Polychlorinated -dibenzo-p-dioxins/furans and -dioxin-like biphenyls in eggs of common terns from lime island,St. Mary's river,Michigan, USA

Population collapse of common tern (Sterna hirundo) from Lime Island in the St. Mary's River, Michigan, USA were related to the 2,3,7,8-chlorine substituted dioxins, furans, dioxin-like PCBs, and other possible factors using unhatch egg target contaminant analysis. The most toxic congeners, 2,3,7,8-TCDD/DF was found in all samples at noticeable concentrations. Magnitude of sum 2,3,7,8-PCDD/DFs were within the range of 39–93?pg/g wet wt. Dioxin-like PCBs were within the range of 360–1230?ng/g wet wt. Great Toxic Equivalent Quantity (TEQ) contributions by 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, and dioxin-like PCBs such as CB-77, CB-126 and CB-105 are considered greatly due to their influence of poor embryo development and consequent damage of embryos of common terns in egg injection studies. However, other organochlorines, heavy metals, and/or synergistic effects also taken in to account. On the whole, TEQs in the tern eggs were greater than the Lowest-Observable-Adverse Effect Level (LOAEL) for bald eagle (Haliaeetus leucocephalus) embryos observed in British Columbia, Canada. Concentrations of dioxin-like PCBs, dioxins, furans in the St. Mary's River food chain are at levels for concern for nesting colonial waterbirds. Eventually, the possible movements of analyzed chemicals downstream from a man-made flood event are discussed.     

Polycyclic aromatic hydrocarbons (PAHs) in multimedia environment of Heshan coal district,Guangxi: distribution,source diagnosis and health risk assessment

Mining activities are among the major culprits of the wide occurrences of soil and water pollution by PAHs in coal district, which have resulted in ecological fragilities and health risk for local residents. Sixteen PAHs in multimedia environment from the Heshan coal district of Guangxi, South China, were measured, aiming to investigate the contamination level, distribution and possible sources and to estimate the potential health risks of PAHs. The average concentrations of 16 PAHs in the coal, coal gangue, soil, surface water and groundwater were 5114.56, 4551.10, 1280.12 ng g^?1, 426.98 and 381.20 ng L^?1, respectively. Additionally, higher soil and water PAH concentrations were detected in the vicinities of coal or coal gangue dump. Composition analysis, isomeric ratio, Pearson correlation analysis and principal component analysis were performed to diagnose the potential sources of PAHs in different environmental matrices, suggesting the dominant inputs of PAHs from coal/coal combustion and coal gangue in the soil and water. Soil and water guidelines and the incremental lifetime risk (ICLR) were used to assess the health risk, showing that soil and water were heavily contaminated by PAHs, and mean ICLR_{coal/coal-gangue} and mean ICLR_soil were both significantly higher than the acceptable levels (1 × 10^?4), posing high potential carcinogenic risk to residents, especially coal workers. This study highlights the environmental pollution problems and public health concerns of coal mining, particularly the potential occupational health hazards of coal miners exposed in Heshan.     

Flexible foraging strategies in a diving seabird with high flight cost

How central-place foragers change search strategy in response to environmental conditions is poorly known. Foragers may vary the total distance travelled and how far they range from the central place in response to variation in the distribution of their prey. One potential reason as to why they would extend the length of their foraging trip and its distance from the colony would be to increase prey quality or quantity, despite incurring higher transit costs. To test this trade-off hypothesis in a species with high flight costs, we recorded the foraging behaviour of razorbills (Alca torca) using state-of-the-art techniques that log both individual horizontal (flight activity) and vertical (dive activity) movements. We show that the distance that razorbills travelled to foraging locations increased with sea-surface temperature, which may relate to higher prey quality or quantity. This relation is supported by an indirect index of patch quality, based on dive profiles, which also increased with travel distance from the colony. Furthermore, we show that this index was highest during the daily peak in diving activity, around midday. Taken together, these results suggest that razorbills are capable of adjusting their search strategies sensitively in response to proximate environmental cues.     

Biomonitors of stream quality in agricultural areas: Fish versus invertebrates

Although the utility of using either fish or benthic invertebrates as biomonitors of stream quality has been clearly shown, there is little comparative information on the usefulness of the groups in any particular situation. We compared fish to invertebrate assemblages in their ability to reflect habitat quality of sediment-impacted streams in agricultural regions of northeast Missouri, USA. Habitat quality was measured by a combination of substrate composition, riparian type, buffer strip width, and land use. Invertebrates were more sensitive to habitat differences when structural measurements, species diversity and ordination, were used. Incorporating ecological measurements, by using the Index of Biological Integrity, increased the information obtained from the fish assemblage. The differential response of the two groups was attributed to the more direct impact of sediments on invertebrate life requisites; the impact of sedimentation on fish is considered more indirect and complex, affecting feeding and reproductive mechanisms.The Unit is sponsored by the US Fish and Wildlife Service, the Missouri Department of Conservation and the University of Missouri.     

煤炭行业的劳工保护和经济社会发展的可持续性分析

中国的煤产量占世界的35％以上，同时重大煤矿事故发生率占约80％。中国最近已决定在全国的煤矿中任命10万名工人安全监察员。这对降低中国的煤矿事故发生率是非常重要的一步。其他已建立了工人安全监察员制度的国家已经积累了许多经验。或许世界上最好的煤矿安全模式要数英国和澳大利亚的。英国“工人监察员”角色早在1872年就已经得到认可。英国已经建立了一套结构合理的法定安全检查体系，该体系由代表法人的安全监察员和工人选举出来的工人安全临察员组成。安全咨询系统是由矿工联盟和政府组成的安全委员会构成。全国矿工联盟聘请了有丰富的安全和生产经验的资深煤矿工程师。英国煤炭局的工作人员和工人监察员都是具有一定水准的专业人士。有了这样的安全组织，英国的事故发生率从1946年迅速下降，从而使英国能宣布其在世界上拥有最安全的煤炭产业。澳大利亚的法律和英国相似，但是主要应用于州立法而不是联邦立法。检察员分为定点监察员和地区监察员两种。定点监察员由工人们选举产生。地区监察员在操作员违规操作并导致危险时有权中止其操作。定点监察员必须参加一个由内阁授权的关于职业安全和健康的培训课程．培训费用由新南威尔士政府承担。新西兰在1992年的职业健康和安全法案（在2002年和2003年有所修改）中阐明了工人安全代表的权利。他们必须由工人们自己选举产生。所有关于健康和安全的措施都是构建在员工参与的基础上，目标是通过工会取得雇员和管理方的一致。工人代表还有权发布隐患通知，并建议员工们在紧急情况下有权停止作业。     

Toxicity and detoxification of Swedish detergents and softener products

Detergents and softeners are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the acute toxicity to Daphnia magna was determined for 26 detergents and five softener Swedish products. Only one of the detergents had a 48-h EC50 > 100 mg/l. The 48-h EC50 for the other 25 detergents ranged from 4 to 85 mg/l. The 48-h EC50 for the five softeners ranged from 15 to 166 mg/l. Detoxification tests, with and without inoculum of sewage organisms, showed that all tested products were detoxified to some extent after 16 days and that the rate of detoxification was considerably higher with addition of sewage organisms. Toxicity to D. magna of the detergents and softeners, and the biotic detoxification rate was correlated with the concentration of surfactants used in formulating the products (more surfactants increased toxicity and a slower rate of detoxification). These results emphasize the importance of biological purification of domestic wastewater containing detergents and a suggested development of less toxic and more easily degradable surfactants.     

The use of heterospecific scent marks by the sweat bee <Emphasis Type="Italic">Halictus aerarius</Emphasis>

To forage effectively amongst flowers, some bee species utilize olfactory cues left by previous visitors in addition to direct assessment of visual cues to identify rewarding flowers. This ability can be more advantageous if the bees can recognize and use scent marks left by heterospecifics, not just marks left by members of their own species. We conducted field experiments to investigate whether the sweat bee Halictus aerarius avoids visiting flowers of trailing water willow Justicia procumbens emptied by other bee species. We found that H. aerarius rejected the flowers visited by both heterospecifics and conspecifics. They also rejected visited flowers artificially replenished with nectar. Our results demonstrate that social bees outside the Apidae can detect marks left on flowers by heterospecifics but that (on this plant species) they are unable to discriminate against flowers by directly detecting nectar volume. H. aerarius exhibited different rejection rates according to the identity of the previous bee species. We suggest that the frequency of rejection responses may depend on the amount of chemical substances left by the previous bee. In general, the use of scent marks left by previous visitors is almost certainly advantageous, enabling foragers to avoid flowers with depleted nectar levels and thereby improving their foraging efficiency.     

The limits to risk aversion: Part 1. The point of indiscriminate decision

The paper uses utility theory to investigate how much should be spent to avert all costs from an industrial accident apart from direct human harm. These “environmental costs” will include those of evacuation, clean-up and business disruption. Assuming the organisation responsible will need to pay such costs, the difference between its expected utility with and without an environmental protection system constitutes a rational decision variable for whether or not the scheme should be installed. The value of utility is dependent on the coefficient of relative risk aversion, “risk-aversion” for short. A model of an organisation's decision-making process has been developed using the ABCD model, linking the organisation's assets, A, the cost of the protection scheme, B, the cost of consequences, C, and the expected utility difference with and without the scheme, D. Increasing the organisation's risk-aversion parameter will tend to make it less reluctant to invest in a protection system, but can bring about such investment only when the scheme is relatively close to financial break-even. For such borderline schemes, the amount the organisation is prepared to spend on the protection system will rise as the risk-aversion increases. The ratio of this sum to the break-even cost is named the “Limiting Risk Multiplier”, the maximum value of which is governed by the maximum feasible value of risk-aversion. However, the mathematical model shows that increasing the risk-aversion will reduce the clarity of decision making generally. Although the reluctance to invest in a protection scheme may change sign and turn into a positive desire to invest as the risk-aversion increases, the absolute value of this parameter is a continuously decreasing function of risk-aversion, tending asymptotically to zero. As a result, discrimination will gradually diminish, being lost altogether at the “point of indiscriminate decision”. Here the decision maker will be able to distinguish neither advantage in installing the scheme nor disadvantage in installing its inverse. There is a close correspondence between this mathematically predicted state and that of panic, where an individual has become so fearful that his actions become random. The point of indiscriminate decision provides a natural upper bound for the value of risk-aversion. This bounds the Limiting Risk Multiplier in turn, and so sets an objective upper limit on the amount that it is rational to spend on an environmental protection system.     

Anomalous arsenic concentrations in groundwaters of an island community, Bowen Island, British Columbia

Recently, occurrences of elevated arsenic concentrations in bedrock groundwaters used for individual and municipal water supplies have been recognised along the mainland coast of southern British Columbia, Canada. An area on Bowen Island (Queen Charlotte Heights community) was chosen to investigate the source(s) of arsenic, geochemical processes controlling its aqueous uptake, the role of geology and structure in the formation of these waters, and the use of hydrogeochemical survey methods for detecting arsenious groundwater regions. Pyrite- arsenopyrite-Cu mineralisation in the Queen Charlotte Heights area is present as veins associated with NE-trending fault zones and as disseminations in marginal breccia and stockwork zones of a ryhodacite porphyry stock. Near surface mineralisation was later altered by supergene events to form minor pyrite- arsenopyrite in a matrix of limonite and clay. Geochemical factors that control the concentration and mobility of arsenic in these groundwaters include: (a) anion exchange of arsenic from clay minerals during cation divalent/univalent exchange processes (water softening) which leads to waters of high pH and high anion exchange capacities; (b) desorption of arsenic from Fe and Al oxyhydroxide minerals during pronounced shifts in pH from acid to alkaline conditions brought on by the water softening process; and (c) stepwise oxidation of arsenopyrite mineralisation to form arsenious sulphate-bearing groundwaters. The inconsistent behaviour of the As3+ and As5+ ions during the complex waterrock interaction processes described above, precludes the use of detailed chemical analyses to predict relative abundances of the more toxic As3+ species. For a full appreciation of the toxic impact of groundwaters containing total arsenic concentrations that are above regulatory guidelines an arsenic speciation analysis is required.