Biomonitoring and environmental management

The advantages of biological monitoring of the environment have been long recognised. Direct measurements on biota of importance rather than the use of chemical surrogates, integration over time and the ability to measure the perhaps subtle changes brought about by minor or intermittent pollution have all been propounded as adantages.There appear to be a variety of barriers to the wider adoption of biomonitoring approaches. The perception that biomonitoring takes longer and is more expensive than chemical monitoring. The idea that chemical measurements are an adequate surrogate for direct measurements of biological change. The belief that interpretation of biological data is complex and uncertain in comparison with chemical data. These widely held myths are addressed and some broad principles to guide the development of biomonitoring programs are developed.     

Detection of hormone mimics in water using a miniturised SPR sensor

The ubiquitous presence of chemicals, both natural andsynthetic, in the environment with the potential to mimichormones that may in turn interfere with the endocrinesystem in both wildlife and humans has in the last decadebecome a major international concern. Hormone mimics orendocrine disrupting compounds (EDCs) are especiallyprevalent in surface and waste-waters and therefore, thereis a need for an at-source or at-line analytical device forthe monitoring of EDC levels.We have incorporated a miniature integrated surface plasmonresonance (SPR) liquid sensor from Texas Instruments into afield analyser and developed a competition/inhibition assayfor a model estrogenic compound in aqueous samples. Theanalyser has the potential for in situ and semi-continuous analysis of EDCs. A novel regeneration schemeemploying the use of a domestic laundry detergent has beenused to remove immobilised assay components between eachassay cycle. The resultant re-usable sensor has beendemonstrated using estrone-3-glucuronide (E3G) as a modelEDC and an anti-E3G antibody producing a current detectionrange of 10 to 150 ng mL^-1.     

Continuous measurement of the DCMU-induced fluorescence response of natural phytoplankton populations

The effect of 3x10^-6 M DCMU [3-(3,4-dichlorophenyl)-1, 1-dimethylurea] on in vivo chlorophyll a fluorescence was observed in nearshore waters of the Southern California Bight. We compared fluorescence readings in the presence and absence of this inhibitor using parallel flow-through fluorometers. The increase in fluorescence induced by DCMU is expressed as the FRI (fluorescence response index). Theory and laboratory studies on batch cultures of phytoplankton suggest that the FRI is correlated with photosynthetic efficiency and/or physiological state, but other studies have produced results in apparent conflict with this interpretation. Although sufficient information does not exist to justify the use of fluorescence response as a precise physiological indicator in the field, we suggest that very low FRI values are a manifestation of photosynthetic debility in a sample. Vertical profiles showed a wide range of the fluorescence response index. At a station close to shore, low FRI values were observed well below the 1% light level, but the fluorescence response of the phytoplankton throughout the euphotic zone was similar to that of growing cultures. Farther offshore, the FRI was depressed near the surface, but increased in the enhanced nutrient conditions of the lower euphotic zone. The patterns observed were strong, and consistent with hypotheses which relate low values of the FRI to diminished photosynthetic capacity.     

Calibrating a model to 30 years of data to capture the accumulation of chloride from winter deicers in a shallow aquifer

Winter deicers are a major source of chloride contamination to shallow aquifers in northern latitudes. In the greater Chicago area of northeast Illinois, chloride has been accumulating for decades and in many places now exceeds the United States Environmental Protection Agency secondary standard of 250 mg/L. MODFLOW-NWT and MT3D-USGS were used to simulate the accumulation of chloride with 30 years of data in the shallow aquifer of Will County in northeast Illinois. This aquifer is composed of unconsolidated sediments, largely from glacial deposits, overlying a fractured dolomite bedrock. To calibrate to observed heads and chloride, the model needed refined geologic features, higher chloride concentrations on cells representing commercial or industrial lands, lower chloride concentrations on cells representing roads, and point source areas to speed chloride's emergence in the aquifer. These point sources are locally significant and could represent different anthropogenic or geologic features, such as municipal stormwater infrastructure. Future simulations indicate that chloride is not at steady state in the shallow aquifer and wells are at risk of exceeding the secondary standard if winter deicing applications are not reduced. It may take decades for the full impacts of reduced deicing rates to be observed in wells, owing to the long residence time of water in the aquifer. This transient model calibration was possible because of the 30-year dataset collected by communities and government agencies.     

A new model for sustainable development: a case study of The Great Bear Rainforest regional plan

This paper describes a new model of sustainable development planning based on a case study of a successful planning process for the Great Bear Rainforest on Canada’s west coast. The planning region is an area of international ecological significance that contains one-quarter of the world’s remaining ancient coastal temperate rainforest. An innovative collaborative planning process was initiated in 1996 to develop a plan for the region that balances social, economic, and environmental values. The plan, which was accepted by consensus agreement of all stakeholders in 2006, uses a new model for sustainable regional development that is based on collaborative planning, collaborative implementation, informal conflict resolution, contextual adaptation incorporating comanagement with indigenous peoples (First Nations), joint fact finding, ecosystem-based management, and integration of social, economic, and environmental objectives.     

Cancer risk assessment of selected hazardous air pollutants in Seattle

The risk estimates calculated from the conventional risk assessment method usually are compound specific and provide limited information for source-specific air quality control. We used a risk apportionment approach, which is a combination of receptor modeling and risk assessment, to estimate source-specific lifetime excess cancer risks of selected hazardous air pollutants. We analyzed the speciated PM(2.5) and VOCs data collected at the Beacon Hill in Seattle, WA between 2000 and 2004 with the Multilinear Engine to first quantify source contributions to the mixture of hazardous air pollutants (HAPs) in terms of mass concentrations. The cancer risk from exposure to each source was then calculated as the sum of all available species' cancer risks in the source feature. We also adopted the bootstrapping technique for the uncertainty analysis. The results showed that the overall cancer risk was 6.09 x 10(-5), with the background (1.61 x 10(-5)), diesel (9.82 x 10(-6)) and wood burning (9.45 x 10(-6)) sources being the primary risk sources. The PM(2.5) mass concentration contributed 20% of the total risk. The 5th percentile of the risk estimates of all sources other than marine and soil were higher than 110(-6). It was also found that the diesel and wood burning sources presented similar cancer risks although the diesel exhaust contributed less to the PM(2.5) mass concentration than the wood burning. This highlights the additional value from such a risk apportionment approach that could be utilized for prioritizing control strategies to reduce the highest population health risks from exposure to HAPs.