Physiological response of 10 phytoplankton species exposed to macondo oil and the dispersant,Corexit

Culture experiments were conducted on ten phytoplankton species to examine their biological and physiological responses during exposure to oil and a combination of oil and dispersant. The species tested included a range of taxa typically found in the Gulf of Mexico such as cyanobacteria, chlorophytes, and diatoms. Cultures were exposed to Macondo surrogate oil using the water accommodated fraction (WAF), and dispersed oil using a chemically enhanced WAF (CEWAF) and diluted CEWAF, to replicate conditions following the Deepwater Horizon spill in the Gulf of Mexico. A range of responses were observed, that could broadly class the algae as either “robust” or “sensitive” to oil and/or dispersant exposure. Robust algae were identified as Synechococcus elongatus, Dunaliella tertiolecta, two pennate diatoms Phaeodactylum tricornutum and Navicula sp., and Skeletonema grethae CCMP775, and were largely unaffected by any of the treatments (no changes to growth rate or time spent in lag phase relative to controls). The rest of the phytoplankton, all centric diatoms, exhibited at least some combination of reduced growth rates or increased lag time in response to oil and/or dispersant exposure. Photophysiology did not have a strong treatment effect, with significant inhibition of photosynthetic efficiency (F_v/F_m) only observed in the CEWAF, if at all. We found that the effects of oil and dispersants on phytoplankton physiology were species‐dependent, and not always detrimental. This has significant implications on how oil spills might impact phytoplankton community structure and bloom dynamics in the Gulf of Mexico, which in turn impacts higher trophic levels.     

Discordant risk: Overweight and cardiometabolic risk in Chinese adults

Objective:

Recent US work identified “metabolically healthy overweight” and “metabolically at risk normal weight” individuals. Less is known for modernizing countries with recent increased obesity.

Design and Methods:

Fasting blood samples, anthropometry and blood pressure from 8,233 adults aged 18‐98 in the 2009 nationwide China Health and Nutrition Survey, were used to determine prevalence of overweight (Asian cut point, BMI ≥23 kg/m²) and five risk factors (prediabetes/diabetes (hemoglobin A1c ≥5.7%) inflammation (high‐sensitivity C‐reactive protein (hsCRP) ≥3 mg/l), prehypertension/hypertension (Systolic blood pressure/diastolic blood pressure≥130/85 mm Hg), high triglycerides (≥150 mg/dl), low high‐density lipoprotein cholesterol (<40 (men)/ <50 mg/dl (women)). Sex‐stratified, logistic, and multinomial logistic regression models estimated concurrent obesity and cardiometabolic risk, with and without abdominal obesity, adjusting for age, smoking, alcohol consumption, physical activity, urbanicity, and income.

Results:

Irrespective of urbanicity, 78.3% of the sample had ≥1 elevated cardiometabolic risk factor (normal weight: 33.2% had ≥1 elevated risk factor; overweight: 5.7% had none). At the age of 18‐30 years, 47.4% had no elevated risk factors, which dropped to 6% by the age 70, largely due to age‐related increase in hypertension risk (18‐30 years: 11%; >70 years: 73%). Abdominal obesity was highly predictive of metabolic risk, irrespective of overweight (e.g., “metabolically at risk overweight” relative to “metabolically healthy normal weight” (men: relative risk ratio (RRR) = 39.06; 95% confidence interval (CI): 23.47, 65.00; women: RRR = 22.26; 95% CI: 17.49, 28.33)).

Conclusion:

A large proportion of Chinese adults have metabolic abnormalities. High hypertension risk with age, underlies the low prevalence of metabolically healthy overweight. Screening for cardiometabolic‐related outcomes dependent upon overweight will likely miss a large portion of the Chinese at risk population.     

Length–mass relationships for lake macroinvertebrates corrected for back-transformation and preservation effects

Coloured dissolved organic matter (CDOM) modifies the light penetration into water bodies due to stronger absorbance of UV and short wavelengths of light. Therefore, in natural waters with high CDOM concentration, the spectrum of sunlight is shifted towards brown, also referred to as brownification. Here, the relation between the spectrophotometrically measured water colour (CDOM) and landscape properties is examined. These properties explained at best > 40% of the CDOM variability among the study lakes larger than 10 km². The key “permanent” landscape variables were lake percentage (Lake_%) in the uppermost catchment area, and the peat land coverage (Peat_%) of the catchment, which indeed was strongly correlated with lake elevation above the sea level. High Lake % indicated low CDOM concentration, while high Peat_% indicated the opposite. Relative to the Peat_% of the catchment, the CDOM concentrations were, on average, slightly higher in medium-size lakes (area 10–100 km²) than in large lakes (area > 100 km²), while relative to Lake_% the concentrations declined more in medium-size lakes.     

A quantitative risk ranking model to evaluate emerging organic contaminants in biosolid amended land and potential transport to drinking water

A quantitative risk ranking model was developed for human exposure to emerging contaminants (EC) following treated municipal sewage sludge (“biosolids”) application to Irish agricultural land. The model encompasses the predicted environmental concentration (PEC) in soil, surface runoff, groundwater, and subsequent drinking water ingestion by humans. Human exposure and subsequent risk was estimated for 16 organic contaminants using a Monte Carlo simulation approach. Nonylphenols ranked the highest across three environmental compartments: concentration in soil (PEC_soil), runoff (PEC_runoff), and groundwater (PEC_groundwater), which had mean values of 5.69 mg/kg, 1.15 × 10^?2 µg/l, and 2.22 × 10^?1 µg/l, respectively. Human health risk was estimated using the LC₅₀ (chemical intake toxicity ratio, (RR)) as a toxicity endpoint combined with PEC_runoff and PEC_groundwater. NP ranked highest for LC₅₀ combined with PEC_runoff and PEC_groundwater (mean RR values 1.10 × 10^?4 and 2.40 × 10^?3, respectively). The model highlighted triclocarban and triclosan as ECs requiring further investigation. A sensitivity analysis revealed that soil sorption coefficient and soil organic carbon were the most important parameters that affected model variance (correlation coefficient –0.89 and –0.30, respectively), highlighting the significance of contaminant and soil properties in influencing risk assessments. This model can help to prioritize emerging contaminants of concern requiring vigilance in environmental compartments.     

Nitrification and utilization of ammonium and nitrate during oil bioremediation at different soil water potentials

Bioremediation of petroleum spills requires aerobic soil conditions and readily available N, which may be susceptible to leaching. Our objectives were to determine the influence of soil water potential on nitrification in the presence of crude oil, the toxicity of oil to NHj‐oxidizing bacteria, and the preferences of microorganisms for NH⁺ ₄ or NO^? ₃. A Weswood clay loam was amended with crude oil to contain 0, 5, and 10% by soil dry weight, and N was added to achieve C:N ratios of 90:1 and 120:1. Soil water potentials were maintained at ‐0.02, ‐0.1, and ‐1.0 kJ/kg or allowed to fluctuate between ‐0.02 and ‐3 kJ/kg. Concentrations of NH⁺ ₄ and NO₃ ^?were measured during an incubation period of 40 d. Nitrification in soil not amended with oil was rapid at water potentials of ‐0.02 and ‐0.1 kJ/kg but inactive at a water potential of ‐1.0 kJ/kg. Oil reduced nitrification rates and populations of NH⁺ ₄‐oxidizing bacteria. Little NO^? ₃ accumulated when the C:N ratio was 120:1, but when the C:N ratio was 90:1, up to 150 μg of NO₃‐N/g of soil accumulated at a soil water potential of ‐0.02 kJ/kg. Soil water potential in the range used did not greatly influence the extent of oil bioremediation but significantly influenced nitrification. Ammonium was preferentially used over NO^? ₃ by microorganisms during oil bioremediation. Nitrate accumulation from urea applied to stimulate oil bioremediation was low when N application matched requirements for oil bioremediation, and nitrification was restricted by controlling soil water content.     

Conductive Li3.08Cr0.02Si0.09V0.9O4 Anode Material: Novel “Zero‐Strain” Characteristic and Superior Electrochemical Li+ Storage

“Zero‐strain” compounds are ideal energy‐storage materials for long‐term cycling because they present negligible volume change and significantly reduce the mechanically induced deterioration during charging–discharging. However, the explored “zero‐strain” compounds are very limited, and their energy densities are low. Here, γ phase Li_3.08Cr_0.02Si_0.09V_0.9O₄ (γ‐LCSVO) is explored as an anode compound for lithium‐ion batteries, and surprisingly its “zero‐strain” Li⁺ storage during Li⁺ insertion–extraction is found through using various state‐of‐the‐art characterization techniques. Li⁺ sequentially inserts into the 4c(1) and 8d sites of γ‐LCSVO, but its maximum unit‐cell volume variation is only ≈0.18%, the smallest among the explored “zero‐strain” compounds. Its mean strain originating from Li⁺ insertion is only 0.07%. Consequently, both γ‐LCSVO nanowires (γ‐LCSVO‐NW) and micrometer‐sized particles (γ‐LCSVO‐MP) exhibit excellent cycling stability with 90.1% and 95.5% capacity retention after as long as 2000 cycles at 10C, respectively. Moreover, γ‐LCSVO‐NW and γ‐LCSVO‐MP respectively deliver large reversible capacities of 445.7 and 305.8 mAh g^?1 at 0.1C, and retain 251.2 and 78.4 mAh g^?1 at 10C. Additionally, γ‐LCSVO shows a suitably safe operating potential of ≈1.0 V, significantly lower than that of the famous “zero‐strain” Li₄Ti₅O₁₂ (≈1.6 V). These merits demonstrate that γ‐LCSVO can be a practical anode compound for stable, high‐energy, fast‐charging, and safe Li⁺ storage.     

Flux-based ozone risk assessment for adult beech forests

Tropospheric ozone (O₃) is a critical threat to forest ecosystems. A stomatal flux-based risk evaluation methodology at the leaf level was established recently in the context of the Convention on Long-Range Transboundary Air Pollution (LRTAP). This study demonstrates improvement and validation of the stomatal flux-effect approach for adult beech with results from the 8-year free-air O₃ enrichment experiment at “Kranzberger Forst” (Germany). The risk assessment module of the SVAT model FO₃REST, being under development for local scale O₃-risk assessment of adult beech stands, was parameterized according to the LRTAP Convention’s Mapping Manual. Mean maximum stomatal conductance for water vapour of 245?mmol H₂O m^?2 PLA s^?1, as suggested in the LRTAP Convention’s Mapping Manual for beech, was affirmed by assessment at “Kranzberger Forst”, resulting in 162?mmol O₃ m^?2 PLA s^?1 upon recommended adjustment of the O₃/water vapour diffusivity ratio to 0.663. Based on this ratio, a provisional corrected flux-effect function was deduced. Modelled Phytotoxic O₃ Doses (POD ₁) and potential O₃-caused losses in biomass formation estimated with a site-specific stomatal conductance algorithm differed slightly only from estimates by the original LRTAP parameterisation. Analysis-derived POD ₁ target value within the meaning of Article 2 of the European Council Directive 2008/50/EC of 10?mmol O₃ m^?2 corresponded to potential loss in biomass formation of about 10?% in ambient air relative to “pre-industrial” conditions. However, exceedance occurred by about a factor of two during the study period, indicating high risk at “Kranzberger Forst” under ambient air. Assessment for doubled O₃ exposure indicated potential underestimation even of the O₃ risk because modelled losses in biomass formation are in the lower range of the standard deviation of the observed ones.     

Bioremediation of Hydrocarbons in Contaminated Wood: A Proof‐of‐Concept Study

A proof‐of‐concept study to evaluate the biological removal of hydrocarbons (naphthalene, n‐hexadecane, and fuel oil #2) from contaminated wood (Southern yellow pine) was conducted using ¹⁴C‐labeled tracers and gas chromatography. Contaminated wood was brought in contact with n‐hexadecane‐degrading Pseudomonas aeruginosa PG201 or naphthalene degrading environmental isolates by the application either on mineral medium agar or filter paper containing a previously grown biomass (“overlay” technique). The experiments showed a significant acceleration of naphthalene removal by biomass. Due to biodegradation combined with evaporation, naphthalene was nearly completely removed (up to 90–98 %) in 4–8 days from freshly contaminated 6 mm‐ and 17 mm‐thick wood samples. The removal of a less volatile hydrocarbon, n‐hexadecane, was less efficient, at 40–60% in 20–40 days, with the only variable significantly affecting this pollutant's removal rate being the moisture content of the medium. Biodegradation experiments with standard heating fuel oil #2 (a representative real‐world contaminant) resulted in significant removal of light hydrocarbons (C₁₀–C₁₆), i.e., more mobile/volatile substrates, in 3 weeks (up to 70 %) whereas heavier hydrocarbons (C₁₇–C₁₉) were less affected. Pollutant mobility in both wood and aqueous media was shown to be the crucial factor affecting the removal efficiency. These results point toward a promising technique to reclaim wooden structures contaminated with volatile and semi‐volatile chemicals.     

Bioactivity of fenchone and Plectranthus glandulosus oil against Prostephanus truncatus and two strains of Sitophilus zeamais

The toxic, repellent and reproduction inhibitory effects of Plectranthus glandulosus essential oil and one of its major compounds, fenchone, were evaluated against adult Prostephanus truncatus (Horn) and for two strains of Sitophilus zeamais Motschulsky from Cameroon and Germany. Maize grains were coated with the oil at 0, 10, 20, 40 and 80 μl/40 g grain and fenchone at 0, 20, 40, 80 and 120 μl/40 g grain. Mortality was assessed over a 7‐day period, followed by the determination of F₁ progeny production. The repellence of the two products was evaluated at five rates (0.5, 1, 3, 5, 10 μl/half disc) in a choice bioassay on filter paper. The oil and fenchone caused significant dose‐dependent mortality to the three insects, with the oil achieving 100% and 90% mortality for the two S. zeamais strains and P. truncatus, respectively, within 1 day of exposure at the dosage of 80 μl/40 g grain. The insects were less susceptible to fenchone compared with the crude oil. The German strain of S. zeamais was susceptible to the oil than the Cameroonian strain. At the dosage of 20 μl/40 g grain, S. zeamais F₁ progeny emergency was completely inhibited by the oil, while 80 μl/40 g grain treatment with fenchone prevented also insect emergence. Plectranthus glandulosus oil generally evoked a maximum per cent repellency of 100% for the three insects, but fenchone caused 55–60% to S. zeamais and 80% to P. truncatus. These results suggest that fenchone, though a major constituent of P. glandulosus oil, may only be a minor component of its bioactivity.     

Influence of temperature on clove oil anaesthesia in flounder (Platichthys flesus Linnaeus, 1758)

The efficacy of clove oil as an anaesthetic in juvenile flounder was evaluated at two temperatures (10–12 and 16–18 °C) and the effective concentration determined. Flounder juveniles with a body length of 9.0–10.2 cm and a weight of 6–14 g were individually exposed to clove oil at concentrations ranging from 200 to 1000 mg L^?1 in a 5‐L bath with three replicates per treatment with 10 fish. The induction and recovery times were recorded in seconds for all doses and temperatures. Temperature had no effect on induction, but higher temperature shortened the recovery time. The effective concentration (EC₅₀) was estimated as 753 (692–820) mg L^?1 for ≤3 min with 95% confidence limits. The study demonstrated that clove oil can be used as an effective anaesthetic in juvenile flounder and that temperature has an effect on recovery time from anaesthesia with clove oil.     

Nongrowing season methane emissions–a significant component of annual emissions across northern ecosystems

Wetlands are the single largest natural source of atmospheric methane (CH₄), a greenhouse gas, and occur extensively in the northern hemisphere. Large discrepancies remain between “bottom‐up” and “top‐down” estimates of northern CH₄ emissions. To explore whether these discrepancies are due to poor representation of nongrowing season CH₄ emissions, we synthesized nongrowing season and annual CH₄ flux measurements from temperate, boreal, and tundra wetlands and uplands. Median nongrowing season wetland emissions ranged from 0.9 g/m² in bogs to 5.2 g/m² in marshes and were dependent on moisture, vegetation, and permafrost. Annual wetland emissions ranged from 0.9 g m^?2 year^?1 in tundra bogs to 78 g m^?2 year^?1 in temperate marshes. Uplands varied from CH₄ sinks to CH₄ sources with a median annual flux of 0.0 ± 0.2 g m^?2 year^?1. The measured fraction of annual CH₄ emissions during the nongrowing season (observed: 13% to 47%) was significantly larger than that was predicted by two process‐based model ensembles, especially between 40° and 60°N (modeled: 4% to 17%). Constraining the model ensembles with the measured nongrowing fraction increased total nongrowing season and annual CH₄ emissions. Using this constraint, the modeled nongrowing season wetland CH₄ flux from >40° north was 6.1 ± 1.5 Tg/year, three times greater than the nongrowing season emissions of the unconstrained model ensemble. The annual wetland CH₄ flux was 37 ± 7 Tg/year from the data‐constrained model ensemble, 25% larger than the unconstrained ensemble. Considering nongrowing season processes is critical for accurately estimating CH₄ emissions from high‐latitude ecosystems, and necessary for constraining the role of wetland emissions in a warming climate.     

Modeling temporal patterns of methane effluxes using multiple regression and random forest in Poyang Lake,China

In this study, we used two statistical models to predict daily CH₄ effluxes and compared the prediction accuracy of two models in Poyang Lake. Statistical models included linear model and Random forest model (RF) which can handle high dimensional non-linear relationships, categorical and continuous predictors, and highly collinear predictor variables. Seven climatic factors and water level data, together with the field CH₄ efflux at monthly intervals from 2011 to 2014 were used for model development and cross-validation. We found that the RF model provided the best prediction accuracy for daily CH₄ effluxes, whereas the linear model gave low prediction accuracy for CH₄ effluxes. The coefficient of determination was 0.93 and 0.63 for the “best” RF and linear models with the same climatic variables, respectively. The “best” linear model had the highest model-performance errors including the mean absolute error, root mean-square error, and the normalized root-mean-square error, followed by the “best” RF models. In addition, cross-validation results for the two “best” models also showed that the RF model was the best model for estimating CH₄ effluxes. We applied the optimum RF model to simulate daily CH₄ effluxes from 1 January 2011 to 31 December 2014, and then estimated the seasonal and annual CH₄ emissions in Poyang Lake. The mean CH₄ efflux in the summer was notably higher than that in the other seasons, with values of 0.097, 0.28, 0.11, and 0.045 mmol m^?2 day^?1 in the spring, in the summer, in the autumn, and in the winter over a 4-year period, respectively. The mean annual emission was 3.13 g m^?2 year^?1, which was considerately lower than the mean global annual emission in lakes and that in the other subtropical lakes of the world. We found that the RF model may be used to estimate CH₄ effluxes and emissions in other lakes in the world.     

3H-reserpine persistently bound "in vivo" to rat brain subcellular components: limited removal by peanut oil extraction

Removal by peanut oil extraction was used to study the binding of the highly liposoluble drug reserpine to rat brain subcellular components. When ³H-reserpine was added to the brain “in vitro” or administered to the animals 1 hr before, the binding was “labile” and most of the drug was removed by peanut oil extraction. In the brain of the animals treated with reserpine 24 hr before, the drug was “persistently” bound to the mitochondrial and microsomal fractions and its removal by peanut oil was comparably reduced.     

Chemical composition and mosquito repellency of essential oil of Conyza newii propagated in different geographical locations of Kenya

Previously, essential oil of Conyza newii (Asterale: Asteracea, Oliv. & Hiern) growing in the northern part of West Pokot (35°E, 1°N) of Kenya was shown to be highly repellent [RD₅₀ = 8.9 × 10^?5 mg/cm², 95% confidence interval (CL)] to Anopheles gambiae s.s. Fumigant toxicity of the oil to the mosquito was also demonstrated. The major constituents of the oil were found to be monoterpenoids, including (S)‐(‐)‐perillyl alcohol, (S)‐(‐)‐perillaldehyde, geraniol, (R)‐(+)‐limonene, trans‐β‐ocimene and 1,8‐cineol. In this study, the chemical composition and repellency of essential oils of the plant seedlings collected from West Pokot (35°E, 1°N) and propagated in seven different geographical regions of Kenya [West Pokot (35°E, 1°N), Kilome (37°E, 1°S), Naivasha (36°E, 0°), Webuye (34°E, 1°N), Nyakach (34°E, 0°), Kericho (35°E, 0°) and Nairobi (36°E, 1°S)] were compared. There were significant variations (P < 0.01, 95% CL) in the relative proportions of the six constituents and this was reflected in the repellency of the essential oils (P < 0.01, 95% CL). Higher repellency of the oil was associated with greater proportions of (S)‐(‐) perillyl alcohol, (S)‐(‐)‐perillaldehyde and geraniol, and lower repellency was associated with an increased proportion of (R)‐(+)‐limonene. The results suggest significant epigenetic (chemotypic) variations in the repellency and composition of C. newii essential oils growing in different regions of Kenya.     

Provocation study of persons with perceived electrical hypersensitivity and controls using magnetic field exposure and recording of electrophysiological characteristics

The aim of the present study was to investigate possible neurophysiological effects of intermittent 15 sec on/off cycle, 60 Hz, 10 μT magnetic field exposure on patients with perceived “electromagnetic hypersensitivity” (EHS), and control subjects during rest and performance of a mental arithmetic task. Twenty participants (15 female, 5 male, 31–60 years old, mean 45.8 ± 0.7 years) were invited from the group of EHS patients. Twenty volunteers (15 female, 5 male, 31–59 years old, mean 45.0 ± 0.7 years?) served as a control group. The test protocol consisted of a set of examinations: EEG, visual evoked potentials, electrodermal activity, ECG, and blood pressure. The total duration of the test was 40 min, divided into two 10 min rest periods and two 10 min periods of mathematical performance. Magnetic field and sham exposures were presented randomly during these periods, resulting in four different conditions: Field‐Rest, Sham‐Rest, Field‐Math, and Sham‐Math. The data showed significant main effects of the Group factor (EHS vs. control subjects) on heart rate (F_1,80 = 20.6; P < 0.01), heart rate spectrum ratio (F_1,80 = 9.5; P = 0.02), and electrodermal activity (F_1,76 = 4.2; P = 0.04), whereas EEG characteristics did not differ between groups. The Condition factor (mathematical task vs. relaxed) showed main effects for heart rate (F_1,80 = 14.8; P < 0.01), heart rate spectrum ratio (F_1,80 = 7.8; P = 0.06), electrodermal activity (F_1,76 = 56.8; P < 0.01), and alpha and theta spectral bands of EEG. Magnetic field exposure did not affect autonomous system or electroencephalographic variables of either group. These data do not indicate that EHS patients or control are affected by low‐level 60 Hz magnetic field exposure. However, persons reporting EHS differed from the control subjects in baseline values of investigated physiological characteristics. Perhaps EHS patients have a rather distinctive physiological predisposition to sensitivity to physical and psychosocial environmental stressors. Bioelectromagnetics 22:457–462, 2001. © 2001 Wiley‐Liss, Inc.     

Limnological regime shifts caused by climate warming and Lesser Snow Goose population expansion in the western Hudson Bay Lowlands (Manitoba,Canada)

Shallow lakes are dominant features in subarctic and Arctic landscapes and are responsive to multiple stressors, which can lead to rapid changes in limnological regimes with consequences for aquatic resources. We address this theme in the coastal tundra region of Wapusk National Park, western Hudson Bay Lowlands (Canada), where climate has warmed during the past century and the Lesser Snow Goose (LSG; Chen caerulescens caerulescens) population has grown rapidly during the past ~40 years. Integration of limnological and paleolimnological analyses documents profound responses of productivity, nutrient cycling, and aquatic habitat to warming at three ponds (“WAP 12”, “WAP 20”, and “WAP 21″), and to LSG disturbance at the two ponds located in an active nesting area (WAP 20, WAP 21). Based on multiparameter analysis of ²¹⁰Pb‐dated sediment records from all three ponds, a regime shift occurred between 1875 and 1900 CE marked by a transition from low productivity, turbid, and nutrient‐poor conditions of the Little Ice Age to conditions of higher productivity, lower nitrogen availability, and the development of benthic biofilm habitat as a result of climate warming. Beginning in the mid‐1970s, sediment records from WAP 20 and WAP 21 reveal a second regime shift characterized by accelerated productivity and increased nitrogen availability. Coupled with 3 years of limnological data, results suggest that increased productivity at WAP 20 and WAP 21 led to atmospheric CO₂ invasion to meet algal photosynthetic demand. This limnological regime shift is attributed to an increase in the supply of catchment‐derived nutrients from the arrival of LSG and their subsequent disturbance to the landscape. Collectively, findings discriminate the consequences of warming and LSG disturbance on tundra ponds from which we identify a suite of sensitive limnological and paleolimnological measures that can be utilized to inform aquatic ecosystem monitoring.     

Acute Effects of Particulate Air Pollution on the Incidence of Coronary Heart Disease in Shanghai,China

Introduction

Evidence based on ecological studies in China suggests that short-term exposure to particulate matter (PM) is associated with cardiovascular mortality. However, there is less evidence of PM-related morbidity for coronary heart disease (CHD) in China. This study aims to investigate the relationship between acute PM exposure and CHD incidence in people aged above 40 in Shanghai.

Methods

Daily CHD events during 2005–2012 were identified from outpatient and emergency department visits. Daily average concentrations for particulate matter with aerodynamic diameter less than 10 microns (PM₁₀) were collected over the 8-year period. Particulate matter with aerodynamic diameter less than 2.5 microns (PM_2.5) were measured from 2009 to 2012. Analyses were performed using quasi-poisson regression models adjusting for confounders, including long-term trend, seasonality, day of the week, public holiday and meteorological factors. The effects were also examined by gender and age group (41–65 years, and >65 years).

Results

There were 619928 CHD outpatient and emergency department visits. The average concentrations of PM₁₀ and PM_2.5 were 81.7μg/m³ and 38.6μg/m³, respectively. Elevated exposure to PM₁₀ and PM_2.5 was related with increased risk of CHD outpatients and emergency department visits in a short time course. A 10 μg/m³ increase in the 2-day PM₁₀ and PM_2.5 was associated with increase of 0.23% (95% CI: 0.12%, 0.34%) and 0.74% (95% CI: 0.44%, 1.04%) in CHD morbidity, respectively. The associations appeared to be more evident in the male and the elderly.

Conclusion

Short-term exposure to high levels of PM₁₀ and PM_2.5 was associated with increased risk of CHD outpatient and emergency department visits. Season, gender and age were effect modifiers of their association.     

Acaricidal effects of <Emphasis Type="Italic">Corymbia citriodora</Emphasis> oil containing <Emphasis Type="Italic">para</Emphasis>-menthane-3,8-diol against nymphs of <Emphasis Type="Italic">Ixodes ricinus</Emphasis> (Acari: Ixodidae)

The toxicity of para-menthane-3,8-diol (PMD), the main arthropod-repellent compound in the oil of the lemon eucalyptus, Corymbia citriodora, was evaluated against nymphs of Ixodes ricinus using five methods (A–E) of a contact toxicity bioassay. Mortality rates were estimated by recording numbers of dead nymphs at 30 min intervals during the first 5 h after the start of exposure and at longer intervals thereafter. The mortality rate increased with increasing concentration of PMD and duration of exposure with a distinct effect after 3.5 h. From the results obtained by methods A, C and E, the LC₅₀ range was 0.035–0.037 mg PMD/cm² and the LC₉₅ range was 0.095–0.097 mg PMD/cm² at 4 h of exposure; the LT₅₀ range was 2.1–2.8 h and the LT₉₅ range was 3.9–4.2 h at 0.1 mg PMD/cm². To determine the duration of toxic activity of PMD, different concentrations (0.002, 0.01, 0.1 mg PMD/cm²) were tested and mortality was recorded at each concentration after 1 h; thereafter new ticks were tested. This test revealed that the lethal activity of PMD remained for 24 h but appeared absent after 48 h. The overall results show that PMD is toxic to nymphs of I. ricinus and may be useful for tick control.     

Dietary Restraint and Control Over “Wanting” Following Consumption of “Forbidden” Food

Eating behavior can be influenced by the rewarding value of food, i.e., “liking” and “wanting.” The objective of this study was to assess in normal‐weight dietary restrained (NR) vs. unrestrained (NU) eaters how rewarding value of food is affected by satiety, and by eating a nonhealthy perceived, dessert‐specific food vs. a healthy perceived, neutral food (chocolate mousse vs. cottage cheese). Subjects (24NR age = 25.0 ± 8.2 years, BMI = 22.3 ± 2.1 kg/m²; 26NU age = 24.8 ± 8.0 years, BMI = 22.1 ± 1.7 kg/m²) came to the university twice, fasted (randomized crossover design). Per test‐session “liking” and “wanting” for 72 items divided in six categories (bread, filling, drinks, dessert, sweets, stationery (placebo)) was measured, before and after consumption of chocolate mousse/cottage cheese, matched for energy content (5.6 kJ/g) and individual daily energy requirements (10%). Chocolate mousse was liked more than cottage cheese (P < 0.05). After consumption of chocolate mousse or cottage cheese, appetite and “liking” vs. placebo were decreased in NR and NU (P < 0.03), whereas “wanting” was only decreased in NR vs. NU (P ≤ 0.01). In NR vs. NU “wanting” was specifically decreased after chocolate mousse vs. cottage cheese; this decrease concerned especially “wanting” for bread and filling (P < 0.05). To conclude, despite similar decreases in appetite and “liking” after a meal in NR and NU, NR decrease “wanting” in contrast to NU. NR decrease “wanting” specifically for a nonhealthy perceived, “delicious,” dessert‐specific food vs. a nutritional identical, yet healthy perceived, slightly less “delicious,” “neutral” food. A healthy perceived food may thus impose greater risk for control of energy intake in NR.     

Importance of Different Volatile Petroleum Hydrocarbon Fractions in Human Health Risk Assessment

Soil vapor data for benzene and four aliphatic and aromatic hydrocarbon fractions from five volatile petroleum hydrocarbon (VPH)-contaminated sites in western Canada were used together with the Canadian Council of Ministers of the Environment (CCME) Canada-Wide Standard for petroleum hydrocarbons to investigate the relative importance of benzene and the different fractions in human health risk assessment. VPH concentrations in soil vapor samples ranged from 4.0 to 4200?mg/m³, of which 0 to 4.6% was BTEX and 90 to 95% was hydrocarbons of the C_5–8 aliphatic fraction. VPH inhalation exposure by an adult receptor in a hypothetical, commercial building was modelled deterministically assuming 16- and 70 year occupational tenures. The magnitude of hazard quotients varied widely between sites, but their hydrocarbon fraction signatures were consistent, and characterized by higher hazard quotients in the C_5–8 and C_9–10 aliphatic and C_9–10 aromatic fractions relative to benzene and the TEX aromatic fraction. This work has shown that the C_5– and C_9–10 aliphatic fractions yield greater relative risk than the commonlyregulated TEX compounds, and that benzene becomes the primary chemical of potential concern only when an occupational tenure approaching 70 years is assumed.