Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
A study in 1997, on mineral levels in acidic compared to alkaline well waters, and in women's hair, revealed higher concentrations of a number of mineral elements like Ca, Mo and Se in alkaline waters and hair. Thus, median Ca levels were six times higher in well water and five times higher in hair from the alkaline area compared to the acidic area. This finding raised the probability of similar differences in vegetables from these areas. Thus, in the year 2006, 60 women who had participated in the study in 1997 were asked to cultivate parsley, lettuce, carrot and chive. During the spring of 2006, the women from the water and hair study of 1997, 30 of them from the acidic area and 30 women from the alkaline district cultivated vegetables: carrot (Daucus carota L), parsley (Petroselinum crispum), chive (Allium schoenoprasum) and lettuce (Eruca sativa). The vegetables were harvested, and rinsed in tap water from the kitchens of the participating women in August. The concentrations of about 35 elements and ions were determined by ICP OES and ICP-MS predominantly. In addition, soil samples from the different cultivators were also analyzed for a number of elements.
Lettuce and parsley showed the highest concentrations of mineral elements per gram dry weight. Only Mo concentrations were significantly higher in all the different vegetables from the alkaline district compared to vegetables from the acidic areas. On the other hand, the concentrations of Ba, Br, Mn, Rb and Zn were higher in all the different vegetables from the acidic area. In the soil, only pH and exchangeable Ca from the alkaline area were higher than from the acidic area, while exchangeable Fe, Mn and Na concentrations were higher in soils from the acidic area. Soil elements like Al, Fe, Li, Ni, Pb, Si, Ti, V, Zn and Zr were found in higher concentrations in lettuce and parsley, which were attributed to soil particles being splashed on the plants by the rain and absorbed by the leaves. Strong correlations appeared between Ca and Sr in all the vegetables, except for carrot. No strong correlations were found between soil elements and vegetable elements, except for soil Mn and carrot/lettuce Mn. The differences in mineral levels in both, vegetables and soils were however small, compared to differences in well waters and hair. It was also suggested that the garden soils on limestone bedrock had been drained of minerals and thereby, the soil had an acidic pH. The contribution of mineral elements to daily intake in humans was considered minor from the analysed vegetables, except for some samples of lettuce that should give significant contributions of Ca, Zn, Mn and Mo.
The main conclusion is that, differences in water and hair mineral levels between the two areas in the earlier study (1997) were not mirrored in vegetables cultivated in 2006. Principally, this suggests that, for humans the mineral intake of some elements from water may be more important than from vegetables.
Persistent compounds are present around almost the entire world. The level of contamination in very old groundwater sources (Cennoman bedrock Mesozoic, approximately 100 millions year old) was assessed. This offers an information about realistic natural background. Together with chemical analysis a toxicity evaluation of sampled sites was performed. Semipermeable membrane devices were applied as a sampling system. Exposed SPMDs were analyzed both for chemical contain of POPs and toxicity properties. The chemical analyses of PAHs were made by HPLC-FLD, PCBs and OCPs were analysed by GC/MS/MS on GCQ or PolarisQ (Thermoquest). Toxicity bioassays on alga Desmodesmus subspicatus, bacteria Vibrio fischeri and crustacean Daphnia magna was performed. The results show very low contamination of groundwater with POPs with concentrations close to detection limits of applied analytical tools. Even this low contamination was possible to rank based on the obtained toxicity data. Toxicity proved to be a good parameter for determination of relative POPs contamination where concentration is near to detection limits and thus correct determination of all POPs cannot be undertaken. Although contamination levels were found to be very low, a secondary contamination of PCBs through the bedrock was observed. Organochlorine pesticides were found at a sampling site near a mouth of the ground watershed. Applied toxicity tests confirmed the presence of toxic substances and marked sites of higher contamination. Application of toxicological parameter Vtox allowed the ranking of assessed sites by their contamination level even in cases where concentrations of pollutants were near or under detection limits and it was not therefore possible to rank the sites on the basis of chemical parameters. Toxicity response of bioassays obtained on SPMDs exposed in clean groundwater can be used as a background toxicity values for further SPMD applications. Secondary contamination with PCBs and pesticides was detected in Cennoman groundwater. Toxicity evaluation of SPMD extract can be used as an effective tool for ranking of general level of water contamination.
KEYWORDS: water quality index, biological parameter, fuzzification, water treatment, Water quality monitoring, fuzzy inference system and water quality software
Determination of status of water quality of a river or any other water sources is highly indeterminate. It is necessary to have a competent model to predict the status of water quality and to advice for type of water treatment for meeting different demands. One such model (UNIQ2007) is developed as an application software in water quality engineering. The unit operates in a fuzzy logic mode including a fuzzification engine receiving a plurality of input variables on its input and being adapted to compute membership function parameters. A processor engine connected downstream of the fuzzification unit will produce fuzzy set, based on fuzzy variable viz. DO, BOD, COD, AN, SS and pH. It has a defuzzification unit operative to translate the inference results into a discrete crisp value of WQI. The UNIQ2007 contains a first memory device connected to the fuzzification unit and containing the set of membership functions, a secondary memory device connected to the defuzzification unit and containing the set of crisp value which appear in the THEN part of the fuzzy rules and an additional memory device connected to the defuzzification unit. More advantageously, UINQ2007 is constructed with control elements having dynamic fuzzy logic properties wherein target non-linearity can be input to result in a perfect evaluation of water quality. The development of the fuzzy model with one river system is explained in this paper. Further the model has been evaluated with the data from few rivers in Malaysia, India and Thailand. This water quality assessor probe can provide better quality index or identify the status of river with 90% perfection. Presently, WQI in most of the countries is referring to physic-chemical parameters only due to great efforts needed to quantify the biological parameters. This study ensures a better method to include pathogens into WQI due to superior capabilities of fuzzy logic in dealing with non-linear, complex and uncertain systems.
In this study, a field experiment was used to evaluate a pea crop (Pisum sativum L.) at Tongwei Experimental Station (35°13'N, 105°14'E), which is in a semiarid region of China. In this experiment, the mean daily temperature was designed to increase by 0.6-2.2 °C throughout the complete growth stage of the pea crop. When the mean daily temperature increased by approximately 2.2 °C, the water use efficiency (WUE) of the pea crop decreased by 30.4%, the duration of the growth stage was shortened by approximately 17 days, the yields were decreased by 17.5%, the number of stems with root-rot sickness were increased by 50.6%, and the input-output ratio (In/Ou) of the pea crop was 1.20. When the mean daily temperature was increased by approximately 1.4 °C, the WUE decreased by 26.1%, the growth stage duration decreased by 10 days, the yields decreased by 11.1%, the number of stems with root-rot sickness increased by 23.3%, and the input-output ratio (In/Ou) was 1.11. In addition, supplementary irrigation was found to be beneficial to the pea yields when the temperature increased. Indeed, application of 60 mm of supplementary irrigation during the complete growth stages of crops that were subjected to an increase in mean daily temperature of 0.6-2.2 °C resulted in crop yields improving by 8.3%-12.8%. Consequently, in this region, supplementary irrigation may play an important role in maintaining pea yields that would otherwise be affected by climate warming. However, the results also show that application of 60 mm of supplementary irrigation does not decrease the number of stems with root-rot sickness and that the In/Ou ratio of pea crops subjected to the same temperature conditions will increase.
Two N-trihalomethylthio fungicides were detected in the atmosphere in the Lower Fraser Valley agricultural region of Canada. Captan was detected in both the particle and gas phase with a dominant particle phase fraction observed in both 2005 and 2006 (only total captan atmospheric concentrations were available for 2004). This provides the first evidence of particle transport as a significant atmospheric transport pathway for captan in an agricultural region in Canada. Weekly captan air concentrations reached maximum levels of 13.2 ng m-3 in June 2006, while for folpet total atmospheric levels were lower with maximum reaching 1.7 ng m-3 in August 2004 and generally <1 ng m3 in 2005 and 2006. Folpet is detected in the atmosphere although not previously reported in usage inventories. In the three years examined (2004-2006) captan concentrations observed a seasonal maximum in atmospheric concentrations during spring to early summer coinciding with expected peak usage period on crops in the Lower Fraser Valley agricultural region located in British Columbia, Canada. No usage data is available in Canada beyond 2003 but these seasonal trends show that captan remains a dominant pesticide used in this agricultural region with no decline in atmospheric concentrations during 2004-2006.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere