Efficiency of perchlorate consumption in road flares, propellants and explosives

When an explosive detonates or a propellant or flare burns, consumption of the energetic filler should be complete but rarely is, especially in the presence of large amounts of non-combustible materials. Herein we examine three types of perchlorate-containing devices to estimate their potential as sources of contamination in their normal mode of functioning. Road flares, rocket propellants and ammonium nitrate (AN) emulsion explosives are potentially significant anthropogenic sources of perchlorate contamination. This laboratory evaluated perchlorate residue from burning of flares and propellants as well as detonations of ammonium nitrate emulsion explosives. Residual perchlorate in commercial products ranged from 0.094 mg perchlorate per gram material (flares) to 0.012 mg perchlorate per gram material (AN emulsion explosives). The rocket propellant formulations, prepared in this laboratory, generated 0.014 mg of perchlorate residue per gram of material.     

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r ² = 0.79–0.91) and CR-24 (r ² = 0.76–0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP.     

A framework for valuing the health benefits of improved bathing water quality in the River Irvine catchment

A simple model predicting bathing water concentrations of Escherichia coli from livestock in the Irvine catchment in SW Scotland has been adapted for intestinal enterococci (IE). This has been used to predict risk of bather illness by extrapolation of published data on bather IE exposure vs incidence of gastro-enteritis. Simulated reduction in the risk of illness by reduced faecal loading was multiplied by a willingness to pay for risk reduction to estimate the annual benefits of mitigation. Health benefits of reducing loading by 75% at Irvine Beach were estimated by a willingness to pay method to be about pound 276k pa. Estimated annualised costs of diffuse pollution mitigation measures across the catchment were higher (> pound 1m), and it is very unlikely that 75% mitigation is achievable with current stocking rates. Further work should explore the influence of uncertainty of model parameters, and use emerging epidemiological information on specific zoonotic pathogens such as E. coli O157 and Cryptosporidium. Other components of the value of clean water should also be included to obtain a complete estimate of the cost:benefit of mitigation.     

CO2 embodied in trade: trends and fossil fuel drivers

Environmental Science and Pollution Research - The amount of CO2 embodied in trade has substantially increased over the last decades. We contribute to understanding the reasons for this evolution...     

Spawning and larval development of the black turban snail Tegula funebralis (Prosobranchia: Trochidae)

An understanding of spawning and larval development can be fundamental to interpreting the abundance, distribution, and population structure of marine invertebrate taxa. Tegula funebralis (A. Adams, 1855), the black turban snail, has been the focus of numerous ecological studies on the Pacific coast of North America. To date, there are only conflicting and anecdotal reports of spawning, and there is no information on larval or juvenile development for this conspicuous and abundant species. On 19 September 1995, two individuals of T. funebralis were observed free-spawning gametes into seawater in tanks at the Oregon Institute of Marine Biology. Embryos and larvae were subsequently reared to metamorphosis and beyond. Development was pelagic and similar to development described for other trochids, and larvae were observed not to feed at any stage. Larvae began to metamorphose at 5.7 to 6.7 d and settled at 260 μm shell length. Juveniles grew ≃ 10 μm in shell length per day and appeared to feed on detritus. Juveniles lacked some adult diagnostic shell characters, including two columellar nodes and a closed umbilicus. In the field, small (<3 mm) juveniles occurred in the adult habitat on all sampling dates between October and March. Small juveniles were found only under rocks and were most abundant under rocks partially buried in coarse sand, suggesting that juveniles may utilize a specific microhabitat within the adult T. funebralis habitat. Received: 7 October 1996 / Accepted: 17 October 1996     

Seasonal variation in territorial response,and other aspects of the ecology of the Australian temperate pomacentrid fish Parma microlepis

The Australian temperate pomacentrid fish Parma microlepis Gunther maintains permanent, interspecifically defended territories. Breeding occurs in late spring (October to December), and juveniles after a pre-settling period of 4 to 6 weeks take up territories in the adult habitat. P. microlepis feed in their territories on benthic algae and invertebrates. Density of fish is significantly correlated with the availability of suitable shelter. There is a variation in the territorial response directed at different species, and a significant correlation exists between intensity of response to a species and its similarity to P. microlepis in use of living space. No significant correlation exists between intensity of response and dietary similarity. P. microlepis defends larger areas in the breeding than in the non-breeding season against those species which represent a possible threat to its breeding success. It shows a reduced tendency to attack juvenile conspecifics at the time of year when they would be settling from the plankton. Responses to species not likely to interfere with breeding success do not vary through the year. P. microlepis is thus seen to have complex territorial responses, specific to the species of intruder and time of year. In this it is quite similar to other territorial pomacentrids (chiefly tropical) for which information exists.     

Impact of improving vehicle front design on the burden of pedestrian injuries in Germany,the United States,and India

Objective: European car design regulations and New Car Assessment Program (NCAP) ratings have led to reductions in pedestrian injuries. The aim of this study was to evaluate the impact of improving vehicle front design on mortality and morbidity due to pedestrian injuries in a European country (Germany) and 2 countries (the United States and India) that do not have pedestrian-focused NCAP testing or design regulations.

Methods: We used data from the International Road Traffic and Accident Database and the Global Burden of Disease project to estimate baseline pedestrian deaths and nonfatal injuries in each country in 2013. The effect of improved passenger car star ratings on probability of pedestrian injury was based on recent evaluations of pedestrian crash data from Germany. The effect of improved heavy motor vehicle (HMV) front end design on pedestrian injuries was based on estimates reported by simulation studies. We used burden of disease methods to estimate population health loss by combining the burden of morbidity and mortality in disability-adjusted life years (DALYs) lost.

Results: Extrapolating from evaluations in Germany suggests that improving front end design of cars can potentially reduce the burden of pedestrian injuries due to cars by up to 24% in the United States and 41% in India. In Germany, where cars comply with the United Nations regulation on pedestrian safety, additional improvements would have led to a 1% reduction. Similarly, improved HMV design would reduce DALYs lost by pedestrian victims hit by HMVs by 20% in each country. Overall, improved vehicle design would reduce DALYs lost to road traffic injuries (RTIs) by 0.8% in Germany, 4.1% in the United States, and 6.7% in India.

Conclusions: Recent evaluations show a strong correlation between Euro NCAP pedestrian scores and real-life pedestrian injuries, suggesting that improved car front end design in Europe has led to substantial reductions in pedestrian injuries. Although the United States has fewer pedestrian crashes, it would nevertheless benefit substantially by adopting similar regulations and instituting pedestrian NCAP testing. The maximum benefit would be realized in low- and middle-income countries like India that have a high proportion of pedestrian crashes. Though crash avoidance technologies are being developed to protect pedestrians, supplemental protection through design regulations may significantly improve injury countermeasures for vulnerable road users.     

On the influence of chemical initial and boundary conditions on annual regional air quality model simulations for North America

The influence of chemical initial conditions and chemical lateral boundary conditions (CLBCs) on long-term regional air quality model simulations was investigated using outputs from an annual simulation of the year 2002 on a North American domain. This simulation was carried out using the AURAMS regional air quality model. It was subdivided into three multi-month segments with two overlap periods (May 15–30 and September 1–30) to allow the segments to be run in parallel. For this approach to work, model predictions had to match very closely by the end of the two-week and four-week overlap periods. The time required for the values of daily domain-average surface PM_2.5 concentration to match for the two simulation segments associated with each of the two overlap periods was four and six days, respectively. For individual locations within the model domain, however, the required spin-up period was as much as nine days, considerably longer than the 2–4-day spin-up period usually assumed in the literature. For ozone, on the other hand, the daily domain-average surface ozone concentration values did not converge for either overlap period. A zero-gradient CLBC had been used for all run segments and species. When a time-invariant CLBC for ozone was used instead, the daily domain-average surface ozone concentration values behaved more realistically and did converge after fewer than three days. A similar improvement was also obtained for individual locations, but with spin-up periods of up to nine days. Model chemical spin-up time thus seems to be dependent on the species considered, the time required for the influence of the inflow boundaries to reach all locations within the domain, and the impact of local emissions sources. These results suggest the use of a spin-up period of longer than one week for a large (continental) domain and long-term simulation of PM_2.5 and O₃ rather than the 2–4 days commonly assumed in the literature.     

VOLATILE ORGANIC COMPOUNDS IN GROUND WATER FROM RURAL PRIVATE WELLS, 1986 TO 19991

ABSTRACT: The U.S. Geological Survey (USGS) collected or compiled data on volatile organic compounds (VOCs) in samples of untreated ground water from 1,926 rural private wells during 1986 to 1999. At least one VOC was detected in 12 percent of samples from rural private wells. Individual VOCs were not commonly detected with the seven most frequently detected compounds found in only 1 to 5 percent of samples at or above a concentration of 0.2 microgram per liter (μg/l). An assessment level of 0.2 μg/l was selected so that comparisons of detection frequencies between VOCs could be made. The seven most frequently detected VOCs were: trichloromethane, methyl tert‐butyl ether, tetrachloroethene, dichlorodifluoromethane, methylbenzene, 1,1,1‐trichloroethane, and 1,2‐dibromo‐3‐chloropropane. Solvents and trihalomethanes were the most frequently detected VOC groups in private wells. The distributions of detections of gasoline oxygenates and fumigants seemed to be related to the use patterns of compounds in these groups. Mixtures were a common mode of occurrence of VOCs with one‐quarter of all samples with detections including two or more VOCs. The concentrations of most detected VOCs were relatively small and only 1.4 percent of samples had one or more VOC concentrations that exceeded a federally established drinking water standard or health criterion.     

Effect of soil compaction on organic carbon amounts and distribution, South-Central Iowa

Soils on the Mormon Trail have been compacted for over 150 years. Bulk density, carbon, and nitrogen samples were taken in 5-cm increments to 20 cm. Bulk density was determined using rings of known volume; total carbon and nitrogen with a LECO CHN-600. Total above ground biomass (AGB) samples were collected by clipping vegetation within a 0.25 m2 frame and were analyzed for carbon. Statistical comparisons were made using a t-test (alpha = 0.05). Bulk density was higher in the on-trail soils from 5 to 20 cm; soil carbon and C/N ratios were higher in the off-trail soils from 10 to 20 cm. AGB and AGB carbon is significantly less on the trail. Results indicate the compacted layer on the trail alters the soil carbon pool by limiting additions of fresh organic matter to the soil, limiting vegetative production, and by "pooling" carbon additions in the upper 10 cm of the soil.