, discharge of contaminant vapor from the vadose-zone source may impact the underlying groundwater. This could contribute to overall risk posed by the site, and delay attainment of groundwater cleanup goals. Second, contaminant vapor from the vadose-zone source may migrate to the land surface and transfer into buildings, thereby causing vapor intrusion. The focus of this research is the development and application of innovative methods for characterizing vadose-zone contamination. Phytoscreening is a new, rapid, and relatively low-cost characterization technology that can be used to screen an area for the presence of select contaminants such as chlorinated VOCs. Phytoscreening is based on the sampling and analysis of plant tissues (branch, trunk, leaf, seed, needle) to detect the presence of contamination in soil and groundwater. Phytoscreening is applied to three sites in Arizona to evaluate its use in semi-arid environments. In addition, all available field data sets have been compiled to examine potential correlations between contaminant concentrations measured for tree tissue and those for groundwater. Contaminant concentrations were detected in tree tissue samples collected from two of the three Arizona sites. A review of the field site data suggests that a correlation exists between PCE and TCE concentrations measured for tree tissue and those measured in groundwater. The correlation can be used to estimate vegetation concentrations when groundwater concentrations are known. The reasonable degree of correlation supports the use of phytoscreening as a robust screening tool to provide a first-order characterization of anticipated concentrations of contaminants in groundwater. This tool can also be used to screen an area for vapor intrusion potential. A sampling method for the determination of chlorinated contaminant vapor concentrations present in the vadose zone, specifically trichloroethene (TCE), has been developed, and was applied at the Tucson International Airport Authority (TIAA) Superfund site. The method was modified from the NIOSH Manual of Analytical Methods (NMAM) # 1022 for TCE, and is targeted to situations requiring cost effective sample collection, particularly for cases when concentrations are at or below maximum contaminant levels (MCLs). In the modified NIOSH method, TCE vapor is sampled using a solid sorbent cartridge containing coconut shell charcoal arranged into primary and secondary sections. Gas Chromatography with Mass Spectrometry is used to confirm and quantify the presence of TCE. The results of laboratory tests demonstrate a maximum TCE vapor load of approximately 22 mg before breakthrough to the secondary section, and a recovery of approximately 97%. The results of a performance comparison test conducted in the field demonstrated that results obtained with the cartridge samplers were similar to those obtained with the use of standard Summa canisters. Landfill waste often serves as a long-term source of volatile organic compounds (VOCs) in the vadose zone. In turn this contamination can have a significant impact on groundwater and on residential or commercial indoor air quality through vapor intrusion. Sulfur hexafluoride (SF₆) was used as the non-reactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well, and analyzed for SF₆, CH₄, CO₂, and VOCs. The travel times determined for SF₆ from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate only gas phase diffusion. In addition, significant concentrations of CH₄ and CO₂ were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF₆ are caused by advective transport associated with landfill gas generation. A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF₆). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local-extraction point, whereas increases were observed for monitoring points located between the local-extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

Arid lands comprise vast regions of terrestrial land, highlighting the importance of understanding their role in the global carbon cycle. The objective of this study was to determine the effect of Prosopis velutina (mesquite), Larrea tridentata (creosote) and a combination of Bouteloua barbata, Bouteloua aristidoides, Aristida adscensionis, and some Cynodon dactylon (mixed grass) vegetation types on soil organic carbon (SOC) dynamics and quality in an arid, hyperthermic ecosystem of southern Arizona. This was accomplished by quantifying vegetation type control over: (i) local scale SOC stocks; (ii) soil aggregate stability; (iii) SOC turnover and microbial community composition; (iv) the distribution of SOC in physically defined fractions; and (v) the thermal nature and composition of SOC. The results from this study demonstrated significant variation in SOC dynamics and quality between vegetation with potential feedbacks to SOC sequestration of atmospheric CO₂.

An invasive variety of the common reed Phragmites australis, the M haplotpye, has been implicated in the spread of this species into North American salt marshes normally dominated by the salt marsh grass Spartina alterniflora (smooth cordgrass). Phragmites australis is spreading into North American coastal marshes that are experiencing reduced salinities, while Spartina spp. are spreading into northern European brackish marshes that are experiencing increased salinities. We compared the salt tolerance and other growth characteristics of the invasive, M haplotype with two native haplotypes (F and AC) in greenhouse experiments. The M haplotype retained 50% of its growth potential up to 0.4 M NaCl, whereas the F and AC haplotypes did not grow above 0.1 M NaCl. The M haplotype produced more shoots per gram of rhizome tissue and had higher relative growth rates than the native haplotypes on both freshwater and saline water treatments. The M haplotype also differed from the native haplotypes in shoot water content and the biometrics of shoots and rhizomes. The results offer an explanation for how the M haplotype is able to spread in coastal salt marshes and support the conclusion of DNA analyses that the M haplotype is a distinct ecotype of P. australis.We then compared the growth, competitive ability, salt tolerance and osmotic adjustment of M haplotype P. australis and S. alterniflora along a salinity gradient in greenhouse experiments. Spartina alterniflora produced new biomass up to 0.60 M NaCl, whereas P. australis did not grow well above 0.2 M NaCl. When the two species were grown in mixed cultures, P. australis was less affected by competition than S. alterniflora at lower salinities but the competitive advantage reversed above 0.2 M NaCl. The greater salt tolerance of S. alterniflora compared to P. australis was due to its ability to use Na+ for osmotic adjustment in the shoots. On the other hand, at low salinities P. australis was more competitive because it produced more shoots per gram of rhizome tissue than S. alterniflora. These studies illustrate how ecophysiological differences shift the competitive advantage from one species to another along a salinity gradient.

In the developed world most of domestic sewage is treated by the activated sludge process, which results in large volumes of sludge or biosolids being produced. This results in millions of tons of biosolids produced each year in the United States, which must either be disposed of or recycled in some manner. Land application is seen as the most economical and beneficial way of handling biosolids. Although the United States Environmental Protection Agency supports and regulates the land application of biosolids, more research is needed to ensure its safe.The Appendix study A assessed the potential of Salmonella regrowth in Class A biosolids pellets and compost after land application. No Salmonella growth occurred in any of the soil/biosolids mixtures regardless of inoculum size or moisture content. While regrowth of Salmonella in biosolids may occur under saturated conditions it does not occur after Class A biosolid land application at typical agronomic rates. The Appendix B study evaluated the sensitivity of BGM and PLC/PRF/5 cell lines for detection of viruses as well as the occurrence and concentration of adenoviruses. The PLC/PRF/5 cell line was more sensitive for the detection of adenovirus and other enteroviruses in raw and Class B biosolids. The Appendix C study determined the potential of regrowth of Salmonella typhimurium in vermicompost and Class A biosolids alone and after addition to soil. In summary, no regrowth of Salmonella was observed, and the die-off of Salmonella was not different in soil, biosolids or vermicompost.

This pioneering investigation focused on the mercury bioaccumulation relationship of bats and insects. Identifying biomarkers that can be extrapolated to humans is necessary. Radio-transmitter-fitted bats were tracked to identify five of their preferred feeding sites within and outside the Cornwall Area of Concern. Bats, insects and guano were collected from the five sites. High THg levels in bats (N= 80) were noted among species and locations but these levels were not correlated with insects. Some individual Myotis lucifugus and Eptesicus fuscus bats had concentrations (10 - 12 ppm and 15 - 26 ppm) that exceeded those from previous studies (7.6 ppm and 1.5 ppm) (Hickey et al., 2001). One-way ANOVA and t-test (two-tailed) established statistical significance among caddisflies by location (p= 0.0013), insect taxa (p <0.001), bat species (p =0.001) and Eptesicus fuscus by location (p= 0.004). Caddisflies were sampled for MeHg (> 50% Hg was MeHg).

Since 1987, the Kerry Wood Nature Centre has run a nature preschool for three-five old children. This study shows the affect it had on the environmental attitudes of former participants, who were 10-12 years old at the time of this study. Interviews and questionnaires with former participants, their families, and a control group investigated: (1) their current environmental attitude and behaviours; and (2) from whence these attitudes and behaviours arose. Past participants had a significantly greater connectedness-to-nature score than their peers did, even several years after leaving the program. The Nature Nursery program, along with other factors, made a measurable and persistent change in the attitude of these children. "Opportunity" in terms of location, parenting, companionship, and time emerged as being important in determining attitude. Children and parents overwhelmingly reported better feelings and behaviour after playing outside. Recommendations to improve early childhood environmental education programs are included.

Urbanised and industrial coastal areas in South Africa are most vulnerable to the effects of marine pollution, and the Kwa-Zulu Natal coastline is particularly at risk. The mussels Perna perna, from a polluted (Isipingo Beach) and unpolluted (Park Rynie) site, and Brachidontes semistriatus were evaluated for their use as potential bioindicator organisms. The mussels were subjected to increasing copper concentration treatments to asses the following biomarker responses: cardiac activity, lysosomal membrane stability, malate dehydrogenase enzyme (MDH) activity and body condition index. Brachidontes semistriatus exhibited significant variations in biomarker responses only when exposed to higher Cu dosages, whereas P. perna from Park Rynie displayed distinct changes in heart rate, lysosomal membrane stability and MDH activity with increasing contaminant exposure. Perna perna from Isipingo Beach displayed significant biomarker variation in cardiac activity and lysosomal membrane stability, however differences in MDH activity were only evident at the highest Cu concentration of 100 mg.L-1. Both species from the different Cu treatments failed to show any significant changes in body condition indices due to the limited time of contaminant exposure. The mussel P. perna was therefore selected as a suitable biomonitoring species, and cardiac activity, lysosomal membrane stability and body condition index were chosen as reliable biomarkers for the study. Native P. perna from KZN responded to a distinct pollution gradient along the coastline by displaying significant bradycardia, reduced lysosomal membrane stability, poor condition indices and high heavy metal tissue concentrations. Durban, Isipingo and Umkomaas were singled out as the most contaminated sites along the coast, and Zinkwazi and Park Rynie as the least polluted. In addition, significant correlations between tissue and sediment metal concentrations suggest that the species is an effective heavy metal bioaccumulator of Cd, Pb, Zn, Cr and Fe. Similar spatial trends in seawater and mussel tissue concentrations in Durban Harbour were identified. Stations in the port located nearest to the freshwater inputs and stormwater drains displayed the highest metal concentrations in tissue and seawater, as well as adverse biomarker responses from transplanted P. perna. These results suggest that Durban Harbour is strongly influenced by tidal exchange and contaminated freshwater inflow entering the harbour. It was also found that reproduction imposes a considerable effect on P. perna body condition as spawning events in winter months result in pronounced body mass loss. The study concluded that P. perna is a highly effective bioindicator species, and cardiac activity, lysosomal membrane stability and body condition index can successfully be employed in marine pollution monitoring programmes. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2009.

The limited range of garrick/leervis Lichia amia, its popularity as a gamefish to all sectors of the marine recreational linefishery and the degradation of many estuaries which function as nurseries for this species, has aroused concern about the stock status of this species. In addition, other than a preliminary investigation conducted by ORI in 1992, relatively little research has been undertaken on this important recreational species. Considering the recreational value of L. amia and the need to provide a scientific basis for its management, a comprehensive stock assessment was required. This study therefore investigated the biology and stock status of L. amia off the South African coast. Through ad hoc biological sampling undertaken from 1978-2007 and validation of growth by means of OTC marking, the growth of the L. amia population was best described as: Lt=1206mmfl(1-e-20[t+1.10 years]). Growth was also determined using tag-recapture and length frequency data. The tag-recapture data was further utilized in illustrating the movement behaviour of L. amia. Trends in catches were determined from the analysis of catch and effort data from the National Marine Linefish System (NMLS) and Boat Launch Site Monitoring System (BLSMS) databases. This showed a decreasing trend in the CPUE of L. amia along the KZN coast over time for all sectors of the KZN marine recreational linefishery investigated. The growth parameter estimates from the length-at-age data were used in undertaking a per-recruit assessment of L. amia. The results of the spawner-biomass-per-recruit (SBPR) model indicate that L. amia is at 14% of its unfished level. According to the South Africa.s Linefish Management Protocol (LMP), the L. amia stock has thus collapsed and appropriate management options to rebuild the stock are discussed. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2008.

The principal objectives of the research are to analyse the distribution and dynamics of plants of the Hadhramaut region and to evaluate the role of the physical parameters and human action on their distribution, survival and conservation. The study area is located in Hadhramaut Governorate and lies in the eastern part of the Republic of Yemen. This is a remote and inaccessible region; however, there has been rapid development in recent years with the discovery of oil, which has had a significant effect on the vegetation and landscape. The Hadhramaut region represents an important area of eastern Yemen, linking eastern and western phyto-geographical units, representing a key transition zone between northeast Africa and Southeast Asia. Previous studies in the study area have only dealt with individual species and there has been no complete botanical survey. Recent floristic studies are turning up new species with many endemic and near endemic plant species. The Hadhramaut region is a desert region, dissected by deep valleys where agriculture is possible and the main towns are surrounded by rocky, dry limestone plateaus. The northern section passes into the deserts of the Rub ‘al Khali or Empty Quarter. Hadhramaut has a long history of human occupation with ancient civilisations well reflected in the archaeological records. Archaeological sites suggest that agriculture, with a related development of irrigation technology, was more widespread during a period when rainfall was more abundant. Initially, a reconnaissance survey of the whole Hadhramaut Governorate was undertaken, leading to the selection the Wadi Hadhramaut for detailed study. Within this study area, three sites were selected for intensive survey. These sites were considered representative of the major landforms and vegetation of the area and reflect the principal patterns of land use. The three sites represent tracts of land that were either unaffected, undergoing change or already altered as a result of oil-related development. Transects were designed to cross each site, from the valley bottoms to the plateau surfaces, passing across the representative landforms and vegetation. Surveys were made of the vegetation associations, their structure and biodiversity, as well as their relationship with environment and human impact. Two preliminary transects were made across the entire region, from the southern coast to the plateau in the northwest and from east to west, in order to place the study area in a regional context. The research is the first detailed vegetation survey in the Hadhramaut region and has revealed relevant data that can be used for further studies in similar habitats or for further management and conservation activities. In the study area, major vegetation associations, their composition and biodiversity were identified and in addition, vegetation and land use maps were generated including local endemic, near-endemic and rare plant species. About 469 plant species have been identified from the Hadhramaut region. There are 107 taxa which are endemic and near-endemic; 68 of these are endemic to Yemen, of these 41 are confined to Hadhramaut region. A total of 134 species belonging to 42 families (about 30% of flora of Hadhramaut region) were recorded in the study area and, of these, seven species are endemic to Yemen (four of them endemic to Hadhramaut region). The study revealed 15 vegetation associations and thirty sociological species groups. The main wadis are covered by desert alluvial shrubland comprising Fagonia indica, Tephrosia apollinea, Cymbopogon schoenanthus, Boerhavia elegans and Dichanthium insculptum with scattered trees of Acacia campoptila. In contrast, much of the fertile lands of the main wadis, such as the bottom of the rocky slopes, are intensively cultivated with palm trees and other annual crops, notably sorghum and wheat. The rocky slopes facing the main wadis and the plateau surface are covered by stony and gravelly desert vegetation dominated by herbaceous plants, namely Stipagrostis hirtigluma, Farsetia linearis, Aristida triticoides, Fagonia paulayana, Boerhavia elegans and Dichanthium insculptum. Within the plateau there are some sloping sites and secondary wadis which support dense vegetation. The vegetation here comprises shrubland or grassland dominated by Jatropha spinosa with Zygophyllum decumbens, Commiphora foliacea, Commiphora kua, Maerua crassifolia. Dichanthium insculptum, Stipagrostis hirtigluma and Farsetia linearis. The research in the Hadhramaut region has revealed the importance of this region in terms of plant biodiversity, and particularly of endemic, rare and near-endemic species, which urgently require further management and conservation activities.

No description available.