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Researchers have assessed the phyto-toxic effects of copper nanoparticles on vegetables grown within urban gardens, comparing increasing doses of these nanoparticles to simulate potential aerial deposition to extreme pollution of CuO-NP in a range of increasing exposure periods. Lettuce and cabbage absorbed high amounts of copper nanoparticles, after 15 days of exposure, which interfered with photosynthesis, respiration and also reduced growth. Under the specific exposure conditions of the study the researchers indicate that metal nanoparticles could lead to potential health risks to humans from the contamination of crops from pollution.
A new study has assessed the vulnerability of 571 European cities to heatwaves, droughts and flooding caused by climate change. The causes of vulnerability differ across Europe and the researchers say the results could be used to design policies to mitigate the impacts.
A new study has looked at the potential of green infrastructure to compensate for the effects of soil sealing generated by urban development. It investigates how green roofs and permeable paving could contribute to flood mitigation in southern Italy. Using a hydraulic model technique, the researchers found that, in this particular urban case, green roofs were more effective than permeable paving. Policies to promote the adoption of sustainable urban drainage systems (SUDS) by the private sector could thus prove more effective under certain circumstances, and policymakers should look at ways to promote SUDS where suitable.
Analysis of the operation of a novel, micro-scale anaerobic digester has shown that this technology could provide a useful means of processing food waste in urban areas. The study found that the digester, located in London and fed mainly with local food waste, avoided 3.9 tonnes of greenhouse gas emissions, while providing biogas for cooking, heat and power. Anaerobic digestion on this scale could play a part in reducing the amount of food waste that goes to landfill1 and contribute to the circular economy.
The move towards smart mobility systems in cities across Italy, specifically in relation to public transport systems (including cycle infrastructure, and cycle and car-sharing schemes) has been assessed in a new study. The researchers say significant progress has been made in light of new guidelines imposed by the European Union, which is often linked to financial investment, as well as the capacity of city planners to implement changes.
Researchers have shown that emissions from vehicles can react with emissions from urban trees and other plants, resulting in a decrease in air quality in cities in summer; this reduces the otherwise positive impacts of urban vegetation. The study, conducted in Berlin, showed that during a July heatwave, 20% of ozone concentrations were due to emissions of volatile organic compounds (VOCs) from vegetation interacting with other pollutants. To reduce this effect, lowering emissions of these other pollutants is crucial.
Researchers have compared the findings of a citizen-science project and a long-running butterfly monitoring scheme in the UK to gain insights into the reliability of data gathering by the public. They found that — contrary to the scepticism with which such projects are sometimes viewed — much of the citizen-recorded data agreed with the findings of more formal monitoring, particularly for species often found in gardens. This indicates that mass-participation sampling not only provides a valuable tool for public engagement, but, in this case, could also provide valid data to inform butterfly conservation.
The available and emerging renewable technologies suitable for urban environments have been assessed in a recent study. Wind and solar technology can now be integrated into building design, and smart grids and metering can more efficiently manage energy production and demand at a local level. Investing in community-level renewable-energy projects can, therefore, help meet the future energy needs of towns and cities.
Water-supply planning that considers the preferences of multiple stakeholders under uncertain and variable future conditions are more robust than planning decisions based on historical conditions, a recent study has stated. Using the Thames river basin in the UK as an example, the researchers present a new computer-modelling approach to assess which combinations of water-management measures best secure future water supply under a wide range of possible future conditions.
Reusing waste water for non-drinking uses in decentralised plumbing networks may improve the efficiency of water supply in urban areas, a new study has found. Modelling this approach in San Francisco, researchers found that, depending on the local geography, a decentralised water supply could lead to energy savings and reductions in greenhouse gas emissions from water treatment of around 30%. Improvements in emerging water-treatment technologies are likely to lead to further savings, which could help increase the efficiency of urban water supply.
A participatory approach to waste management has been tested in Naples, Italy, a city which has experienced ongoing problems with the collection of municipal waste. This study tested a toolkit, which uses stakeholder engagement to improve waste-management decision-making. Residents and other stakeholders supported the use of a technological innovation to develop biomass fuel from municipal waste.
New figures on how much titanium dioxide nanomaterial (TiO2-NM) could be released into the environment from photocatalytic cement — a new type of self-cleaning cement — are presented in a recent study. Based on experimental test results, the researchers estimate that between 0.015% and 0.033% of photocatalytic cement’s TiO2-NM content could potentially escape over several years of cement use, depending on the level of cement porosity. The study could help inform environmental risk assessment of TiO2-NM, as well as safer design of nano-products (i.e. commercialised products incorporating nanomaterials).
Natural water-retention measures, which ‘keep the rain where it falls’, have great potential to be used as part of flood-risk management plans. But their benefits for downstream urban areas can bring costs to the upstream agricultural areas where they are installed, a recent analysis explains. The researchers behind this analysis suggest that we need new and/or improved policies and institutions to oversee the trade-offs and benefits for agriculture and flood management, and a better scientific understanding of the measures’ likely impact on urban flood risk.
As the sources and severity of noise pollution continue to grow, there is a need for new approaches to reduce exposure. This Future Brief looks at the complex and pervasive problem of noise pollution: a problem with no single solution, requiring a combination of short-, medium- and long-term approaches and careful consideration of the nature of the noise source.
The effect on bats of the replacement of mercury lamps with light-emitting diodes (LEDs) in street lighting has been investigated in a recent study. Artificial light affects bat species differently and the activity of species normally more sensitive to light were affected less by the new LED street lamps than by traditional mercury lamps. Use of LEDs may, therefore, help to reduce the impacts of outdoor lighting on light-sensitive bats, if used at an appropriate level.
A method for assessing urban neighbourhoods’ resilience to flooding has been presented in a recent study. The method identifies features of urban landscapes that contribute to three elements of flood resilience: resistance, absorption and recovery. In a German case study, the tool shows that the features which make a waterfront neighbourhood of Hamburg more flood resilient include high bridges, open public spaces and flood-protected basements.
A recent study has found that bumblebees in Saxony-Anhalt, Germany are more successful at pollinating urban areas than agricultural land. Urban areas also had higher flower diversity and more potential nesting areas for bees compared to agricultural areas. However, the abundance of bee parasites was also higher in urban areas, although this was not found to negatively impact on pollination. This demonstrates the value of urban green spaces as habitat for pollinators.
No cities are yet fully car-free, but many have managed or plan to restrict access to city centres for privately owned combustion-engine passenger cars. Health benefits will come from reduced traffic-related air pollution, less noise and lower levels of heat emitted from vehicles. The greatest health benefit, however, is likely to come from increased physical activity as people walk, cycle and move to catch public transport, according to a review of the potential health benefits of car-free cities.
Researchers have estimated that, annually, almost 3 000 deaths (i.e. 20% of mortality) in Barcelona, Spain, are premature, and would be preventable if residents lived in urban environments that met international exposure recommendations for physical activity, air pollution, noise, heat and access to green spaces. The results emphasise the need to reduce motorised traffic, promote active and public transport, and provide adequate green space to encourage exercise and mitigate the impacts of environmental hazards in cities.
Street lighting reduces the number of moths at ground level and increases flight activity at the level of the lights, shows new research. Less pollen was transported by moths at lit sites in the UK study as a result of the disruptive effects on moth behaviour. The study highlights the need to consider both the direct and indirect ecological impacts of artificial light.
Lower socioeconomic status is generally associated with poorer health, and both air and noise pollution contribute to a wide range of other factors influencing human health. But do these health inequalities arise because of increased exposure to pollution, increased sensitivity to exposure, increased vulnerabilities, or some combination? This In-depth Report presents evidence on whether people in deprived areas are more affected by air and noise pollution — and suffer greater consequences — than wealthier populations.
Urban gardeners in Barcelona, Spain, identified 20 ecosystem service benefits, from pollination to environmental learning, in a recent study. Cultural ecosystem services — mainly related to the opportunity for residents to interact with nature — were the most common and highly valued of the ecosystem services identified.
Researchers have presented a comprehensive new classification manual of asbestos-containing products (ACP), materials (ACM) and waste (ACW) in a recent study. They also mapped suitable landfill sites for the proper disposal of ACW in Italy and developed guidance on assigning ACW to correct European Waste Catalogue (EWC) codes. The research will help operators engaged in asbestos waste disposal across Europe and should contribute to aims for the total removal of asbestos from the EU.
Weathering of treated wood and other construction materials can lead to the release of chemicals into the environment. Researchers have investigated the release of biocides from wood and roof paints, demonstrating that the amount of water in contact with exposed surfaces is a key factor in determining the level of active chemicals released. The study provides guidance for testing biocidal products in line with the European Biocidal Products Regulation.
Global interest in urban agriculture is growing. However, the importance of local context is not reflected in current governance approaches, argues a new study which evaluated urban agriculture in Belgium and Poland. The authors say that considering city-specific factors can help urban agriculture achieve its full potential, and recommend a broader policymaking strategy that considers the benefits beyond food production.
People who live in the most ‘activity-friendly’ neighbourhoods do up to 1.5 hours more physical activity a week than those in the least supportive neighbourhoods. This is according to a new international study which measured levels of exercise — mainly walking for recreation or transport — in relation to the urban environment across 14 diverse cities. The results show how urban design — such as parks and local amenities — can promote healthy lifestyles which also bring environmental benefits, such as better air quality, through reduced car use.
Constructed wetlands are used in many countries as green infrastructure to treat waste water, but may also be biodiversity hotspots, a new study suggests. This study reports on a constructed wetland in an urban area of Italy, which increased the number of plant taxa — including several plants of conservation concern — by over 200%. The researchers say the ability of constructed wetlands to enhance biodiversity could support local development.
Artificial light — such as street lighting and passing car headlights — has an impact on plants. A new study suggests there could also be broader implications for the interactions of herbivores and pollinators. The study highlights that disrupting seasonal light cues with artificial light has far-reaching effects, including: mismatches in timing with herbivores; altering the development of agricultural crops; inhibiting flowering in wild species; decreasing periods of darkness necessary for plant repair from environmental pollutants; and causing barriers to nocturnal pollinator species.
Land and soil are limited natural resources essential to all human life. One of the major environmental challenges facing Europe is an increasing demand for development, which threatens ecosystem services. This Future Brief focuses on how land and soil could be used efficiently to continue to provide these functions and services for generations to come.
Underground trains are among the most widely used public transport systems in cities worldwide. A study investigating the chemical composition and source of particles in Barcelona subway stations found that a new station design, with sliding doors that separate the platform from the tunnel and good ventilation, reduced the concentration of fine particulate matter (PM2.5) by over 50% compared with older station designs.
The economic costs of replacing energy inefficient high-pressure mercury (HPM) lamps, used in outdoor lighting, with more efficient alternatives have been explored in a recent study. High-pressure sodium (HPS) lamps would be more cost effective than light-emitting-diode (LED) technology, although the researchers say LEDs could become more economical in the future.
Cool pavements, which can be used to reduce the Urban Heat Island (UHI) effect, where towns and cities are warmer than surrounding rural areas, have been reviewed in new research. The review found that reflective pavements can reduce temperatures by up to 20°C and are more durable than evaporative pavements, which are less effective at temperature reduction but may have other benefits, such as reducing runoff.
Research using the Environmental Quality Index (EQI) linked increased risk of preterm birth with poor air quality, but not with overall low environmental quality. The study is one of the first to explore the relationship between preterm birth and environmental quality across a range of different environmental domains (including water, air, land, built environment and sociodemographic aspects).
The health risks associated with climate-induced changes to indoor environments are explored in a new study. UK-based researchers synthesised findings of how climate change — and mitigation and adaptation measures — might affect the inside of buildings, through overheating, air quality, allergies and infections, flood risk and other exposure risks.
Greenbelt policies in Germany, used to curb urban sprawl, are effective in protecting open spaces and the valuable natural resources they cover, a new study has found. Nevertheless, urban development can ‘leapfrog’ greenbelts, hopping over them into areas with less restrictive planning policies. Researchers recommend that such areas are also included in urban development control plans.
Living near to green spaces may reduce likelihood of death due to any cause, and especially due to cardiovascular disease, according to a new study. The review is the first to systematically evaluate the evidence linking green spaces to risk of death.
Dense urban environments have significant resource-saving potential and serve as good platforms for climate change mitigation. This study reviewed an initiative to improve use of energy and water in Rotterdam, highlighting factors important for success including exchanges in close geographic proximity and private-sector participation.
Hydrocarbons are precursors to hazardous air pollutants including ozone and particulate matter. Hydrocarbons from diesel make up over 50% of all hydrocarbons in the air in London, a new study has found. The authors also estimate that they contribute up to half of total ozone production potential in London, and say future air quality control strategies must focus more on these pollutants.
Measurements of individual vehicle emissions are usually made in laboratory tests. In this study, researchers followed cars driving in real conditions to measure emissions of air pollutants, including black carbon and nitrogen oxides. The study shows that diesel cars contribute disproportionately to air pollution, and highlights the value of on-road measurements.
The emissions of two perfluoroalkyl acids (PFAAs) into the Danube River Basin have been estimated in a test of four different hypotheses regarding the factors affecting those emissions. The results were used to simulate water concentrations for comparison with measured data. The researchers found that incorporating wastewater treatment information and wealth distribution alongside population data can improve the accuracy of emissions estimates.
Approximately 1000 km2 of agricultural or natural land is lost every year in the EU due to land-use change. When this occurs close to residential areas, it can lead to conflict with local people. This study explored the views of local people in Romania, and compared them to experts. The authors discuss similarities and differences, and say that participation, where both locals and experts communicate, is key to developing effective land use policies.
The traditional method for estimating contamination levels of vegetables grown in contaminated soils may not be as reliable as previously thought, a new study finds. A new risk assessment technique showed that the daily intake of cadmium in lettuce grown in soils near Swedish glasswork sites was above the safety threshold for a fifth of the study population.
Green roofs have been proposed to mitigate flooding in urban areas. This study combined field experiments and numerical simulations to investigate the ability of green roofs to absorb rainwater. The authors describe how green roofs can be most effective at mitigating flooding, providing findings which will be important for policy on green infrastructure.
Carbon emissions from Dutch road networks could be reduced by almost a third if more innovative materials and processes were used, a new study suggests. Researchers assessed the potential benefits associated with 10 innovations in road construction and maintenance, and compared them to conventional materials and processes.
Long-term exposure to traffic-related air particle pollution is linked with type 2 diabetes, a new study in Germany has found. Furthermore, the study found that people living close to busy roads were at greater risk of developing the disease than those living further away.
Urban waterways can provide foraging opportunities for a range of bat species. However researchers have found that bats in the UK are negatively affected by high levels of invasive plant species and urban development near waterways. The researchers highlight the value these often disregarded urban spaces can have for ecosystems, and suggest ways to improve the biodiversity of waterways.
Sustainable urban waste management has progressed over recent decades, with recycling of waste becoming a routine activity across the EU. However, the increasing volume and complexity of waste poses ongoing challenges for policymakers and municipal administrators. New research suggests that a rethink around how household waste is sorted could lead to more resources being recovered from solid waste.
Several mitigation techniques can greatly reduce spray drift pollution from pesticide spraying in agricultural systems, shows a new study. Researchers tested the effectiveness of several strategies; results ranged from a 38% reduction in spray drift using low-drift equipment to a 98% reduction when hedgerows are present alongside fields.
Exposure of primary schoolchildren to outdoor green spaces is linked to an improvement in their cognitive development, finds a new study, which is the first of its kind. The association may be partly explained by reductions in traffic-related air pollution (TRAP) near green areas.
Urban green spaces provide important ecosystem services in cities, from recreation to the mitigation of noise and air pollution. This study quantified the ecosystem services (ES) provided by green spaces in Rotterdam, the Netherlands, using new methods to evaluate high-resolution land-cover data. The findings show that different types of green space provide different ES, highlighting the importance of careful design during city planning. The authors say their method to map ES supply will aid the design of healthy, climate-resilient cities.
Animal-train collisions are an important cause of animal mortality. This study tested the ability of a device that emits natural warning calls to reduce risk of animals being hit by trains in central Poland. Animals, including roe deer (Capreolus capreolus), red fox (Vulpes vulpes) and brown hare (Lepus europaeus) escaped in most cases. The authors say the device is an effective means of risk reduction as it allows animals to escape train tracks earlier and more often.
Congestion charges are an effective means of reducing road traffic, but are often strongly opposed by the public. This study combined quantitative and qualitative methods to explore attitudes towards congestion charging in Spain, finding that opposition is reduced when revenues are spent on environmental improvements.
Green spaces like urban parks can counteract the loss of plant and animal species caused by urbanisation. For many city dwellers, parks provide most of their experiences of natural spaces. Researchers have compared different methods of park management in Paris and Berlin, and assessed how they influence citizens' attitudes towards nature.
Human-generated noise can reduce the foraging activity of wildlife and should be taken into account during conservation planning, a new study suggests. The test showed that traffic noise decreased the foraging activity of Daubenton’s bat (Myotis daubentonii) by inducing an avoidance response. The new experimental approach could be used to identify how noise disturbs any species capable of detecting noise.
The declining number of bee and wasp species in England has been linked to historic changes in land-use in a recent study. Researchers say that policies which promote diverse landscapes offer more opportunities for bees and wasps to nest and forage and are best for conserving these insect pollinators.
Contact with nature in urban areas can have numerous health benefits, a new study finds. The researchers found people whose homes had views of different kinds of vegetation had significantly lower levels of stress hormones, indicating that green spaces play an important role in healthy cities.
Urban agriculture is becoming increasingly popular. A recent assessment of rooftop farming in Barcelona shows differing attitudes towards the practice, and provides important recommendations for the development of agricultural policy for the 21st century, such as including food production as a potential use of rooftops in planning legislation.
Every kilometre travelled by car incurs costs to the individual and society that are more than six times those of travelling by bicycle, a new study suggests. The researchers presented a cost-benefit analysis developed for Copenhagen, finding that cars resulted in costs of 0.50 €/km in comparison to 0.08 €/km for bikes.
Simple characteristics of plant species - such as height or leaf size - can be used to predict the ecosystem services provided by the green roofs they grow on, a new study suggests. The researchers suggest that their method could be used to screen the thousands of potential plant species in order to optimize green roof design.
Urban areas may support higher levels of bee diversity than expected, new research has shown. The UK-wide study compared three different habitat types - nature reserves, farmland, and urban areas - and found a higher number of different bee species in urban areas than farmland. However, the overall pollinator diversity, which included species of bees, flies, hoverflies and butterflies, did not differ significantly between all three landscape types. The researchers call for more attention to be paid to the role of green spaces in cities which can be important habitats for pollinators.
Simply supplying more scientific information on the environment may not be enough to persuade urban planners to give greater consideration to the environment, suggests new research. The Dutch study suggests that environmental values also need to be made more important to municipal decision makers.
Doctors prescribe fewer antidepressants in urban areas with more trees on the street, according to recent UK research. The study examined the link between mental health and wellbeing and the presence of trees in London neighbourhoods. Its findings support the idea that maintaining a link to nature, even in an urban area, may help provide a healthy living environment.
Rooftop gardens in cities could provide more than three quarters of the vegetables consumed in them, a case study from Bologna, Italy, suggests. If all suitable flat roof space was used for urban agriculture, rooftop gardens in the city could supply around 12 500 tons of vegetables a year whilst also providing a range of ecosystem services, the researchers say.
The decline of urban populations and abandonment of buildings and land could provide an opportunity to promote ecosystem services, a new study suggests. The researchers examined the relationships between the use of abandoned land and ecosystem services, providing insight into the pros and cons of different urban planning policies.
The complexity of environmental issues and a lack of co-operation or shared objectives between parties involved in urban planning are preventing promotion of environmental sustainability, a new study suggests. The Finnish research, based on focus groups with 32 professionals in urban planning and environmental sustainability, suggests that the short-term economic goals of local authorities, the complexity of environmental sustainability, and a lack of co-operation between different decision-making groups in urban planning were creating barriers to achieving sustainability.
Green walls, designed so they are covered in vegetation, could help cut the amount of noise that enters buildings, a new study has found. In lab. tests, researchers found that a modular green wall system reduced sound levels by 15 decibels (dB). This leads them to believe that it is a promising sound reduction device that could improve quality-of-life for city residents.
Careful planting and pruning is needed to ensure that air pollution in tree-lined streets is minimised, new research suggests. While planting trees in urban areas can have many benefits, such as enhancing biodiversity, trees can trap particulate matter pollution, say the study’s authors.
City children who spend lots of time in green spaces, such as parks, and at the beach are less likely to have emotional and social difficulties, indicates new research from Barcelona. The study of over 2000 children supports theories that green and blue infrastructure have benefits for our health and wellbeing.
Which types of buildings will require the least energy for heating and cooling under climate change? A study in Vienna, Austria, looked at the balance between heating and cooling demand in four different types of buildings. The research provides a method that could be useful for other European cities trying to adapt to climate change.
Bike share programmes appear to have successfully reduced private car use in Brisbane, Melbourne, Washington DC, Minnesota and London, suggests recent research. In London, however, high demand for vans to transport bicycles between docking stations may have increased overall motor vehicle use in the city.
Greening urban areas can reduce the number of people dying from heat-related health problems, according to a recent study. The researchers found that doubling vegetation cover in central Melbourne could reduce heat-related mortality of the elderly by up to 28% during heat waves.
Cyclists with pollution monitors and GPS trackers attached to their bicycles have produced detailed maps of Antwerp’s air quality, as part of a recent study. Their data show that a gap of just a few metres between cycle lanes and cars significantly reduces cyclists’ risk of inhaling high levels of ultrafine particle pollution.
Adding compost to compacted urban soils can provide a lasting effect that aids tree growth, new research indicates. Urban soils improved with added organic material are less compacted after five years compared with soils that have not been treated with organic composts, the study suggests.
Managing urban green spaces to ensure that they have a good mix of tree species, including some older and larger trees, can enhance species diversity of woodland birds, a new study has shown. The study, carried out in Prague, Czech Republic, also showed that the presence of water bodies increased the number of species of woodland birds.
Transport policies that produce physically segregated cycle lanes on main roads, combined with low-speed local streets, will boost numbers of cyclists and provide the best financial return on investment, new research suggests. Using Auckland, New Zealand as a case study the researchers showed that the economic benefits of this policy can outweigh the costs by more than 20 times.
Regular use of green space in a city setting may be linked to reduced risk of heart disease, a new Lithuanian study suggests. The authors found that people who lived closer to green spaces suffered fewer symptoms of heart disease over a four-year period, and that regular park users were at lower risk based on factors such as weight, physical activity and diabetes.
Simple measures to upgrade buildings by improvements to insulation or heating systems could result in energy savings of up to 85% in Italian homes, according to recent research. Across Europe, such measures could potentially provide energy savings of more than 40% on average, say the researchers.
Urbanising arable land can have serious economic consequences as a result of the reduction in food production and loss of ecosystem services, according to recent research. The loss of 15 000 ha of productive soils during 2003-2008 on the Emilia-Romagna Plain in Italy cost approximately €19 million in carbon storage, €100 million in wheat production and €270 million in raw materials, the researchers estimate.
The urban heat island (UHI) effect can be completely offset by using 'cool' and 'green' roofs, finds new research from the US. However, the study also found that different roofs may affect rainfall and energy demand, and that their efficiency varies with location.
Particulate matter (PM) emissions from domestic wood burning in London are higher than the PM reductions achieved through London’s Low Emission Zone, finds a new study. The research suggests that increases in wood burning could risk undermining policies aimed at meeting EU PM10 targets.
Two shared electric car schemes, in Berlin and Paris, have been examined by a recent study. Although both schemes are progressive, Berlin's takes an 'inter-modal' approach to encouraging sustainable mobility, because it integrates electric cars into the wider public transport system. The scheme in Paris, however, focuses on cars as the main form of transport.
Although cities are typically low in biodiversity, they can provide important refuges for native species, new research shows. Urban planning making use of green infrastructure can enhance city habitats and may help reduce the loss of biodiversity that follows urban expansion, the researchers say.
Moving to an area with good access to green spaces has a positive, lasting effect on residents' mental health, new research suggests. The study shows that people who move to greener areas report considerably improved mental health three years after leaving their previous neighbourhood.
Car use could be reduced through careful urban planning, according to the results of a new German study. By combining data on driving behaviour and high-resolution satellite imagery, the researchers show how patterns of land and car use are connected.
New software has been developed to rate the health risks of different activities in the urban environment, for example, cycling or driving in different areas of a city. 'CENSE' is based on a variety of different pollutants and environmental health hazards encountered in urban environments and may provide a useful tool for urban planning and improving residents’ quality of life, its developers say.
Researchers have developed a new risk assessment scheme for invasive alien species that not only predicts their direct effects on biodiversity, but also their impacts on ecosystem services. Furthermore, the scheme allows sources of uncertainty in a species’ impact to be identified, and can be applied to a range of different species.
Air quality in the Greek city of Thessaloniki has worsened during the recent economic crisis, as residents burn more wood and other types of biomass to keep warm. A recent study has found a 30% increase in the concentration of fine particle (PM2.5) emissions associated with wood smoke from residential heating in 2012 and 2013, with implications for the health of local residents.
Air pollution from the world’s megacities not only has local impacts, but can spread to remote regions of the world. Recent research has highlighted, for example, that megacities are a source of black carbon pollution in lowest kilometre of atmosphere in the Arctic, with European megacities contributing more than others.
Costs of installing, maintaining and disposing of some green wall systems may outweigh the value of some of their benefits for householders, a recent study suggests. While the researchers omitted some of the wider social benefits, they found that reductions in heating and air conditioning costs, longevity of green walls and increases in property values did not compensate for their costs. The researchers suggest that government incentives to lower set-up costs could significantly increase the walls’ economic sustainability.
Cities located in biodiversity hotspots can provide valuable refuges for a wide range of plants, a recent study suggests. Of the 379 plant species and sub-species recorded in the city of Ioannina, Greece, 27 were of conservation interest. Town planners can ensure that cities play an important role in supporting regional biodiversity when designing future urban developments, the researchers say.
Density in the urban environment can encompass a multitude of factors such as population or dwelling density or the density of green areas. A new study surveyed professionals regarding how decisions on urban density are made, and has revealed that many feel that developers make most of these decisions, but that local authority planners should have more influence.
Investment in cycling initiatives, such as creating new cycle lanes or providing training, can increase the number of people who routinely cycle to work, a new large-scale study in the UK suggests. Town-wide cycling initiatives seemed to be particularly successful when they included workplace measures such as bike lockers, showers and cycle parking.
Factors influencing people's decisions about how they travel to work are highlighted in a new study on commuting in Europe. Key findings include: cycling rates increase with the length of a city's bicycle network and public transport use rises with a city's population and GDP per capita. Based on the findings, the researchers propose policy measures for reducing the number of car journeys.