Air pollution may be linked with an increased risk of developing dementia, research suggests.

A London-based study, published in BMJ Open, found an association between the neurodegenerative condition and exposure to nitrogen dioxide and microscopic particles known as PM2.5.

Alzheimer’s Research UK described it is a “growing area of research”, but said the results should be treated with caution.

The researchers, from the University of London, Imperial College and King’s College London, used anonymous patient health records from the Clinical Practice Research Datalink, which collects data from GP practices.

They focused on 131,000 patients aged between 50 and 79 in 2004, who had not been diagnosed with dementia, registered at 75 general practices within the M25.

The health of the patients was tracked for an average of seven years, until they were diagnosed with dementia, died or left their GP practice.

Between 2005 and 2013, a total of 2181 patients (1.7 per cent) were diagnosed with dementia, 39 per cent of whom had Alzheimer’s disease and 29 per cent of whom had vascular dementia.

These diagnoses were found to be linked to ambient levels of nitrogen dioxide and PM2.5, based on estimates taken near the homes of patients in 2004.

Those living in areas with the top fifth of nitrogen dioxide levels had a 40 per cent increased risk of being diagnosed with dementia compared with those living in areas with the lowest, the researchers said.

A similar increase was seen with levels of PM2.5, they added.

The associations could not be explained by factors known to influence the development of the condition, but the links were more consistent for Alzheimer’s disease than vascular dementia.

The authors said:

“With the future global burden of dementia likely to be substantial, further epidemiological work is urgently needed to confirm and understand better recent findings linking air pollution to dementia.

“Our results suggest both regional and urban background pollutants may be as important as near-traffic pollutants.

“The cause of these neurodegenerative diseases is still largely unknown and may be multifactorial.

“While toxicants from air pollution have several plausible pathways to reach the brain, how and when they may influence neurodegeneration remains speculative.”

Read more: Future Build

Exclusive: Critics have played down ability of current electric cars to reduce CO2 levels, but new analysis shows significant impact

Replacing a fossil fuel-powered car with an electric model can halve greenhouse gas emissions over the course of the vehicle’s lifetime, according to a new report.

The finding challenges reports by the UK press, other transport research groups and the fossil fuel industry that have underestimated the rise of electric vehicles (EVs) and their capacity for cutting emissions.

Released ahead of the world’s first zero emission vehicle summit in Birmingham, experts hope these results will drive a rapid switch to electric vehicles.

It is well established that a transition to electric vehicles will immediately reduce toxic air pollution, but the impact on carbon emissions has been less clear.

Critics have pointed to the carbon-intensive process of battery manufacture and the relatively small share of Britain’s electricity supply coming from renewables as factors that stop EVs reaching their full CO2-cutting potential.

“The take up of EVs in the UK, as elsewhere, continues to grow fast and sales have just passed 4 million globally,” said Andy Eastlake, managing director of the Low Carbon Vehicle Partnership.

“While no one doubts the air quality benefits of zero tailpipe emissions, critics often question the overall life cycle greenhouse gas impacts.”

However, the new European Climate Foundation-commissioned report used 2017 data to demonstrate that owners of EVs – particularly smaller models – are already playing a big role in helping the climate.

Transport is now the sector that contributes most to the UK’s greenhouse gas emissions, and the Committee on Climate Change has urged the government to improve on their current plan to ensure all new diesel and petrol vehicles are banned from 2040.

In their role as the government’s climate advisers, the committee has called for “more stretching targets” to ensure most new cars and vans are electric by 2030.

Transport secretary Chris Grayling revealed his “Road to Zero” strategy in July to make the UK “the best country in the world in which to develop and manufacture zero-emission vehicles”.

Aurelien Schuller from French consulting firm Carbone 4, one of the report’s co-authors, said their new study revealed “there is no time to waste in the UK’s transition to EVs”.

“Thanks to an already-significant decarbonisation of its electricity generation through coal phase-out the UK is already in a position to make significant cuts in the greenhouse gases from its transport sector,” he said.

The research concluded that a smaller EV produces around 15 tonnes of CO2 from construction through to scrapping, compared to an average of 32 tonnes for the equivalent petrol or diesel car.

Read more: Independent

• Many antipollution systems deactivate at high temperatures
• Paris bans older cars after pollution soars in heat wave

Europeans aren’t just sweating through the long, hot summer. City dwellers may be coughing and wheezing more, too.

Diesel vehicles, which still command nearly half the market for new cars, are left with barely any pollution controls when temperatures soar above 35 degrees Celsius (95 Fahrenheit), according to France’s Petroleum and New Energies Research Institute. That means smog-inducing nitrogen oxide emissions that were at the center of the Volkswagen AG scandal spew into the environment unchecked.

“There are higher emissions of nitrogen oxides because the setups don’t work as well when it’s very hot,” said Gaetan Monnier, who heads the unit that led random government probes of cars after the VW scandal. “The atmosphere is also more reactive during a heatwave, making the level of cars’ emissions even more of an issue.”

Carmakers have been under scrutiny since the 2015 scandal that revealed VW had rigged the emissions setup in some 11 million diesel cars globally, the main emitters of nitrogen oxides. While sales have dropped as consumers fret over driving bans, diesels still made up 45 percent of new vehicle sales in Western Europe last year. Excessive emissions of the pollutant linked to premature deaths and respiratory problems have prompted the European Union to sue France, Germany, U.K., Romania and Hungary in May after failing for years to comply.

On-road tests have shown emissions clean-up systems start to reduce their effectiveness in cold temperatures as well as above 30 degrees.

Read more: Bloomberg

A nine-year-old girl’s fatal asthma attack has been linked to illegally high levels of air pollution.

Ella Kissi-Debrah lived 25m (80ft) from London’s South Circular Road – a notorious pollution “hotspot”.

She experienced three years of seizures and hospital stays before her death in February 2013. During that time, local air pollution levels breached EU legal limits.

No individual death has previously been directly linked to air pollution.

According to a report by one of the UK’s leading experts on asthma and air pollution, Prof Stephen Holgate, there was a “striking association” between Ella’s emergency hospital admissions and recorded spikes in nitrogen dioxide (NO2) and PM10s, the most noxious pollutants.

His report said there was a “real prospect that without unlawful levels of air pollution, Ella would not have died”.

The evidence will be submitted in an appeal to the attorney general to re-open an inquest in to Ella’s death.

Ella often walked to school along the South Circular Road and Lewisham High Street, a journey that would take 30-40 minutes. Or she would be driven and have to sit for lengthy periods in traffic jams.

Read more: BBC