D. Mike Revitt

Heavy metal concentrations and toxicity in water and sediment from stormwater ponds and sedimentation tanks.

Sedimentation is a widely used technique in structural best management practices to remove pollutants from stormwater. However, concerns have been expressed about the environmental impacts that may be exerted by the trapped pollutants. This study has concentrated on stormwater ponds and sedimentation tanks and reports on the accumulated metal concentrations (Cd, Cr, Ni, Pb, and Zn) and the associated toxicity to the bacteria Vibrio fischeri. The metal concentrations are compared with guidelines and the toxicity results are assessed in relation to samples for which metal concentrations either exceed or conform to these values. The water phase metal concentrations were highest in the ponds whereas the sedimentation tanks exhibited a distinct decrease towards the outlet. However, none of the water samples demonstrated toxicity even though the concentrations of Cu, Pb, and Zn exceeded the threshold values for the compared guidelines. The facilities with higher traffic intensities had elevated sediment concentrations of Cr, Cu, Ni, and Zn which increased towards the outlet for the sedimentation tanks in agreement with the highest percentage of fine particles. The sediments in both treatment facilities exhibited the expected toxic responses in line with their affinity for heavy metals but the role of organic carbon content is highlighted.

CONSTRUCTED WETLAND CONTROL OF BOD LEVELS IN AIRPORT RUNOFF

A surface water treatment system consisting of an aeration reservoir and pond (holding capacities 45,000 and 19,000 m3) and a network of 12 horizontal subsurface flow gravel-filled constructed wetland cells of different sizes (total surface area 2.08 ha) and planted with Phragmites australis, was commissioned at Heathrow Airport, London, United Kingdom, in the winter of 2002. Ongoing monitoring of the treatment system has shown significant reductions in the biochemical oxygen demand (BOD5) throughout the system with levels decreasing by up to 76.7% across the constructed wetland cells following high anti- and de-icing fluid applications. However, continued exposure to BOD5 concentrations exceeding the design target has resulted in anaerobic conditions in the wetland. The addition of nutrients to the treatment system has resulted in improved removal efficiency for elevated BOD5 loadings in the aerated reservoir from 25.5% to 47.5%, The addition of different nutrient dosing regimes to complementary pilot-scale planted and unplanted vertical flow columns showed average but statistically insignificant BOD5 removal percentage increases from 61.9 ± 21.1% to 70.8 ± 26.5%, respectively, in planted columns over a 7-day period. There is an overall improvement in the performance of the system, but operational reviews are continuing.

Assessment of storm water ecotoxicity using a battery of biotests

As part of the European Union 5th Framework Programme (EU FP5) sustainable storm water management project DayWater, an international monitoring programme was established to investigate the ecotoxicity of highway and urban runoff samples. This involved the collection of samples from a total of 35 storm events from sites in Sweden (Lulea and Stockholm), Germany (Wuppertal), and France (Nantes). To enable both chronic and acute end points to be addressed, the ecotoxicity tests were performed using rotifers (Brachionus calyciflorus), bacteria (Vibrio ficherii), and algae (Pseudokirchneriella subcapitata). Samples collected at the Stockholm site were additionally analysed for a range of water quality parameters enabling this site to be considered from a combined physico-chemical and ecotoxicological perspective. This paper provides an overview of the results of the whole monitoring programme and demonstrates that storm water frequently exerts a toxic effect. Although the levels of ecotoxicity detected were found to vary greatly in relation to sites, storm events and test organisms, further analysis demonstrated a moderately strong correlation between the responses of algae and rotifer tests. Microtox was generally found to be the most responsive test in terms of both frequency of detection of toxicity and level at which a toxic impact could be detected.

Antiinflammatory and hepatoprotective medicinal herbs as potential substitutes for bear bile

Practitioners of traditional Chinese medicine (TCM) commonly prescribe medicinal formulations relying on the purported synergism of a combination of plant species, sometimes incorporating animal parts and minerals. Bear bile, obtained from either wild or farmed bears, is a commonly used constituent of traditional medicine formulations. With several bear species now listed under Convention on International Trade in Endangered Species of Wild Fauna and Flora as threatened with extinction and with bear farming being actively campaigned against on ethical grounds, it is important to seek and promote alternatives to the use of bear bile as medicine. This chapter describes and evaluates the scientific data relating to the efficacy of bear bile and potential alternatives to its use, including the use of bile from other animal species, the use of synthetic chemical alternatives, and the use of herbal substitutes. Scientific studies have confirmed the efficacy of bear bile as an antiinflammatory and a hepatoprotective agent. Ursodeoxycholic acid (UDCA), the active component of bear bile is used in a synthetic form in Western medicine and can serve as an alternative to bear bile in the treatment and management of certain cholestatic liver conditions. In TCM practice, bile from domesticated animal species (such as cattle, chicken, and pig) has been used as a substitute for bear bile. Following evaluation of TCM literature and pharmacological/clinical data, the authors propose six plant species, either as single herbs or in combination, Gardenia jasminoides (zhī zi; ), Scutellaria baicalensis (huáng qín; ), Coptis chinensis (huáng lián, ), Phellodendron amurense (huáng băi; ), Andrographis paniculata (chuan xin lian; ), and Rheum palmatum (dà huang; ), two medicinal Kampo formulations, Orengedokuto, Dia-Orengedokuto (which originated from traditional Chinese herbal formula Huanglian Jiedu Tang, ), and two individual phytochemicals (berberine and andrographolide) as alternatives to bear bile. The proposed herbal alternatives are frequently found listed in traditional formulations also containing bear bile, usually with different therapeutic roles ascribed to them. The existing evidence base for the effectiveness of herbal alternatives is sufficiently strong for TCM practitioners and consumers to consider using these without the addition of bear bile. This consideration is driven by the imperative to protect populations of bears from overexploitation in the wild and when farmed. However, for the identified alternatives to be accepted by users, it is essential that researchers and TCM practitioners collaborate effectively to initiate consumer behavior change.