Susanne M. Charlesworth

A comparative study of heavy metal concentration and distribution in deposited street dusts in a large and a small urban area: Birmingham and Coventry, West Midlands, UK

Results are presented from a study of the distribution of heavy metals in street dusts of two cities in Midland England. The first (Birmingham) is a large urban area (population of 2.3 million), the second, Coventry, a small one (population of 0.3 million). Several trends were identified from Birmingham: higher concentrations were located near industrial areas in the northwest of the city and within the ring road. However, lower concentrations were found to the southwest in areas of mainly residential properties and parks. High values were also identified in association with junctions controlled by traffic lights where vehicles were likely to stop regularly. This last trend was further investigated in Coventry, where it was found that concentrations of heavy metals at junctions controlled by traffic signals and by pedestrian-controlled pelican lights (Mounted Pelican Controller, MPCs) were lower than those found in Birmingham, apart from Ni.

Heavy metals in the hydrological cycle: Trends and explanation

This paper reviews the major sources and transport characteristics of heavy metals in the hydrological cycle. It is demonstrated that heavy metal releases to the environment have changed from 19th and early 20th century production-related activities to consumption-oriented factors in more recent times. The relative roles of particle size, sorption and desorption processes, partitioning and the chemical speciation of heavy metals on fine sediments are identified to understand the likely fate of heavy metals released into fluvial systems. It is argued that the spatial and temporal distribution of heavy metals in the river corridor depends not only on an understanding of metal solubility and speciation, but also on an understanding of sediment dynamics which control, for example, floodplain alluviation and the accumulation of metals in the bottom sediments of contaminated rivers, lakes and reservoirs. Existing long- and short-term records are examined to identify the current state of knowledge about the factors which affect heavy metal releases into aquatic environments. With limited exceptions, it is shown that few long-term studies of trends in heavy metal transport are available although, for some major rivers, limited data on trends in metal concentration exists. Palaeolimnological reconstruction techniques, based on an analysis of lake and reservoir sediments, are identified as a possible means of supplementing monitored records of heavy metal transport. Although numerous studies have suggested that trends in atmospheric contamination, mining and urbanization may be identified in the bottom sediment record, other research has shown that the radionuclide-based chronology and the heavy metal distribution within the sediment are more likely to be a function of post-depositional remobilization than the history of metal loading to the basin. Despite these limitations, it is shown that the incorporation of reservoir bottom sediment analysis into a heavy metal research programme, based in river corridors of Midland England, provides an opportunity to identify and quantify the relative contribution of point and non-point contributions to the heavy metal budget and to relate trends in metal contamination to specific periods of catchment disturbance.

The distribution of heavy metals in deposited urban dusts and sediments, Coventry, England

Samples of urban dusts and sediments have been collected and categorised into three compartment those which act mainly as sources, those undergoing transport and those which have been deposited. The sediments were fractionated into < 63 μm to match similar sized lacustrine sediments and < 2 mm to represent natural and anthropogenic fluvially transported sediments. Preliminary results of total heavy metals analysis show that the < 2 mm fraction of the source group exhibits the greatest variabilty in metal concentrations. Overall, however, the < 63 μm fraction dominates regardless of compartment. Some heavy metal concentrations decrease through the source‐transport‐deposit process, possibly due to selective onward transport of finer material or other anthropogenic processes unique to the urban environment (e.g. street cleansing). Site‐specificity is indicated in a comparison with other similar studies.

Influence of industry on the geochemical urban environment of Mieres (Spain) and associated health risk.

This study is concerned with the elemental composition of soils and street dust collected in an historical industrial city of approximately 27 000 inhabitants, where old Hg mining and metallurgical activities strongly affected the load of heavy metals in the urban environment. For the purpose of the study, representative samples of soils and street dust were collected at different locations in the whole urban area (3 km2). Elevated mean concentrations of As in soils and street dust (69 and 135 μg g−1, respectively), and Hg (3.07 and 4.24 μg g−1, respectively), compared to background levels and to those found in other cities, reflect the anomalous geochemical nature of these materials and the strong influence exerted by the old mining sites.

Floodplain lakes as sinks for sediment-associated contaminants--a new source of proxy hydrological data?

Lake and reservoir sediments often contain valuable records of sediment yield history and sediment-associated nutrient and contaminant transport spanning timescales from decades to millennia. Nevertheless, there have been few attempts to evaluate floodplain lakes as a source of proxy hydrological data for reconstructing short-term trends in sediment-associated nutrient and contaminant transport. Results from an analysis of floodplain lake sediment cores suggested good preservation of the 137Cs record, which provided an absolute dating control. Changes in the concentration of sediment-associated heavy metals and phosphorus were observed downcore and the analysis of mineral magnetic properties and particle size were used to identify the influx of sediment associated with high magnitude, low frequency flood events. Although floodplain lake-sediments only preserve a partial record, they may provide a valuable source of proxy hydrological data for reconstructing trends in sediment and sediment-associated contaminant transport where long-term sediment monitoring programmes are not available.

Rainfall–Runoff Simulations to Assess the Potential of SuDS for Mitigating Flooding in Highly Urbanized Catchments

Sustainable Urban Drainage Systems (SuDS) constitute an alternative to conventional drainage when managing stormwater in cities, reducing the impact of urbanization by decreasing the amount of runoff generated by a rainfall event. This paper shows the potential benefits of installing different types of SuDS in preventing flooding in comparison with the common urban drainage strategies consisting of sewer networks of manholes and pipes. The impact of these systems on urban water was studied using Geographic Information Systems (GIS), which are useful tools when both delineating catchments and parameterizing the elements that define a stormwater drainage system. Taking these GIS-based data as inputs, a series of rainfall–runoff simulations were run in a real catchment located in the city of Donostia (Northern Spain) using stormwater computer models, in order to compare the flow rates and depths produced by a design storm before and after installing SuDS. The proposed methodology overcomes the lack of precision found in former GIS-based stormwater approaches when dealing with the modeling of highly urbanized catchments, while the results demonstrated the usefulness of these systems in reducing the volume of water generated after a rainfall event and their ability to prevent localized flooding and surcharges along the sewer network.

‘Water and environmental systems’: achieving student‐centred learning objectives with an undergraduate journal

Abstract We describe an innovative and successful method of empowering physical geography students in the process of learning hydrology. In the last eight years at Coventry University, we have set students the challenge of providing articles for their own journal as part of two modular courses. Although the basic challenge of presenting a paper for ‘publication’ has not changed, the organisation and structure of the assessment has evolved in the light of responses to student questionnaires, and in response to rising student numbers which impose resource limitations. This paper describes the evolution of the assignment and the assessment procedure, identifies the educational benefits and evaluates the learning outcomes of this autonomous learning exercise. Although the use of group‐centred activities and assessments in higher education has in part offset the pressures of marking loads on teachers, this benefit is rarely perceived by students who generally wish to be assessed on individual rather than group...

The transport of particulate-associated heavy metals from source to deposit in the urban environment, Coventry, UK

Abstract Examination of the speciation of heavy metals in urban deposits shows that it is independent of the two particle sizes chosen (

Gamma-emitting radionuclides and metallic elements in urban dusts and sediments, Coventry, UK: implications of dosages for dispersal and disposal

Abstract Gully pot sediments and pavement and road gutter dusts have been collected from the city of Coventry in the West Midlands, UK. These samples have been subjected to metallic element analysis and the activity of a number of gamma-emitting radionuclides have been measured in order to assess whether they exceed published trigger or action levels, and whether their disposal or dispersal may have implications for receiving landfills and/or water courses. Results indicate above-background levels of metallic elements in dusts and sediments with Cu and Zn exceeding ICRCL action levels in some cases. The highest activities of some radionuclides are found in road gutter and street dusts and the lowest activities are found in gully pot sediments. Road dusts are more likely to be recirculated into the ambient air by passing traffic and could potentially pose a risk to pedestrians. The effective dose rates calculated for these dusts and sediments indicate that some samples approach and even exceed the 1 mSv y-1 limit to members of the public recommended by ICRP (1991). Some individual nuclides exceed their clearance levels laid down in the revised basic safety standards of the 1993b Radioactive Substances Act, 1993 (DoETR, 1999), bv as much as 2.5 times. This is especially true of 210Pbun and 7Be, two fallout nuclides, and also of 40K.

Water resources in the built environment: management issues and solutions

This book comprises three parts and eight sections, which are collated into twenty–nine chapters. The first part of the book (Sections 2, 3 and 4) addresses management issues and solutions to minimise water shortages and provide water security for society; whilst the second part of the book (Sections 5 and 6) addresses management issues and solutions to control excessive rainfall and minimise flooding impacts. The latter part of the book (Section 7) contextualises the issues of the earlier sections within international case studies from the developing world. Section 1 forms the introduction to the book and provides insights into issues and examples of the need to balance water resources from the extremes of having too little (drought) versus having too much (flooding). Section 2 introduces water demand, policy and cost and gives insights into water strategy, policy and legislation for meeting water demand, whilst also looking at the issues of regulating, privatising and economics of water. Section 3 concentrates on water infrastructure and supply and presents insights into issues of large scale water storage, the impacts of powering the water industry, treatment of water to meet potable supply standards and delivering supplies in buildings. Section 4 assembles chapters dealing with water conservation and bestows insights into the concept of achieving water neutral housing developments, building regulation attempts to reduce water usage, reaping water from rainwater and greywater harvesting, and an innovative approach to utilising inland waterways. Section 5 centres on flooding responses and reinstatement and furnishes insights into measuring and monitoring rainfall, engineered schemes for managing and protecting communities from floodwater, the economic cost of flooding, burdens on the insurance sector, and a holistic approach to property flood protection. Section 6 ponders on flood solutions in the urban landscape and proffers insights into sustainable drainage systems, together with pavement drainage and green infrastructure benefits, the role of constructed wetlands and the treatment of wastewater. Section 7 contextualises international case studies with insights into water resources issues in Africa and Asia. Section 8 converges with a summary of the book and offers insights into the lessons that can be learnt for the future of water resources management.