Unlocking Cities’ Dirty Secrets.

Unlocking cities’ dirty secrets.

Grime is found on every surface in urban environments. Buildings, statues, street signs and pavements are all covered with a grimy layer of chemicals from cars, factories and other polluting sources.

We’ve always thought that once this layer has been deposited on a surface the complex mixture of organic and inorganic chemical pollutants contained within it are locked in, remaining in their resting place until a window cleaner or street sweeper scrapes them off.

New observations suggest this isn’t correct. James Donaldson from the University of Toronto, Canada, and his collaborators in Leipzig, Germany, now believe sunlight can cause nitrogen compounds to be re-released from the grime and recycled back into the atmosphere. Here, these compounds once again contribute to ozone and smog.

The researchers have carried out a series of lab and field – or in this case, city street – experiments that support their claim. First, grime collected in Toronto was examined using infrared spectrometry to determine its composition. It was then exposed to artificial sunlight in the lab, and its composition reassessed. Nitrate components in the sample were observed to rapidly leave the grime when it was exposed to light.

The next series of experiments took place over a six week period on a street in Leipzig. The team collected grime on glass beads (made of the same type of glass as windows) stored on a two-tiered structure that resembled takeaway pizza boxes stacked on top of each other. The beads in the top tier were exposed to natural sunlight, while those in the lower tier were shaded from the sun’s rays.

The team then took both sets of beads back to the lab and analysed the chemicals deposited on them. The beads kept in the shade contained 10% more nitrates than those exposed to the sun, supporting the earlier lab-based findings that nitrogen compounds can escape grime with the help of light. An extended year-long version of this study is still running in Toronto.

Back in the lab, the Toronto arm of the team have analysed the gas phase products released when artificial sunlight is shone on real grime, finding that nitrogen dioxide and nitrous acid are both released. Both are important air pollutants.

These findings may eventually lead to improved models for estimating the quality of urban air, but there remain a number of questions – such as the effect of humidity or varying amounts of sunlight – to be answered first.

Efforts to reveal the secrets of urban air pollution, and therefore improve our models, are vital for enabling policymakers to make good decisions about keeping air pollution at safe levels. The end goal is, of course, to ensure we can all breathe easily when spending time in our cities.

Cat On Roof, Window Cleaner Goes Home, Another In-Doors

Window cleaner Nick Glover with little Molly.

Window Cleaner Rescues Kitten Being Attacked by Angry Birds: A window cleaner became a hero for a day when he came to the rescue of a stranded kitten that was stuck on a roof in Bourne. The RSPCA has said a special thank you to cleaner Nick Glover who managed to rescue little Molly after she crept out of her home in Essex Way and climbed up onto a roof top.

The 12-week-old kitten was spotted by a concerned member of the public who said Molly was being “dive-bombed” by some magpies and crows. RSPCA animal welfare officer Becky Harper was called to attend the incident but the cat was too far up for her to reach. But instead of calling out the fire service to rescue Molly, it was suggested a call be made to local window cleaner Nick Glover. Becky said: “Nick immediately offered to help and arrived within 10 minutes.

“He then climbed up his ladder and gently picked up little Molly and carried her back down to safety where she was reunited with her owner. “She was a little cold and hungry but apart from that fine. “I just hope this experience puts her off climbing on to roofs in the future although it’s still a bit of a mystery how she managed to get up there considering how tiny she is. “I would really like to say thank you to Nick for helping Molly so quickly and he gave his time free of charge. “He saved calling the fire brigade out and it is great that this had a happy ending.”

David Sewell "was worried and he went home."

A window cleaner deserted his car after smashing it into a lamp-post on a South Tyneside street. David Sewell crashed his Ford Fiesta on Hedworth Lane, Boldon Colliery, on the night of June 28. The 34-year-old abandoned his car, but police traced him from the number plate. Sewell, of Eskdale Drive, Jarrow, pleaded guilty to failing to stop after an accident, failing to report an accident and careless driving at South Tyneside Magistrates’ Court yesterday. The court heard he lost concentration because “he had a lot on his mind”.

Paul Anderson, prosecuting, said: “When police arrived at the scene of the crash the driver had left. “He was eventually traced and accepted he had been driving it. “He said he wasn’t concentrating because he had a lot on his mind because he had recently lost some money. “He told the police he was scared so ran off in a state of panic. “There is no suggestion he had been drinking.”

Charlton James Carr, defending, said: “He was driving and had a momentary lapse going round a bend and collided with the lamp-post. “We don’t know how much damage he caused to it but we do know that his car, which was worth £600, was effectively written off. “He panicked because in 2006 he was given a two-year prison sentence for something totally different and was released three and a half years ago. “He was worried and he went home. “There was no-one else involved and no one was injured.”

Mr Carr told the court that when the police went to his house to speak to him about the smash, Sewell wasn’t at home but called them back when he found out they had been to see him. He added: “He didn’t try and concoct a cock-and-bull story, he was honest with them. “He is a self-employed window cleaner with two children and a partner to support. If he loses his licence they will suffer.” Magistrates added seven points on to Sewell’s driving licence and fined him £100. He was also ordered to pay £85 costs and a £20 victim surcharge.

He navigates his home using LED flashlights and candles.

Rare Medical Condition Forces SF Man To Live In Darkness: Extreme photosenstivity means SF man is harmed by cell phone glow. The light is unkind to John Kapellas. In fact, the light burns him. Sunlight or artificial, a ray of sun or a shine from a smartphone's screen, light causes the 59-year old to break out in blisters, according to the San Francisco Chronicle. This extreme form of photosensitivity means Kapellas rarely leaves a darkened San Francisco apartment. This kind of affliction is extremely rare, the experts say. Usually, people with photosensitivity can cope with artificial light.

John is lit by one of the small LED flashlights he often uses as he poses for a portrait in the blacked-out bedroom of his apartment in San Francisco. John Kapellas is a sculptor who lives in almost complete darkness since being diagnosed 5 years ago with solar urticaria, an extreme form of photo sensitivity that produces burns and hives with even small exposures to light.

But not Kapellas, who used to run a window-washing business. He must block even the light from his microwave and refrigerator, according to the newspaper. Doctors are unsure what caused his case, the newspaper reported. He has been HIV positive since 1988, and it is possible the disease or the combination of drugs he is on may had led to it. He navigates his home using LED flashlights and candles, the newspaper reported, but still remains upbeat.

John Kapellas spent a large part of his life outdoors. He ran a window-washing business for 29 years and, for a time, he and sculptor Daniel Goldstein collaborated on a series of successful public-art installations.

New Feel Good Glass

Fraunhofer researchers have developed a window coating (not pictured) that lets in more light in the wavelengths that have a beneficial effect on our sense of well-being.

Window coating improves mood by letting more light in: With many of us spending more and more time indoors, it can be a struggle to get the amount of sunlight our bodies crave. Modern heat-insulating, sun-protection glazing doesn’t help, as it reflects a noticeable percentage of the incident sunlight in the part of the spectrum that governs our hormonal balance. Researchers at the Fraunhofer Institute for Silicate Research (ISC) have developed a coating for windows that lets in more light, in particular those wavelengths of light that have a beneficial effect on our sense of well-being.

While the human retina is most sensitive to light at the peak emission wavelength of sunlight, which brightens a room the most, Walther Glaubitt, a researcher at the Fraunhofer Institute for Silicate Research ISC in Würzburg, says our biorhythms aren’t affected by these wavelengths. Rather, it is blue light that has an impact on our sense of well-being.

According to Glaubitt’s team colleague Dr. Jörn Probst, this is because there are special receptors at the end of the nerve connection that connect the human retina to the hypothalamus – the control center for the autonomic control system – that are sensitive to blue light. These receptors convert the blue light into light-and-dark signals that are sent to the part of the brain that functions as our biological clock, where, amongst other things, the nerve impulses regulate melatonin levels.

Melatonin levels help regulate the sleep-wake cycle, with high levels of melatonin caused by a lack of light leading to problems sleeping and concentrating, as well as depression and other psychological impairments. Seasonal Affective Disorder, or SAD, can be one potential outcome from high melatonin levels.

The new coating, which Fraunhofer researchers developed with the help of industry partners, is particularly transmissive to light in the blue part of the spectrum - at wavelengths between 450 and 500 nanometers, but its transmissivity is increased across the entire range from 380 to 580 nanometers, which the researchers say is the portion of the spectrum responsible for promoting well-being. When applied to a window, the inorganic coating is barely perceptible as it is only 0.1 micrometers thick. It also has no effect on the heat-insulating properties of the window.

Currently, the ISC researchers have only applied the coating to the side of the glass that faces into the cavity between panes. They believe that coating both the inside and outside of the window will up the light transmissivity at 460 nanometers from the current 79 percent to around 98 percent.

UNIGLAS GmbH & Co. KG, which worked with Fraunhofer to bring the coating to market maturity, is set to launch a triple-glazing product featuring the coating, which is marketed under the name UNIGLAS | VITAL feel-good glass. This product boasts light transmissivity at 460 nanometers of 79 percent. However, this is with the coating only applied to the side of the glass facing into the cavity between panels. The ISC researchers believe that applying the coating to both the inside and outside of the windows, as they plan to do in the future, will result in windows with around 95 percent light transmissivity at 460 nanometers.

More news on this glass coating:

Science Blog

New glass coating makes you feel as if window is permanently open.

Feel-good glass for windows.

VITAL feel-good glass replaces pain with happy pane.