Status of feral oilseed rape in Europe: its minor role as a GM impurity and its potential as a reservoir of transgene persistence

Purpose  

Feral oilseed rape has become widespread in Europe on waysides and waste ground. Its potential as a source of GM impurity in oilseed rape harvests is quantified, for the first time, by a consistent analysis applied over a wide range of study areas in Europe.     

Spatial and temporal variations in NO2 distributions over Beijing,China measured by imaging differential optical absorption spectroscopy

During the CAREBEIJING campaign in 2006, imaging differential optical absorption spectroscopy (I-DOAS) measurements were made from 08:00 to 16:00 on September 9 and 10 over Beijing, China. Detailed images of the near-surface NO₂ differential slant column density (DSCD) distribution over Beijing were obtained. Images with less than a 30-min temporal resolution showed both horizontal and vertical variations in NO₂ distributions. For DSCD to mixing ratio conversion, path length along the lines of I-DOAS lines of sight was estimated using the light-extinction coefficient and Ångstrom exponent data obtained by a transmissometer and a sunphotometer, respectively. Mixing ratios measured by an in-situ NO₂ analyzer were compared with those estimated by the I-DOAS instrument. The obtained temporal and spatial variations in NO₂ distributions measured by I-DOAS for the two days are interpreted with consideration of the locations of the major NO_x sources and local wind conditions. I-DOAS measurements have been applied in this study for estimating NO₂ distribution over an urban area with multiple and distributed emission sources. Results are obtained for estimated temporal and spatial NO₂ distributions over the urban atmosphere; demonstrating the capability of the I-DOAS technique. We discuss in this paper the use of I-DOAS measurements to estimate the NO₂ distribution over an urban area with multiple distributed emission sources.     

Chemical characteristics of long-range transport aerosol at background sites in Korea

In this study, background concentration sites of Deokjeok and Gosan, which were deemed suitable for monitoring the impact of long-range transported air pollutants, were selected. An investigation of the source types of pollutants, their locations, and relative quantitative contributions to the particulate concentrations at both sites using appropriate methodologies to make initial estimations was conducted. Episodic measurements of PM_2.5, PM₁₀, and size distribution, along with its ion and carbon components were performed from 2005 to 2007, and a comprehensive analysis of the results was conducted utilizing back trajectory analysis. As for frequency of wind direction, it was quite apparent that the two sites are heavily influenced by air masses originating from the eastern and northern regions of China. For PM_2.5 and PM₁₀, the mass concentrations from north and east China were higher than other cases, originating from the ocean. In the northerly-wind case, meteorological properties for Deokjeok and Gosan and the influence of carbon emissions from northwest Korea resulted in a changing of air mass properties during transport. As was the case with mass concentration, the highest contribution for ionic and carbon components of PM_2.5 and PM₁₀ for both sites appeared for the westerly wind case. A specially high relative contribution, greater than 1.4 times, was apparent in the secondary aerosol case because of a large influence of long-range transported pollutants from east China. Carbon components exhibited different behaviors for the northerly and westerly wind cases compared with secondary aerosol. The major reason for this discrepancy appears to be the carbon emissions from northwest Korea.     

Assimilating concentration observations for transport and dispersion modeling in a meandering wind field

Assimilating concentration data into an atmospheric transport and dispersion model can provide information to improve downwind concentration forecasts. The forecast model is typically a one-way coupled set of equations: the meteorological equations impact the concentration, but the concentration does not generally affect the meteorological field. Thus, indirect methods of using concentration data to influence the meteorological variables are required. The problem studied here involves a simple wind field forcing Gaussian dispersion. Two methods of assimilating concentration data to infer the wind direction are demonstrated. The first method is Lagrangian in nature and treats the puff as an entity using feature extraction coupled with nudging. The second method is an Eulerian field approach akin to traditional variational approaches, but minimizes the error by using a genetic algorithm (GA) to directly optimize the match between observations and predictions. Both methods show success at inferring the wind field. The GA-variational method, however, is more accurate but requires more computational time. Dynamic assimilation of a continuous release modeled by a Gaussian plume is also demonstrated using the genetic algorithm approach.     

Cumulative impact of GM herbicide-tolerant cropping on arable plants assessed through species-based and functional taxonomies

Background, aim and scope

In a gradualist approach to the introduction of crop biotechnology, the findings of experimentation at one scale are used to predict the outcome of moving to a higher scale of deployment. Movement through scales had occurred for certain genetically modified herbicide-tolerant (GMHT) crops in the UK as far as large-scale field trials. However, the land area occupied by these trials was still <1% of the area occupied by the respective non-GM crops. Some means is needed to predict the direction and size of the effect of increasing the area of GMHT cropping on ecological variables such as the diversity among species and trophic interactions. Species-accumulation curves are examined here as a method of indicating regional-scale impacts on botanical diversity from multiple field experiments.

Materials and methods

Data were used from experiments on the effect of (GMHT) crops and non-GM, or conventional, comparators in fields sown with four crop types (beet, maize, spring and winter oilseed rape) at a total of 250 sites in the UK between 2000 and 2003. Indices of biodiversity were measured in a split-field design comparing GMHT with the farmers’ usual weed management. In the original analyses based on the means at site level, effects were detected on the mass of weeds in the three spring crops and the proportion of broadleaf and grass weeds in winter oilseed rape, but not on indices of plant species diversity. To explore the links between site means and total taxa, accumulation curves were constructed based on the number of plant species (a pool of around 250 species in total) and the number of plant functional types (24), inferred from the general life-history characteristics of a species.

Results

Species accumulation differed between GMHT and conventional treatments in direction and size, depending on the type of crop and its conventional management. Differences were mostly in the asymptote of the curve, indicative of the maximum number of species found in a treatment, rather than the steepness of the curve. In winter oilseed rape, 8% more species were accumulated in the GMHT treatment, mainly as a result of the encouragement of grass species by the herbicide when applied in the autumn. (Overall, GMHT winter oilseed rape had strong negative effects on both the food web and the potential weed burden by increasing the biomass of grasses and decreasing that of broadleaf weeds.) In maize, 33% more species—a substantial increase—were accumulated in the GMHT than in the conventional, consistent with the latter’s highly suppressive weed management using triazine herbicides. In the spring oilseed rape and beet, fewer species (around 10%) were accumulated in the GMHT than the conventional. The GMHT treatments did not remove or add any functional (life history) types, however. Differences in species accumulation between treatments appeared to be caused by loss or gain of rarer species. The generality of this effect was confirmed by simulations of species accumulation in which the species complement at each of 50 sites was drawn from a regional pool and subjected to reducing treatment at each site. Shifts in the species-accumulation parameters, comparable to those measured, occurred only when a treatment removed the rarer species at each site.

Discussion

Species accumulation provided a set of simple curve-parameters that captured the net result of numerous local effects of treatments on plant species and, in some instances, the balance between grass and broadleaf types. The direction of effect was not the same in the four crops and depended on the severity of the conventional treatment and on complex interactions between season, herbicide and crop. The accumulation curves gave an indication of potential positive or negative consequences for regional species pools of replacing a conventional practice with GMHT weed management. In this and related studies, a range of indicators, through which diversity was assessed by both species and functional type, and at both site and regional scales, gave more insight into effects of GMHT treatment than provided by any one indicator.

Conclusions

Species accumulation was shown to discriminate at the regional scale between agronomic treatments that had little effect on species number at the field scale. While a comprehensive assessment of GM cropping needs to include an examination of regional effects, as here, the costs of doing this in all instances would be prohibitive. Simulations of diversity-reducing treatments could provide a theoretical framework for predicting the likely regional effects from in-field plant dynamics.

Recommendations and perspectives

Accumulation curves potentially offer a means of linking within-site effects to regional impacts on biodiversity resulting from any change in agricultural practice. To guide empirical measurement, there is a scope to apply a methodology such as individual-based modelling at the field scale to explore the links between agronomic treatments and the relative abundance of plant types. The framework needs to be validated in practice, using species-based and functional taxonomies, the latter defined by measured rather than inferred traits.     

Monitoring of environmental contaminants in raw bovine milk and estimates of dietary intakes of children in South Korea

Persistent organic pollutants (POPs) are ubiquitous residual contaminants in the environment and in the food chain. Milk is an important matrix for monitoring POP contamination. This study determined the concentrations of POPs including polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in raw bovine milk, and the data was used to estimate dietary intakes in South Korea. The average concentrations of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw milk were 0.29 ng g⁻¹ fat, 0.50 ng g⁻¹ fat, 0.27 pg TEQ g⁻¹ fat, and 0.33 pg TEQ g⁻¹ fat, respectively. No significant relationship was found between the concentrations of analytes and the regions sampled. The dietary intakes of PBDEs from the consumption of milk was calculated to be 0.26, 0.10, and 0.05 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of HCB was calculated to be 0.44, 0.16, and 0.09 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of PCDD/Fs and DL-PCBs was calculated to be 0.78, 0.29, and 0.16 pg TEQ kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. These results indicated that the residual levels of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw bovine milk were within safe levels.     

Reduction of toxicity of antimicrobial compounds by degradation processes using activated sludge,gamma radiation,and UV

The occurrence and persistence of pharmacologically active compounds in the environment has been an increasingly important issue. The objectives of this study were to investigate the decomposition of aqueous antimicrobial compounds using activated sludge, γ-irradiation, and UV treatment, and to evaluate the toxicity towards green algae, Pseudokirchneriella subcapitata, before and after treatment. Tetracycline (TCN), lincomycin (LMC) and sulfamethazine (SMZ) were used as target compounds. Gamma (γ)-irradiation showed the highest removal efficiency for all target compounds, while UV and activated sludge treatment showed compound-dependent removal efficiencies. TCN and SMZ were well degraded by all three treatment methods. However, LMC showed extremely low removal efficiency for UV and activated sludge treatments. Overall, the algal toxicity after degradation processes was significantly decreased, and was closely correlated to removal efficiency. However, in the case of γ-irradiated TCN, UV and activated sludge treated LMC as well as sludge treated SMZ, the observed toxicity was higher than expected, which indicates the substantial generation of byproducts or transformed compounds of a greater toxicity in the treated sample. Consequently, γ-radiation treatment could be an effective method for removal of recalcitrant compounds such as antibiotics.     

II. Incidence of Acute Respiratory Illness

A study of acute respiratory illness was conducted from November 1968 through April 1969 among families residing in an area of relatively high nitrogen dioxide exposure, in an area of elevated suspended particulate exposure, and in two control areas of Greater Chattanooga. Respiratory illness rates were consistently higher in all family segments in the high-nitrogen dioxide exposure area when rates were averaged for the entire 24 weeks of study, the A₂/Hong-Kong epidemic period, or post-epidemic interval. A relative excess in respiratory illness of 18.8 percent was found among families exposed to elevated NO₂ concentrations and an excess of 10.4 percent was found among families in the elevated-suspended particulate exposure area.     

Optimization of two-step catalyzed biodiesel production from soybean waste cooking oil

An acid–base-catalyst-based two-step biodiesel production experiment from soybean waste cooking oil was carried out to identify which parameter is the most influential among the experimental parameters by using the Taguchi method. Heterogeneous catalysts were used to avoid a water-consuming homogeneous catalyst removal process. Ferric sulfate and calcium oxide were used as acid and base catalysts, respectively, for the heterogeneous reaction. Reaction time and methanol-to-triglyceride mole ratio were significant factors. The optimum parameters for step 1 (acid esterification) were 4 h of reaction time, 4 wt. % of ferric sulfate amount, a 16:1 methanol to triglyceride mole ratio, and 400 rpm of mixing speed, respectively. For the transesterification step, the most influential factor was reaction time, and CaO amount was significant as well. On the other hand, the mole ratio of methanol and oil was relatively less significant. Optimum parameters were 3 h of reaction time, 2 wt. % of CaO, and a 12:1 methanol to triglyceride mole ratio with mixing speed at 400 rpm in this experimental range. Under the optimum conditions, waste cooking oil with 5.27 mg KOH/g of acid value was converted into crude biodiesel by a two-step process with fatty acid methyl ester content reaching 89.8 % without any further post-purification.