Plutonium from global fallout recorded in an ice core from the Belukha glacier, Siberian Altai

Ice cores from glaciers situated near anthropogenic sources of air pollution provide important archives of the emissions of species with short atmospheric lifetimes. Here we present the history of atmospheric Pu fallout reconstructed from an ice core from the Belukha glacier in the Siberian Altai. Fourteen ice core samples covering the time period 1941-1986 were selected for Pu analysis, chemically processed, and measured using accelerator mass spectrometry. The Pu concentration peaks in 1963, coinciding with the maximum of the nuclear weapons tests and in concordance with the 3H activity concentration peak. The shapes of the 239Pu and 3H profiles reflect two main periods of atmospheric nuclear test activity: premoratorium testing before 1958 and postmoratorium testing in 1961 and 1962. Premoratorium tests contribute about 45% of the integrated Pu inventory. The average 240Pu/239Pu isotopic ratio is 0.18 +/- 0.05, indicating that a large majority of the Pu in the Belukha glacier originates from global stratospheric fallout rather than from direct tropospheric input.     

Plutonium isotopes in settling particles: transport and scavenging of Pu in the western Northwest Pacific

We examined the vertical distributions of 239+240Pu activity and 240Pu/239Pu atom ratio in settling particles and quantified the particulate 239+240Pu fluxes in the water column in the western Northwest Pacific. Settling particle samples were collected using sediment traps. Plutonium isotopes were analyzed using a sector field high-resolution ICP-MS. To the best of our knowledge, this is the first time that both Pu activity and Pu isotope ratio data have been obtained for settling particles in the Pacific Ocean. The high (>0.18) 240Pu/239Pu atom ratios in settling particles indicate that plutonium from the Pacific Proving Grounds (PPG) source in the central Pacific is transported toward the western Northwest Pacific. Evidence indicates that Pu scavenging onto the settling particles is strongly dependent upon the bulk mass flux. The results suggest that advective lateral transport of dissolved Pu from the open ocean to the ocean margin and removal of Pu into the margin sediments by particle scavenging is a common phenomenon in the Pacific Ocean. Plutonium can be considered as a useful tracer to study the transport and fate of other contaminants that readily adsorb to particles in marine environments.     

Survey of levels of cadmium in oysters,mussels, clams and scallops from the Pacific Northwest coast of Canada

Field and retail collections of bivalves from the Pacific Northwest, Canada, were analysed for cadmium concentrations by atomic absorption spectrophotometry (AAS). Both collections of varnish (Nuttallia obscurata) and manila (Venerupis philippinarum) clams contained cadmium concentrations of less than 0.5 µg g^?1, well below international safety guidelines of 1 and 2 µg g^?1 wet weight cadmium for the European and Hong Kong markets, respectively, as well as the 2 µg g^?1 safety guideline set by the Codex Alimentarius Commission (CAC). Cadmium concentrations in retail collections of the Pacific oyster, Crassostrea gigas, were generally above 2 µg g^?1 wet weight (range = 1.5–3.56 µg g^?1). Retail collections of the mussel, Mytilus spp., contained cadmium concentrations below the 2 µg g^?1 wet weight guideline, but not always the 1 µg g^?1 limit (range = 0.15?1.8 µg g^?1). However, field collections of Mytilus spp. contained cadmium concentrations between 0.35 and 4.00 µg g^?1 wet weight, and depending on sampling location, concentrations exceeded the CAC guidelines by more than two-fold. Locations where mussels had high cadmium concentrations correlated with regions that had previously reported high values for cadmium in Pacific oysters (r = 0.65; p < 0.05). Of the various shellfish analysed, the four species of scallops, Chlamys hastata, C. rubida, Crassadoma gigantea, and Patinopecten yessoensis, contained the greatest concentrations of cadmium, in excess of 5 µg g^?1 wet weight (range = 4.97–8.98 µg g^?1) with the greatest concentrations determined for C. gigantea. Cadmium concentrations in shellfish from the Pacific Northwest are greater than values reported for shellfish from other regions of the world and consumers need be aware of Health Canada consumption guidelines for shellfish from this region.     

Sediment record and atmospheric deposition of brominated flame retardants and organochlorine compounds in Lake Thun, Switzerland: lessons from the past and evaluation of the present

Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was compared to the respective historical profiles of legacy organochlorine compounds in three dated sediment cores from a prealpine lake (Lake Thun, Switzerland). Concentrations of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) started to increase in the 1980s-1990s. In the more recent sediment layers, PBDEs still had steady or increasing concentrations, whereas for HBCDs one sediment core revealed a decreasing trend. In contrast to the contemporary BFRs, concentrations of legacy organochlorines, such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and dichlorodiphenyl trichloroethane (DDT), peaked in deeper sediment layers deposited some decades ago. Measurements of atmospheric deposition and evaluation of wastewater discharges pointtoward deposition on the lake surface as a relevant input pathway and wastewater as a minor source of POPs in Lake Thun. The effect of the environmental awareness and the regulations taken in the 1970s to reduce environmental pollution of organochlorines is well reflected in the analyzed sediment cores. The sediment burden closely follows estimated time trends of consumption and emission of PCBs and DDT. The current residues in sediment of BFRs are still lower than the historical peak levels of organochlorines. However, current atmospheric deposition of BFRs is similar to deposition of PCBs. Considering the high amount of BFRs presently stocked in the anthroposphere in flame proofed materials, further measures to reduce emissions during BFRs life cycle are recommended to prevent high environmental pollution as it occurred for the organochlorine compounds.     

Lingonberry (Vaccinium vitis-idaea L.) grown in the Pacific Northwest of North America: Anthocyanin and free amino acid composition

Lingonberries and their products are popular and generally accessible in Europe, though in the US they are uncommon and considered a minor berry/fruit crop. The on-going interest in potential health benefits from berry consumption has heightened interest in broadening the selection of berry/fruit crops in the US. This study measured total phenolics, total tannins, complete anthocyanin content, and total (and individual) free amino acid composition for each of five lingonberry cultivars. Cultivars Ida, Koralle, Linnea, Sanna, and Sussi were grown in Oregon, USA, and had only been evaluated previously for their horticultural traits. All five cultivars contained the three anticipated anthocyanins (by HPLC): cyanidin-3-galactoside (main anthocyanin found in these berries), cyanidin-3-glucoside, and cyanidin-3-arabinoside. These lingonberries’ total anthocyanin content ranged from 27.4 (‘Linnea’) to 52.6 (‘Ida’) mg/100 g fw. They contained 22 free amino acids (FFAs) and total FAAs ranged from 28.92 (‘Sanna’) to 70.38 (‘Koralle’) mg/100 g fw. Asparagine (ASN) was the leading FAA (22–34% of the total FAAs) for all five cultivars. This is the first report on lingonberry FAA content.     

The fraction of ischaemic heart disease and stroke attributable to smoking in the WHO Western Pacific and South-East Asian regions

Background

Tobacco will soon be the biggest cause of death worldwide, with the greatest burden being borne by low and middle‐income countries where 8/10 smokers now live.

Objective

This study aimed to quantify the direct burden of smoking for cardiovascular diseases (CVD) by calculating the population attributable fractions (PAF) for fatal ischaemic heart disease (IHD) and stroke (haemorrhagic and ischaemic) for all 38 countries in the World Health Organization Western Pacific and South East Asian regions.

Design and subjects

Sex‐specific prevalence of smoking was obtained from existing data. Estimates of the hazard ratio (HR) for IHD and stroke with smoking as an independent risk factor were obtained from the ∼600 000 adult subjects in the Asia Pacific Cohort Studies Collaboration (APCSC). HR estimates and prevalence were then used to calculate sex‐specific PAF for IHD and stroke by country.

Results

The prevalence of smoking in the 33 countries, for which relevant data could be obtained, ranged from 28–82% in males and from 1–65% in females. The fraction of IHD attributable to smoking ranged from 13–33% in males and from <1–28% in females. The percentage of haemorrhagic stroke attributable to smoking ranged from 4–12% in males and from <1–9% in females. Corresponding figures for ischaemic stroke were 11–27% in males and <1–22% in females.

Conclusions

Up to 30% of some cardiovascular fatalities can be attributed to smoking. This is likely an underestimate of the current burden of smoking on CVD, given that the smoking epidemic has developed further since many of the studies were conducted.     

Magnification and toxicity of PCBs, PCDDs, and PCDFs in upriver-migrating Pacific salmon

The depletion of lipids associated with pre-spawning migration of Pacific salmon has the potential to magnify concentrations of hydrophobic organic contaminants (HOCs), which elevates risk of toxic effects. We present data from a field study of sockeye salmon (Oncorhynchus nerka) migrating to spawn in Great Central Lake, BC, which demonstrate that pre-spawning migration causes a magnification of PCB, PCDD, and PCDF concentrations in female gonads (1.9-2.5-fold), female soma (3.4-5.6-fold), and male soma (5.6-9.7-fold). We further develop a model of prespawning migration chemical magnification for sockeye salmon stocks as a function of migration distance. This model is shown to be consistent with available empirical data on pre-spawning magnification and predicts magnification factors ranging between 1.4 and 7.9 in gonad and between 1.6 and 10.4 in soma in seven Pacific salmon stocks in British Columbia. Post-migration (prespawning) toxic equivalent dioxin concentrations in roe were measured to be approximately 3 pg/g lipid in salmon from the Great Central Lake sockeye stock and estimated to range between 1.5 pg/g lipid for the shortest-migrating stocks and 7 pg/g lipid for the longest-migrating stocks. Concentrations in certain stocks approach or exceed the concentration of 3 pg/g lipid associated with 30% egg mortality in Oncorhynchus mykiss. This indicates the potential for population-level effects of current contaminant levels. It also suggests that historic contaminant concentrations, which were greater than current concentrations, may have contributed significantly to the decline of certain Pacific salmon stocks in British Columbia.     

The vital role of science in global policy decision-making: An analysis of past, current, and forecasted trends and issues in global red meat trade and policy

As global populations and economies change, the dynamics of global trade and policy change as well. In analyzing the past trends and projections for global populations, economic developments, animal product production and consumption, global trade policy, and current issues being faced, one can begin to make some predictions or projections as to how the global red meat and poultry infrastructure will change and, more importantly, point to areas where a proactive approach is necessary to shape these changes to meet the most globally beneficial end. Many issues face the global red meat industry, from food safety to animal disease, and are becoming more and more complicated as consumer knowledge increases and as politics intervene. Internationalized science is key and vital in the future of global trade policy as science can address the more informed consumer in a manner, which reduces anxiety over unknowns. The role of the industry is to provide the information and knowledge to the consumer necessary to convey the validity of globally accepted standards, which relate to ensuring consumer safety, animal welfare, and provide assurances that these standards are being met within the production sector.     

A 50-year record of platinum, iridium, and rhodium in Antarctic snow: volcanic and anthropogenic sources

Antarctic snow preserves an atmospheric archive that enables the study of global atmospheric changes and anthropogenic disturbances from the past. We report atmospheric deposition rates of platinum group elements (PGEs) in Antarctica during the last ～ 50 years based on determinations of Pt, Ir, and Rh in snow samples collected from Queen Maud Land, East Antarctica to evaluate changes in the global atmospheric budget of these noble metals. The 50-year average PGE concentrations in Antarctic snow were 17 fg g(-1) (4.7-76 fg g(-1)) for Pt, 0.12 fg g(-1) (<0.05-0.34 fg g(-1)) for Ir, and 0.71 fg g(-1) (0.12-8.8 fg g(-1)) for Rh. The concentration peaks for Pt, Ir, and Rh were observed at depths corresponding to volcanic eruption periods, indicating that PGEs can be used as a good tracer of volcanic activity in the past. A significant increase in concentrations and crustal enrichment factors for Pt and a slight enhancement in enrichment factors for Rh were observed after the 1980s. This suggests that there has been large-scale atmospheric pollution for Pt and probably for Rh since the 1980s, which may be attributed to the increasing emissions of these metals from anthropogenic sources such as automobile catalysts and metal production processes.     

Pu and U atom ratios and concentration factors in reservoir 11 and Asanov Swamp, Mayak PA: an application of accelerator mass spectrometry

Mayak Production Association, East Ural, Russia, was established to produce weapons-grade plutonium. Routine discharges and accidents at Mayak PA contaminated large areas, including the Techa River. The objectives of the present work were to study atom ratios for plutonium and, for the first time to our knowledge, uranium isotopes in water, soil, grass, and aquatic biota samples from Reservoir 11 and the Asanov Swamp, downstream from Mayak PA. Atom ratios (240Pu/239Pu, 236U/235U, 235U/238U) were determined using accelerator mass spectrometry to confirm radionuclide source characteristics and calculate activities and concentration factors for the studied samples. The lowest 240Pu/239Pu atom ratios were consistently found in Asanov Swamp samples (approximately 0.019), indicating a major contribution from early discharges of weapons-grade Pu. 240Pu/239Pu atom ratios in Reservoir 11 were higher, indicating influence from more recent civil reprocessing. The presence of 236U is usually indicative of fuel irradiation; 236U/235U ratios increase from weapons to civil sources. Our new data show that Asanov samples had lower 236U/ 235U ratios than Reservoir 11 samples (0.0005-0.0045 for Asanov compared with 0.0074-0.0153 for Reservoir 11) in agreement with Pu results. Pu and U concentration factors calculated for vegetation and biota samples at Mayak were comparable with corresponding values found in the literature.     

New peat bog record of atmospheric lead pollution in Switzerland: Pb concentrations,enrichment factors,isotopic composition,and organolead species

A peat core collected at Etang de la Gruère, an ombrotrophic bog in the Jura Mountains of Switzerland, was analyzed for organolead species (DEL, TEL, DML, and TML) using GC-MIP AES, Pb isotopes using TIMS, and total Pb using XRF and age-dated using 210Pb. The earliest occurrence of quantifiable alkyllead is found at a depth of 24 cm, which is dated at AD 1946 +/- 3; this finding is consistent with the introduction of leaded gasoline in Switzerland in 1947. The maximum concentration of alkyllead (2.89 ng/g) is found at 5 cm, which is dated at AD 1988 +/- 2. This same sample yielded 206Pb/207Pb = 1.1254, which is the least radiogenic value in the entire 2K core and comparable to the isotopic composition of Pb in leaded gasoline. The highest concentrations of DML (906 ng/g) and DEL (1906 ng/g) also were found in this sample. Total alkyllead never accounts for more than 0.02% of total Pb in any given sample. The spatial and temporal variations in organolead species is matched by the changes in the isotopic composition of Pb over the same interval. Despite this, the decline in anthropogenic Pb pre-dates the maximum in total alkyllead and minimum 206Pb/207Pb, indicating that atmospheric Pb emissions had already begun their decline prior to the introduction of unleaded gasoline. In fact the decline in anthropogenic Pb was probably in response to the introduction of legislation, first in Germany and later in the European Union, establishing a maximum allowable concentration of Pb in gasoline.     

全球油菜产业现状与我国油菜产业问题、对策北大核心CSCD

为了深入研究全球环境下我国油料供给中的突出问题,保障我国油料供应安全,推动我国油菜产业高质量发展,详细调研、分析了全球和我国油菜产业发展现状及存在的主要问题,并提出相应对策。结果表明:全球油菜籽供需缺口较大、油菜产品价格涨幅明显;我国油菜产品产量和消费量仍维持高位、库存持续减少;我国油菜产业发展在育种、产业化、国民需求和国际贸易方面均存在一些问题。基于上述问题,提出通过提升油菜种质资源建设和利用,强化转基因育种研究和应用,加强适应全程机械化的优质品种研发,提高市场调控和财政补贴,实施差异化战略提升食用油品质,拓展进口渠道增加油料储备,最终促进我国油菜产业高质量发展和保障油料供给安全。     

煎炸油中核心醛的GC-MS分析及变化趋势研究

采用气-质联用定性定量检测煎炸油中核心醛并分析其随煎炸时间的变化趋势。结果表明,在菜籽油煎炸薯条12 h的油样中检出3种核心醛,即8-氧代辛酸(8-oxo)、9-氧代壬酸(9-oxo)和10-氧代-8-癸烯酸(10-oxo-8)。菜籽油煎炸薯条12 h后油样中核心醛的总量约为1. 63 mg/g,与煎炸鸡块和鱼排油样中的含量有显著性差异(p 0. 05)。大豆油和调和油煎炸花生的油样中3种核心醛含量差异不大,平均约为1. 12 mg/g,其中核心醛9-oxo占总量的50%以上。煎炸使油脂中核心醛含量显著增加,煎炸食材和煎炸油脂肪酸组成对核心醛含量有影响。     

Influence of Asian and Western United States urban areas and fires on the atmospheric transport of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and fluorotelomer alcohols in the Western United States

Atmospheric measurements of semivolatile organic compounds (SOCs) were made at Mt Bachelor Observatory (MBO), located in Oregon's Cascade Range, to understand the trans-Pacific and regional transport of SOCs from urban areas. High volume air sampling (approximately 644 m3 for 24 h periods) of both the gas and particulate phases was conducted from April 19, 2004 to May 13, 2006 (n = 69); including NASA's INTEX-B campaign in spring 2006 (n = 34 of 69). Air mass back trajectories were calculated and were used to calculate source region impact factors (SRIFs), the percentage of time the sampled air mass resided in a given source region. Particulate-phase polycyclic aromatic hydrocarbon (PAH) concentrations at MBO increased with the percentage of air mass time in Asia and, in conjunction with other data, provided strong evidence that particulate-phase PAHs are emitted from Asia and undergo trans-Pacific atmospheric transport to North America. Gas-phase PAH and fluorotelomer alcohol (FTOH) concentrations significantly increased with the percentage of air mass time in California's urban areas, whereas retene and polychlorinated biphenyl (PCB) concentrations increased with the percentage of air mass time in Oregon and during regional fire events. In addition, sigma(gas-phase) PAH, retene, and levoglucosan concentrations were significantly correlated (p-value < 0.001) with sigma(PCB) concentrations, suggesting that increased atmospheric PCB concentrations were associated with fires due to the volatilization of stored PCBs from soil and vegetation.