Anthropogenic mercury emissions in China

An inventory of mercury emissions from anthropogenic activities in China is compiled for the year 1999 from official statistical data. We estimate that China's emissions were 536 (±236) t of total mercury. This value includes open biomass burning, but does not include natural sources or re-emission of previously deposited mercury. Approximately 45% of the Hg comes from non-ferrous metals smelting, 38% from coal combustion, and 17% from miscellaneous activities, of which battery and fluorescent lamp production and cement production are the largest. Emissions are heaviest in Liaoning and Guangdong Provinces, where extensive smelting occurs, and in Guizhou Province, where there is much small-scale combustion of high-Hg coal without emission control devices. Emissions are gridded at 30×30 min spatial resolution. We estimate that 56% of the Hg in China is released as Hg⁰, 32% as Hg²⁺, and 12% as Hg^p. Particulate mercury emissions are high in China due to heavy burning of coal in residential and small industrial settings without PM controls. Emissions of Hg²⁺ from coal-fired power plants are high due to the absence of flue-gas desulfurization units, which tend to dissolve the soluble divalent mercury. Metals smelting operations favor the production of elemental mercury. Much of the Hg is released from small-scale activities in rather remote areas, and therefore the activity levels are quite uncertain. Also, emissions test data for Chinese sources are lacking, causing uncertainties in Hg emission factors and removal efficiencies. Overall, we calculate an uncertainty level of ±44% (95% confidence interval) in the estimate of total emissions. We recommend field testing of coal combustors and smelters in China to improve the accuracy of these estimates.     

Source characterization and identification by real-time single particle mass spectrometry

A Real-Time Single Particle Mass Spectrometer, RSMS-3, was deployed to Wilmington, Delaware to study regional and local contributions to fine and ultra-fine urban particulate matter (PM). Approximately two-thirds of PM₁ consisted of internally mixed secondary aerosol. The remaining one-third was externally mixed including biomass burning (13%), fossil fuel combustion (7%) and various industrial sources (13%). In this last group, particle classes containing specific combinations of transition and/or heavy metals gave wind-rose plots consistent with specific point sources. For example, particles containing V and Ni were detected from different wind directions than those containing V and Fe. Samples from two industrial emission stacks, a steel manufacturing facility 10 km away and a coal-fired electrical power generation facility 5 km away, were analyzed and compared to the ambient data set. In each case, a direct correlation was found: a Pb–Zn–K–Na class for the steel manufacturing facility and an Fe–La/Ce class for the power generation facility. The ambient particle classes showed additional small signals from secondary components indicating atmospheric processing. Ambient particle classes containing only a subset of these elements, such as Zn only, Fe only and Pb–K only, were nonspecific, that is, the wind-rose plots were more diffuse and the particles could not be mapped to individual sources. The merits of stack sampling as an aid to interpreting single particle data sets are discussed.     

Fate of isoxaben in a containerized plant rhizosphere system

Commercial production of ornamental plants is an important industry in the United States and involves a complex technology that includes the use of herbicides. Isoxaben[N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide] is a pre-emergence herbicide used for controlling weeds in many areas including containerized ornamental plants. Degradation was studied in potting mix (80% bark, 20% sand) with three different regimes (sterile, bulk and rhizosphere). The rhizosphere regime contained Switch Grass (Panicum virgatum), and plants were allowed to grow for 14 days before adding isoxaben (10 microg/g potting mix). Isoxaben was degraded to 0.5 microg/g in 60 days giving a half-life of 7 days. Two degradation products were detected: 3-nitrophthalic acid in the rhizosphere and bulk regimes and 4-methoxyphenol in the sterile regime. Microbial population shifts were determined by fatty acid methyl ester profile analysis and were influenced by the introduction of a plant (rhizosphere regime) and by isoxaben addition.     

Validation of quasi-induced exposure representativeness assumption among young drivers

Objective: Young driver studies have applied quasi-induced exposure (QIE) methods to assess relationships between demographic and behavioral factors and at-fault crash involvement, but QIE's primary assumption of representativeness has not yet been validated among young drivers. Determining whether nonresponsible young drivers in clean (i.e., only one driver is responsible) 2-vehicle crashes are reasonably representative of the general young driving population is an important step toward ensuring valid QIE use in young driver studies. We applied previously established validation methods to conduct the first study, to our knowledge, focused on validating the QIE representativeness assumption in a young driver population.

Methods: We utilized New Jersey's state crash and licensing databases (2008–2012) to examine the representativeness assumption among 17- to 20-year-old nonresponsible drivers involved in clean multivehicle crashes. It has been hypothesized that if not-at-fault drivers in clean 2-vehicle crashes are a true representation of the driving population, it would be expected that nonresponsible drivers in clean 3-or-more-vehicle crashes also represent this same driving population (Jiang and Lyles 2010 Jiang XG, Lyles RW. A review of the validity of the underlying assumptions of quasi-induced exposure. Accid Anal Prev. 2010;42:1352–1358.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Thus, we compared distributions of age, gender, and vehicle type among (1) nonresponsible young drivers in clean 2-vehicle crashes and (2) the first nonresponsible young driver in clean crashes involving 3 or more vehicles to (3) all other nonresponsible young drivers in clean crashes involving 3 or more vehicles. Distributions were compared using chi-square tests and conditional logistic regression; analyses were conducted for all young drivers and stratified by license status (intermediate vs. fully licensed drivers), crash location, and time of day of the crash.

Results: There were 41,323 nonresponsible drivers in clean 2-vehicle crashes and 6,464 nonresponsible drivers in clean 3-or-more-vehicle crashes. Overall, we found that the distributions of age, gender, and vehicle type were not statistically significantly different between the 3 groups; in each group, approximately one fourth of drivers were represented in each age from age 17 through 20, half were males, and approximately 80% were driving a car/station wagon/minivan. In general, conclusions held when we evaluated the assumption within intermediate and fully licensed young drivers separately and by crash location and time.

Conclusions: It appears that the representativeness assumption holds among the population of young NJ drivers. We encourage young driver studies utilizing QIE methods to conduct internal validation studies to ensure appropriate application of these methods and we propose utilization of QIE methods to address broader foundational and applied questions in young driver safety.     

Do females pay attention to secondary sexual coloration in vervet monkeys (Chlorocebus aethiops)?

Several primate species show sexual dichromatism with males displaying conspicuous coloration of the pelage or skin. Studies of scrotal coloration in male vervet monkeys (Chlorocebus aethiops) suggest that it is an important intrasexual signal, with relatively dark, colourful males dominating paler males. To date, no studies have examined the influence of male colour on intersexual social interactions in vervet monkeys. The primary goal of the present study was to evaluate whether female vervet monkeys attend to male coloration. We experimentally introduced females, housed with either “pale” or “dark” males, to stimulus males whose scrota were pale, dark, or pale but painted to look dark. Overall, during introductions, females did not differ in time spent directing affiliative behaviour toward pale, dark, and painted males; however, females, permanently housed with dark males, spent significantly more time directing affiliative behaviour toward pale than painted males. When the stimulus male was pale, affiliative exchanges between males and females were longer than when the stimulus male was painted. Home male colour was not related to female-initiated aggression. Home male colour was also not related to male-initiated aggression, although painted stimulus males were more likely to initiate aggression than pale stimulus males. These findings lead us to conclude that females pay attention to male coloration, but do not bias their interactions toward males solely on the basis of natural male coloration.     

Remediation and future land use: Incorporating reuse considerations into Superfund activities

The U.S. Environmental Protection Agency (US EPA) is placing increased emphasis on the selection and implementation of remedies that accommodate the reasonably anticipated future use of contaminated land. These remedies result in the long‐term protection of human health and the environment. Postconstruction reuse of the land can significantly benefit communities in other ways as well. The launching of the Superfund Redevelopment Initiative in 1999 and the Return to Use Initiative in 2004 reflects an evolution in the US EPA's understanding of what actions can be taken to support the reuse of Superfund sites from discovery through long‐term stewardship. Through these initiatives, the US EPA has increased its understanding of site reuse and continues to explore and implement reuse assessment, reuse planning, and other tools effective in integrating reuse considerations with response activities throughout the remedial process. © 2005 Wiley Periodicals, Inc.     

Sex differences in survival costs of reproduction in a promiscuous primate

In sexually promiscuous mammals, female reproductive effort is mainly expressed through gestation, lactation, and maternal care, whereas male reproductive effort is mainly manifested as mating effort. In this study, we investigated whether reproduction has significant survival costs for a seasonally breeding, sexually promiscuous species, the rhesus macaque, and whether these costs occur at different times of the year for females and males, namely in the birth and the mating season, respectively. The study was conducted with the rhesus macaque population on Cayo Santiago, Puerto Rico. Data on 7,402 births and 922 deaths over a 45-year period were analyzed. Births were concentrated between November and April, while conceptions occurred between May and October. As predicted, female mortality probability peaked in the birth season whereas male mortality probability peaked in the mating season. Furthermore, as the onset of the birth season gradually shifted over the years in relation to climatic changes, there was a concomitant shift in the seasonal peaks of male and female mortality. Taken together, our findings provide the first evidence of sex differences in the survival costs of reproduction in nonhuman primates and suggest that reproduction has significant fitness costs even in environments with abundant food and absence of predation.     

Demographic shifts around drinking water supply reservoirs in North Carolina,USA

Infrastructure intended to serve the public good frequently has implications for environmental justice and social sustainability. Drinking water supplies for sub/urban areas in North Carolina, USA, have regularly been secured by constructing dams to impound reservoirs. We used high-resolution, publicly available US Census data to explore whether 66 such reservoirs in North Carolina have induced demographic shifts in the communities that find themselves adjacent to the newly created lakeshores. Our principal findings include: (1) The ratio of white people to non-white people was significantly higher in communities within 0.5 miles of reservoir shorelines than in more distant communities; (2) even as North Carolina overall became less white from 1990 to 2010, the ratio of white people to non-white people within the 0.5 miles of the shoreline increased relative to the overall ratio in the State; and (3) similar, but less distinct, shifts in per capita income occurred during the period. Our results are consistent with the proposition that reservoirs have induced demographic shifts in communities adjacent to newly created lakeshores similar to the shifts associated with environmental gentrification and amenity migration, and may now be associated with perpetuating those shifts. These findings raise concerns about environmental justice and social sustainability that should be considered when planning and building infrastructure that creates environmental amenities. Where reservoirs are being planned, social costs, including the costs of demographic shifts associated with environmental gentrification or amenity migration, and disproportionate regulatory burdens, should be mitigated through innovative policy if possible.     

Green Remediation or Sustainable Remediation: Moving From Dialogue to Common Practice

Different points of view have emerged concerning how to best consider and address the largely unexamined ancillary environmental impacts, and more particularly the social and economic impacts, of remediation activities. These views are generally categorized as “green remediation” and “sustainable remediation.” This article dissects the commonalities and differences between “green” and “sustainable” remediation approaches. Several key obstacles to the broader implementation of sustainable remediation practices are identified. Similarities identified among the two concepts offer a common ground and areas of collaboration. The objective of this article is to support maturation of the remediation industry by addressing the opposition to and supporting the implementation of sustainable remediation practices, including offering recommendations for a path forward. ©2015 Wiley Periodicals, Inc.     

A Comparison of Three Federal Datasets for Thermoelectric Water Withdrawals in the United States for 2010

Historically, thermoelectric water withdrawal has been estimated by the Energy Information Administration (EIA) and the U.S. Geological Survey's (USGS) water‐use compilations. Recently, the USGS developed models for estimating withdrawal at thermoelectric plants to provide estimates independent from plant operator‐reported withdrawal data. This article compares three federal datasets of thermoelectric withdrawals for the United States in 2010: one based on the USGS water‐use compilation, another based on EIA data, and the third based on USGS model‐estimated data. The withdrawal data varied widely. Many plants had three different withdrawal values, and for approximately 54% of the plants the largest withdrawal value was twice the smallest, or larger. The causes of discrepancies among withdrawal estimates included definitional differences, definitional noise, and various nondefinitional causes. The uncertainty in national totals can be characterized by the range among the three datasets, from 5,640 m³/s (129 billion gallons per day [bgd]) to 6,954 m³/s (158 bgd), or by the aggregate difference between the smallest and largest values at each plant, from 4,014 m³/s (92 bgd) to 8,590 m³/s (196 bgd). When used to assess the accuracy of reported values, the USGS model estimates identify plants that need to be reviewed.