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. 相似文献
Summary The ecological consequence of the effects of different social conditions on the behaviour of females with infants were examined in two different-sized groups of long-tailed macaques (Macaca fascicularis) that inhabited adjacent home ranges in Gunung Leuser National Park in Indonesia. This study aims to test predictions of the within-group competition/predation avoidance hypothesis of social organization. Females, particularly those carrying an infant, are considered to experience the most direct effects of environmental constraints on fitness prospects. Data on maintenance behaviour, height in canopy and spatial position were collected for five mothers in a small group and eight mothers in a large group. Comparisons were made on the basis of group size and dominance rank. Mothers from the large group spent less time feeding on clumped fruits and more time foraging on dispersed food items. Lower-ranking mothers, undergoing the highest rate of within-group competition, foraged most. For macaques in the study area, predation risk is considered to decrease with height in the canopy. Mothers in the small group, assumed to be more susceptible to predation, remained substantially higher in the canopy than mothers in the large group. In both groups, mothers adjusted their height to their spatial position in the group. Lower-ranking mothers were more often found without neighbours, presumably to avoid feeding competition. As a result they stay higher in the canopy than higher-ranking mothers. The results clearly demonstrate that individual females in the same reproductive state and living in the same area, but in different social environments, adapted their behaviour according to the hypothesis.
Correspondence to: D.R. Vos 相似文献
The aspirations, motivations and choices of individual European citizens are a major driver of the future of global, European and local land use. However, until now no land use study has explicitly attempted to find out how the general public wants to live in the future. This paper forms a first attempt to survey European citizens to understand their desired future lives in relation to consequences for European land use. We used a crowdsourcing experiment to elicit visions from young Europeans about their lives in 2040. Participants completed a graphic novel around carefully selected questions, allowing them to create a story of their imagined future lives in pictures. The methodology worked well, and the sample seemed reasonably representative albeit skewed towards an educated population. In total, 1131 responses from 29 countries were received. Results show a strong desire for change, and for more sustainable lifestyles. There is desire for local and ecologically friendly food production, to eat less meat, to have access to green infrastructure and the ability to cycle to work. However, international travel remains popular, and the desire for extensive food production and owning detached houses with gardens will likely result in complex land use trade-offs. Future work could focus more specifically on quantifying these trade-offs and inform respondents about the consequences of their lifestyle choices. This was a first attempt to use crowdsourcing to understand citizen visions for their lives in the future, and our lessons learned will help future studies improve representativeness and increase responses.
Today, environment pollution control is a matter of concern, everybody is willing to make a product that should be ecofriendly. Nowadays, water resources are full of untreated waste materials, discharge of hazardous and toxic dyes coming from textile and other chemical industries. These environmental hazards are difficult to remove by commercial water treatment plans, thus we need something that would present an efficient means for removal of these hazards. In this research paper, we have synthesize silver nanoparticle in a green way by using aqueous extract of Allium cepa (onion), and further these silver nanoparticle were tested for the catalytic degradation of various dyes by UV/Visible spectroscopy and silver nanoparticle showed reduction in dyes intensity after a particular period of incubation time. SEM and TEM, Particle size and Zeta potential analysis was done to analyze the surface morphology, particle size range and stability of the silver nanoparticle. Greenly synthesized silver nanoparticle was found to be spherical in shape, having particle size value ranged from 50 to 100 nm with a zeta potential value of ?29 mV. An EDX spectroscopy method was used to confirm the presence of silver nanoparticle in the synthesized material. An X-ray crystallography was done to ensure the crystallinity of the silver nanoparticle. Further an ATR-FTIR was performed to confirm the capping of the silver nanoparticle with the phenolic group of the onion. All these study emphasized that silver nanoparticle capped with onion (AgNPs@Ac) is the excellent catalyst for the reduction of hazardous and toxic dyes as well as they serve best purpose of the eco-friendly approach. 相似文献
Neonicotinoid pesticides were first introduced in the mid-1990s, and since then, their use has grown rapidly. They are now the most widely used class of insecticides in the world, with the majority of applications coming from seed dressings. Neonicotinoids are water-soluble, and so can be taken up by a developing plant and can be found inside vascular tissues and foliage, providing protection against herbivorous insects. However, only approximately 5% of the neonicotinoid active ingredient is taken up by crop plants and most instead disperses into the wider environment. Since the mid-2000s, several studies raised concerns that neonicotinoids may be having a negative effect on non-target organisms, in particular on honeybees and bumblebees. In response to these studies, the European Food Safety Authority (EFSA) was commissioned to produce risk assessments for the use of clothianidin, imidacloprid and thiamethoxam and their impact on bees. These risk assessments concluded that the use of these compounds on certain flowering crops poses a high risk to bees. On the basis of these findings, the European Union adopted a partial ban on these substances in May 2013. The purpose of the present paper is to collate and summarise scientific evidence published since 2013 that investigates the impact of neonicotinoids on non-target organisms. Whilst much of the recent work has focused on the impact of neonicotinoids on bees, a growing body of evidence demonstrates that persistent, low levels of neonicotinoids can have negative impacts on a wide range of free-living organisms. 相似文献
Global climate change, along with continued habitat loss and fragmentation, is now recognized as being a major threat to future
biodiversity. There is a very real threat to species, arising from the need to shift their ranges in the future to track regions
of suitable climate. The Important Bird Area (IBA) network is a series of sites designed to conserve avian diversity in the
face of current threats from factors such as habitat loss and fragmentation. However, in common with other networks, the IBA
network is based on the assumption that the climate will remain unchanged in the future. In this article, we provide a method
to simulate the occurrence of species of conservation concern in protected areas, which could be used as a first-step approach
to assess the potential impacts of climate change upon such species in protected areas. We use species-climate response surface
models to relate the occurrence of 12 biome-restricted African species to climate data at a coarse (quarter degree-degree
latitude-longitude) resolution and then intersect the grid model output with IBA outlines to simulate the occurrence of the
species in South African IBAs. Our results demonstrate that this relatively simple technique provides good simulations of
current species' occurrence in protected areas. We then use basic habitat data for IBAs along with habitat preference data
for the species to reduce over-prediction and further improve predictive ability. This approach can be used with future climate
change scenarios to highlight vulnerable species in IBAs in the future and allow practical recommendations to be made to enhance
the IBA network and minimize the predicted impacts of climate change. 相似文献
Major benefits were weighed against major costs associated with recent saltcedar control efforts along the Middle Pecos River,
New Mexico. The area of study was restricted to both sides of the channel and excluded tributaries along the 370 km between
Sumner and Brantley dams. Direct costs (helicopter spraying, dead tree removal, and revegetation) within the study area were
estimated to be $2.2 million but possibly rising to $6.4 million with the adoption of an aggressive revegetation program.
Indirect costs associated with increased potential for erosion and reservoir sedimentation would raise the costs due to increased
evaporation from more extensive shallows in the Pecos River as it enters Brantley Reservoir. Actions such as dredging are
unlikely given the conservative amount of sediment calculated (about 1% of the reservoir pool). The potential for water salvage
was identified as the only tangible benefit likely to be realized under the current control strategy. Estimates of evapotranspiration
(ET) using Landsat TM data allowed estimation of potential water salvage as the difference in ET before and after treatment,
an amount totaling 7.41 million m3 (6010 acre-ft) per year. Previous saltcedar control efforts of roughly the same magnitude found that salvaged ET recharged
groundwater and no additional flows were realized within the river. Thus, the value of this recharge is probably less than
the lowest value quoted for actual in-channel flow, and estimated to be < $63,000 per year. Though couched in terms of costs
and benefits, this paper is focused on what can be considered the key trade-off under a complete eradication strategy: water
salvage vs. erosion and sedimentation. It differs from previous efforts by focusing on evaluating the impacts of actual control
efforts within a specific system. Total costs (direct plus potential indirect) far outweighed benefits in this simple comparison
and are expected to be ongoing. Problems induced by saltcedar control may permanently reduce reservoir capacity and increase
reservoir evaporation rates, which could further deplete supplies on this water short system. These potential negative consequences
highlight that such costs and benefits need to be considered before initiating extensive saltcedar control programs on river
systems of the western United States. 相似文献
Abstract Passive samplers have been shown to be an inexpensive alternative to direct sampling. Diffusion denuders have been developed to measure the concentration of species such as ammonia (NH3), which is in equilibrium with particulate ammonium nitrate. Conventional denuder sampling that inherently requires air pumps and, therefore, electrical power. To estimate emissions of NH3 from a fugitive source would require an array of active samplers and meteorological measurements to estimate the flux. A recently developed fabric denuder was configured in an open tube to passively sample NH3 flux. Passive and active samplers were collocated at a dairy farm at the California State University, Fresno, Agricultural Research Facility. During this comparison study, NH3 flux measurements were made at the dairy farm lagoon before and after the lagoon underwent acidification. Comparisons were made of the flux measurements obtained directly from the passive flux denuder and those calculated from an active filter pack sampler and wind velocity. The results show significant correlation between the two methods, although a correction factor needed to be applied to directly compare the two techniques. This passive sampling approach significantly reduces the cost and complexity of sampling and has the potential to economically develop a larger inventory base for ambient NH3 emissions. 相似文献
Monitoring of cyclic volatile methylsiloxanes (cVMS) carried out at Anglian Water’s Broadholme sewage treatment plant (STP) is described. The method deployed used headspace gas chromatography/mass spectrometry (HS-GC/MS) and the addition of isotopically labelled cVMS to correct for partitioning in samples containing high levels of particulate and dissolved organic carbon. The method was capable of measuring cVMS in raw sewage samples, with recoveries of 80%, 85% and 71% respectively, for D4, D5 and D6. The limit of quantification was 0.2 μg L−1 for all three substances. Recoveries close to 100% were observed for all cVMS spiked into treated effluent (LOQ = 0.01 μg L−1). Despite the volatile nature of cVMS and its ubiquitous presence in the ambient atmosphere, the methods deployed showed excellent recoveries, reproducibility and quantification limits. A distinct diurnal variation in cVMS concentration, probably linked with the use of personal care products was observed for raw sewage but not in treated sewage effluent. The estimated per capita consumption of D5 (∼2.7 mg cap−1 d−1) derived for the population served by this plant was significantly lower than that derived in the Environment Agency (UK) risk assessment (11.6 mg cap−1 d−1). The cVMS were highly removed during sewage treatment with efficiencies greater than 98%. The methods and findings of this pilot study can be used as the basis for future studies on the fate of cVMS substances in STPs. 相似文献