Air pollution is a major contributor to several respiratory problems, it affects the whole population in general but children are more susceptible. Exposure to automobile exhaust is associated with increased respiratory symptoms and may impair lung function in children. In view of this, the study was conducted among the children of Delhi, the capital city of India, where ambient air quality was much above the National Ambient Air Quality Standards. The study was conducted in children aged 9-17 years. Pulmonary function test was carried out following the guideline of American Thoracic Society using a portable, electronic spirometer. Air quality data was collected from Central and State Pollution Control Boards. In addition, the level of particulate matter in indoor air was measured by portable laser photometer. Lung function was reduced in 43.5% schoolchildren of the urban area compared with 25.7% of control group. The urban children had increased prevalence of restrictive, obstructive, as well as combined type of lung functions deficits. Besides higher prevalence, the magnitude of lung function deficits was also much more in them. After controlling potential confounders like season, socioeconomic conditions and ETS, PM10 level in ambient air was found to be associated with restrictive (OR = 1.35, 95% CI 1.07-1.58), obstructive (OR = 1.45, 95% CI 1.16-1.82), and combined type of lung function deficits (OR = 1.74, 95% CI 1.37-2.71) in children. Spearman's rank correlation test reaffirmed the association. The study confirms that the level of air pollution is affecting the children.

The residual brine of the Cerro Prieto Geothermal Field (CPGF) is disposed in an evaporation pond. The seepage of this pond has contaminated the water and agricultural soil around it. The contamination of the groundwater towards the southwest by the evaporation pond, in the direction of the regional flow, has been shown before. Hydrogeochemical modeling (PHREEQCI) and Schoeller and Piper diagrams have been used in this work to show that the chemical composition of the groundwater in villages neighboring CPGF is the product of mixing between irrigation water from the Colorado River and brine from the evaporation pond. The high potassium concentration in the water and the relative increase in concentration of sodium and chlorides along the flow path as well as the hydrogeochemical models for this system explain this mixing process. This work will allow proposing new managing techniques to avoid the presence of the residual brine in the groundwater of agricultural lands.

Water quality trends from 1970 to 2005 were defined along 30 Delaware streams in the Delaware and Chesapeake Bay watersheds in the USA. Water quality improved or was constant at 69% of stations since 1990 and at 80% of stations since 1970/1980. Dissolved oxygen (DO) improved or was constant at 73% of streams since 1990 and 32% of streams since 1970/1980. Total suspended sediment improved or was constant at 75% of streams since 1990 and 100% of streams since 1970/1980. Enterococcus bacteria improved or remained constant at 80% of streams since 1990 and 93% of streams since 1970/1980. Total Kjeldahl nitrogen improved or was constant at 48% of streams since 1990 and 100% of streams since 1970/1980. Total phosphorus improved or was constant at 66% of streams since 1990 and 85% of streams since 1970/1980. During 2001-2005, median levels were good or fair at 100% of the stations for DO, 78% for sediment, 50% for bacteria, 59% for nitrogen, and 56% for phosphorus. Good water quality correlates with high amounts of forest area (>25%) in Delaware watersheds. Since the Federal Clean Water Act Amendments of the 1970s, improving Delaware water quality stations (50) outnumbered degrading stations (23) by a 2:1 margin. Since 1990, degrading water quality stations (46) exceeded improving stations (38) mostly due to deteriorating nitrogen levels in half of Delaware streams, a reversal from early gains achieved since the 1970s. Over the last three and a half decades, watershed strategies have improved or preserved water quality along Delaware streams; however, greater emphasis is needed to curb recently resurging increases in nitrogen levels.

The photodegradation of azo dyes aqueous solution has been investigated using TiO₂ as catalyst in sunlight. The effect of amount of catalyst, concentration of dye, and pH value on the degradation of Direct Blue 78 was observed. A complete degradation of 100 mg/L Direct Blue 78 solution under solar irradiation was achieved in 6 h at pH 3.0, dosage of TiO₂ 1.0 g/L. A possible pathway for the photodegradation of Direct Blue 78 in sunlight was proposed.

Phytoextraction is a soil remediation technique involving plants that concentrate heavy metals in their shoots, which may be removed from the area by harvest. The application of synthetic chelants to soil increases metal solubility, and therefore enhances phytoextraction. However, synthetic chelants degrade poorly in soil, and metal leaching poses a threat to human and animal health. The aim of this study is to assess the use of two biodegradable chelants (citric acid and nitrilotriacetic acid (NTA)) for Pb phytoextraction by maize from a soil contaminated by battery-casing disposal. In order to assess the behavior of a non-degradable chelant, ethylenediaminetetraacetic acid (EDTA) was also included in the experiment. The chelants NTA and EDTA were applied to soil pots at rates of 0, 3, 5, 7, and 10 mmol kg⁻¹ of soil. The rates used to citric acid were 0, 5, 10, 15, and 30 mmol kg⁻¹. Maize plants were grown for 72 days and chelants were applied 9 days before harvest. Soil samples were extracted with CaCl₂ to assess the Pb solubility after chelants application. The results showed that NTA was more efficient than citric acid to solubilize Pb from soil; however, citric acid promoted higher net removal of Pb (120 mg pot⁻¹) than NTA (57 mg pot⁻¹). Thus, the use of citric acid, a biodegradable organic acid, could be feasible for enhancing the phytoextraction of Pb from the site studied with no environmental constraints.

Cultures of the flagellate Isochrysis galbana were used to carry out the ecotoxicological evaluation of four PAHs [(naphthalene, phenanthrene, pyrene (Pyr) and fluoranthene (Flu)] by monitoring growth rate and the fluorescence variables F ₀, F m, F v and F v/F m, determined with a fast repetition rate fluorometer. The results presented in this investigation showed that F v was a suitable endpoint in acute ecotoxicological tests with marine phytoplankton. The derived effective concentrations followed the known narcotic mechanism of toxicity and showed sensitivity levels comparable to marine invertebrate embryo-larval bioassays. Pyr and Flu showed the lowest EC₁₀, which ranged between 168-279 and 189-697 nM, respectively.

Three organic wastes (banana skin (BS), brewery spent grain (BSG), and spent mushroom compost (SMC)) were used for bioremediation of soil spiked with used engine oil to determine the potential of these organic wastes in enhancing biodegradation of used oil in soil. The rates of biodegradation of the oil were studied for a period of 84 days under laboratory conditions. Hydrocarbon-utilizing bacterial counts were high in all the organic waste-amended soil ranging between 10.2 × 10⁶ and 80.5 × 10⁶ CFU/g compared to unamended control soil throughout the 84 days of study. Oil-contaminated soil amended with BSG showed the highest reduction in total petroleum hydrocarbon with net loss of 26.76% in 84 days compared to other treatments. First-order kinetic model revealed that BSG was the best of the three organic wastes used with biodegradation rate constant of 0.3163 day⁻¹ and half-life of 2.19 days. The results obtained demonstrated the potential of organic wastes for oil bioremediation in the order BSG > BS > SMC.

In this work, we evaluated the effect of harmful ecotoxins, 4,5,6-trichloroguaicol (4,5,6-TCG) and tetrachloroguaiacol (TeCG), on the oxidation of the fluorescent probe dihydrorhodamine 123, the content of free phenols and the level of the total, oxidized and reduced glutathione in the leaves of reed canary grass (Phalaris arudinacea). Furthermore, the effect on the activity of guaiacol peroxidase and glutathione S-transferase was investigated. Both 4,5,6-TCG and TeCG increased the activity of guaiacol peroxidase and glutathione S-transferase, they also elevated the content of free phenols and the level of the total glutathione. A stronger effect was exerted by tetrachloroguaiacol, which strongly increased the level of the total glutathione and the content of free phenols on the 3rd and 6th day of the experiment. The activity of glutathione S-transferase was more intensively induced by trichloroguaiacol. Both 4,5,6-TCG and TeCG oxidized dihydrorodamine 123 and the effect was stronger in the presence of magnesium ions.

This paper investigated the influence of low-intensity ultrasound in biological nitrification and denitrification. The results showed that the nitrification activity of activated sludge could not be promoted significantly by ultrasound in 5-40 min with intensities ranging from 0.1 to 1.2 W cm⁻². It suggested the fact that nitrifying bacteria were insensitive to ultrasound, possibly related with their specific structures of cell membrane and ways of metabolism. Whereas, biological denitrification was enhanced quite remarkably by ultrasound and the optimal results were achieved at the ultrasonic intensity of 0.2 W cm⁻² and the irradiation time of 10 min. Compared with the control without ultrasonic irradiation, it took 5 h for the enhancement of denitrification rates induced by the optimum ultrasound to reach its peak level (16%). Therefore, ultrasound with intensity of 0.2 W cm⁻² could be employed in the biological denitrification system for 10 min every 5 h to obtain the optimal effect theoretically.