Simulating Distribution of Trihalomethane in Tap Water in the Area Receiving a Combination of Advanced Treated Water and Conventionally Treated Different Source Water: 1998, 1999 and 2002 Data on Osaka Prefecture and Its Surrounding Cities,Japan

Empirical equations for explaining trihalomethane (THM) distribution were established based on data on tap water in Osaka City before and after starting the advanced treatment and were represented by the following equations for bromodichloromethane (S₁), dibromochloromethane (S₂) and bromoform distribution factors (S₃) as a function of chloroform distribution factor (S₀), respectively: S₁ = ?0.97S ₀ ²  + 0.75S₀ + 0.19 (regression coefficient: r = 0.71), S₂ = 0.13S ₀ ² ?0.76S₀ + 0.51 (r = 0.98) and S₃ = 0.83S ₀ ² ?0.99S₀ + 0.30 (r = 0.97). Further, the derived equations were verified by THMs data of Osaka Prefecture and its surrounding cities (except for Osaka City), receiving a combination of advanced treated water and conventionally treated different source water.     

Is Advanced Treated Water Truly High Quality?: the Answer from a Viewpoint of Cancer Risk Induced by Trihalomethane Class

Before and after switching to the advanced treatment, a total of 48 trihalomethanes measurements was made at household taps in the specific distribution area in Osaka City, Japan. An average of total trihalomethanes concentrations in advanced treated water was three-fifths of that in conventionally treated water. The average lifetime cancer risks for total trihalomethanes were 48.5 × 10⁻⁶ in conventionally treated water and 44.8 × 10⁻⁶ in advanced treated water, which were higher than 10⁻⁶, the negligible risk level. Surprisingly, the average lifetime cancer risk of conventionally treated water was not significantly different from that of advanced treated water. The highest value of hazard index found was an order of magnitude lower than unity.     

Toxicity of Cadmium,Anthracene, and Their Mixture to <Emphasis Type="Italic">Desmodesmus subspicatus</Emphasis> Estimated by Algal Growth-Inhibition ISO Standard Test

Cells of Desmodesmus subspicatus 86.81 were used to examine the toxicity of cadmium chloride (CdCl₂) and anthracene (ANT) applied individually and in combination. The experiments were performed according to standardized ISO (International Organization for Standardization) 8692 protocol (2004). Parameters measured were the number of cells and chlorophyll a fluorescence parameters. E_rC₁₀ and E_rC₅₀ values (growth rate [r] inhibition by 10% and 50%, respectively) for single toxicants were determined separately. The effect of mixtures of the substances (Cd + ANT) at concentrations corresponding to E_rC₁₀ (E_rC₁₀ + E_rC₁₀) and E_rC₅₀ (E_rC₅₀ + E_rC₅₀) values was characterized. The toxicity of individual chemicals after a 72-h exposure was as follows: ANT (E_rC₁₀ = 0.06; E_rC₅₀ = 0.26 mg l⁻¹) and CdCl₂ (E_rC₁₀ = 0.12; E_rC₅₀ = 0.30 mg l⁻¹). The combination Cd + ANT decreased the population growth rate more strongly than the substances applied individually. Cadmium at a concentration corresponding to E_rC₁₀ slightly influenced the parameters of chlorophyll a fluorescence as measured by the OJIP test (O, J, I, and P are the different steps of fluorescence induction curve), whereas the influence of ANT was not statistically significant. In Cd + ANT–treated samples, the photosynthetic “vitality” (PI), the maximum quantum yield of primary photochemistry (φ_Po), and the fraction of active PS II reaction centre (RC) decreased, but the values of ABS/RC, TR₀/RC, and DI₀/RC increased. The type of interaction between Cd and ANT depended on the concentration of chemicals used. When the substances were applied at concentrations of E_rC₁₀, synergistic effects were observed, whereas the mixture of chemicals used at an E_rC₅₀ concentration showed an antagonistic interaction.     

Effects of Nitrite and Toxic <Emphasis Type="Italic">Microcystis Aeruginosa</Emphasis> PCC7806 on the Growth of Freshwater Rotifer <Emphasis Type="Italic">Brachionus Calyciflorus</Emphasis>

Over the last two centuries, anthropogenic activities have increased the nitrogen amount in aquatic ecosystems, which has resulted in increased occurrences of blooms of cyanobacteria. This study investigated the effects of nitrite and the cyanobacterium Microcystis aeruginosa on population growth in the rotifer Brachionus calyciflorus. The rotifer was treated for 12 days with nitrite alone (medium containing 0, 3, 6, 10 mg NO₂ ⁻ –N L⁻¹), M. aeruginosa alone (medium containing 0 mg NO₂ ⁻–N L⁻¹ + 5.0 × 10⁵ cell ml⁻¹ M. aeruginosa precultured at 0, 3, 6, 10 mg NO₂ ⁻–N L⁻¹), and nitrite in combination with M. aeruginosa (medium containing 3, 10 mg NO₂ ⁻–N L⁻¹ + 5.0 × 10⁵ cell ml⁻¹ M. aeruginosa precultured at corresponding nitrite concentrations). We observed that a nitrite concentration of 10 mg NO₂ ⁻–N L⁻¹ markedly inhibited the growth of B. calyciflorus; however, rotifer growth declined slightly in the presence of M. aeruginosa precultured at 6 mg NO₂ ⁻–N L⁻¹. Furthermore, reduced population growth of B. calyciflorus was observed when it was treated with both nitrite and M. aeruginosa compared to nitrite alone or M. aeruginosa alone. These results suggested that a high tolerance of B. calyciflorus to nitrite levels may be attributed to the absence of specific respiratory structures and pigments; and that the increased toxicity of nitrite in combination with M. aeruginosa may have been due to increased production of microcystin. It is also possible that nitrite and microcystin could act in a synergistic way in causing toxicity.     

Acidic Gases and Nitrate and Sulfate Particles in the Atmosphere in the City of Guadalajara,México

Atmospheric concentrations of nitrous acid, nitric acid, nitrate and sulfate particles were obtained in this study from April to June 2008 in the center of the city of Guadalajara, while concentrations of ozone, sulfur dioxide, nitrogen dioxide and meteorological parameters (temperature and relative humidity), were acquired by the Secretaría del Medio Ambiente para el Desarrollo Sustentable del Estado de Jalisco (SEMADES). The results showed that nitric acid (2.7 μg m⁻³) was 2.7 times higher than nitrous acid (1.0 μg m⁻³). The sulfur dioxide (SO₂) concentration indicated an opposite trend to sulfate (SO₄ ²⁻), with the average concentration of SO₂ (6.9 μg m⁻³) higher in almost the entire period of study. The sulfur conversion ratio (Fs, 24.9%) and nitrogen conversion ratio (Fn, 6.2%), were revealed to be similar to that reported in other urban areas during warm seasons. It is also noted that ozone is not the main oxidizer of nitrogen dioxide and sulfur dioxide. This determination was made by taking into account the slightly positively correlation determined for Fn (r² = 0.084) and Fs (r² = 0.092) with ozone that perhaps suggests there are other oxidizing species such as the radical OH, which are playing an important role in the processes of atmospheric oxidation in this area.     

Toxicity Prediction of Antibiotics on Luminescent Bacteria, Photobacterium phosphoreum, Based on Their Quantitative Structure–Activity Relationship Models

Acute toxicity (EC_50–30 min) and chronic toxicity (EC_50–24 h) of 21 antibiotics on Photobacterium phosphoreum was observed and Quantitative structure–activity relationship (QSAR) models were developed, respectively. By comparing these two QSAR models, the following model was established, log(1/EC_50–24 h) = 1.8283 + 1.1503log(1/EC_50–30 min) + 0.2872Elomo − 0.0901DM + 0.0003PMIZ + 0.0088PSA − 0.0382SD, r ² = 0.8513, where Elomo is lowest occupied molecular energy, DM is dipole moment, PMIZ is principal moment of inertia Z, PSA is polar surface area, and SD is sum of degrees. It provides a good way for us to obtain EC_50–24 h from EC_50–30 min, because the later is far easier to observe than the former.     

Predicting the Accumulation of Organic Contaminants from Soil by Plants

Analytic expressions for maximum chemical concentration attained in plants, and time this takes for uptake from surrounding soil were derived from a simple two-compartment soil/water–plant model. To illustrate, for the antibiotic norflxacin undergoing first order loss in the soil/water phase with a rate constant of 0.544 days⁻¹, maximum concentration in soybean P _MAX is predicted to occur after 2.79 days exposure and be independent of initial soil/water concentration SW ₀ of 52.5 mg kg⁻¹ dry weight. For soybean, the relationship between P _MAX and SW ₀ is P _MAX  = 0.047SW ₀, resulting in predicted maximum levels of 2.20 mg kg⁻¹ dry weight. Modelled plant concentrations agreed well with experimental data (R ² = 0.91).     

Seasonal Variation in Physicochemical Parameters and Heavy Metals in Water of Upper Lake of Bhopal

Heavy metal pollution of fresh water is the single most important environmental threat to the future. Upper Lake is a freshwater lake, which is the major source of drinking water in the city of Bhopal, the capital city of M.P., the central province of India, but due to anthropogenic activities this lake is being polluted. During the investigation heavy metals and physicochemical parameters were analyzed to determine the water quality seasonally in the year of 2006 and 2007. All the physicochemical parameters except DO (6.50–6.97 mg l⁻¹), Free CO₂ (0.8–1.6 mg l⁻¹) and BOD (5.47–6.85 mg l⁻¹) were below the prescribed limit as recommended by Bureau of Indian Standards (BIS) for drinking water standards. In case of heavy metals, Ni (0.173–0.253 mg l⁻¹) and Cr (0.047–0.087 mg l⁻¹) were found beyond the prescribed limits (0.02 and 0.05 mg l⁻¹, respectively), whereas Pb (0.057–0.087 mg l⁻¹), Cu (0.016–0.020 mg l⁻¹) and Hg (0.0006–0.0011 mg l⁻¹) were within the safe limit. This study reveals that water of upper lake is partially polluted with heavy metals. It is recommended that strict vigilance and constant monitoring are needed to maintain water quality of the lake, which is a major source of potable water for the Bhopal city.     

Occurrence of Perfluoroalkyl Substances in Fish and Water from the Svitava and Svratka Rivers,Czech Republic

Perfluoroalkyl substances (PFHxS, FHUEA, PFOA, PFOS, FOSA, N-methyl FOSA and PFNA) from seven sites on the Svitava and Svratka rivers in the Brno conurbation (Czech Republic) were determined in fish blood plasma and water. Concentrations of PFHxS, FHUEA, FOSA, and N-methyl FOSA were below detection limits. Major compound in fish blood was PFOS (38.9–57.8 ng mL⁻¹), followed by PFNA and PFOA. In water, the major compound detected was PFOA (1.7–178.0 ng mL⁻¹), followed by PFOS and PFNA. A significant (p < 0.05) correlation for PFOA concentration in blood plasma and water was found (r = 0.74).     

Non-point Contamination Homogenizes the Water Quality of Pampean Streams

The aim of this research was to study the effects on streams water quality of non-point contamination as agriculture and cattle farming activities at a basin with pampean characteristics located at the upper Reconquista River Basin. Eight reaches with different uses in their neighboring zones were selected with the proposed to detect differences at the water quality among them. SRP range was 0–0.60 mgP.PO₄⁻³/L, ammonia 1–137.3 μgN-NH4⁺/L and nitrate 0–4.15 mgN-NO₃ ⁻/L. There was high similitude and homogeneous physicochemical characteristics at the different reaches of the streams. The high levels of dissolved nutrients showed similar eutrophication conditions at the streams.     

Removal of Methyl Parathion in Water,by <Emphasis Type="Italic">Dugesia dorotocephala</Emphasis>

The aim of this study was to determine the efficiency of Dugesia dorotocephala on Methyl parathion removal. An initial concentration of 1.25 μg mL⁻¹ of MeP was used to evaluate the removal capacity of planarian. A first-order removal kinetics was obtained with a disappearance rate constant (k _r) of 0.49 days⁻¹ and 69% efficiency on contaminant removal. This is significantly different (p < 0.5) from the degradation occurring in control systems, leading us to conclude that D. dorotocephala effectively removes MeP from contaminated water.     

Characteristics and Sources of Water-Soluble Ionic Species Associated with PM10 Particles in the Ambient Air of Central India

PM₁₀ aerosol samples were collected in Durg City, India from July 2009 to June 2010 using an Andersen aerosol sampler and analyzed for eight water-soluble ionic species, namely, Na⁺, NH₄ ⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃ ⁻ and SO₄ ²⁻ by ion chromatography. The annual average concentration of PM₁₀ (253.5 ± 99.4 μg/m³) was four times higher than the Indian National Ambient Air Quality Standard of 60 μg/m³ prescribed by the Central Pollution Control Board, India. The three most abundant ions were SO₄ ²⁻, NO₃ ⁻, and NH₄ ⁺, with average concentrations of 8.88 ± 4.81, 5.63 ± 2.22, and 5.18 ± 1.76 μg/m³, respectively, and in turn accounting for 27.1 %, 16.5 %, and 15.5 % of the total water-soluble ions analyzed. Seasonal variation was similar for all secondary ions i.e., SO₄ ²⁻, NO₃ ⁻, and NH₄ ⁺, with high concentrations during winter and low concentrations during monsoon. Varimax Rotated Component Matrix principal component analysis identified secondary aerosols, crustal resuspension, and coal and biomass burning as common sources of PM₁₀ in Durg City, India.     

Determination of Field-Incurred Chlorfluazuron Residues in the Peach

Chlorfluazuron residues were determined in the peaches that were sprayed at dosage (a.i. 0.0167 kg 10a⁻¹), using an analytical method that was validated as follows; r ² = 0.9999, 0.02 mg kg⁻¹ (LOQ) and 87.8–93.6% (recovery). The residues from all samples were lower than the MRL (0.5 mg kg⁻¹, Korea). A maximum 0.27 mg kg⁻¹ of chlorfluazuron was detected in the samples applied at 6 days before harvest. The results signify that the 10% SC product would be used safely as an insecticide if it is applied two or three times onto peaches, with applications given until 6 days prior to harvest.     

Relationships Between Leaching of Methylmercury from the Soil and the Basic Characteristics of Alkali Soil Polluted by Mercury in Guizhou China

To determine the relationship between soluble methylmercury and soil characteristics which was contaminated by mercury, several experiments were conducted. As a result, a good correlation was founding between the leached methylmercury level from soil and the EC (electronic conductivity) level of soil. Moreover, to grasp the relationship between soluble methylmercury and soluble anions from soil, several anions (Cl⁻, NO³⁻, SO₄ ²⁻) were measured using the ion chromatography method. Although the correlation coefficient was small (r = 0.40), only a correlation between the level of SO₄ ²⁻ and leached methylmercury was recognized.     

Effects of Environmental Factors on the Uptake Rates of Dissolved Nitrogen by a Salt-water Green Alga (<Emphasis Type="Italic">Oocystis borgei</Emphasis> Snow)

Uptake rates for dissolved nitrogen (DN) by a marine alga (Oocystis borgei) were examined in a ¹⁵N tracer experiment. Maximal uptake rates for all forms of DN were observed at temperatures between 25 and 30°C and at algal concentrations between 3.22 × 10⁸ and 4.78 × 10⁸ cell L⁻¹. Light intensity required to achieve the maximal uptake rate was 45 μmol m⁻² s⁻¹ for dissolved inorganic nitrogen (DIN = NO₃ ⁻, NO₂ ⁻, NH₄ ⁺) and methionine, and 126 μmol m⁻² s⁻¹ for urea. Salinity required to achieve the maximal uptake rate was 12.85 ppt for DIN, 19.89 ppt for urea and 26.2 ppt for methionine.     

A study on prevalence of multi-drug-resistant (MDR) Salmonella in water sprinkled on fresh vegetables in Bareilly, Moradabad, and Kanpur (northern Indian cities)

Water-borne and food-borne diseases are common in summers and monsoons in India. This study between March 2004 to September 2004 on microbiological quality of water used by vegetable vendors to keep their vegetables fresh was conducted to asses the role of water as a source of Salmonella. Of the 309 samples collected from Bareilly (80 vegetable vendors, 47 ponds, five municipal water taps), Moradabad (74 vegetable vendors, three ponds, five municipal water taps) and Kanpur (84 vegetable vendors, six ponds, five municipal water taps), 82 (26.5%) and 27 (8.7%) had Escherichia coli and Salmonella enterica strains, respectively. The study revealed that sprinkling water was contaminated with 0.00–6.81 log₁₀ cfu ml⁻¹ of coliforms, 4.16 log₁₀ to 9.46 log₁₀ cfu ml⁻¹ of heterotrophic aerobic bacteria, 0.00 to 7.23 log₁₀ cfu ml⁻¹ of non-lactose fermenters, 0.00 to 5.56 log₁₀ cfu ml⁻¹ of Salmonella and 0.00 to 7.77 log₁₀ cfu ml⁻¹ of yeast and moulds. Similarly, microbial counts in pond water samples (Bareilly) were 0.00 to 6.06 log₁₀ cfu ml⁻¹ of faecal coliforms, 5.12 log₁₀ to 8.09 log₁₀ cfu ml⁻¹ of heterotrophic aerobic bacteria, 0.00 to 6.37 log₁₀ cfu ml⁻¹ of non-lactose fermenters, 0.00 to 5.73 log₁₀ cfu ml⁻¹ of Salmonella and 0.00 to 7.82 cfu log₁₀ ml⁻¹ of yeasts and moulds. Presence of Salmonella in water sample had negative correlation with number of coliforms and positive correlation with number of non-lactose fermenters, as of the 16 (6.7%) Salmonella positive samples of water from vegetable vendors, ten were negative for coliforms. Similarly, of the 11 pond-water samples positive for Salmonella, six were negative for coliforms, and negative correlation (−0.55) between coliform count and Salmonella was statistically significant (r_0.01). On the other hand, Salmonella counts could be positively correlated (r_0.01) with counts of non-lactose fermenters. Salmonella isolates from water for sprinkling on vegetables belonged to S. Anatum (1), S. Newport (1), S. Saintpaul (6), S. Virchow (4) and S. Weltevreden (4) serovars while isolates pond water samples belonged to S. Saintpaul (9) and S. Newport (2) serovars. Except two Salmonella isolates (one each of serovar S. Anatum and S. Weltevreden), all had multiple drug resistance and could be classified into 21 resistotypes. All the Salmonella isolates were sensitive to ceftriaxone and streptomycin while resistant to sulphamethizole. The study indicated that pond water (used by farmers for washing vegetables) and water used by vegetable vendors for sprinkling on vegetables might have an important role as a source of multiple-drug-resistant zoonotic Salmonella.     

Seasonal Change in the Atmospheric Concentration of Particulate Polycyclic Aromatic Hydrocarbons in Ho Chi Minh City, Vietnam

We analyzed atmospheric particulate polycyclic aromatic hydrocarbons (PAHs) in Ho Chi Minh City, Vietnam, for 19 months. The average concentrations of total PAHs at dry and rainy seasons were 4.28 ± 2.83 and 15.71 ± 8.21 ng m⁻³, respectively. The use of motorcycles without catalytic converters, estimated to be main emission sources of PAHs, would be higher during the dry season. PAH concentrations show a negative correlation with sunshine duration (r = −0.51). Furthermore, the ratio of average PAH concentration in the dry season to that in the rainy season shows a positive correlation with photolytic half-life (r = 0.94). Thus, seasonal changes in PAH concentrations are attributable to their photolytic degradation.     

Soil Test Phosphorus as an Indicator of Nitrate–Nitrogen Leaching Risk in Tile Drainage Water

A 2 year tile drainage study of 39 fields in Nova Scotia, Canada was conducted. Weekly nitrate–nitrogen (NO₃–N) concentrations were highest in spring and fall during high flow. Fields receiving poultry or swine manure had elevated drainage NO₃–N and soil test phosphorus. Water quality guidelines for NO₃–N (10 mg L⁻¹) were exceeded on 90% of rotations (corn-grass or corn-grain) and 13% of long-term cover fields. A significant correlation between NO₃–N and soil test P (r ² = 0.42; p < 0.001) was found. The 10 mg L⁻¹ guideline was exceeded at 100% of fields with soil test phosphorus >200 mg kg⁻¹ and 60% overall.