Assessment of the environmental exposure of honeybees to particulate matter containing neonicotinoid insecticides coming from corn coated seeds

Since seed coating with neonicotinoid insecticides was introduced in the late 1990s, European beekeepers have reported severe colony losses in the period of corn sowing (spring). As a consequence, seed-coating neonicotinoid insecticides that are used worldwide on corn crops have been blamed for honeybee decline. In view of the currently increasing crop production, and also of corn as a renewable energy source, the correct use of these insecticides within sustainable agriculture is a cause of concern. In this paper, a probable--but so far underestimated--route of environmental exposure of honeybees to and intoxication with neonicotinoid insecticides, namely, the atmospheric emission of particulate matter containing the insecticide by drilling machines, has been quantitatively studied. Using optimized analytical procedures, quantitative measurements of both the emitted particulate and the consequent direct contamination of single bees approaching the drilling machine during the foraging activity have been determined. Experimental results show that the environmental release of particles containing neonicotinoids can produce high exposure levels for bees, with lethal effects compatible with colony losses phenomena observed by beekeepers.     

Robust imaging of hippocampal inner structure at 7T: in vivo acquisition protocol and methodological choices

Objective

Motion-robust multi-slab imaging of hippocampal inner structure in vivo at 7T.

Materials and methods

Motion is a crucial issue for ultra-high resolution imaging, such as can be achieved with 7T MRI. An acquisition protocol was designed for imaging hippocampal inner structure at 7T. It relies on a compromise between anatomical details visibility and robustness to motion. In order to reduce acquisition time and motion artifacts, the full slab covering the hippocampus was split into separate slabs with lower acquisition time. A robust registration approach was implemented to combine the acquired slabs within a final 3D-consistent high-resolution slab covering the whole hippocampus. Evaluation was performed on 50 subjects overall, made of three groups of subjects acquired using three acquisition settings; it focused on three issues: visibility of hippocampal inner structure, robustness to motion artifacts and registration procedure performance.

Results

Overall, T2-weighted acquisitions with interleaved slabs proved robust. Multi-slab registration yielded high quality datasets in 96 % of the subjects, thus compatible with further analyses of hippocampal inner structure.

Conclusion

Multi-slab acquisition and registration setting is efficient for reducing acquisition time and consequently motion artifacts for ultra-high resolution imaging of the inner structure of the hippocampus.

     

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) in the abiotic environment: surface water and precipitation from Ontario, Canada

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of PBDEs, and also as compounds of natural origin in the marine environment; however, there has only been very limited study of their presence in the abiotic environment. In the present study, OH-PBDEs were determined in samples of surface water and precipitation (rain and snow) collected from sites in Ontario, Canada. OH-PBDEs were detected in all the samples analyzed, although half of the observed peaks did not correspond to any of the 18 authentic standards available. Fluxes of sigmaOH-PBDEs ranged from 3.5 to 190 pg/m2 in snow and from 15 to 170 pg/m2/day in rain, and those were higher at three of the southern Ontario locations relative to a single northern remote site. Concentrations of sigmaOH-PBDEs ranged from 2.2 to 70 pg/L in water and from < 1 to 420 pg/g in particulate organic carbon (POC), and higher values were found near sewage treatment plant (STP) outfalls in Lake Ontario. Partition coefficients (log K(oc)) for OH-PBDEs ranged from 4.0 to 5.1. The results in this study suggest that OH-PBDEs are ubiquitous in the abiotic environment and most likely are produced through reaction of PBDEs with atmospheric OH radicals. As well, they may be present in surface waters near STPs due to oxidation of PBDEs and inflows from metabolism by humans and animals.     

Particle emissions from pellets stoves and modern and old-type wood stoves

The purpose of this work is to characterise particle emissions from pellets stoves and modern and old-type residential wood stoves. The mass concentration of particulate material in the hot flue gas was 19-82 mg/MJ, roughly the same for wood stoves and pellets stoves, but the old-type wood stoves tended to emit even higher quantities. Furthermore, during combustion of wood logs the considerably higher emission of organic gaseous carbon indicates an additional contribution to the emission from secondarily formed condensable organic particles.The particle mass emitted was dominated by fine particles (<1 ??m) in all cases. The fine particle maximum was displaced towards larger size during inefficient combustion, e.g. during the start-up phase. The number concentration of particles from wood stoves was 1.0·10¹⁴-6.0·10¹⁴ #/MJ, from pellets 3.0·10¹³-5.0·10¹³ #/MJ, and in all cases dominated by fine particles. Efficient combustion of pellets resulted mainly in inorganic particles, dominated by potassium sulphate and potassium chloride. Zinc, the second most frequent metal, and calcium showed the highest concentrations among the less volatile components. The lowest concentration detected was for cadmium, about 10⁵ times lower than for potassium.     

Media training for diabetes prevention: a participatory evaluation.

The Media and the Message - Promoting Healthy Eating and Active Living for Diabetes Prevention was a project aimed at raising awareness of diabetes risk factors and enhancing the public's access to credible, up-to-date, healthy eating and active living messages in the media. Cross-country workshops were held to teach media strategies and key diabetes prevention messages to multidisciplinary groups of health professionals. Evaluation was integral to the project; both the process and outcomes were assessed using Health Canada's Population Health Approach. Timeline and budget were tracked. Questionnaires were created to evaluate advisory committee conference calls and to determine participants' perceptions of the 19 workshops and resources. A pre-workshop/post-workshop and three-month follow-up questionnaire format, along with an online media-tracking tool, was used to collect outcome data and to measure changes in confidence and media behaviour. Sixty-three percent of participants (150 of 238) reported that multidisciplinary workshops were very valuable. Three-month follow-up revealed a significant increase in confidence in all media activities taught at the workshops, although this failed to translate into increased media activity. Sixty-eight percent (78 of 115) of responding participants disseminated workshop learning. Detailed evaluation revealed that multidisciplinary workshops are valued and effective in increasing confidence. However, eliciting behaviour change following a workshop remains a challenge.     

An outbreak of salmonella chester infection in Canada: rare serotype, uncommon exposure, and unusual population demographic facilitate rapid identification of food vehicle

Salmonella Chester infection has rarely been reported in the literature. In 2010, 33 case patients were reported in 2 months in four Canadian provinces. We conducted an outbreak investigation in collaboration with public health agencies, food safety specialists, regulatory agencies, grocery store chains, and the product distributor. We used case patient interviews, customer loyalty cards, and microbiological testing of clinical and food samples to identify nationally distributed head cheese as the food vehicle responsible for the outbreak. The rare serotype, a limited affected demographic group, and an uncommon exposure led to the rapid identification of the source. Control measures were implemented within 9 days of notification of the outbreak.     

Quantifying the contribution of different sorption mechanisms for 2,4-dichlorophenoxyacetic acid sorption by several variable-charge soils

Previous research with phenolic, carboxylic, and urea type organic acids demonstrated that hydrophilic sorption was primarily due to anion exchange, which was linearly correlated to chemical acidity (pKa) and the soil anion exchange capacity. However, for dichlorophenoxyacetic acid (2,4-D), sorption by a kaolinitic soil was much higher than expected relative to all other organic acid-soil data. The enhanced sorption was hypothesized to involve calcium bridging of 2,4-D to hydrophilic domains. In this study, the mechanisms contributing to 2,4-D sorption by variable-charged soils were probed and quantified by measuring sorption from CaCl2, KCl, CaSO4, KH2PO4, and Ca(H2PO4)2 solutions. Linear sorption coefficients estimated for 2,4-D sorption from the different electrolytes decreased as follows: CaCl2 > KCl > CaSO4 > Ca(H2PO4)2 approximately equal to KH2PO4. Differences in 2,4-D sorption from CaCl2 and phosphate solutions were attributed to sorption by hydrophilic domains, which ranged between 46 and 94% across soils. Differences in 2,4-D sorption from CaCl2 and KCl were attributed specifically to Ca-bridging between 2,4-D's carboxyl group and the silanol edge on kaolinite and quartz and ranged from negligible to 40% depending on the soil mineral type. Differences in sorption from CaCl2 and CaSO4 was attributed to anion exchange, which ranged from 16 to 91%, followed the trends with pKa developed previously for other organic acids, and correlated well to the soil anion to cation exchange capacity ratio (AEC/CEC). The sum of anion exchange and Ca-bridging contributions agreed well with the sorption estimated to be from hydrophilic domains. All other sorption was attributed to hydrophobic processes, which correlated well to a linear free-energy relationship between pH-dependent organic carbon-normalized sorption coefficients and pH-dependent octanol-water partition coefficients developed for several other organic acids.     

Levels of PCBs and their metabolites in the serum of residents of a highly contaminated area in eastern Slovakia

The over-riding aim of the present investigation was to obtain information concerning exposure that can be used as a basis for studies on the health of individuals residing in the Michalovce area of eastern Slovakia which is heavily contaminated by polychlorinated biphenyls (PCBs). Accordingly, this work focused on determination of serum concentrations of hydroxylated (OH-PCBs) and methylsulfonyl-substituted (MeSO2-PCBs) metabolites of PCBs. One hundred and twenty-two men and women, 20-59 years of age, living in the contaminated area and 175 from the control Stropkov/Svidnik district were selected randomly from 2047 sampled individuals. Following a specially designed cleanup, the levels of various congeners of OH-PCBs and MeSO2-PCBs in their serum were quantitated by gas chromatography and mass spectrometry, with comparison to authentic reference standards. The median concentrations of PCB congeners and their OH-PCB and MeSO2-PCB metabolites were 2-3-fold higher in residents of Michalovce than in the control region. The levels of certain OH-PCB metabolites were in the same high range as those of individual PCB congeners, whereas the MeSO2-PCB levels were significantly lower. The PCB and their metabolites were present at slightly higher concentrations in men than in women, and the serum levels of PCBs and MeSO2-PCBs increased with increasing age. Thus, the environmental contamination resulting from previous industrial production of PCBs has led to elevated concentrations of PCBs and their metabolites in the serum of individuals living in the Michalovce area.