Study of urban atmospheric pollution in Navarre (Northern Spain)

An ambient air quality study was undertaken in two cities (Pamplona and Alsasua) of the Province of Navarre in northern Spain from July 2001 to June 2004. The data were obtained from two urban monitoring sites. At both monitoring sites, ambient levels of ozone, NO_x, and SO₂ were measured. Simultaneously with levels of PM₁₀ measured at Alsasua (using a laser particle counter), PM₁₀ levels were also determined at Pamplona (using a beta attenuation monitor). Mean annual PM₁₀ concentrations in Pamplona and Alsasua reached 30 and 28 μg m⁻³, respectively. These concentrations are typical for urban background sites in Northern Spain. By using meteorological information and back trajectories, it was found that the number of exceedances of the daily PM₁₀ limit as well as the PM₁₀ temporal variation was highly influenced by air masses from North Africa. Although North African transport was observed on only 9% of the days, it contributed the highest observed PM₁₀ levels. Transport from the Atlantic Ocean was observed on 68% of the days; transport from Europe on 13%; low transport and local influences on 7%; and transport from the Mediterranean region on 3% of the days. The mean O₃ concentrations were 45 and 55 μg m⁻³ in Pamplona and Alsasua, respectively, which were above the values reported for the main Spanish cities. The mean NO and NO₂ levels were very similar in both sites (12 and 26 μg m⁻³, respectively). Mean SO₂ levels were 8 μg m⁻³ in Pamplona and 5 μg m⁻³ in Alsasua. Hourly levels of PM₁₀, NO and NO₂ showed similar variations with the typically two coincident maximums during traffic rush hours demonstrating a major anthropogenic origin of PM₁₀, in spite of the sporadic dust outbreaks.     

Concentrations of PM2.5-associated OC, EC, and PCDD/Fs measured during the 2003 wildfire season in Missoula, Montana

Throughout August and September, 2003, wildfires burned in close proximity to Missoula, Montana, with smoke emanating from the fires impacting the valley for much of the summer. This presented the perfect opportunity to measure the levels of polychlorinated dibenzodioxins and dibenzofurans (PCDD/F) comprising ambient forest fire smoke particles impacting the Missoula Valley. An air sampler at the Montana Department of Environmental Quality's (DEQ) compliance site in Missoula measured hourly averages of PM₁₀ throughout the fire season. Three collocated PM_2.5 cyclones collected 24-h smoke samples using quartz filters and Polyurethane Foam (PUF) sorbent cartridges. From the quartz filters, concentrations of Organic and Elemental Carbon (OC/EC) were measured, while PCDD/F were measured from one set of a filter (particle phase) and PUF (vapor phase) aggregate of samples in an attempt to also investigate the different phases of PCDD/F in forest fire smoke impaired communities.Hourly PM₁₀ concentrations peaked at 302.9 μg m⁻³ on August 15. The highest OC concentration (115.6 μg m⁻³) was measured between August 21–22, and the highest EC concentration of 10.5 μg m⁻³ was measured August 20–21. Measurable concentrations of PM_2.5 associated PCDD/Fs were not detected from a representative aggregate sample, with the exception of small amounts of 1,2,3,4,6,7,8-heptachlorodibenzodioxin and octachlorodibenzodioxin. PM_2.5 samples collected during the smoke events were composed of approximately 65% OC. However, the OC fraction of the particles collected in the smoke impaired Missoula valley was not composed of significant amounts of PCDD/F.     

Atmosphic pollutants study of particles ionic species during high wind speed (>7 m s-1) near Taiwan strait in central Taiwan from 2004 to 2005

This study monitored atmospheric pollutants during high wind speed (> 7 m s⁻¹) at two sampling sites: Taichung Harbor (TH) and Wuci traffic (WT) during March 2004 to January 2005 in central Taiwan. The correlation coefficient (R ²) between TSP, PM_2.5, PM_2.5−10 particle concentration vs. wind speed at the TH and WT sampling site during high wind speed (< 7 m s⁻¹) were also displayed in this study. In addition, the correlation coefficients between TSP, PM_2.5 and PM_2.5−10 of ionic species vs. high wind speed were also observed. The results indicated that the correlation coefficient order was TSP > PM_2.5−10 > PM_2.5 for particle at both sampling sites near Taiwan strait. In addition, the concentration of Cl⁻, NO₃ ⁻, SO₄ ²⁻, NH₄ ⁺, Mg²⁺, Ca²⁺ and Na⁺ were also analyzed in this study.     

Influence of Meteorological Parameters on Particulates and Atmospheric Pollutants at Taichung Harbor Sampling Site

Atmospheric aerosol particles and metallic concentrations, ionic species were monitored at the Experimental harbor of Taichung sampling site in this study. This work attempted to characterize metallic elements and ionic species associated with meteorological conditions variation on atmospheric particulate matter in TSP, PM_2.5, PM_2.5–10. The concentration distribution trend between TSP, PM_2.5, PM_2.5–10 particle concentration at the TH (Taichung harbor) sampling site were also displayed in this study. Besides, the meteorological conditions variation of metallic elements (Fe, Mg, Cr, Cu, Zn, Mn and Pb) and ions species (Cl⁻, NO₃ ⁻, SO₄ ²⁻, NH₄ ⁺, Mg²⁺, Ca²⁺ and Na⁺) concentrations attached with those particulate were also analyzed in this study. On non-parametric (Spearman) correlation analysis, the results indicated that the meteorological conditions have high correlation at largest particulate concentrations for TSP at TH sampling site in this study. In addition, the temperature and relative humidity of meteorological conditions that played a key role to affect particulate matter (PM) and have higher correlations then other meteorological conditions such as wind speed and atmospheric pressure. The parameter temperature and relative humidity also have high correlations with atmospheric pollutants compared with those of the other meteorological variables (wind speed, atmospheric pressure and prevalent wind direction). In addition, relative statistical equations between pollutants and meteorological variables were also characterized in this study.     

Interactions of Atmospheric Deposition with Coniferous Canopies in Estonia

Throughfall and open field bulk precipitation were measured at three coniferous sites during 1995–2002 in the framework of ICP Integrated Monitoring and at five coniferous sites during 1996–2002 in the framework of ICP Forests (Level II). The coniferous canopies acted as a sink for nitrate and ammonium and as a source for base cations: Ca²⁺, Mg²⁺ and K⁺. The estimated share of SO₄–S dry deposition from total deposition was 1.5–4 times higher for dormant period compared to growing period. During the study period average annual throughfall and bulk deposition of SO₄–S decreased significantly, 2.8 and 2.3 times, respectively. Throughfall enrichment with base cations increased in the order Mg < Na < Ca < K. Using Na as a tracer ion, average dry deposition and canopy leaching were calculated. Leaching was the dominant process for TF enrichment by potassium. Leaching of base cations occurred during growing as well as dormant period. The calculated internal flux of Ca²⁺ and Mg²⁺ varied in the range of 0.6–2.0 and 0.6–1.2 kg ha⁻¹ per year in spruce and pine stands, respectively. The internal circulation of K⁺ was significantly higher (8.9–10.9 kg ha⁻¹ per year) in spruce stands than in pine stands (2.7–4.4 kg ha⁻¹ per year).     

Spatial and Temporal Variations in Trace Metal Concentrations in the Cockle, Austrovenus Stutchburyi from Otago, New Zealand

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993–1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (μg g⁻¹ dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3–60 μg g⁻¹ for Cu, 40–118 μg g⁻¹ for Zn, 2–12 μg g⁻¹ for Mn, 5–35 μg g⁻¹ for Ni and 1–44 μg g⁻¹ for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.     

Spatial Variability and Monitoring of Pb Contamination of Farming Soils Affected by Industry

In this study, the relationship between some physico-chemical properties of soils and lead contamination in soil due to emission from industrial operations in Samsun province of Turkey was investigated. The extent of timely contamination was studied by comparing the obtained results with the results of the study conducted in the same region in 1998. An area of 225 km² (15 km × 15 km), which was divided into 1000 × 1000 m grid squares (16 lines in the east and south directions), was selected within the industrial area. The total of 256 grid points was obtained and soil samples were collected from three depths (0–5, 5–15, and 15–30 cm) of each grid center in 2004. The total Pb concentrations of soil samples were determined as 65.84–527.04 μg g⁻¹ at 0–5 cm in depth, 58.50 – 399.54 μg g⁻¹ at 5–15 cm in depth, and 44.65–330.07 μg g⁻¹ at 15–30 cm in depth. DTPA-extractable Pb concentrations of soils were found to be in the range of 1.52–9.03 μg g⁻¹, 0.54–7.09 μg g⁻¹, 0.19–6.13 μg g⁻¹ at 0–5, 5–15, and 15–30 cm depths, respectively. There were significant relationships between both total or DTPA-extractable Pb concentrations and selected physico-chemical properties of soil. According to enrichment factor (EF) values calculated from the total Pb concentrations, 11.3% of the study area (225 km²) was enriched with Pb in high level, but 77% of the area was in significant enrichment level with Pb. The average total and DTPA-extractable Pb concentrations increased as 11 and 13%, respectively in comparison with the results of 1998.     

Cyanobacterial Flora from Polluted Marine Shores

Citation of cyanobacterial cultures from the shores of south west coast of Gujarat, India and their relationship with sea water quality, influenced by extensive pollutant runoff is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of suspended solids (60–1000 mg l⁻¹) and nutrients (PO₄ ⁻P: 1.3–4 μmole l⁻¹ and NO₃ ⁻N: 12.5–17.8 μmole l⁻¹) were persistent throughout the analysis. Community structure is seen to be influenced by such persistent pollution. Twenty nine cyanobacterial species were isolated belonging to 9 genera of 4 families, with an elevated occurrence of Oscillatoria and Lyngbya species. No heterocystous cyanobacteria were isolated throughout the study.     

Evaluation of A Sampling Strategy for Estimation of Long-term Pm2.5 Exposure for Epidemiological Studies

As part of the European Community Respiratory Health Survey (ECRHS) PM_2.5 (particles collected with an upper 50% cut point of 2.5 μm aerodynamic diameter) was measured using an EPA-WINS (Environmetal Protection Agency Well Impactor Ninety-six) sampler. The monitoring schedule was restricted to 7 days per month for one year. Simultaneously, during this one year study period a collocated Harvard Impactor (HI) was run on a daily basis in Erfurt, Germany. Here we validated the reliability of annual, seasonal and monthly means estimated using the ECRHS scheme (measurements taken less than 25% of the whole study period) with the ‘true’ long-term averages, which were estimated using all available daily means.The daily PM_2.5 means, obtained by both instruments operated in parallel, were only slightly different (the mean difference between EPA-WINS and HI was 1.8 μg m⁻³ and 2.8 μg m⁻³ for the winter means). The values obtained by the two instruments were highly correlated (r = 0.95).In view of that negligible difference, no additional bias was seen with respect to the annual and the winter means estimated by the two different sampling strategies (the difference was 1.7 μg m⁻³ and 2.7 μg m⁻³, respectively). Monthly means, however, can only be considered to be a crude estimate that may substantially under- or overestimate the true monthly mean value.     

Determination of imazosulfuron persistence in rice crop and soil

Imazosulfuron is a new post-emergence sulfonylurea herbicide. It is highly active at low application rates to control annual and perennial broad-leaf weeds and sedges in rice. There is increasing concerned about the persistence of pesticide residues in soils, crop produce and subsequent contamination of groundwater. Thus persistence of imazosulfuron residues under field condition was evaluated. Imazosulfuron was applied at 30, 40, 50 and 60 a. i. g ha ⁻¹ rates, 4 days after transplanting of rice as post-emergence herbicide. Soil and plant samples treated with imazosulfuron were collected at 60, 90 and 120 days after herbicide application and analyzed for residues. Rice grains and straw samples were sampled at harvest (120 days). Residues of imazosulfuron in soil were not found after 90 and 120 DAS (days after spraying). Rice grains contained 0.006, 0.009 μg g⁻¹ residues at 50 and 60 g ha ⁻¹ application rates. 0.009 and 0.039 μg g⁻¹ residues of imazosulfuron were detected at 50 and 60 g/ha rates respectively in rice straw. Residues of imazosulfuron were not detected applied at 30 and 40 g ha⁻¹ in rice grains and straw, respectively and can be safely applied to the transplanted rice.     

Sources and distribution of trace metals in the saricay stream basin of southwestern turkey

Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as mass ratio): Co: 5–476 μg g⁻¹, Cr: 15–1308 μg g⁻¹, Cu: 7–128 μg g⁻¹, Fe: 1120–13210 μg g⁻¹, Mn: 150–2613 μg g⁻¹, Ni: 102–390 μg g⁻¹, Pb: 0.7–31.3 μg g⁻¹ and Zn: 18–304 μg g⁻¹, whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5–20.7 μg L⁻¹, Cr: 20.3–284 μg L⁻¹, Cu: 170–840 μg L⁻¹, Fe: 176–1830 μg L⁻¹, Mn: 29.3–387 μg L⁻¹, and Ni: 4.3–21.9 μg L⁻¹. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA) and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison. The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges.     

Quantifying Carbon Budgets Of Conifer Mediterranean Forest Ecosystems, Turkey

Abstact Aboveground biomass, aboveground litterfall, and leaf litter decomposition of five indigenous tree stands (pure stands ofPinus brutia,Pinus nigra,Cedrus libani,Juniperus excelsa, and a mixed stand ofAbies cilicica,P. nigra, andC. libani) were measured in an eastern Mediterranean evergreen needleleaf forest of Turkey. Measurements were converted to regional scale estimates of carbon (C) stocks and fluxes of forest ecosystems, based on general non-site-specific allometric relationships. Mean C stock of the conifer forests was estimated as 97.8± 79 Mg C ha⁻¹consisting of 83.0 ± 67 Mg C ha⁻¹in the aboveground and 14.8 ± 12 Mg C ha⁻¹in the belowground biomass. The forest stands had mean soil organic carbon (SOC) and nitrogen (SON) stocks of 172.0 ± 25.7 Mg C ha⁻¹and 9.2 ± 1.2 Mg N ha⁻¹, respectively. Mean total monthly litterfall was 376.2± 191.3 kg C ha⁻¹, ranging from 641 ± 385 kg C ha⁻¹forPinus brutiato 286 ± 82 kg C ha⁻¹forCedrus libani. Decomposition rate constants (k) for pine needles were 0.0016 forCedrus libani, 0.0009 forPinus nigra, 0.0006 for the mixed stand, and 0.0005 day⁻¹forPinus brutiaand Juniperus excelsa. Estimation of components of the C budgets revealed that the forest ecosystems were net C sinks, with a mean sequestration rate of 2.0 ± 1.1 Mg C ha⁻¹ yr⁻¹ranging from 3.2 ± 2 Mg C ha⁻¹forPinus brutiato 1.6 ± 0.6 Mg C ha⁻¹forCedrus libani. Mean net ecosystem productivity (NEP) resulted in sequestration of 98.4 ± 54.1 Gg CO₂ yr⁻¹from the atmosphere when extrapolated for the entire study area of 134.2 km²(Gg = 10⁹ g). The quantitative C data from the study revealed the significance of the conifer Mediterranean forests as C sinks     

Facile and Sensitive Spectrophotometric Determination of Carbosulfan in Formulations and Environmental Samples

Facile, selective and sensitive spectrophotometric method has been developed for the determination of carbosulfan in insecticidal formulations, fortified water, food grains, agriculture wastewater and soil samples with newly synthesized reagents. The method was based on acid and alkaline hydrolysis of the carbosulfan pesticide, and the resultant hydrolysis product of carbosulfan was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with λ _max of 464 nm or interaction with 2,6-dibromo-4-nitroaniline to produce yellow colored product with λ _max of 408 nm or coupling with 2,4,6-tribromoaniline to form red colored product has a λ _max of 471 nm. Under optimal conditions, Beer’s law range for 2,6-dibromo-4-methylaniline (DBMA) was found to be 0.2–12.0 μg ml⁻¹, 0.6–16.0 μg ml⁻¹ for 2,6-dibromo-4-nitroaniline (DBNA) and 0.4–15.0 μg ml⁻¹ for 2,4,6-tribromoaniline (TBA). The molar absorptivity of the color systems were found to be 3.112 × 10⁴ l mol⁻¹ cm⁻¹ for DBMA, 3.214 × 10⁴ l mol⁻¹ cm⁻¹ for DBNA and 3.881 × 10⁴ l mol⁻¹ cm⁻¹ for TBA. Sandell’s of the color reactions are 0.013 μg cm⁻² (DBMA), 0.012 μg cm⁻² (DBNA) and 0.011 μg cm⁻² (TBA) respectively. The effect of the non-target species on the determination of carbosulfan was studied to enhance the selectivity of the proposed methods. The formation of colored derivatives with the coupling agents is instantaneous and stable for 28, 30, and 26 h. Performance of the proposed methods were compared statistically in terms Student’s F and t-tests with the reported methods. An erratum to this article can be found at     

Applicability of high rate transpiration system for treatment of biologically treated distillery effluent

The biologically treated distillery effluent (BTDE) contains intense colour, high total dissolved solids (TDS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). These properties even after primary, secondary and tertiary treatments contain high concentrations of TDS, COD and BOD. The paper highlights the safe disposal and treatment of BTDE on land through High Rate Transpiration System (HRTS). HRTS is a zero discharge, low cost, high-tech method for improving the quality of BTDE for potential reuse. The experiments conducted at bench and pilot scale showed that HRTS having coconut husk as a bedding material could successfully treat the BTDE with a hydraulic load of 200 m³ ha⁻¹ day⁻¹ having BOD of 100 mg l⁻¹ and 500 m³ ha⁻¹ day⁻¹ having BOD of 500 mg l⁻¹ with average COD load of 0.686 and 2.88 ton ha⁻¹ day⁻¹ during the post and pre monsoon periods respectively. There was no significant increase in the organic carbon of the soil irrigated with BTDE. The concentrations of various pollutants analyzed in the leachate were within the prescribed limit for the drinking water sources. The colour removal was 99 to 100% and BOD and COD were possible to treat with optimum hydraulic loading of BTDE through HRTS planted with Dendrocalamus strictus.     

Polycyclic aromatic hydrocarbons in bulk PM2.5 and size-segregated aerosol particle samples measured in an urban environment

To analyze polycyclic aromatic hydrocarbons (PAHs) at an urban site in Seoul, South Korea, 24-hr ambient air PM_2.5 samples were collected during five intensive sampling periods between November 1998 and December 1999. To determine the PAH size distribution, 3-day size-segregated aerosol samples were also collected in December 1999. Concentrations of the 16 PAHs in the PM_2.5 particles ranged from 3.9 to 119.9 ng m⁻³ with a mean of 24.3 ng m⁻³.An exceptionally high concentration of PAHs(∼120 ng m⁻³) observed during a haze event in December 1999 was likely influenced more by diesel vehicle exhaust than by gasoline exhaust, as well as air stagnation, as evidenced by the low carbon monoxide/elemental carbon (CO/EC) ratio of 205 found in this study and results reported by previous studies. The total PAHs associated with the size-segregated particles showed unimodal distributions. Compared to the unimodal size distributions of PAHs with modal peaks at < 0.12 μm measured in highway tunnels in Los Angeles (Venkataraman and Friedlander, 1994), four- to six-ring PAHs in our study had unimodal size distributions, peaking at the larger size range of 0.28–0.53 μm, suggesting the coagulation of freshly emitted ultrafine particles during transport to the sampling site. Further, the fraction of PAHs associated with coarse particles(> 1.8 μm) increased as the molecular weight of the PAHs decreased due to volatilization of fine particles followed by condensation onto coarse particles.     

Status of insecticide contamination of soil and water in Haryana, India

Twelve samples each of soil and ground water were collected from paddy-wheat, paddy-cotton, sugarcane fields and tube wells from same or near by fields around Hisar, Haryana, India during 2002–2003 to monitor pesticide residues. Residues were estimated by GC-ECD and GC-NPD systems equipped with capillary columns for organochlorine, synthetic pyrethroid and organophosphate insecticides. In soil, HCH (0.002–0.051 μg g⁻¹), DDT (0.001–0.066 μg g⁻¹), endosulfan (0.002–0.039 μg g⁻¹) and chlordane (0.0002–0.019 μg g⁻¹) among organochlorines, cypermethrin (0.001–0.035 μg g⁻¹) and fenvalerate (0.001–0.022 μg g⁻¹) among synthetic pyrethroids and chlorpyriphos (0.002–0.172 μg g⁻¹), malathion (0.002–0.008 μg g⁻¹), quinalphos (0.001–0.010 μg g⁻¹) among organophosphates were detected. Dominant contaminants were DDT, cypermethrin and chlorpyriphos from the respective groups. In water samples, HCH, DDT, endosulfan and cypermethrin residues were observed frequently. Only chlorpyriphos among organophosphates was detected in 10 samples. On consideration of tube well water for drinking purpose, about 80% samples were found to contain residues above the regulatory limits.     

Persistence and risk assessment of spiromesifen on tomato in India: a multilocational study

Supervised field trials were conducted at four different agro-climatic locations of India to evaluate the dissipation pattern and risk assessment of spiromesifen on tomato. Spiromesifen 240 SC was sprayed on tomato at 150 and 300 g a.i.?ha^?1. Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10 and 15 days after treatment and soil at 15 days after treatment. Quantification of residues was done on gas chromatograph–mass spectrophotometer in selective ion monitoring mode in the mass range of 271–274 (m/z). The limit of quantification of the method was found to be 0.05 mg kg^?1, while the limit of determination was 0.015 mg kg^?1. Residues were found below the LOQ of 0.05 mg kg^?1 in 10 days at both the doses of application at all the locations. Spiromesifen dissipated with a half-life of 0.93–1.38 days at the recommended rate of application and 1.04–1.34 days at the double the rate of application. Residues of spiromesifen in soil were detectable level (<0.05 mg kg^?1) after 15 days of treatment. A preharvest interval (PHI) of 1 day has been recommended on tomato on the basis of data generated under All India Network Project on Pesticide Residues. Spiromesifen 240 SC has been registered for its use on tomato by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of spiromesifen on tomato has been fixed by Food Safety Standard Authority of India, Ministry of Health and Family Welfare, Government of India as 0.3 μg/g after its risk assessment.     

Estimates of soil erosion using cesium-137 tracer models

The soil erosion was studied by ¹³⁷Cs technique in Yatagan basin in Western Turkey, where there exist intensive agricultural activities. This region is subject to serious soil loss problems and yet there is not any erosion data towards soil management and control guidelines. During the soil survey studies, the soil profiles were examined carefully to select the reference points. The soil samples were collected from the slope facets in three different study areas (Kırtas, Peynirli and Kayısalan Hills). Three different models were applied for erosion rate calculations in undisturbed and cultivated sites. The profile distribution model (PDM) was used for undisturbed soils, while proportional model (PM) and simplified mass balance model (SMBM) were used for cultivated soils. The mean annual erosion rates found using PDM in undisturbed soils were 15 t ha⁻¹ year⁻¹ at the Peynirli Hill and 27 t ha⁻¹ year⁻¹ at the Kırtas Hill. With the PM and SMBM in cultivated soils at Kayışalan, the mean annual erosion rates were obtained to be 65 and 116 t ha⁻¹ year⁻¹, respectively. The results of ¹³⁷Cs technique were compared with the results of the Universal Soil Loss Equation (USLE).     

Bioconcentration and Phytotoxicity of Cd in Eichhornia crassipes

Plants of Eichhornia crassipes grown at various levels of cadmium ranging from 0.1 to 100 μg ml⁻¹ accumulated Cd in a concentration and duration dependent manner. At all levels, Cd accumulation by various plant tissues followed the order roots shoot leaves. Approximately 80% of total Cd was accumulated by plant at highest concentration (100 μg ml⁻¹) used in the experiment. Cadmium induced phytotoxicity appears at 25.0 μg ml⁻¹ resulting into reduced levels of chlorophyll, protein and in vivo nitrate reductase activity of the plant. However, a slight induction of these physiological variables was obtained at lowest Cd (0.1 μg ml⁻¹) concentration. In contrast, carotenoid content increased at highest Cd concentration i.e., 100 μg ml⁻¹. Similar effects at low and high levels of Cd was obtained with respect to mitotic index and micronuclei in root meristem of the plant. It could be inferred that Cd toxicity in plant is differential depending upon the low and high concentration of Cd in the medium.     

Dissipation of Endosulfan and Dichlorvos Residues In/On Cauliflower Curds

Dissipation behaviour of endosulfan and dichlorvos in/on cauliflower, variety Snowball-16, was studied during rabi season (Sep.–March) 2003–2004. Endosulfan and dichlorvos were sprayed @ 350 and 110g a.i. with 115 g a.i., respectively, 80 days after transplanting. Samples were taken at the interval of 0 (1h after spray), 3, 5, 7, and 10 days after spray (DAS) in triplicate and residues were estimated on GC-ECD system equipped with capillary column. The initial deposits of 3.452 and 0.295μgg⁻¹ of endosulfan and dichlorvos dissipated to 0.084 (97.56%) and 0.009 (96.95%), respectively after 10 DAS. Residues of endosulfan reached below maximum residue limit of 2μgg⁻¹ one day after spray and of dichlorvos were below MRL value of 0.5μgg⁻¹ even on 0 day. Dissipation pattern followed first order kinetics for both the insecticides with half life periods of 1.81 and 2.08 days for endosulfan and dichlorvos, respectively.