Water quality indices as indicators of ecosystem change

The operational management of water quality requires a methodology that can provide precise information on cycles and trends in water quality in an objective and reproducible manner. Such information can be provided by the adoption of a water quality indexing system. The continuous scale afforded by a water quality index allows changes in river water quality to be highlighted. At the same time the sub-division of this scale into a series of water quality and water use categories provides an easy means of relating information to government and public.The development of four independent water quality indices (WQIs) is outlined. These have been applied to data for a number of UK river reaches. The results of these applications indicate the utility of these indices in the classification of water quality and the monitoring of ecosystem change.     

Higher plants as indicators and accumulators of gaseous air pollution

Some higher plant species or varieties are very sensitive to certain gaseous air pollutants, and the resulting effects show sometimes more or less specific, well-visible and measurable symptoms.On this basis several species and varieties of natural and cultivated plants have been selected to serve as biological indicators for the possible presence of certain air polluting substances. But these indicator plants may also be used for the quantitative determination of the effect intensities of the air pollutants involved.Besides, some plant species or varieties may accumulate certain components of air pollution, without changing these substances, in such a way that after accumulation in the plants these substances may be analyzed physicochemically (qualitatively and quantitatively).Definitions are proposed and examples are given of both indicator and accumulator plants. Also information is displayed on the methods for the use of plants as indicators and accumulators of air pollutants (standardized system of plant cultivation and exposure). Some applications of biomonitoring the effects of air pollution with plants are discussed and illustrated with data from The Netherlands.Paper presented at a Symposium held on 14 and 15 October 1982, in Utrecht, The Netherlands.     

Influence of a portable air treatment unit on health-related quality indicators of indoor air in a classroom

During periods of two weeks in February and June 2010 the performance of portable air treatment units (PATUs) was evaluated in a primary school classroom using indicators of indoor air quality. Air samples were collected in an undisturbed setting on weekend days and in an occupied setting during teaching hours. In the first week PATUs were turned off and in the second week they were turned on. On weekend days PATUs reduced indoor levels of PM-10 by 87% in February and by 70% in June compared to weekend days when PATUs were turned off. On schooldays, indoor PM-10 was increased by 6% in February and reduced by 42% in June. For PM-2.5 reductions on weekend days were 89% in February and 80% in June. On school days PM-2.5 was increased by 15% in February and reduced by 83% in June. Turning on the PATUs reduced total VOC by 80% on weekend days and by 57% on school days (but not in June). No influence on formaldehyde, NO(2), O(3) and molds was observed. PATUs appeared to be less effective in removal of air pollutants when used in an occupied classroom compared to an unoccupied setting. Our study suggests that such devices should be tested in real-life settings to evaluate their influence on indoor air quality.     

Using diatoms as quality indicators for a newly-formed urban lake and its catchment

Periphytic diatoms were studied to evaluate the water quality of a newly created lake, formed by the enclosure of the formerly tidal Cardiff Bay (Wales, UK), and the effects of two inflowing rivers which drain densely populated and industrialised catchments. Seven sites in Cardiff Bay and two locations on the inflowing rivers were monitored for diatoms and water chemistry over 2 years. Water quality was assessed using a revised UK trophic diatom index (TDI) and new methods to determine ecological quality ratios and ecological status classes as required by the EU Water Framework Directive. Diatom assemblages reflected spatiotemporal variations in environmental conditions between the rivers and Cardiff Bay and within the bay. In the bay, diatoms reflected differences in river quality and possibly local pollution in certain areas of the lake. High values of the TDI indicated eutrophic to hypertrophic conditions in both rivers and in the bay and diatoms indicated poor ecological status.     

Lichens as Bioindicators of Atmospheric Heavy Metal Pollution in Singapore

Lichens have been used as bioindicators in various atmospheric pollution assessments in several countries. This study presents the first data on levels of heavy metals (As, Cd, Cu, Ni, Pb, and Zn) in lichens at different locations in Singapore, Southeast Asia. Singapore is a fully industrialised island nation, with a prevailing tropical climate and a population of 4 million people within a confined land area of less than 700 km². The ubiquitous lichen species, Dirinaria picta was collected from six sample sites across Singapore and analysed for heavy metals using inductively coupled plasma mass spectrometry (ICPMS). No significant relationship existed between metal levels in lichen and soil, indicating that accumulated metals in lichen are primarily derived from the atmosphere. Peak concentrations of zinc (83.55 μg g⁻¹), copper (45.13 μg g⁻¹) and lead (16.59 μg g⁻¹) in lichens were found at Sembawang, Jurong and the National University of Singapore campus which are locations associated with heavy petroleum and shipping industries, and road traffic respectively. The mean heavy metal levels of lichen samples in Singapore were found to be at the upper range of values reported in the literature for temperate countries.     

Air pollution exposure monitoring and estimation. Part III. Development of new types of air quality indicators

The temporal pattern of exposure to a specific compound may affect health in several ways. Exposure to pollution can have short-term effects or long-term effects. For some compounds there is a threshold under which there is no presumed measurable effect, whereas for other compounds, there is no presumed threshold. For short-term effects, the exposure to a high concentration of a compound one day may either increase or decrease the response if values of the same compound become high again the next day. Adaptation to effects of short-term exposure to ozone, for example, is reported. Similarly, health response to sudden high peaks of concentration may also possibly differ in effect from those to peaks attained more gradually. For long-term effects of some compounds, the cumulative exposure may be more decisive in influencing health. This paper proposes and describes in detail several air quality indicators that reflect the time variability and the episodic nature of air pollution exposure, as an attempt to represent the temporal aspects of pollution exposure that may have important effects on health. Mean concentrations, 98th percentile and maximum values are the traditional indicators for estimating exposure. The temporal variability of particulate matter (PM10) and NO2, however, is here described by means of: (1) the rate of change of pollution as the difference between two consecutive hourly or daily values, and of (2) episodes, described in terms of number, duration and inter-episode period, maximum concentration in the episode, and integrated episode exposure.     

Estimating air quality impacts

LEONARD ORTOLANO has written a textbook, Environmental Planning and Decision Making, that is ideal for introducing undergraduates to the field of environmental planning. His three chapters on environmental impact assessment (from 16 chapters overall) present a range of impact assessment methods in a helpful decision-making context. Specific techniques for considering biological factors in planning, evaluating the visual qualities of the environment, assessing noise impacts, assessing air quality impacts, and assessing impacts on water resources are also covered in five additional chapters. Professional planners and engineers should find this introduction to the approaches employed by specialists of various kinds helpful. With the permission of the publisher, John Wiley and Sons, we here reprint Chapter 15, “Estimating Air Quality Impacts,” from Ortolano's excellent book. This straightforward presentation of a six-step process for establishing the air quality impacts of proposed development projects is a model of clarity.     

Meadow birds as indicators

The use of birds as indicators for ‘biological qualities’ is not without risks, and should always be based on a sound knowledge of population dynamics and ecological requirements of the species involved. Meadow birds form a comparatively well-studied group of waders, which breed in Dutch grasslands, heavily influenced by agricultural management. The individual species show different tolerances to intensity levels of management, and can therefore be used as indicators for these levels.     

Taraxacum species as environmental indicators for grassland management

A classification of the microspecies of the genus Taraxacum was made in a range from low to highly dynamic habitats based on qualitative inventories of grasslands under different management conditions. After several years of constant management, a characteristic species composition occurs. Under mowing (hayfield) conditions, dandelions disappear over a period of about twenty years in a sequence where the low-dynamic species T. adamii and T. nordstedtii are the last to vanish. Different microspecies in the section Vulgaria in one field can show small differences in response to environmental conditions, even where no other directly visible indication exists. New appearance of highly dynamic species can indicate disturbance of some kind or other within a relatively short period. The classification adopted seems to be correlated with the phosphate content of the soil. Differences in two easily perceptible morphological characteristics, namely position of the outer bracts and colour of the leaf-stem, fit into the established sequence. Small changes in these characteristics indicate conditions in the field that are improving or worsening from a nature-conservation point of view. A system is introduced in which merely these two morphological characters, without further taxonomical knowledge, can be used for an evaluation of grasslands and the impact of management practice.     

Bioaerosols as contributors to poor air quality in Taichung City, Taiwan

Bioaerosols are a type of suspended sediments that contribute to poor air quality in Taiwan. Bioaerosols include allergens such as: fungi, bacteria, actinomycetes, arthropods and protozoa, as well as microbial products such as mycotoxins, endotoxins and glucans. When allergens and microbial products are suspended in the air, local air quality will be influenced adversely. In addition, when the particle size is small enough to pass through the respiratory tract entering the human body, the health of the local population is also threatened. Therefore, the purpose of this study is to attempt to understand the concentration and types of bacteria and the bacteria numbers for various particle size ranges during a study period of June 2005 to February 2006 in Taichung City, Central Taiwan. The results indicate that the total average bacterial concentration by using NA medium incubated for 48 h were 8.0 × 10², 1.4 × 10³, 2.4 × 10³ and 1.3 × 10³, 1.9 × 10³, 3.5 × 10³ cfu/m³ for CMES, TRIPS and RFS sampling sites during the daytime and nighttime period of June 2005 to February 2006. Moreover, the total average bacterial concentration by using R₂A medium incubated for 48 h were 8.5 × 10², 1.5 × 10³, 2.2 × 10³ and 1.2 × 10³, 1.7 × 10³, 2.5 × 10³ cfu/m³ for CMES, TRIPS and RFS sampling sites the daytime and nighttime during the same sampling period. The total average bacteria concentration was the same in either NA or R₂A medium for the same sampling times or sites. The total average bacterial concentration was higher in daytime period than that of nighttime period for CMES, TRIPS and RFS sampling sites. The high average bacterial concentration was found in the particle size range of 0.53–0.71 mm (average bioaerosol size was in the range of 2.1–4.7 μm) for each sampling site. Also, 20 kinds of bacteria exceeded levels for each sampling site and were classified as according to shape: rod, coccus and filamentous.     

Plants as indicators of urban air pollution (ozone and trace elements) in Pisa, Italy

A biennial integrated survey, based on the use of vascular plants for the bioindication of the effects of tropospheric ozone, was performed in the area of Pisa (Tuscany, Central Italy). It also investigated the distribution of selected trace elements in plants and the data were compared with those obtained from the use of passive samplers, automatic analysers of ozone and lichen biodiversity. Photochemically produced ozone proved to be present during the warm season, with maximum hourly means surpassing 100 ppb: the use of supersensitive tobacco Bel-W3 confirmed the value of detailed, cost-effective, monitoring surveys. Trials with clover clones demonstrate that sensitive plants undergo severe biomass reduction in the current ozone regime. The mean NC-S (clover clone sensitive to ozone):NC-R (resistant) biomass ratio ranged from 0.7 (in 1999) to 0.5 (in 2000). The economic impact of these reductions deserves attention. The data obtained using passive ozone samplers exceeded those obtained using an automatic analyser. The mapping of epiphytic lichen biodiversity was not related to the geographical ozone distribution as can be seen from the tobacco's response. Lettuce plants grown under standardized conditions were used positively as bioaccumulators of trace elements: Pb was abundantly recovered, but a large portion of this element was removed by washing.     

Modified grey model for estimating traffic tunnel air quality

This study compared three forecasting models based on the mean absolute percentage errors (MAPE) of their accuracy in forecasting air pollution in a traffic tunnel: the Grey model (GM), the combination model used four sample point and five sample point prediction with GM (1,1)(GM(1,1)^4 + 5), and the modified grey model (MGM). An MGM was combined using the four points of the original sequence using the original grey prediction GM (1,1) for short-term forecasting. The proposed method cannot only enhance the prediction accuracy of the original grey model, but can also solve the jump data forecasting problem something for which the original grey model is inappropriate. The MAPE was applied to the models, and the MGM found the proposed method to be simple and efficient. The MAPE of MGM, calculated over 3 h of forecasts, were as follows: 10.12 (Upwind), 10.07 (Middle) and 7.68 (Downwind) for CO; 10.79 (Upwind), 6.05 (Middle) and 5.98 (Downwind) for NO _x , and 11.67 (Upwind), 7.32 (Middle) and 4.56 (Downwind) for NMHC. The MGM model results reveal that the combined forecasts can significantly decrease the overall forecasting error. Results of this demonstrate that MGM can accurately forecast air pollution in the Kaohsiung Chung–Cheng Tunnel.     

A decision support system for air quality network design

In the last few years, due to the implementation of European and Italian laws, public agencies are in urgent need of objective criteria and methodologies for the correct location of air quality monitoring networks. This paper describes MoNet, a decision support system oriented to network designers, to help them in the choice of the number and the location of instruments in an assigned area. The package includes a model base consisting of a set of pollution diffusion simulation models and two optimization algorithms for network location and allows the user to integrate his or her own subjective knowledge of the problem with the results of the simulations performed by means of objective techniques. The package has been applied to revise the air quality network located in an industrial and urban area of Northern Italy. The results of the simulations performed by using different diffusion models, location algorithms and problem constraints are shown and discussed in the concluding section.     

A method for facilitating the use of algae growing on tree trunks as bioindicators of air quality

The abundance of epiphytic green algae has been observed to correlate strongly with air quality in several studies. In contrast to lichens, the abundance of green algae is difficult to measure accurately by visual observation. A new method based on photography and digital image processing was developed to estimate the chlorophyll content of algae growing on the bark of pine. Calibration data for the method was collected from polluted areas by spectrophotometric analysis of chlorophyll density.