Research & News

An unintended negative consequence of cleaning up our air could be to increase the severity of heatwaves in some places, according to a recent modelling study conducted by researchers at the University of Edinburgh.
Whilst most observers recognise the pressing need to reduce ambient air pollution for health reasons, the reduction in production of aerosol at ground level, which can act as cloud condensation nuclei when transported into the atmosphere, mean that average daytime maximum temperatures would be increased.

While the adverse health effects of gasoline and diesel exhaust particulates are relatively well known, less is known about effects from the particles produced by aircraft jet engines.
A collaborative study between the University of Bern, Empa and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) has shown that damage to lung cells and inflammation can occur after direct exposure to primary particles from an aircraft engine, with effects relating to the operating conditions of the turbine engine and fuel composition.

A campaign led by local businesses in Chiang Mai, northern Thailand has drawn attention to the very high levels of air pollution by selling ‘souvenir’ jars of air collected in the city. Crop burning experienced on an annual basis from January through to April contributes to seasonally high PM concentrations. Each jar is labelled with the PM2.5 concentration observed on the day it was bottled.

Outdoor air pollution has been regulated for decades and is of great current public concern because of the adverse health outcomes linked with exposure, but comparatively little is known about the chemistry of the indoor environment where most people spend most of their time.
A large-scale collaborative field study led by Colorado State University, and University of Colorado at Boulder aimed to investigate indoor chemistry, including aerosol concentration and size distribution and aerosol precursors such as VOCs, over a series of days in which a range of activities, including cooking Thanksgiving dinner, were undertaken.

The Government’s updated Clean Air Strategy includes a move towards tougher regulation of particulate emissions from domestic wood burners and open stoves. Increasing in popularity over the last decade, solid fuel sources are thought to contribute 38% of the UK’s emissions of particulate matter.
However, awareness of the pollution problem caused by these sources is low compared to more well-known sources such as traffic. The most polluting fuels are due to be phased out, and stoves sold by 2022 must adhere to stricter emissions limits than many presently on the market. Advice to wood stove users aimed at reducing their emission of (and their own exposure to) PM by the consumer group Which? suggests….

An optomechanical trap capable of controlling and measuring nanoparticles as small as 150 nm has been developed by researchers at the University of Vienna and Delft University of Technology.

Using a photonic crystal cavity made of silicon nitride on a silicon substrate, a silica particle can be trapped a few hundred nanometres above the crystal surface, within the interference between the 1064 nm wavelength laser beam used and its reflection from the crystal surface. The particle position is altered using a dichroic mirror in the beam path. Coupling between the particle displacement and phase fluctuations provides up to two orders of magnitude higher sensitivity per photon than more traditional ‘far-field’ methods for nanoparticle optical trapping thanks to low optical losses, the authors claim.