Effects of glyphosate spray-drift on plant flowering.

Recent studies have shown that sub-lethal doses of herbicides may affect plant flowering, however, no study has established a direct relationship between the concentrations of deposited herbicide and plant flowering. Here the aim was to investigate the relationship between herbicide spray drift deposited on non-target plants and plant flowering in a realistic agro-ecosystem setting. The concentrations of the herbicide glyphosate deposited on plants were estimated by measuring the concentration of a dye tracer applied together with the herbicide. The estimated maximal and average deposition of glyphosate within the experimental area corresponded to 30 g glyphosate/ha (2.08% of the label rate of 1440 g a.i./ha) and 2.4 g glyphosate/ha (0.15% label rate), respectively, and the concentrations decreased rapidly with increasing distance from the spraying track. However, there were not a unique relation between distance and deposition, which indicate that heterogeneities of turbulence, wind speed and/or direction can strongly influence the deposition from 1 min to another during spraying. The effects of glyphosate on cumulative flower numbers and flowering time were modelled using Gompertz growth models on four non-target species. Glyphosate had a significantly negative effect on the cumulative number of flowers on Trifolium pratense and Lotus corniculatus, whereas there were no significant effects on Trifolium repens, and a positive, but non-significant, effect on number of flowers on Cichorium intybus. Glyphosate did not affect the flowering time of any of the four species significantly. Lack of floral resources is known to be of major importance for pollinator declines. The implications of the presented results for pesticide risk assessment are discussed.

Low personal exposure to benzene and 1,3-butadiene in the Swedish petroleum refinery industry.

PURPOSE: Petroleum refinery workers are exposed to the carcinogens benzene and 1,3-butadiene. Declining exposures have been reported internationally but information on current exposure in the Swedish refinery industry is limited. The aim was to examine refinery workers' personal exposure to benzene and 1,3-butadiene and increase awareness of exposure conditions by collaboration with involved refineries. METHODS: Altogether 505 repeated personal exposure measurements were performed among workers at two refineries. Full-shift measurements were conducted in different exposure groups using Perkin Elmer diffusive samplers filled with Carbopack X. Mean levels were calculated using mixed-effects models. A large fraction of measurements below the limit of detection (LOD) required imputation of computer-generated data. RESULTS: Mean benzene exposure among process technicians was 15.3 µg/m3 (95% CI 10.4-22.5 µg/m3) and 13.7 µg/m3 (95% CI 8.3-22.7 µg/m3) for Refinery 1 and 2, respectively. Process technicians working outdoors had higher exposure than maintenance workers (20.7 versus 5.9 µg/m3, p < 0.01). Working in the harbour and tank park (Refinery 1), compared with the process area, was associated with higher exposure. The 1,3-butadiene exposure was low, 5.4 and 1.8 µg/m3, respectively. The total variation was generally attributed to within-worker variability. CONCLUSIONS: Low benzene and 1,3-butadiene levels were found among refinery workers. Mean benzene exposure was about 1% of the Swedish occupational limit (1500 µg/m3) and for 1,3-butadiene, exposure was even lower. A large fraction of values below the LOD can be managed by carefully modelled, computer-generated data.

Personal exposure to benzene and 1,3-butadiene during petroleum refinery turnarounds and work in the oil harbour.

PURPOSE: Petroleum refinery workers' exposure to the carcinogens benzene and 1,3-butadiene has decreased during normal operations. However, certain occupational groups or events at the refineries still involve a risk of higher exposures. The aim of this study was to examine the personal exposure to benzene and 1,3-butadiene at refinery turnarounds and during work in the oil harbour. METHODS: Personal exposure measurements of benzene and 1,3-butadiene were taken during work shifts, with a priori assumed higher benzene exposure, using PerkinElmer diffusive samplers filled with Carbopack X. Mean exposure levels were calculated, and repeated exposure measurements, when available, were assessed using mixed effect models. Group and individual compliance with the Swedish occupational exposure limit (OEL) was tested for the different exposure groups. RESULTS: Mean benzene exposure levels for refinery workers during the three measured turnarounds were 150, 610 and 960 µg/m3, and mean exposures for oil harbour workers and sewage tanker drivers were 310 and 360 µg/m3, respectively. Higher exposures were associated with handling benzene-rich products. Most occupational groups did not comply with the Swedish OEL for benzene nor did the individuals within the groups. The exposure to 1,3-butadiene was very low, between <1 and 3 % of the Swedish OEL. CONCLUSIONS: Work within the petroleum refinery industry, with potential exposure to open product streams containing higher fractions of benzene, pose a risk of personal benzene exposures exceeding the OEL. Refinery workers performing these work tasks frequently, such as contractors, sewage tanker drivers and oil harbour workers, need to be identified and protected.

Herbicide impact on non-target plant reproduction: what are the toxicological and ecological implications?

Declining plant diversity and abundance have been widely reported in agro-ecosystems of North America and Europe. Intensive use of herbicides within cropfields and the associated drift in adjacent habitats are partly responsible for this change. The objectives of this work were to quantify the phenological stages of non-target plants in in-situ field situations during herbicide spray and to compare plant susceptibility at different phenological stages. Results demonstrated that a large number of non-target plants had reached reproductive stages during herbicide spray events in woodlots and hedgerows, both in Canada and Denmark where vegetation varies considerably. In addition, delays in flowering and reduced seed production occurred widely on plants sprayed at the seedling stage or at later reproductive periods, with plants sprayed at reproductive stages often exhibiting more sensitivity than those sprayed as seedlings. Ecological risk assessments need to include reproductive endpoints.

PET imaging of the in vivo brain acetylcholinesterase activity and nicotine binding in galantamine-treated patients with AD.

The effect of galantamine treatment on cortical acetylcholinesterase (AChE) activity and nicotinic receptor binding was investigated by positron emission tomography (PET) in 18 patients with mild Alzheimer's disease (AD) in relation to galantamine concentration and the patients' cognitive performances. The first 3 months of the study was of a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24mg/day) and 6 patients the placebo, and this was followed by 9 months' galantamine treatment in all patients. The patients underwent PET examinations to measure cortical AChE activity ((11)C-PMP) and (11)C-nicotine binding. Neuropsychological tests were performed throughout the study. Inhibition (30-40%) of cortical AChE activity was observed after 3 weeks to 12 months of galantamine treatment. No significant change in mean cortical (11)C-nicotine binding was observed during the study. (11)C-Nicotine binding, however, positively correlated with plasma galantamine concentration. Both the changes of AChE activity and (11)C-nicotine binding correlated positively with the results of a cognitive test of attention. In conclusion, galantamine caused sustained AChE inhibition for up to 12 months. At the individual level, the in vivo cortical AChE inhibition and (11)C-nicotine binding were associated with changes in the attention domain of cognition rather than episodic memory.

Sustained cholinesterase inhibition in AD patients receiving rivastigmine for 12 months.

OBJECTIVE: To study the long-term dual inhibitory effects of rivastigmine on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in patients with AD. METHODS: Eleven patients with mild AD received rivastigmine for 12 months. Cholinesterase (ChE) activities in the CSF and plasma were assessed colorimetrically. Immunoblot analysis was used to evaluate AChE isoforms. Neuropsychiatric tests were performed throughout the study. RESULTS: At 12 months, the mean dose of rivastigmine was 8.6 mg/d and specific activities of ChE in the CSF were lower than baseline values (by 36% for AChE and 45% for BuChE), correlating with parallel reductions in the plasma (27% for AChE and 33% for BuChE). The reduction of specific activities in the CSF, but not in the plasma, appeared to be dependent on the dose and duration of treatment. Scores of some of the neuropsychological tests associated with memory and attention were correlated with both plasma and CSF AChE and BuChE inhibition for up to 6 months. Immunoblot analysis revealed up-regulation of the "read-through" AChE isoform (AChE-R), whereas levels of the synaptic isoform were unchanged. CONCLUSIONS: Rivastigmine causes persistent inhibition of AChE and BuChE in CSF as well as plasma. The persistent CSF inhibition contrasts with earlier findings after long-term treatment by the reversible ChE inhibitor tacrine, which demonstrated increased AChE activity in the CSF but not in the blood. Rivastigmine's effects on the preferential up-regulation of the AChE-R isoform may have a favorable effect on disease stabilization.

Concentration of organochlorine pesticides in wine corks.

Wine corks were extracted and analyzed for 23 organochlorine pesticides, including alpha-, beta-, and gamma-hexachlorocyclohexanes (HCH), hexachlorobenzene, DDT, DDE and DDD, chlordane, endosulfan, dieldrin, aldrin, and endrin. This was done to investigate the occurrence, concentrations, composition profiles, and possible sources of organochlorine contamination. All groups of compounds were detected in every sample investigated, with the exception of aldrin and endrin. The total concentrations of organochlorine compounds in all samples ranged from 75-120 ng/g lipid, and for most compounds, the concentrations of organochlorines in cork were consistent with published data for other plant tissues. Differences in the relative abundances of the various classes of organochlorine pesticides were substantial and were probably due to differences in the pesticide usage practices of the various regions in which the cork producing trees were grown.

Dietary uptake and elimination of selected polychlorinated biphenyl congeners and hexachlorobenzene in earthworms.

Earthworms (Eisenia foetida) were given food contaminated with hexachlorobenzene (HxCBz) and 20 tetra- to heptachlorinated biphenyls (PCBs). The PCBs were selected to cover a wide range of physicochemical properties. The uptake efficiencies, uptake rate constants, and elimination rate constants in worms varied between the 20 PCBs. The uptake efficiencies were between 10 and 68%. The PCBs that were eliminated fastest contained few chlorine atoms, had more polar characteristics, and were sterically hindered. Slowest was the elimination for less polar PCBs with six or seven chlorine atoms such as the non-ortho-substituted PCB 169. Elimination half-lives varied between 6 and 25 d. The biomagnification factors (BMFs) for the PCBs and HxCBz averaged 0.1 based on lipids and 0.04 based on wet (worms) and dry (food) weight. Worm cocoons were analyzed for PCBs for the first time. The PCB pattern in the cocoons differed from the adult worms by the comparatively higher load of non-ortho PCBs. By studying congeners covering a large range of PCB physicochemical characteristics, their fate within the environmental and the factors influencing biological responses can be better understood.

Concentrations and spatial variations of polybrominated diphenyl ethers and other organohalogen compounds in Great Lakes air.

Air samples were analyzed from urban, rural, and remote sites near the Great Lakes to investigate the occurrence, concentrations, and spatial and temporal differences of polybrominated diphenyl ethers (PBDE) in air. The concentrations of PBDEs were compared to those of other organohalogen compounds such as PCBs and organochlorine pesticides. The samples were collected in 1997-1999 as part of the Integrated Atmospheric Deposition Network (IADN). To minimize the variability of the data, we selected only samples taken when the atmospheric temperature was 20 +/- 3 degrees C. PBDEs were found in all samples, indicating that these compounds are widely distributed and that they can be transported through the atmosphere to remote areas. The total concentrations of PBDEs were similar to some of the organochlorine pesticides such as sigmaDDT and ranged from 5 pg/m3 near Lake Superior to about 52 pg/m3 in Chicago. In fact, the spatial trend was well correlated to those of PCBs. Our results indicate a relatively constant level from mid-1997 to mid-1999. At 20 +/- 3 degrees C, about 80% of the tetrabromo homologues are in the gas phase and about 70% of the hexabromo homologues are associated with the particle phase. Thus, particle-to-gas partitioning in the atmosphere is an important process for these compounds.

[Residues of chlordane in fish in the Gulf of Gdansk]. / Pozostalosci chlordanu w rybach w Zatoce Gdanskiej.

Concentrations, composition and spatial variations of the residues of the pesticide Chlordane were determined in several species of fish caught in Gulf of Gdansk. The residues of Chlordane (cis-i trans-chlordane, cis-i trans-nonachlor, oxychlordane, heptachlor, heptachlor epoxide, MC4, MC5, MC6, MC7, U82 and U83) were found in all fish examined, however, the concentrations noted were low, i.e. from 0.40 to 12 ng/g wet weight. Among the Chlordane constituents and metabolites determined trans-naonachlor, cis-chlordane, oxychlordan, heptachlor epoxide, cis-nonachlor, MC5, MC6 and trans-chlordane were dominated, and MC4, MC7, U82 and U83 were minor compounds. No heptachlor residues were found in fish examined. A small concentrations and specific composition of the residues of Chlordane and its metabolites determined in fish from the Gulf of Gdansk do indicate on a distant sources of pollution with that pesticide--mainly transported and deposited via the atmosphere.

Organochlorine compounds in the Gulf of Bothnia: sediment and benthic species.

Surface sediment, amphipods (Monoporeia affinis), isopods (Saduria entomon) and fourhorn sculpins (Oncocottus quadricornis) were collected at two coastal stations in the Gulf of Bothnia, one in the Bothnian Bay and the other in the Bothnian Sea. The objective was to study the concentrations, composition profiles, bioaccumulation features and spatial differences of organochlorine compounds such as hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz), chlordanes (CHLs), dieldrin, Mirex and polychlorinated biphenyls (PCBs). All groups of compounds were found in every sample investigated, with the exception of Mirex that was not detected in the sediment samples. The concentrations for e.g. PCBs and CHLs ranged from 700 to 2400 and 70 to 400 ng/g lipid in the specimens. For the corresponding sediments the results were 9.0-9.3 ng/g dw for PCBs and 0.54-0.57 ng/g dw for CHLs, respectively. Bioaccumulation differences between the species with regard to both degree of and type of compound were observed. The highest accumulation potential was found for the cyclodiene compounds including CHLs and Mirex in isopod. Finally, there were only small concentration and bioaccumulation differences between the two stations.

[Dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 on fish in the Gulf of Gdansk]. / Dieldryna, aldryna, endryna, izodryna, endosulfan 1 i 2 w rybach w Zatoce Gdanskiej.

The residues of dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 has been determined in a several species of fish caught in the Gulf of Gdansk in 1992. The method of measurement was capillary gas chromatograph and low resolution mass spectrometry (HRGC/LRMS) after a nondestructive extraction and clean-up step with a further fractionation of the extract on Florisil column. Apart from dieldrin no other cyclodiene pesticides studied were found in fishes in detectable amounts, and for dieldrin concentrations ranged from 0.84 to 6.6 ng/g wet weight.

[DDT and it metabolites in fish in the Gulf of Gdansk]. / DDT i jego metabolity w rybach w Zatoce Gdanskiej.

The residues of DDT and its metabolites (DDTs; p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE, o,p'-DDE i p,p'-DDMU) has been determined in ten species of edible fish caught in the Gulf of Gdansk in 1992. The method of measurement was capillary gas chromatography and low resolution mass spectrometry (HRGC/LRMS) after a nondestructive extraction and clean-up step with a further fractionation of the extract on Florisil column. All fish examined contained detectable residues of DDTs, and the concentrations ranged from 28 to 310 ng/g wet weight. o,p'-DDT accounted from 0.4 to 2.5% to DDTs content. The residue concentration of DDTs in herring (110 ng/g wet weight and 1100 ng/g lipid weight) in 1992 was threefold lower than in the years 1979-1983 and fourteen fold lower than in 1969-1973.

Concentrations and biomagnification of 17 chlordane compounds and other organochlorines in harbour porpoise (Phocoena phocoena) and herring from the southern Baltic Sea.

Four species of harbour porpoise (Phocoena phocoena) and one herring (Clupea harengus) sample from the southern Baltic Sea were analysed in an attempt to study the concentration and biomagnification of 17 chlordane related compounds (CHLs) including 12 components present in technical chlordane, the toxic metabolites oxychlordane and cis-hepatchlorepoxide and the photoconversion products photoheptachlor and two photo-cis-chlordanes. The concentration and biomagnification ability of CHLs were also compared to other organochlorines such as HCHs (hexachlorocyclohexanes), hexachlorobenzene, DDTs, dieldrin, mirex and PCBs (polychlorinated biphenyls). Of the CHLs analysed, 16 were detected in porpoise and 15 in herring including the photoconversion products. In both species the highest concentrations were found for PCBs and DDTs. The concentration of PCBs and CHLs in porpoise varied from 5700-16,000 and 470-1250 ng/g lipid, and in herring from 1300 and 49 ng/g lipid, respectively. The biomagnification factor (BMF: concentration in organism/concentration in food; all lipid normalized) in porpoise was found to be high for CHLs followed by dieldrin and lowest for HCHs. Among the CHLs, a big variation of BMF (BMF range approximately 1-50) was found e.g., the nonachlorinated compounds biomagnified to the highest degree followed by cis-heptachlorepoxide, photoheptachlor and oxychlordane.

Concentrations, biomagnification and spatial variation of organochlorine compounds in a pelagic food web in the northern part of the Baltic Sea.

Zooplankton, mysis (Mysis sp.) and herring (Clupea harengus) were collected at two pelagic locations in the northern part of the Baltic Sea, one in Bothnian Bay (BB) and the other in the Bothnian Sea (BS), in order to investigate concentrations, composition profiles, biomagnification features and spatial differences of organochlorine contaminants. Compounds included in this study are hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz), chlordanes (CHLs), dieldrin, mirex and polychlorinated biphenyls (PCBs). All groups of compound were detected in every sample investigated, with the exception of mirex that was detected only in the herring samples. The concentrations of organochlorine compounds in all samples ranged, e.g. from 250 to 1500 ng/g lipid for PCBs and from 6 to 150 ng/g lipid for CHLs. The biomagnification factor (BMF) is calculated as the concentration of the compounds in the organism divided by the concentration in food normalised to lipids. In the zooplankton-mysis-herring food web, large variations in BMFs between the different compound groups were observed. The highest BMFs were obtained for the CHLs followed by the DDTs and the lowest for the HCHs. Nonachlorinated CHLs had the highest BMFs within the group of CHLs and for the DDTs p,p'-DDT had a higher biomagnification potential than its metabolites p,p'-DDE and p,p'-DDD. Finally, concentration and biomagnification differences between the two stations were observed. The herring in the southernmost station (BS) displayed approximately two- to sixfold higher biomagnification than the herring from the north (BB).

Concentrations and spatial variations of cyclodienes and other organochlorines in herring and perch from the Baltic Sea.

Herring (Clupea harengus) and perch (Perca fluviatilis) were collected in the northern and southern Baltic Sea and analyzed for the presence of the cyclodiene pesticides chlordane (CHL), heptachlor, aldrin, dieldrin, endrin, isodrin, endosulfan and mirex, as well as other organochlorine contaminants, hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz) and polychlorinated biphenyls (PCBs) in order to investigate concentrations, accumulation and differences in geographical distribution. In the northern part of the Baltic Sea, Gulf of Bothnia, herring were collected at two pelagic stations, one in the Bothnian Bay (BB) and the other in the Bothnian Sea (BS), respectively; perch were collected at four coastal locations along the Swedish coast. All these locations were selected to represent background areas except one in the vicinity of an industrialised and contaminated area. Both specimens were also caught in the southern part of the Baltic Sea, in the Gulf of Gdansk (GG), Poland, a potentially highly polluted area. From the eight cyclodiene pesticides analyzed, three were detected in herring and perch samples, including 12 different CHL-related compounds, dieldrin and mirex. To our knowledge, it is the first time that mirex has been detected in samples from the Baltic Sea. Neither heptachlor, aldrin, endrin, isodrin nor endosulfan were found. However, HCHs, DDTs, HCBz and PCBs were found in every sample investigated, and the concentrations ranged e.g. for the cyclodiene chemicals dieldrin and CHL-related compounds from 30 to 170 ng/g lipid and for PCBs from 360 to 5400 ng/g lipid, both fish species included. Differences in contamination burden between the sites can be seen, e.g. for herring the BB and GG locals were similar, and generally lower than BS for all chemicals except that of DDT where GG was the highest. For the perch samples the industrialised location had markedly higher concentrations of HCBz and PCBs than the other locations. This species also identifies GG as the most DDT contaminated site among the three studied areas.

Dialysis with semipermeable membranes as an efficient lipid removal method in the analysis of bioaccumulative chemicals.

Herein is a procedure described using a semipermeable membrane (SPM) for enrichment of organic chemicals from lipid-containing samples. Dialysis with SPMs in an organic solvent can separate organochlorine contaminants such as non-, mono-, and di-o-PCBs, PCDDs, PCDFs, PCDTs, PCNs, pesticides, and PAHs from lipids. The method is nondestructive and more than 20 g of lipid can be dialyzed in a single membrane with acceptable recoveries of the internal standards, nearly independent of amount and type of lipid dialyzed. The lipid removal process shows good consistency between subsamples, and the lipid content can be reduced by 90-99%, depending on species and amount lipid. Neither triglycerides nor phospholipids were obtained in the dialysate fraction. The utility and reliability of the method is displayed by good precision for 72 PCBs and 27 organochlorine pesticides in the concentration range 0.05-50 micrograms/sample for triplicate subsamples, by the consistency in PCDD/F levels compared to a classic analytical procedure, and by the analysis of the above listed chemicals in approximately 200 biological samples of a wide variety of types. This technique can also be used as an enrichment device for contaminants when huge amounts of lipids are extracted for toxicological studies. Moreover, it is possible to use SPM to cleanup other samples from molecules with relatively high masses, e.g. sediments, soil, compost, and tar materials.

Concentrations and biomagnification of polychlorinated naphthalenes in black cormorants Phalacrocorax carbo sinensis from the Gulf of Gdansk, Baltic Sea.

Black cormorants, Phalacrocorax carbo sinensis (the breast muscles and liver) originating from the colony near Katy Rybackie on the south coast of the Gulf of Gdansk, Baltic Sea, were collected in 1992 and analysed for polychlorinated naphthalenes. PCNs were determined employing a multi-residue procedure including a non-destructive wide-bore open-tube extraction step, cleanup using semipermeable polyethylene membrane, HPLC fractionation of planar compounds on activated carbon column and final separation and identification and quantification with HRGC/HRMS. Tetra- to hepta-CNs were found in all samples examined, and penta- and next tetra-CNs were dominating homologue groups. Dominating members in the fingerprint of PCNs in black cormorants were 1,3,5,7-T4CN (no. 42); 1,2,3,5,7-/1,2,4,6,7-P5CN (no. 52/60); 1,2,4,6,8-P5CN (no. 61); 1,2,3,4,6,7-/1,2,3,5,6,7-H6CN (no. 66/67); 1,2,4,6-/1,2,4,7-/1,2,5,7-T4CN (no. 33/34); 1,2,4,5,7-P5CN (no. 58); and 1,2,4,7,8-P5CN (no. 62). When related to potential food items, black cormorants biomagnify in their body many PCNs and the congeners no. 42 and 66/67 show highest biomagnification factor (BMF) values.

Presentation of a foreign peptide on the surface of tomato bushy stunt virus.

A 13-amino-acid peptide derived from the V3 loop of human immunodeficiency virus (HIV-1) glycoprotein 120 (gp120) was attached as a C-terminal gene fusion to the coat protein of tomato bushy stunt virus (TBSV). The architecture of this plant virus permitted external display of the foreign sequence 180 times on the surface of the chimaeric virus particle. The chimaera replicated to a level similar to wild-type TBSV and the foreign sequence was retained through six sequential passages in plants. The HIV epitope was detected on the surface of the virus capsid by a V3-specific monoclonal antibody and by human sera from HIV-1-positive patients, demonstrating the potential of using plant-derived chimaeric particles for diagnostic purposes. Chimaeric virus also induced a specific immune response to the foreign HIV epitope when injected into NMRI mice.