The influence of seawater temperature on zooid size and growth rate in Pentapora fascialis (Bryozoa: Cheilostomata)

Zooid size variation and growth banding in the bryozoan Pentapora fascialis, collected from the South of Great Britain to the South of Italy, were investigated in order to test their relationship with the variation of seawater temperature. Zooid length appeared to be more sensitive than zooid area and width to temperature variation. The longest zooids were budded in localities that typically experience low seasonal variation in temperature (3.2–7.5°C) and low mean annual temperature (about 11°C). Zooid length demonstrated the strongest relationship with the range of seasonal variation in temperature rather than the mean annual temperature. Growth bands produced during colder months were less high than those produced during warmer months. Measurements of these alternating bands were used to calculate growth rate of the laminae, ranging from 20.7 at Plymouth to 29.3 mm year⁻¹ at Tino Island. Significant differences in zooid length were found between the two bands, with longer zooids within the band developed in colder months and shorter zooids in bands produced in the warmer period. We conclude that zooid size can be used as an environmental proxy of the seasonal temperature regimes experienced by the species.     

Decrease of Pb bioavailability in solis by addition of phosphate ions

Bioavailability of Pb in contaminated soils can be highly decreased by conversion of labile Pb species into pyromorphite Pb₅(PO₄)₃Cl, induced by amendment with a phosphate source. However, PO₄ ³⁻ can be specifically adsorbed on goethite α-Fe(OH)₃ present in soils. We demonstrate that despite the stability of phosphate ions adsorbed on goethite surface, the reaction between goethite-adsorbed phosphates and aqueous lead in the presence of Cl⁻ results in crystallization of pyromorphite. Two morphological forms of pyromorphite formed on goethite were observed: 1) incrustations, indicating direct reaction of Pb and Cl ions with PO₄ ³⁻ adsorbed on goethite surface, and 2) aggregates of pyromorphite crystals indicating that the reaction with PO₄ ³⁻ ions took place in the volume of the solution. This suggests that precipitation of pyromorphite is faster than desorption of phosphates and that aqueous Pb may serve as a sink for phosphate ions by shifting the equilibrium and inducing PO₄ ³⁻ desorption.     

塔基图穆保护区——库克群岛的社区所属生态旅游明星

塔基图穆保护区 1996年创建于库克群岛的拉罗汤加岛 , 其目标是为了当前和未来生产者的利 益而对生物多样性实施保护 . 只有当地人民对其土地和资源拥有所有权 . 生态旅游将成为该 保护区的主要经济活动 . 在土地所有者同意和支持下 , 一个有指导的 " 大自然漫步 " 已经组 织起来 .     

Pilot study of sources of lead exposure in Moscow,Russia

This preliminary investigation of sources of lead exposure in Moscow, Russia, by Russian and US collaborators measured lead in paint, interior dust, and drinking water in seven day-care centres, and in petrol, soil and canned food. Some paint samples exceeded US regulatory standards for lead in paint on surfaces (0.5%). Dust lead loadings were < 1.7 g cm^–2 and below the guidance levels of the US EPA. Drinking water lead concentrations were at or below the US drinking water standard of 15 g L^–1. Lead concentrations in petrol from Moscow vehicles and petrol stations were consistent with a regulation banning the sale of leaded petrol within the Moscow City limits. Except for baby food, lead levels were higher in the Russian canned foods (range 6 to 1240 g kg^–1, dry weight) compared to corresponding US canned foods, with ratios of Russian to US levels of up to 120:1 for evaporated milk. Lead concentrations in soil generally ranged from 500 to 2000 g g^–1, levels that would trigger hazard reduction measures according to US EPA guidance. These findings, together with the use of lead in petrol outside Moscow, indicate multiple sources of lead exposure in Russia. Priorities for future research are discussed including the establishment of interlaboratory quality control programmes.     

Acute injuries resulting from accidents involving powered mobility devices (PMDs)—Development and outcomes of PMD-related accidents in Sweden

Objective: Powered mobility devices (PMDs) are commonly used as aids for older people and people with disabilities, subgroups of vulnarable road users (VRUs) who are rarely noted in traffic safety contexts. However, the problem of accidents involving PMD drivers has been reported in many countries where these vehicles have become increasingly popular.

The aim of this study is to extract and analyze national PMD-related accident and injury data reported to the Swedish Traffic Accident Data Acquisition (STRADA) database. The results will provide valuable insight into the risks and obstacles that PMD drivers are exposed to in the traffic environment and may contribute to improving the mobility of this group in the long term.

Methods: The current study is based on data from 743 accidents and 998 persons. An analysis was performed on a subset of data (N?=?301) in order to investigate the development of accidents over a period of 10 years. Thereafter, each accident in the whole data set was registered as either single (N?=?427) or collision (N?=?315).

Results: The results show that there was a 3-fold increase in the number of PMD-related accidents reported to STRADA during the period 2007–2016.

With regard to single accidents, collisions, as well as fatalities, the injury statistics were dominated by males. Single accidents were more common than collisions (N?=?427 and N?=?316, respectively) and the level of injury sustained in each type of accident is on par.

The vast majority of single accidents resulted in the PMD driver impacting the ground (87%), due to either PMD turnover (71%) or the driver falling out of the PMD (16%). The reason for many of the single accidents was a difference in ground level (34%, typically a curb).

Cars, trucks, or buses were involved in 67% of collision events; these occured predominantly at junctions or intersections (70%).

Abbreviated Injury Scale (AIS) 3+ injuries were dominated by hip and head injuries in both single accidents and collision events.

Conclusions: The present study shows that further research on PMD accidents is required, with regard to both single accidents and collision events. To ensure that appropriate decisions are made, future work should follow up on injury trends and further improve the quality of PDM-related accident data. Improved vehicle stability and design, increased usage of safety equipment, proper training programs, effective maintenance services, and development of a supporting infrastructure would contribute to increased safety for PMD drivers.     

The effect of consumption of pork enriched by organic selenium on selenium status and lipid profile in blood serum of consumers

Abstract

The aim of the research was to evaluate the effect of consumption of selenium-enriched pork on selected health indicators of probands. The intake of feed mixture with increased organic selenium at the dose of 0.3?mg.kg^?1 probably increases selenium concentration in MSM (musculus semimembranosus). In the pork enriched with organic selenium, the concentration was higher by 1.045?±?0.10?mg.kg^?1 compared with the control group 0.701?±?0.05?mg.kg^?1 at significance P?<?0.001. Sixteen participants in the experiment were represented by 8 men at the average age of 41.5?±?11.9?years and 8 women at the average age of 41.4?±?7.9?years. All the probands consumed meat enriched with selenium three times a week during one month. By consumption of the enriched pork, there was an increase of the selenium concentration in blood serum of probands traced with selenium increase from 73.19?±?15.68?μg.L^?1 to 73.73?±?15.13?μg.L^?1 (P?>?0.05). From the results we can see that consumption of enriched pork with selenium was significantly manifested in lowering of total cholesterol levels, which was associated with LDL cholesterol lowering (P?<?0.05). Differences among the HDL cholesterol and triglycerides samples were not significant.     

Airborne emissions of mercury from municipal solid waste. I: new measurements from six operating landfills in Florida

Mercury-bearing material enters municipal landfills from a wide array of sources, including fluorescent lights, batteries, electrical switches, thermometers, and general waste; however, the fate of mercury (Hg) in landfills has not been widely studied. Using automated flux chambers and downwind atmospheric sampling, we quantified the primary pathways of Hg vapor releases to the atmosphere at six municipal landfill operations in Florida. These pathways included landfill gas (LFG) releases from active vent systems, passive emissions from landfill surface covers, and emissions from daily activities at each working face (WF). We spiked the WF at two sites with known Hg sources; these were readily detected downwind, and were used to test our emission modeling approaches. Gaseous elemental mercury (Hg(O)) was released to the atmosphere at readily detectable rates from all sources measured; rates ranged from approximately 1-10 ng m(-2) hr(-1) over aged landfill cover, from approximately 8-20 mg/hr from LFG flares (LFG included Hg(O) at microg/m3 concentrations), and from approximately 200-400 mg/hr at the WF. These fluxes exceed our earlier published estimates. Attempts to identify specific Hg sources in excavated and sorted waste indicated few readily identifiable sources; because of effective mixing and diffusion of Hg(O), the entire waste mass acts as a source. We estimate that atmospheric Hg releases from municipal landfill operations in the state of Florida are on the order of 10-50 kg/yr, substantially larger than our original estimates, but still a small fraction of current overall anthropogenic losses.     

Airborne emissions of mercury from municipal solid waste. II: potential losses of airborne mercury before landfill

Waste distribution and compaction at the working face of municipal waste landfills releases mercury vapor (Hg(o)) to the atmosphere, as does the flaring of landfill gas. Waste storage and processing before its addition to the landfill also has the potential to release Hg(o) to the air if it is initially present or formed by chemical reduction of Hg(II) to Hg(o) within collected waste. We measured the release of Hg vapor to the atmosphere during dumpster and transfer station activities and waste storage before landfilling at a municipal landfill operation in central Florida. We also quantified the potential contribution of specific Hg-bearing wastes, including mercury (Hg) thermometers and fluorescent bulbs, and searched for primary Hg sources in sorted wastes at three different landfills. Surprisingly large fluxes were estimated for Hg losses at transfer facilities (approximately 100 mg/hr) and from dumpsters in the field (approximately 30 mg/hr for 1000 dumpsters), suggesting that Hg emissions occurring before landfilling may constitute a significant fraction of the total emission from the disposal/landfill cycle and a need for more measurements on these sources. Reducing conditions of landfill burial were obviously not needed to generate strong Hg(o) signals, indicating that much of the Hg was already present in a metallic (Hg(o)) form. Attempts to identify specific Hg sources in excavated and sorted waste indicated few readily identifiable sources; because of effective mixing and diffusion of Hg(o), the entire waste mass acts as a source. Broken fluorescent bulbs and thermometers in dumpsters emitted Hg(o) at 10 to >100 microg/hr and continued to act as near constant sources for several days.     

Multivariate characterization of polycyclic aromatic hydrocarbons using semi-empirical molecule orbital calculations and physical data

Multivariate characterization of 60 polycyclic aromatic hydrocarbons (PAHs) was performed using data from literature and semi-empirical molecular orbital calculations. This dataset was analyzed by principal component analysis and projections to latent structures by means of partial least square. The PAHs were found to distribute in the chemical domain in several groups mainly governed by the number of aromatic rings and the number of five-membered rings. The multivariate model and training set was used to predict GC retention times on a non-polar column (DB-5). Using a 2(4) experimental design on the principal components of the chemical characterization model, a test set of PAHs was selected dependent on the distribution in the chemical domain of the PAHs. Such a test set is expected to improve selection of PAHs for future testing and modeling of both biological and chemical responses. Although the model of GC retention times was good, the precision was however not good enough for practical use.     

Environmental labeling of car tires--toxicity to Daphnia magna can be used as a screening method

Car tires contain several water-soluble compounds that can leach into water and have toxic effects on aquatic organisms. Due to tire wear, 10,000 tonnes of rubber particles end up along the Swedish roads every year. This leads to a diffuse input of emissions of several compounds. Emissions of polyaromatic hydrocarbons (PAHs) are of particular concern. PAHs are ingredients of the high aromatic oil (HA oil) that is used in the rubber as a softener and as a filler. The exclusion of HA oils from car tires has started, and an environmental labeling of tires could make HA oils obsolete. The toxicity to Daphnia magna from 12 randomly selected car tires was tested in this study. Rubber from the tread of the tires was grated into small pieces, to simulate material from tire wear, and the rubber was equilibrated with dilution water for 72 h before addition of test organisms. The 24-h EC50s of the rubber pieces ranged from 0.29 to 32 gl-1, and the 48-h EC50s ranged from 0.0625 to 2.41 gl-1. Summer tires were more toxic than winter tires. After the 48-h exposure, the daphnids were exposed to UV-light for 2 h, to determine if the tires contained compounds that were phototoxic. After UV-activation the EC50s ranged from 0.0625 to 0.38 gl-1. Four of the 12 tires had a very distinct photoactivation, with a toxicity increase of >10 times. This study has shown that the used method for toxicity testing with Daphnia magna according to ISO 6341 could be used as a basis for environmental labeling of car tires.