Health risk assessment of potentially harmful elements and dietary minerals from vegetables irrigated with untreated wastewater,Pakistan

In the developing world, vegetables are commonly grown in suburban areas irrigated with untreated wastewater containing potentially harmful elements (PHEs). In Pakistan, there is no published work on the bioaccessibility aspect of PHEs and dietary minerals (DMs) in sewage-irrigated soil or the vegetables grown on such soils in Pakistan. Several industrial districts of Pakistan were selected for assessment of the risk associated with the ingestion of vegetables grown over sewage-irrigated soils. Both the total and bioaccessible fraction of PHEs (Cd, Co, Cr, Ni, and Pb) and DMs (Fe, Cu, Mn, Zn, Ca, Mg, and I) in soils and vegetable samples were measured. The concentrations of these PHEs and DMs in sewage-irrigated and control soils were below published upper threshold limits. However, compared to control soils, sewage irrigation over the years decreased soil pH (7.7 vs 8.1) and enhanced dissolved organic carbon (1.8 vs 0.8 %), which could enhance the phyto-availability of PHEs and DMs to crops. Of the PHEs and DMs, the highest transfer factor (soil to plant) was noted for Cd and Ca, respectively. Concentrations of PHEs in most of the sewage-irrigated vegetables were below the published upper threshold limits, except for Cd in the fruiting portion of eggplant and bell pepper (0.06–0.08 mg/kg Cd, dry weight) at three locations in Gujarat and Kasur districts. The bioaccessible fraction of PHEs can reduce the context of dietary intake measurements compared to total concentrations, but differences between both measurements were not significant for Cd. Since the soils of the sampled districts are not overly contaminated compared to control sites, vegetables grown over sewage-irrigated soils would provide an opportunity to harvest mineral-rich vegetables potentially providing consumers 62, 60, 12, 104, and 63 % higher dietary intake of Cu, Mn, Zn, Ca, and Mg, respectively. Based on Fe and vanadium correlations in vegetables, it is inferred that a significant proportion of total dietary Fe intake could be contributed by soil particles adhered to the consumable portion of vegetables. Faecal sterol ratios were used to identify and distinguish the source of faecal contamination in soils from Gujranwala, Gujarat, and Lahore districts, confirming the presence of human-derived sewage biomarkers at different stages of environmental alteration. A strong correlation of some metals with soil organic matter concentration was observed, but none with sewage biomarkers.     

Why do <Emphasis Type="Italic">Manduca sexta</Emphasis> feed from white flowers? Innate and learnt colour preferences in a hawkmoth

Flower colour is an important signal used by flowering plants to attract pollinators. Many anthophilous insects have an innate colour preference that is displayed during their first foraging bouts and which could help them locate their first nectar reward. Nevertheless, learning capabilities allow insects to switch their colour preferences with experience and thus, to track variation in floral nectar availability. Manduca sexta, a crepuscular hawkmoth widely studied as a model system for sensory physiology and behaviour, visits mostly white, night-blooming flowers lacking UV reflectance throughout its range in the Americas. Nevertheless, the spectral sensitivity of the feeding behaviour of naïve moths shows a narrow peak around 450 nm wavelengths, suggesting an innate preference for the colour blue. Under more natural conditions (i.e. broader wavelength reflectance) than in previous studies, we used dual choice experiments with blue- and white-coloured feeders to investigate the innate preference of naïve moths and trained different groups to each colour to evaluate their learning capabilities. We confirmed the innate preference of M. sexta for blue and found that these moths were able to switch colour preferences after training experience. These results unequivocally demonstrate that M. sexta moths innately prefer blue when presented against white flower models and offer novel experimental evidence supporting the hypothesis that learning capabilities could be involved in their foraging preferences, including their widely observed attraction to white flowers in nature.     

Sediment and nutrient dynamics during snowmelt runoff generation in a southern Taiga catchment of Russia

The water quality of the Volga catchment, Russia, is diminished and major nutrients reach critical levels. Proper management strategies depend on process knowledge about nutrient sources and pathways as well as appropriate models. For the 18.8 km² experimental catchment Lubazhinkha, 100 km south of Moscow, a monitoring scheme was conducted to identify runoff generation and nutrient source areas. The grey forest soils of the catchment are utilized with arable land and pasture (54%) and forest areas. The received results show a high intra-annual and inter-annual dynamic of the snowmelt runoff generation as major hydrological process. Overall sediment export rates during the 3 years of snowmelt investigation from 2003 to 2005 are low with a maximum of 0.33 t ha⁻¹ during snowmelt period 2005 and effectively reduced by a dam at the catchment outlet. Also, the total phosphorus loss from the catchment is low reaching from 0.03 to 0.35 kg ha⁻¹ during the snowmelt periods. However, sediment and total phosphorus concentrations vary within one snowmelt event and can reach high concentrations. Detailed analysis of element concentrations during snowmelt events allows an identification of different flow components and runoff generating mechanisms. During low flow situations phosphorus and dissolved organic carbon are transferred from the arable soils with slow flow components to the channel. In contrast to this situation, the sources of sediment and nutrients split up temporarily and spatially during high flow situations. Aside arable fields that are source of sediment and phosphorus during snowmelt episodes, the forested areas were detected as major source for the export of dissolved organic carbon with surface runoff. In particular these areas are characterized by a late thawing of the topsoil which causes a delayed peak of dissolved organic carbon concentration. The awareness of the dynamic and complex catchment reaction during snowmelt events is of importance for the development of proper management strategies.     

Evaluation of olive oil mill wastewater toxicity on spinach

Background, aim, and scope

Olive oil mill wastewater (OMW), a by-product of the olive oil extraction process, is annually produced in huge amounts in olive-growing areas and represents a significant environmental problem in Mediterranean areas. We studied the impact of OMW dilutions (1:20 and 1:10) on spinach plants in order to evaluate OMW dilutions as a low-cost alternative method for the disposal of this waste.

Materials and methods

The effects of OMW dilutions were evaluated on seed germination, shoot and root elongation, biomass production, nutrient uptake and translocation, ascorbic acid content, polyphenols, photosynthetic pigments, and photosynthetic performance of spinach.

Results

Plant biomass was more affected than plant height and total chlorophyll; carotenoid and ascorbic acid content progressively decreased with decreasing OMW dilution. Exposure to both OMW dilutions resulted in overaccumulation of total polyphenols, which were negatively correlated to plant biomass and nutrients. Nutrient (Fe, Ca, and Mg) content was insufficient leading to reduced growth. Water use efficiency decreased mainly due to decreased CO₂ assimilation rate rather than to a decline of transpiration rate. Disturbances in photosystem II (PSII) photochemical efficiency could be better envisaged by the ratio between variable fluorescence and initial fluorescence (Fv/Fo), which showed much greater amplitude than the maximal photochemical efficiency of PSII photochemistry (Fv/Fm).

Conclusions

From the data obtained, it is suggested that 1:20 OMW dilutions are still phytotoxic and that higher OMW dilutions should be used in order to use this waste for the irrigation of spinach plants.     

Indicators of sustainable production: framework and methodology

This paper presents a new tool for promoting business sustainability — indicators of sustainable production. It first introduces the concept of sustainable production as defined by the Lowell Center for Sustainable Production, University of Massachusetts Lowell. Indicators of sustainable production are discussed next, including their dimensions and desirable qualities. Based on the Lowell Center Indicator Framework, the authors suggest a new methodology of core and supplemental indicators for raising companies' awareness and measuring their progress toward sustainable production systems. Twenty-two core indicators are proposed and a detailed guidance for their application is included. An eight-step model provides a context for indicator implementation. The paper concludes with a summary of the strengths and weaknesses of the methodology as well as recommendations for testing the indicators.     

Early ultrasound diagnosis of Neu–Laxova syndrome

We report the mid-trimester prenatal diagnosis of Neu–Laxova syndrome (NLS) in two at risk families utilizing serial sonographic examinations. Ultrasound and pathologic findings from seven affected pregnancies, the largest case series of NLS to date, are presented. One fetus had anencephaly and incomplete rachischisis, an anomaly that has not been previously reported in association with NLS. Ultrasonographic detection of severe intrauterine growth restriction (IUGR), abnormally postured limbs, microcephaly, and edema allowed prenatal diagnosis of NLS in five of these at risk pregnancies during the mid-trimester. Growth curves derived from serial sonograms reveal abnormalities of all standard biometric measurements. The growth discrepancy was most pronounced in the measurements of the biparietal diameter, which were consistently less than two standard deviations below the mean across all gestational ages. This case series confirms that aberrant growth and anomalies may be detected sufficiently early in gestation to permit prenatal diagnosis of NLS. Copyright © 2001 John Wiley & Sons, Ltd.     

Second-trimester maternal serum alpha-fetoprotein (MSAFP) iselevated in women with adverse pregnancy outcome associated with inherited thrombophilias

Obstetric complications, such as severe pre-eclampsia, fetal growth restriction, abruptio placentae, or stillbirth are associated with abnormally elevated second-trimester maternal serum alpha-fetoprotein (MSAFP) and β subunit of human chorionic gonadotrophin (βhCG). This has been attributed to placental abnormalities. Women with thrombophilias have been shown to have abnormalities of the placenta resulting in adverse pregnancy outcome in these patients. The purpose of the present study was to evaluate whether women with pregnancy complications and inherited thrombophilias have abnormally elevated second-trimester MSAFP or βhCG. Sixty-two women with pregnancy complications were tested for inherited thrombophilias several months after delivery. The thrombophilia group included 29 women with pregnancy complications and an inherited thrombophilia and the control group included 33 other patients without thrombophilia. Patients in the thrombophilia group had a higher median MoM MSAFP compared to the controls (1.337 vs 1.086, p=0.0516). The incidence of abnormally elevated MSAFP (>2.5 MoM) was also significantly higher in the thrombophilia group compared to controls (21% vs 3%, p=0.04). Neither the median MoM βhCG nor the incidence of abnormally elevated βhCG were significantly different between the groups. We conclude that second trimester MSAFP, but not βhCG, is abnormally elevated in patients with thrombophilia and obstetric complications. Copyright © 2001 John Wiley & Sons, Ltd.     

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies. Copyright © 2001 John Wiley & Sons, Ltd.     

The use of multiple tracers for tracking wastewater discharges in freshwater systems

The assessment of potential impacts of wastewater effluent discharges in freshwater systems requires an understanding of the likely degrees of dilution and potential zones of influence. In this study, four tracers commonly present in wastewater effluents were monitored to compare their relative effectiveness in determining areas in freshwater systems that are likely to be impacted by effluent discharges. The four tracers selected were the human pharmaceutical carbamazepine, anthropogenic gadolinium, fluorescent-dissolved organic matter (fDOM), and electrical conductivity (EC). The four tracers were monitored longitudinally in two distinct freshwater systems receiving wastewater effluents, where one site had a high level of effluent dilution (effluent <1 % of total flow) and the other site had a low level of effluent dilution (effluent ～50 % of total flow). At both sites, the selected tracers exhibited a similar pattern of response intensity downstream of discharge points relative to undiluted wastewater effluent, although a number of anomalies were noted between the tracers. Both EC and fDOM are non-specific to human influences, and both had a high background response, relative to the highly sensitive carbamazepine and anthropogenic gadolinium responses, although the ease of measuring EC and fDOM would make them more adaptable in highly variable systems. However, the greater sensitivity and selectivity of carbamazepine and gadolinium would make their combination with EC and fDOM as tracers of wastewater effluent discharges highly desirable to overcome potential limitations of individual tracers.     

Water quality test based on dielectrophoretic measurements of fresh water algae Selenastrum capricornutum

A method is described whereby dielectrophoresis of algal cells is used to perform rapid water quality analysis, specifically detecting the presence of CuSO4. The dielectric collection spectrum of the fresh water alga Selenastrum capricornutum was determined for a range of concentrations of CuSO4 from 25 mg L(-1) to 0.25 mg L(-1) for exposure times of 15 min and 18 h. In all cases increasing the concentration of CuSO4 reduced cell collection, but a step reduction was observed in collection between 2 mg L(-1) and 5 mg L(-1). This method has potential for forming a rapid, low-cost test for water quality with broad specificity and significantly reduced analysis time compared to current methods.