The promotion of good indoor air quality in schools is of particular public concern for two main reasons: (1) school-age children spend at least 30% of their time inside classrooms and (2) indoor air quality in urban areas is substantially influenced by the outdoor pollutants, exposing tenants to potentially toxic substances. Two schools in Curitiba, Brazil, were selected to characterize the gaseous compounds indoor and outdoor of the classrooms. The concentrations of benzene, toluene, ethylbenzene, and the isomers xylenes (BTEX); NO₂; SO₂; O₃; acetic acid (HAc); and formic acid (HFor) were assessed using passive diffusion tubes. BTEX were analyzed by gas chromatography-ion trap mass spectrometry and other collected gasses by ion chromatography. The concentration of NO₂ varied between 9.5 and 23 µg m⁻³, whereas SO₂ showed an interval from 0.1 to 4.8 µg m⁻³. Within the schools, BTEX concentrations were predominant. Formic and acetic acids inside the classrooms revealed intermediate concentrations of 1.5 µg m⁻³ and 1.2 µg m⁻³, respectively.

Changes in deposition exert effects on forests. Some evidence for a slow recovery of strongly alkalised forest soils after a reduction in alkaline pollution exists, but the recovery rate is little known. The objective of this study was to estimate temporal soil reaction changes. For this purpose, measurements of soil reaction under a beech forest near magnesite works in Central Slovakia were taken in 1991 and 2006, following the alkaline pollution reduction in 1992. As a result, the mean active soil reaction decreased from pH 7.8 to 6.6. Beyond the range of beech stemflow, which amplifies water and acid pollution inputs into soils locally, soil reaction dropped from pH 7.8 to 6.8. The effect of stemflow on local exchangeable reaction minima was detected even before the pollution reduction. The logarithmic function fitted on the pH data indicates considerable differences between neutralisation rates within and outside the stemflow zone.

In this biological oxygen demand (BOD) study, the manometric respirometric BOD OxiTop® method was used to monitor the biodegradation of two summer grade (SFO 1 and 2) and two winter grade light fuel oils (WFO 1 and 2) in OECD 301 F conditions, in groundwater, and in two different Finnish forest soils (mineral-poor and mineral-rich). The biodegradation measurements in the OECD 301 F conditions were carried out in two nutrient solutions for 28 days. In both solutions WFO 1 reached the highest biodegradation degree, 32% in the solution OECD 301 F, and 70% in a solution containing additional ammonium chloride. In groundwater conditions all the biodegradation degrees of fuel oils remained below 2% within the 28-day period. SFO 1 reached the highest 30 day biodegradability (4%) in mineral-poor soil, 18% in mineral-rich soil. In a 189-day measurement in a mineral-rich soil, the biodegradation degree for the SFO 1 was 94%. The manometric respirometric method proved to be a very suitable and practicable measurement method for the purpose of biodegradation studies of highly volatile light fuel oils, because in this method samples are treated to a lesser degree than in conventional methods, and dilutions are not needed. Results also indicated a considerable effect of conditions on the biodegradability in both water and soil environments. The results of these biodegradation studies could be used when planning in situ treatment methods based on natural biodegradation. In situ treatment methods are eco-efficient, and are especially suitable for sparsely populated sites.

The emission of platinum group elements (PGEs) from automobile catalytic converters has led to rapid increases in Pt, Pd, and Rh concentrations in roadside media. This article represents the first systematic study in Greece to assess PGE levels in road dust and roadside soil and their temporal variation on a seasonal basis over a 12-month period. Road dust and roadside soil samples were analyzed by graphite furnace atomic absorption spectrometry following microwave digestion. Concentrations of PGE in all samples were above the average upper crust values and local background levels, with maximum values of 306.4 ng/g Pt, 18.2 ng/g Pd, and 64.6 ng/g Rh in road dust and 225 ng/g Pt, 14.0 ng/g Pd, and 49.5 ng/g Rh in roadside soil. PGE ratios were not consistent with known catalytic converter composition throughout the sampling period reflecting the high emission of Rh from new catalytic converters. Spatial variations were influenced by various factors like driving style, matrix composition, diurnal change in traffic volume, and climatic conditions. With regard to seasonal variations, systematic changes in the temporal distribution of PGE levels were observed and followed a similar pattern between the two matrices. Except PGEs, Pb levels were determined, since it has been a typical indicator of vehicle-derived environmental lead pollution. The data indicate that despite the use of unleaded gasoline, traffic-related sources of Pb that induce levels above the local background have not been eliminated.

The acquired immunity consists of two pathways namely the humoral immunity that defends the host against extracellular pathogens such as bacteria and the cell-mediated immunity that defends the host against intracellular pathogens such as Mycobacterium tuberculosis and viruses and also against cancers. The aim of this study is to determine the effects of river water collected from pristine and contaminated sites along the Eerste River, South Africa on inflammation, humoral and acquired immune pathways. Hydrophobic extracts were prepared from water collected at contaminated and pristine sites. Inflammatory activity was determined by measuring interleukin (IL)-6 levels synthesized by whole blood after incubation with the extracts. For determining the effects on acquired immunity, phytohemagglutinin stimulated whole blood from healthy volunteers was incubated with extracts. The effect on humoral immunity was determined using IL-10 as biomarker, while interferon-gamma was used as biomarker for cell-mediated immunity. The results obtained show that water from the sites downstream from human activity induced IL-6, a biomarker of inflammation. Extracts collected from a site downstream from an informal housing settlement suppressed biomarkers of both humoral and cell-mediated immunity. Water from sites impacted by human activity can potentially suppress the acquired immune system and this can pose a health risk to people using this water source. Studies must be done to investigate the long-term effects of the contaminated water on animals in vivo.

Deji Reservoir is situated in the middle of Taiwan on the upstream catchment of the Dajia stream with an area of over 60,160 ha. The embankment stands 180 m high and is the tallest concrete arch dam in Taiwan. This dam stores 1.7 billion cubic meters of valid volume water. It provides over 370 million kilowatt-hours of electricity annually. It is also an important facility for operating flood control, hydroelectricity, irrigation, public water supply, etc. Seventy-two percent of the terrain is at 2,000- to 3,000-m altitude, and 5.2% is above 3,200-m altitude. More than 59% of the area is covered with steep topography of 55% slope. Only 7.9% of the area is shown with gentle slopes of less than 30% slope, which are located among the two banks of main streams with the altitudes ranging from 1,500 to 2,500 m. Most of the gentle slopes are used for temperate zone fruit, vegetable, and tea plantations. This land-use immediately adjoins a reservoir catchment region, resulting in an enormous impact on the mountainous environment. This study reviewed human-developed land-use area to properly address and evaluate norms for mitigating the impacts on the reservoir. The initial investigation brought up the parameters of gradient, slope movement types and processes, distance to the reservoir, location of developed area and distance with the farm road, etc. Local investigation and global information system technology were conducted in this research. We focused on segregating the terrain types of indisposed land-use. A different land-use management strategy is also analyzed.

Wastewater contains varieties of carbonaceous and nitrogenous compounds that undergo complicated biodegradation processes in wastewater treatment plants. How these different compounds are degraded by activated sludge in aerobic conditions is still a mystery. Researchers have been trying to interpret it using the oxygen uptake rate (OUR) derived from the respirograms of respective substrates. Several models have been proposed to interpret the substrate removal mechanisms using the experimental observations. Have we succeeded in understanding the messages by activated sludge correctly using these models? In this paper, the distinctive nature of the respirograms when activated sludge is fed with different substrates and the biokinetic models that have been developed to explain the substrate removal mechanisms using derived OUR profiles are reviewed. In addition, a sensitivity study was conducted on the recently evolved simultaneous storage and growth model to investigate the influence of key parameters on OUR profiles during the biodegradation process.

The delafossite CuCrO₂ is a promising candidate for the visible light driven catalysis. The NO₂ ⁻ removal by photoelectrochemical process is studied under mild conditions, close to that encountered in the natural environment. CuCrO₂ exhibits a long term chemical stability with a corrosion rate of 0.34 μmol m⁻² year⁻¹ in KCl (0.5 M). A forbidden band of 1.3 eV has been evaluated from the diffuse reflectance spectrum. The flat band potential (-0.07 V SCE) determined from the Mott-Schottky plot is close to the photocurrent onset potential (0 V SCE). Hence, the conduction band is positioned at -1.08 V SCE and thus lies below the NO₂ ⁻ level leading to a feasible reduction upon visible illumination. The conversion occurs in less than ~5 h with a quantum efficiency of ~0.5%. The possibility of identifying the reaction products via the intensity-potential characteristics was explored by using standard solutions. The decrease of the conversion rate over time is attributed to the competitive water reduction. In absence of catalyst, NO₂ ⁻ is oxidized to NO₃ ⁻ in air equilibrated solution and the reaction follows a first order kinetic with a half life of 21 h, NO₃ ⁻ has been identified by iodometry through copper titration.

Information on tradeoffs among water quantity and quality attributes at a watershed scale is important in developing effective watershed conservation policies. Assessment of these multiattribute tradeoffs, a focus of this study, is often a low priority in policy design. A combination of simulation modeling and statistical assessment was used to evaluate the significance of relationships among runoff, sediment, nitrate, and phosphorus loading in 115 subwatersheds of the Blackstone River Watershed in southern New England. We observed high variability in rates of runoff, nitrate, phosphorus, and sediment loading among subwatersheds. Results of the regression analysis indicate a high correlation between nitrate and surface runoff, emphasizing the importance of stormwater management in mitigating nutrient loads. A significant relationship exists between mineral phosphorus and sediment yield in watersheds that could inform strategies to mitigate eutrophication problems in phosphorus-limited systems such as some inland water bodies. The tradeoff analysis proposed can be used in policy design and to assess the implications of various policies to address multiple pollutants.

The loss of pendimethalin, a selective herbicide, was determined in runoff water from loamy soil plots of various surface slopes cultivated with tobacco, over a period of 193 days. Conditions were selected to simulate agricultural practices employed in the Mediterranean region. The surface slopes of plots were 0%, 2.5%, 5%, 7.5%, and 10% and both cultivated and uncultivated (control) areas were simultaneously monitored. The cumulative losses of pendimethalin in surface runoff, as percentage of the initial applied active ingredient, were 0.067% for tilled and 0.098% for untilled soil of 10% slope, while for the plots of 0% slope they were ten times lower, 0.006% and 0.009% respectively. The maximum concentrations in runoff water reached 15.87 μg L⁻¹ and were detected after the second run off event. The dissipation in top soil was studied for a period of 129 days. The half-lives that were calculated using first order kinetics ranged from 23 to 27.2 days in non-cropped soil and from 22.3 to 26.2 in tobacco plots.