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1.
An enhanced dual coil 2,4-dinitrophenylhydrazine (DNPH) derivatization method (dual coil/DNPH) allowed the quantitative determination of formaldehyde (HCHO) in ambient air. In this method, traceable HCHO was collected using a coil sampler connected in series and lacking a long sampling tube. It was then analyzed using liquid chromatography followed by UV detection of the DNPH derivatives. The method is based on the reaction of formaldehyde with DNPH to produce 2,4-dinitrophenylhydrazone. The detection limits (3σ) were 0.10–0.40 ppbv with a precision ranging from 0.84 to 4.09% RSD. The results of dual coil/DNPH and conventional DNPH cartridge methods were generally well correlated: HCHO (dual coil/DNPH) = 0.97 (±0.13) vs. HCHO (DNPH Cartridge) + 0.33 (±0.33), r = 0.82. The dual coil/DNPH method was used to measure gaseous HCHO in the atmosphere of Metropolitan Seoul during the summer 2000 and 2001, and in Gwangju during the fall of 2001 and 2002. The daytime mean concentration of HCHO was 4.52 (±5.69) and 3.21 (±1.27) ppbv in Metropolitan Seoul for 10–12 August 2000 and 29–31 May 2001, respectively, and 1.73 (±0.98), 3.04 (±2.25), 2.70 (±1.70), and 2.01 (±2.28) ppbv in Gwangju City during 22–27 September 2001, 17–24 October 2001, 9–13 October 2002, and 28 October to 2 November 2002, respectively. The HCHO in Seoul from 10–12 August 2000 was mainly the result of photochemical processes, while direct emissions from vehicles and long-range transport of air from China contributed during 29–31 May 2001. During 22–27 September 2001, 17–24 October 2001, and 9–13 October 2002 in Gwangju, the HCHO came primarily from photochemical processes, although some air affected by biomass burning admixed in the late afternoon. The increase in the HCHO concentration on 20 October 2001 and from 28 October to 2 November 2002 was attributed mainly to direct emissions from biomass burning in farmland near the measurement site.  相似文献   

2.
We assessed the quality and pollution status of source surface waters in Zaria, Nigeria by monitoring the nature, cause and extent of pollution in Samaru stream, Kubanni River and Kubanni dam over a period of 10 months, between March and December 2002. A total of 228 water samples was collected from 12 sites and analysed for a total of ten physicochemical and one bacteriological quality indicators, using standard methods. Aesthetic water quality impairment parameters were also observed. The mean values of most water quality parameters were significantly higher (P < 0.05) in both the stream and river than in the dam. There was no significant correlation between faecal coliform counts (FCC) and water temperature (in the range 15–33°C); pH (5.77–7.32); and turbidity (1.4–567 NTU). The high FCC ranged from 2.0 × 101 to 1.6 × 106 MPN/100 ml and exceeded the WHO standards for drinking water and water used for fresh-produce irrigation, and correlated positively (P < 0.05) with conductivity (in the range 68–1,029 μS/cm); TDS (10.0–70.0 mg/l); TSS (10.0–70.0 mg/l); Cl (7.5–181 mg/l); PO4P (0.01–0.41 mg/l); NO3N (0.6–3.8 mg/l) and BOD5 (0.1–14.9 mg/l). The main pollution sources were municipal wastewater, stormwater runoffs, the ABU sewage treatment plant, abattoir effluents and irrigation farms treated with chemical fertilisers. We conclude that these water bodies are potentially hazardous to public health and that proper sewage treatment and river quality monitoring are needed to warn against hazards to public health.  相似文献   

3.
This study aimed to optimise the methodology for the use of Corophium insidiosum in a bioassay. Taking into account that it would be suitable to execute the bioassay with organisms having a good sensitivity during the year and low mortality in control sediment, the influence of different temperatures (10–15–20 and 25°C) has been examined. C. insidiosum was collected during August, November 2005 and January 2006, in Mar Piccolo basin (Ionian sea). The results obtained show that this species mortality in the negative control sediment, ranged from 2.6 ± 0.6% at 10°C in August to 17 ± 2.2% at 20°C in November, at different temperatures tested. At 20°C there were significant differences in mortality among different months examined. Indeed no relationship among months was found at 15°C. Significant differences between August and November at 25°C, between November and January were not found at 10°C. The 96-h LC50 values found for cadmium at all temperature experimental conditions ranged from 2.11 mg/l (1.57–2.82) to 0.70 mg/l (0.54–0.93). The highest values were found at 10°C in November and January. The results showed that the optimal temperature for the bioassay seems to be between 15°C and 20°C. Even if, at 20°C the mortality differs significantly among organisms sampled.  相似文献   

4.
A serious forest decline of Betula ermanii Cham. has been observed at Mt. Mae-Shirane, Oku-Nikko, Japan, where high ozone (O3) concentration and severe water deficiency have been measured. In order to consider the possibility whether O3 and/or water stresses could have been the causes of the forest decline of B. ermanii, plant growth experiments were conducted in environment-controlled growth cabinets. Two-year-old seedlings of B. ermanii were exposed to either charcoal-filtered air (O3 concentration <5 ppb) or 50 ppb O3 (daily average, ranging between 20–100 ppb) for 123 days at 20.0/12.5 ± 1.0°C (day/night) and 70/80 ± 7% relative humidity (day/night). Simultaneously, seedlings were treated with three watering regime: 1.0 < pF < 1.8 (no water stress), 1.8 < pF < 2.5 (mild water stress) or 2.5 < pF < 3.0 (severe water stress). O3 exposure significantly reduced the dry weights of leaf, root and the whole plant, while water stress significantly reduced the dry weights of each organ and the whole plant. Significant reductions of net photosynthesis, transpiration and stomatal conductance were also observed under O3 and/or water deficiency treatments, while contents of RuBP carboxylase/oxygenase (Rubisco), chlorophyll a+b and some essential nutrient elements (N, P, K, Mg and Ca) were not markedly changed. It was suggested that the decrease in net photosynthetic rate induced mainly by stomatal closure was the major cause of the growth reduction under O3 and/or water stresses. No significant interactions between O3 and water stresses were observed in terms of the depression of dry matter production, which suggested that simultaneous stress treatments of O3 exposure and water deficiency could affect the tree growth of B. ermanii additively.  相似文献   

5.
Chemistry of groundwater in Gulbarga district, Karnataka, India   总被引:1,自引:0,他引:1  
Groundwater quality of Gulbarga District is extensively monitored for two years of study period from October 1999 to September 2001. Twenty-five different sampling stations were selected for the study purpose in the city and five selected villages in the district. Gulbarga districts lies in the northern plains of Karnataka State, covers an area of 16,244 km2 and lies between 16°-11′ and 17°-19′N latitude and 76°-54′E longitude The study revealed that the water sources in the area are heavily polluted. The major water quality parameters exceeding the permissible limits during all the seasons are total hardness, calcium hardness, magnesium hardness, alkalinity and MPN (Bacterial count) and other parameters have shown distinctive variation in different stations and season. Most of these parameters are correlated with one another. Statistical analysis of the data is presented.  相似文献   

6.
Atmospheric surface aerosol radiative forcing (SARF) ΔF, forcing efficiency ΔFe and fractional forcing efficiency ΔFFe evaluated from cloud-screened narrowband spectral and thermal-offset-corrected radiometric observations during the Asia dust outbreak episodes in Gwangju, Republic of Korea are reported in this study. Columnar aerosol optical properties (aerosol optical depth (AOD), τ , Angstrom exponent α, mass concentration of fine and coarse mode particles) were also reported for the station between January 2000 and May 2001 consisting of 211cloud-free days. Results indicate that majority of the AOD were within the range 0.25–0.45 while some high aerosol events in which AODs ≥ 0.6 were observed during the severe dust episodes. For example, AOD increases from annual average value of 0.34 ± 0.13 at 501 nm to values >0.60 during the major dust events of March 27–30 and April 7–9, 2000, respectively. The α 501–870 nm which is often used as a qualitative indicator of aerosol particle size had values ranging from 0.01 to 1.77. The diurnal forcing efficiency ΔDFe at Gwangju was estimated to be −81.10 ± 5.14 W m −2/τ 501 nm and −47.09 ± 2.20 W m −2/τ 501 nm for the total solar broadband and visible band pass, respectively while the fractional diurnal forcing efficiency ΔFDFe were −15.8 ± 0.64%/τ 501 nm and −22.87 ± 1.13%/τ 501 nm for the same band passes. Analyses of the 5-day air-mass back trajectories were further developed for Gwangju in order to classify the air-mass and types of aerosol reaching the site during the Asia dust episodes.  相似文献   

7.
This work presents the vertical distributions of ozone and meteorological parameters observed with tethered ozonesondes and meteorological radiosondes in the lower atmosphere during an ozone episode on March 25–27, 2003, in Kaohsiung City in southern Taiwan. Kaohsiung is a coastal industrial city with inland mountain ranges to the east. Extremely complicated ozone structures were identified that spanned day and night during the experimental period. During afternoons, the lower atmosphere was divided into two stratified air layers with substantially different ozone concentrations. On the episode day (March 26), average ozone concentration in the near-ground layer was 85 ppb and the aloft layer was 140 ppb. A very high ozone peak of 199 ppb measured aloft likely resulted from an elevated large point source. Several no-ozone air layers, distributed throughout 400–750 m, were observed to transport onshore during the nigh. As well, elevated ozone layers peaking at 60–90 ppb and 90–160 ppb were detected below and above the no-ozone air layers, respectively. These complicated ozone structures were likely formed through titration of plumes from large point sources and the circulations of sea breezes or combined sea-breeze/mountain flows in the study area.  相似文献   

8.
This study presents concentration levels of pollutants (lead, and cadmium) in tissues (livers, kidneys, muscles, and bones) of shorebirds (Kentish Plovers (n = 5), Mongolian Plovers (n = 2), Dunlins (n = 6), Great Knots (n = 10), Terek Sandpipers (n = 10)) from Yeongjong Island, Korea in the East Asian–Australian migration flyways during the autumn migration in 1994–1995. Lead concentrations in livers, in kidneys, in muscles, and in bones were significantly different among shorebird species. Lead concentrations in livers of Kentish Plovers (4.76 ± 2.72 μg/wet g), Mongolian Plovers (2.05 μg/wet g), Dunlins (3.77 ± 1.07 μg/wet g), and Great Knots (4.27 ± 3.19 μg/wet g) were less than the toxic level, and lead concentrations in livers of Terek Sandpipers (1.20 ± 0.94 μg/wet g) were at the background level. Cadmium concentrations in livers, in kidneys, in muscles, and in bones did not vary among shorebirds, and concentrations of cadmium in livers and in kidneys were at background level (respectively, approximate 1 μg/wet g, approximate 2.67 μg/wet g) in all shorebird species. We suggest that interspecific differences of lead and cadmium concentrations were attributed to differences in exposure time and differences of diet, microhabitats in wintering ground. In livers and kidney of shorebirds from Yeongjong Island, lead and cadmium concentrations were higher than other locations previously reported.  相似文献   

9.
This is the first study related to the effects of cadmium (Cd) on the development and hatching of eggs of Loligo vulgaris. The eggs were exposed to concentrations varying from 10 to 100,000 μg Cd/l for up to 1 month. During the study period natural sea water salinity (37 PSU), ambient temperature (ranging 16.5–21.5°C) and light conditions of 12-h light: 12-h dark for 744-h were used prior to the hatching. For 96-h, mortality rate of 100% of the eggs was found at cadmium concentration of 100,000 μg Cd/l, and the same mortality rate of the eggs were found at 1,000 and 10,000 μg Cd/l for 744-h and 696-h, respectively. Hatching took place between hours 456 and 576 in the control group and between hours 480 and 576 in 10 and 100 μg Cd/l groups. Total hatching rates were calculated to be 98.2 ± 1.6% for control group, 99.4 ± 0.6% for 10 μg Cd/l group and 98.6 ± 1.2% for 100 μg Cd/l group. Hatching successes were estimated as 69.5 ± 13.8% for control group, 84.5 ± 8.2% for 10 μg Cd/l group and 76.9 ± 5.9% for 100 μg Cd/l group. In the 100,000 μg Cd/l treatment, the egg degeneration began from animal pole of the eggs in 16 h, and 50% and 100% of them died in the initial stage at 72-h and 96-h, respectively. In the 10,000 μg Cd/l group, the eggs which reached at stage 19 (IX) were deformed and 50% and 100% of them died at 312-h and 696-h, respectively. In 1,000 μg Cd/l group, however, the eggs developed abnormally from stage 21 (X–XI) and reached at stage 29 (XIX), and 50% and 100% of them died in 624-h and in 744-h, respectively. There were significant differences in survival rates of the eggs among the concentrations (p < 0.05). The current study demonstrated that Cd adversely affects the development, survival and hatching of L. vulgaris eggs; however, no mortality was observed in 10 μg Cd/l and 100 μg Cd/l groups.  相似文献   

10.
In the present study, we investigated the concentrations and distribution of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in intestine, liver, and muscle samples of 11 common buzzards (Buteo buteo) from Sicily used as bioindicator for monitoring pollution in environment. All samples of common buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. Quantitative determination of OCs and PCBs in the samples examined has been carried out using HRGC-ECD and GC-MS. The results obtained show the presence of concentrations of ∑DDT and ∑PCB in almost all samples. Regarding ∑DDT (4,4-DDE, 2,4-DDD, 4,4-DDD, 2,4-DDT, and 4,4-DDT), the highest concentrations were found in intestine (0.411 ± 0.050 μg/g) followed by muscle (0.130 ± 0.017 μg/g) and liver samples (0.109 ± 0.014 μg/g). As regards the ∑PCB congeners (PCB-28, PCB-52, PCB-95, PCB-99, PCB-101, PCB-110, PCB-138, PCB-146, PCB-149, PCB-151, PCB-153, PCB-170, PCB-177, PCB-180, PCB-183, and PCB-187), the highest concentrations were found in intestine (1.686 ± 0.144 μg/g) followed by liver (1.064 ± 0.162 μg/g) and muscle samples (0.797 ± 0.078 μg/g). Our data deserve particular attention not only for their significance but especially because they were recorded in Sicily, a region with a very low risk of environmental pollution due to the shortage of industries.  相似文献   

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