Interaction of tobacco etch or tobacco vein mottling virus and ozone on biomass changes in burley tobacco

Burley tobacco is susceptible to several different types of virus diseases that suppress plant growth and development. Two viruses, tobacco etch virus (TEV) and tobacco vein mottling virus (TVMV), are particularly damaging to burley. Burley tobacco cultivars resistant to these two viruses are currently being developed. Some of these cultivars also show differential sensitivity to ozone (O3). Recent field observations have suggested that burley tobacco infected with TEV and TVMV was more sensitive to O3 than non-virus-infected tobacco. Experiments were designed to identify interactions between O3 and each of the two virus diseases. Three cultivars, Burley 21, Burley 49, and Greeneville 131, which were differentially sensitive to O3 and both virus diseases, were grown in a charcoal-filtered greenhouse environment. Tobacco plants of each cultivar were inoculated with TEV or TVMV, and virus infected and virus-free plants were exposed to 0.0, 0.05, 0.2, and 0.4 ppm O3 (1 ppm of O3 is equivalent to 1960 microg m(-3)), 3h day(-1), 5 days week(-1) for 3 weeks in continuous-stirred tank reactor exposure chambers in the greenhouse. Exposures were begun after systemic virus symptoms were expressed in inoculated plants. The suppression of lead and stem dry weight by increasing O3 concentrations was less in TEV-infected burley cultivars than in noninfected burley cultivars. Tobacco vein mottling virus infection enhanced biomass suppression by O3 on Burley 21 and on Greeneville 131, but not on Burley 49. Thus, the interactions with O3 were dependent on specific virus-cultivar combinations.     

Real-time measurement of outdoor tobacco smoke particles

The current lack of empirical data on outdoor tobacco smoke (OTS) levels impedes OTS exposure and risk assessments. We sought to measure peak and time-averaged OTS concentrations in common outdoor settings near smokers and to explore the determinants of time-varying OTS levels, including the effects of source proximity and wind. Using five types of real-time airborne particle monitoring devices, we obtained more than 8000 min worth of continuous monitoring data, during which there were measurable OTS levels. Measurement intervals ranged from 2 sec to 1 min for the different instruments. We monitored OTS levels during 15 on-site visits to 10 outdoor public places where active cigar and cigarette smokers were present, including parks, sidewalk cafés, and restaurant and pub patios. For three of the visits and during 4 additional days of monitoring outdoors and indoors at a private residence, we controlled smoking activity at precise distances from monitored positions. The overall average OTS respirable particle concentration for the surveys of public places during smoking was approximately 30 microg m(-3). OTS exhibited sharp spikes in particle mass concentration during smoking that sometimes exceeded 1000 microg m(-3) at distances within 0.5 m of the source. Some average concentrations over the duration of a cigarette and within 0.5 m exceeded 200 microg m(-3), with some average downwind levels exceeding 500 microg m(-3). OTS levels in a constant upwind direction from an active cigarette source were nearly zero. OTS levels also approached zero at distances greater than approximately 2 m from a single cigarette. During periods of active smoking, peak and average OTS levels near smokers rivaled indoor tobacco smoke concentrations. However, OTS levels dropped almost instantly after smoking activity ceased. Based on our results, it is possible for OTS to present a nuisance or hazard under certain conditions of wind and smoker proximity.     

Biomethanation of tobacco waste

Tobacco is an important cash crop produced in considerable quantities in India. During cigarette manufacturing large quantities of tobacco waste are produced annually and its disposal is a serious ecological problem. In the present study a process for the biodegradation of tobacco waste, under methanogenic conditions, was developed so that environmental pollution can be reduced while producing biogas as a useful energy source. The methanogenic bacterial consortium developed for the anaerobic degradation of tobacco waste without any chemical pretreatment in a single stage digester at 15 days HRT (hydraulic retention time) has been successfully scaled-up to install a 10 m(3) biogas plant. The gas yields (1 kg(-1 TS fed) day(-1)) varied from 169 to 282 depending on the ambient temperatures. The methane content in the biogas produced was 60%. The pH and VFA content of the digested slurry were 6.8 +/- 0.1 and 599 mg litre(-1), respectively. Nicotine, COD and BOD reductions were 75, 60 and 80%, respectively.     

Screening of antibiotic residues in fresh milk of Kathmandu Valley,Nepal

The prevalence of two groups of antibiotics; namely penicillin and sulfonamides was studied in fresh milk available in Kathmandu Valley of Nepal. The milk samples (n = 140) were collected from three different sources; individual farmers, cottage dairies and organized dairies of Kathmandu valley. Qualitative and semi-quantitative analysis with rapid screening kits revealed that 23% samples were positive for antibiotic residues in the fresh milk for penicillin and sulfonamide groups (1–256 µg/kg). High performance liquid chromatography (HPLC) analyses detected 81% samples positive for amoxicillin (68–802 µg/kg), 41% for sulfadimethoxine (31–69 µg/kg), 27% for penicillin G (13–353 µg/kg), and 12% for ampicillin (0.5–92 µg/kg). Due to the precision and accuracy of liquid chromatography method, it detected more positive samples and consequently presented higher prevalence than the rapid screening kits. The antibiotic residues were found above the maximum residue limits that presented serious threat to consumer health and raised a serious concern regarding the implementation and monitoring of international regulations in developing countries.     

Bioavailability to grains of rice of aged and fresh DDD and DDE in soils

DDT had been widely used around the world before 1980s and is still under production and use for non-agricultural purposes in China. Because of their special physicochemical properties, p,p'-DDT and its main metabolites, p,p'-DDD and p,p'-DDE, accumulated and persisted in the environment, presenting potential menace on biota. A green-house study was conducted to determine the bioavailability of p,p'-DDD and p,p'-DDE to grains of rice and the influences of traditional Chinese farming practices on their bioaccumulation. Paddy rice and dry rice were grown in submerged paddy soils and non-submerged upland soils, respectively. Two types of soil, Hydragric Anthrosols (An) and Hydragric Acrisols (Ac), were employed. Bioaccumulation factors (BAFs) of DDE ranged from 0.67 for rice grown in non-submerged An to 0.84 in submerged An in the control group, whilst BAFs were all below 0.04 in experimental groups. BAFs of DDD varied from 1.39 for submerged An to 2.26 for submerged Ac in original soils. In contrast, BAFs were between 0.05 for non-submerged Ac and 0.08 for submerged An in DDD-contaminated soils. Flooding seemed to have two contradictory effects on the DDE/DDD accumulation by rice: on one hand, it made the pollutants more mobile and bioavailable; while on the other hand, it enhanced the degradation and binding of POPs. Adding rice straw to the soils protected DDE from being taken up yet promoted DDD accumulation by rice. Furthermore, the distinct inorganic component of the soils might also play an important role in the environmental activities of POPs.     

Leaching of heavy metals and alkylphenolic compounds from fresh and dried sewage sludge

Reusing sewage sludge as a soil fertiliser has become a common alternative to disposal. Although this practice has a few benefits, it may contribute to the medium- and long-term contamination of the trophic chain because sewage sludge may contain heavy metals and organic contaminants. As the leaching of contaminants may depend on the sludge pre-treatment, the leaching of heavy metals (Cu, Ni, Pb, Zn and Cr) and alkylphenolic compounds (APCs) (octylphenol (OP), nonylphenol (NP), nonylphenol-mono-ethoxylate (NP₁EO)) was investigated in five fresh and 40 °C dried sewage sludge samples from north-eastern Spain. FT-IR analyses and full-scan GC-MS chromatograms showed that sludge drying changed the nature of organic compounds leading to changes in their solubility. Moreover, sludge drying led to a higher relative contribution of dissolved organic carbon than the particulate organic carbon in the leachates. Leaching of Pb, Zn and Cr was below 5 % in both fresh and dried sludge samples, whereas Cu and Ni leached at rates up to 12 and 43 %, respectively, in some of the dried sludge samples. The leaching yields of OP, NP and NP₁EO ranged from 1.3 to 35 % for fresh samples, but they decreased from 0.8 to 3.4 % in dried samples. The decrease in the leachability of APCs observed in dried sludge samples might be attributed to the fact that these compounds are associated with particulate organic matter, with significantly lower concentration or even absent in dried sludge than in fresh sludge samples. Therefore, it is recommended to dry the sludge before its disposal.     

Biological responses to the chemical recovery of acidified fresh waters in the UK

We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving water chemistry, "recovery" in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic interactions are influencing the rate of recovery of certain groups of organisms at particular sites.     

Dispersibility of crude oil in fresh water

The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever considered for use in fresh water environments. Previous studies on the chemical dispersion of crude oil in fresh water neither identified the dispersants that were investigated nor described the chemistry of the surfactants used. This information is necessary for developing a more fundamental understanding of chemical dispersion of crude oil at low salinity. Therefore, we evaluated the relationship between surfactant chemistry and dispersion effectiveness. We found that dispersants can be designed to drive an oil slick into the freshwater column with the same efficiency as in salt water as long as the hydrophilic-lipophilic balance is optimum.     

Determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in fresh water fish

Validated sample preparation procedures and high resolution gas chromatography-high resolution mass spectrometry techniques were utilized for the quantitative measurement of 4 to 695 pg/g (ppt) levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD) in the edible portions of fish from the state of Michigan. The methodology and the analytical results are presented.     

Collection and analysis of Nicotine as a marker for environmental tobacco smoke

Nicotine is a potential marker for environmental tobacco smoke (ETS) because it is unique to tobacco smoke and is a major constituent of the smoke. An air sampling method is presented which efficiently collects both particulate and vapor phase nicotine. Two filters are assembled in tandem in a personal sampling cassette. The first filter collects total or size fractional particules and the second is treated with sodium bisulfate to collect vapor phase nicotine and nicotine which has volatilized from the paniculate material collected on the first filler. The nicotine is then desorbed from the filters and analyzed by gas chromatography with nitrogen sensitive detection. The sampling method was evaluated in an environmental chamber under controlled conditions of temperature, humidity, ventilation and smoking rate. It was then employed in a field study of particulate exposures of railroad office workers and railroad mechanics to determine the portion of the particulate exposure attributable to environmental tobacco smoke. The method was found to be efficient and sensitive for the determination of nicotine levels in air.     

Light and clomazone effects on tobacco (Nicotiana tabacum) callus and leaf discs

The effects of clomazone on the growth of tobacco (Nicotiana tabacum L. 'NC2326') callus and leaf discs were studied under four light regimes. Callus cultures and leaf discs were grown on Murashige and Skoog medium supplemented with IAA and kinetin. Light regimes were: dark grown callus kept in the dark and also transferred to the light; light grown callus kept in the light and also transferred to the dark. Two-month-old callus (cultured for 2 months from initiation) grew more rapidly than twelve-month-old callus (cultured for 12 months from initiation) under all conditions tested. Callus transferred from light to dark, or from dark to light, increased in fresh weight slower than did the callus maintained totally in light or dark. Clomazone (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) at 140 mg l(-1) or more was lethal to both callus and leaf discs whereas 10 mg l(-1) was stimulatory to growth. Callus tissue responded to clomazone differently depending on the light regime under which it was grown. While clomazone may be affecting the isoprenoid pathway in the callus and leaf disks resulting in growth inhibition, it is possible that other target sites are also being affected and contribute to the reduced growth.     

烟草工业废弃物中提取氨基酸

以生产烟碱及茄尼醇后的烟叶废渣为原料,采用酸水解及活性炭脱色处理提取氨基酸,研究了酸水解中HCl用量、水解时间以及活性炭脱色处理中活性炭处理方式、pH、活性炭用量、脱色温度和脱色时间等因素对氨基酸收率和脱色率的影响。结果表明,最佳水解条件:以6 mol/L HCl溶液为水解液,在120℃、料液比1∶18条件下,水解12 h,所得水解液经以下工艺脱色处理:0.25%KOH处理活性炭、pH=10、活性炭用量为2.5%、脱色温度80℃、脱色40 min,所得产物氨基酸收率86.65%,脱色率达84.31%。     

Dissipation of phosalone and diazinon in fresh and dried alfalfa

The objectives of this study were to determine the persistence of phosalone (S-6-chloro-2,3-dihydro-2-oxobenzoxazol-3-ylmethyl O, O-diethyl phosphorodithioate) and diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) residues in fresh and baled alfalfa under field conditions. Plots of alfalfa were sprayed with each insecticide. Fresh alfalfa was sampled up to 20 days after treatment, and dried alfalfa was sampled up to 25 weeks after baling. Samples were analyzed for residues using high performance liquid chromatography (HPLC) equipped with a UV detector. The half-lives of diazinon and phosalone in fresh alfalfa were 1.8 and 3.3 days, respectively. In baled alfalfa the half-life of diazinon and phosalone were 2.8 and 16.7 weeks, respectively. No diazinon residues were detected in baled alfalfa, sampled after week 9, although the concentration of phosalone found at week 25 was 5.51 mg/kg.     

Chemical composition of fresh snowfalls at Palmer Station,Antarctica

A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64°46′S, 64°05′W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium, sulfate, magnesium, calcium, potassium, fluoride, ammonium, and nitrate, excluding hydrogen and hydroxide. The pH of these samples ranged between 4.0–6.2. The relatively low nitrate and relatively high sulfate concentrations found in our samples are consistent with the results of other studies for this region of Antarctica. The ions and pH do not appear to favor a particular wind direction during this period. The total deposition of sulfate and flouride via snowfall between 10 January and 10 February is conservatively estimated to be 4.78 and 1.3 kg km^-2, respectively.     

Dissipation of fenoxycarb and pyriproxyfen in fresh and canned peach

The objective of this work was to determine the dissipation of fenoxycarb and pyriproxyfen in fresh and canned peaches in order to know the levels of residues that can reach consumers in real circumstances. Two field dissipation studies were carried out, one of them at the pre-harvest interval (PHI) with good agricultural practice (GAP) and the other one in a situation of critical agricultural practice (CAP). Two canning dissipation studies were carried out for samples from both agricultural situations in an industrial pilot plant and the dissipation was determined in each relevant step. An analytical methodology was used including acetone-dichloromethane extraction, purification and analysis by liquid chromatography and diode array detection (LC-DAD) with a limit of quantification (LOQ) of 0.05 mg/kg. It was validated under SANCO/10232/2006 Guidelines. These pesticides complied with the official maximum residue limits (MRLs) in peaches at the PHI with good agricultural practices. In hypothetical situation of a second application at the PHI, fenoxycarb and pyriproxyfen residues were above the MRLs in peaches. The canning study reduced the residues to no detectable levels in the cans for consumers.