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.

A test currently under development for certifying levels of vehicle emissions may not adequately represent real world driving conditions, a new study suggests. The authors measured emissions during the new Worldwide Light-Duty Test Cycle (WLTC) compared with those in existing driving cycles and highlighted areas where the test could be potentially improved.

Citizen scientists have helped to map pollution across the Netherlands using their smartphones. Their results, produced by thousands of volunteers, are presented in a study which shows how a combination of mass participation and smartphone technology can be a powerful approach to environmental monitoring.

Levels of the air pollutant PM_2.5 in Europe will continue to fall in 2020, concludes a recent study. Furthermore, deposition of nitrogen from air pollution will also drop. The outlook seems less positive for ground-level ozone, however, as large amounts of this pollutant continue drift over to Europe from other continents.

Real time monitoring of public health during two periods of high air pollution in the UK showed that there were an estimated 3 500 extra healthcare visits for acute respiratory symptoms and approximately 500 for severe asthma during these spells in 2014. The results of this research are presented in a new study which demonstrates the value of such ‘syndromic surveillance’ systems for exploring air quality’s effects on human health.

Greenhouse gas (GHG) inventories are significantly underestimating methane emissions from a region in the southwest of the United States, and potentially elsewhere, a new study has found. The authors of the study suggest that satellite data could be used to identify and quantify new sources of methane, such as fracking.

Effective greenhouse gas (GHG) mitigation measures to stabilise global temperature change to no more than 2°C above pre-industrial temperatures would also substantially reduce air pollutant emissions, recent research predicts. A variety of mitigation options are available, including switching from fossil fuels to renewable sources of energy. To achieve the necessary GHG emission reductions, one key option is to impose carbon taxes. However, these would need to be high to help achieve this target, according to the study’s authors.

Models that predict how nitrogen from the air is deposited in the sea could be useful in predicting algal blooms. Based on the knowledge that excess nitrogen increases algal growth rates, researchers simulated nitrogen deposition in the North Sea and suggested that, using predicted weather data, it might be possible to adapt this approach to predict algal blooms.

PM_2.5 air pollution can have a significant impact on human health, not only for local populations, but also in regions far from its source of emission, shows a new study. The study calculates ‘damage factors’ to human health of PM_2.5 and in different parts of the world.

Emissions from well-regulated household waste incinerators do not reduce the quality of vegetables and milk produced nearby, a Dutch study suggests. Researchers found that levels of certain contaminants were similar whether vegetables and milk came from the area surrounding three incinerators, or from elsewhere in the Netherlands. They say biomonitoring programmes could offer a way to increase the understanding of the real impacts of waste incineration and to improve communication between waste management companies and local communities.

Switching to the best available emission control technologies could eliminate 99% of particulate matter pollution 'hotspots', a new study suggests. The researchers reached this conclusion by expanding the local-scale capabilities of an existing computer model that estimates the effects of air pollution policies and control measures.

Ammonia released by nitrogen fertilisers in Spanish agriculture could be reduced by up to 82% with only a very minimal impact on crop yield, finds new research. This could be achieved by combining optimised management of manure with the use of non-urea synthetic fertilisers.

The chances of a child developing Autism Spectrum Disorder (ASD) are higher if the mother is exposed to high levels of fine particulate air pollution during pregnancy, a recent study suggests. This increased risk was associated specifically with exposure in the last three months of pregnancy, the researchers found.

Exposure to gaseous and particulate matter pollution have been found to increase the immediate risk of stroke, a review of medical studies has shown. The increased risk is most pronounced the same day as the exposure, and for fine particles the increased risk persists over several days. The authors hope information from this study will help policymakers to develop suitable controls to limit the risks posed by these harmful air pollutants.

Deposition of heavy metals and nitrogen is falling across Europe, a new study suggests. The researchers used the levels of these pollutants in mosses as indicators of how deposition has changed from 1990 to 2010. These reductions are likely to be the result of effective air pollution policies, they say.

Under the United Nations Minamata Convention on mercury, China and India could avoid a combined 242 tonnes of mercury emissions in 2050 from coal-fired power plants, a new study predicts. This amount is equal to approximately 12% of total emissions in 2010. While the benefits will be mostly regional, lower mercury deposition in surrounding oceans is good news for Europeans who eat fish sourced from those waters.

As well as contributing to the greenhouse effect, aircraft emissions have an important impact on air quality and human health. This study, which quantified the effect of civil aviation emissions across the globe, suggests they could be responsible for 16 000 premature deaths every year, at an annual cost of over €18 billion. The air quality costs of aviation were similar to its climate costs, and over 10 times larger than accident and noise costs.

Over 2500 tons of the air pollutants nitrogen oxides (NOx), sulphur dioxide (SO2) and particulate matter with a diameter of less than 2.5 micrometers (PM2.5) were released by cruise ships across the five busiest Greek cruise ports during 2013, a new study found. The researchers also examined the costs of the potential health impacts of this pollution, finding they could be as high as 24.3 million Euros.

Changes in the home that increase energy efficiency, such as improved insulation and ventilation control, have the potential to reduce indoor air pollution. This study assessed the health impact of interventions in the UK arising from changes to indoor concentrations of fine particulate matter and found that such changes could improve health and increase life expectancy for men and women by three and two months, respectively.

Globally, more than 3.2 million premature deaths per year are attributed to exposure to ambient fine particulate matter (PM2.5). A new study estimates that 2.1 million premature deaths could be avoided if countries achieved the WHO guideline for PM2.5. Even meeting their closest WHO interim concentration targets could avoid 750 000 (23%) deaths attributed to PM2.5 per year.

Groups of chemicals used as flame retardants were present in the bodies of Antarctic rock cod (Trematomus bernacchii), young gentoo penguin (Pygoscelis papua), and brown skua seabird (Stercorarius antarcticus) collected from King George Island, Antarctica. This study is the first to find some of these chemicals in Antarctica, confirming that they undergo long-range transport and can reach isolated areas where they are not widely produced or used.

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.

A link between particulate matter (PM) exposure and inflammatory disease has been shown by many studies, but few have explored how the chemical composition of PM influences inflammatory processes. This study investigated the connection between different components of PM and markers of inflammation in the blood, finding that long-term exposure to transition metals, emitted by traffic and industry, may cause chronic inflammation.

A new study quantifies the economic and environmental potential of powering docked ships in European ports using local electricity networks. The authors give key recommendations on policy actions to enable implementation in European harbours.

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.

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.

Ships that reduce their speed use less fuel, which lowers costs for shipping companies. The slow steaming practice also cuts nitrogen oxides (NOx) emissions. A study found that ships travelling on four European routes lowered their NOx emissions by 12% during the economic crisis of 2008/2009. Shipping continues to be a major way of transporting goods, however, and as the global economy recovers the researchers and civil society call for additional measures to reduce NOx emissions from shipping and improve air quality in Europe.

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.

The BIOAMBIENT.ES project is the first human biomonitoring programme to estimate levels of environmental pollutants at national level in Spain. This study reports its findings on polycyclic aromatic hydrocarbons (PAHs), chemicals that are ubiquitous in the environment. The results will help to establish reference values, identify highly exposed populations and evaluate effectiveness of policies.

For economic and political reasons, freight shipping has begun to utilise shorter routes across Arctic waters. This study assessed the costs, emissions and climate impact of trade using the Northern Sea Route between the Northern Pacific and Europe. It concludes that there are no overall climate benefits to using this route, even though it reduces voyage distance, due to the additional impact of emissions in the Arctic region.

Ozone harms pollen viability of tomatoes, leading to reduced fruit weight, size and quality, a recent study has revealed. The researchers suggest the effect of ozone on pollen could be a useful way to rapidly test for pollution-induced stress on crop plants in risk assessments.

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.

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.

In September 2015, the United States Environmental Protection Agency (EPA) alleged that Volkswagen (VW) violated the US Clean Air Act by fitting ‘defeat devices’ in their light-duty diesel vehicles to falsify the results of emissions tests. According to a study assessing the potential impact of this decision, an extra 59 early deaths in the US are likely to be caused by exposure to PM2.5 and ozone.

Due to regulation on sulphur emissions, liquefied natural gas (LNG) has increased in use as a maritime fuel. This study measured exhaust gases from a ship with dual-fuel engines running on LNG and marine gas oil (MGO). Although NOX and CO2 emissions were lower for LNG compared to MGO, hydrocarbon and carbon monoxide emissions were higher. The authors say future work should reconsider the climate impact of LNG.

Health impact assessments (HIAs) provide information on the potential health impacts of policies, and are important for developing regulation on air pollution. In this study, researchers evaluated the metrics currently used in air quality HIAs to provide recommendations for their use in policy.

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.

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).

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.

European buildings built in the 1950s, 60s and 70s may contribute towards levels of toxins in the body, a new study suggests. Polychlorinated biphenyls (PCBs) were found at elevated levels in children that lived in houses and studied in schools built during this period, before PCBs were more thoroughly regulated in the construction industry. Although food is generally a more concentrated source of these toxins, the authors say exposure through these environments should be minimised wherever possible.

Mercury levels in bream (Abramis brama) collected from six European sampling sites from 2007 to 2013 exceeded the Water Framework Directive’s safety limit for fish in all but one site in 2012, a new study discovers. The findings suggest greater efforts need to be made to prevent mercury pollution.

Different modelling approaches are used to design and assess air quality plans across Europe. This study assessed the strengths and weaknesses of these different approaches. The researchers conclude that a large variety of models is in use, without a preferred or standard model having emerged yet. They identify integrating local-scale and large-scale models and verifying models with measurements as the most important challenges.

The ship-recycling industry — which dismantles old and decommissioned ships, enabling the re-use of valuable materials — is a major supplier of steel and an important part of the economy in many countries, such as Bangladesh, India, Pakistan and Turkey. However, mounting evidence of negative impacts undermines the industry’s contribution to sustainable development. This Thematic Issue presents a selection of recent research on the environmental and human impacts of shipbreaking.

Dangerously high air pollution in the vicinity of shipbreaking yards has been detected by a recent study, where the concentrations of toxic chemicals in the air were found to be above carcinogenic risk limits (as set by the World Health Organisation). The research, carried out in Chittagong, Bangladesh, noted that shipbreaking activities and the subsequent processing and treatment of materials – particularly the burning of waste — result in emissions of persistent organic pollutants (POPs).

Pollutants emitted by human activities have caused declines in air quality and drastic changes to climate. Despite being inextricably linked, these two major environmental issues tend to be viewed separately by policy. However, in certain instances, considering these issues together could lead to strategies that benefit both, according to a newly published review.

Oxygen decline is occurring in many of the world’s oceans and has important consequences for marine ecosystems, but the causes are not fully understood. Aerosol pollutants may be partly responsible, according to a new study which modelled the effects of atmospheric pollution over the Pacific Ocean. The findings suggest that air pollution can exacerbate climate impacts on the ocean, even when the source is far away.

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.

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.

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.

Nitrous oxide (N₂O) is a potent greenhouse gas and atmospheric pollutant. A new study proposes tackling both problems by removing N₂O from the atmosphere using a combination of two innovative technologies — photocatalytic breakdown of the N₂O to nitrogen and oxygen, and this within a solar chimney power plant that generates renewable electricity. Although some way off from commercial development, the researchers say this approach is feasible, and they outline how these two technologies can be integrated to reduce the climate impact and polluting effects of N₂O emissions.