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From the archives
Views From the archives hide their vulnerability. One, PM Consultants in Portland, Oregon, closed suddenly in July after an attack. Educating management is necessary, but we need a concomitant emphasis on “you get what you pay for”.
It isn’t necessarily good just because it is green 24 August, p 6 From Hugh McAdams, Glasgow, UK You report on CityTrees – moss walls from Berlin-based firm Green City Solutions. Glasgow installed two on busy streets in 2017. I calculate that they removed less than 0.02 per cent of the city’s pollutants each year. They have now disappeared. As Scully notes, researchers at the Netherlands Organisation for Applied Scientific Research found that eight moss walls installed in Amsterdam failed to reduce the concentration of pollutants. The makers of the trees don’t make any outlandish claims – so why have 50 been installed in European cities, costing about $60,000 each?
How well do wind tunnels simulate mountain air? 14 September, p 14 From Sandy Henderson, Dunblane, Stirling, UK Chelsea Whyte reports that wind-tunnel experiments on bar-headed geese show their blood cools in low-oxygen conditions, simulating those they face crossing the Himalayas. Cooler blood can carry more oxygen. Did the researchers recreate the low pressure and temperature that the birds would encounter 7000 metres up? At low pressure, it is harder for the wings to transfer heat to the passing air and cool the blood. That might be
balanced in real life by the greater temperature gradient at altitude. The editor writes: The experiment didn’t mimic pressure or temperature at high altitudes, just oxygen levels. But if the birds’ blood running cold makes them more efficient at sealevel pressures, the effect is likely to be even stronger at altitude.
I am not so happy with Ola Rosling’s cheery statistics 7 September, p 46 From Arne Maus, Nesoddtangen, Norway I agree with Ola Rosling that we should base our views on facts, but I see problems with the statistics he presents. One graph shows the risk of dying in a plane crash as one per 10 billion passenger miles. No flights are 1 mile long and most of the risk is at take-off and landing. It would be better to give the risk per flight. Another states that the fraction of Earth’s surface in protected reserves increased from 0.03 per cent in 1900 to 14.7 per cent in 2016. This says only that certain nations are trying to save some of their land. Pristine forests and nature are clearly suffering as the Amazon, parts of Indonesia and elsewhere are burned to make way for farmland. ❚
For the record ❚ The photograph we used to illustrate our report on climate change increasing the risk of heavy rainfall and storm surges in coastal areas was of Mytholmroyd, West Yorkshire, UK, which has flooded but is around 90 metres above sea level and a 70-kilometre walk from the coast (28 September, p 18).
Want to get in touch?
Send letters to New Scientist, 25 Bedford Street, London WC2E 9ES or [email protected]; see terms at newscientist.com/letters
25 years ago, New Scientist was celebrating a milestone in eradicating the scourge of polio IT WAS a rare example of a straight-up good news story. “Polio has been eradicated in the western hemisphere, officials at the Pan American Health Organization declared last week,” we wrote in our 8 October 1994 issue. Polio is a viral disease that is typically transmitted by the ingestion of faecal matter, often through infected water supplies. If the virus enters the central nervous system, it can cause muscle weakness and paralysis, and sometimes death or long-term disabilities. Effective polio vaccines were first developed in the 1950s, but a coordinated global fight to eradicate the disease began in earnest in 1988. The disease was officially eliminated in China, Australia and 34 other western Pacific countries in 2000. Europe was declared polio-free in 2002. “The last known polio case in the Americas was a Peruvian boy called Luis Fermin who contracted the virus in August 1991,” we wrote. Models suggested that if the virus were still circulating there, at least one case of polio-induced paralysis would have occurred in the following three years. There had been none. Other animals can’t carry polio, so once the world’s human population is finally purged of it, there will be no reservoir from which the natural virus can emerge to reinfect us. Afghanistan and Pakistan are the last remaining regions with wild polio cases; there are fewer than 100 a year. Will the scourge of polio now vanish from human memory? Probably not. For a start, there is an attenuated strain present in the popular and effective trivalent oral polio vaccine itself. This strain can persist in the environment and regain the ability to cause polio. Such a strain was probably responsible last month for the first cases of polio recorded in the Philippines since the virus was declared eradicated there in 2000. We discussed one ingenious solution to this problem in March 2017, when we reported on some nifty gene editing that resulted in a live vaccine with a lower risk of mutating into a virulent form. More worrying, perhaps, is that a team of researchers in 2002 built the polio virus from scratch in the lab, using nothing more than genetic sequence information from public databases and readily available technology. The price of liberty from polio will be eternal vigilance. Simon Ings
To find more from the archives, visit newscientist.com/old-scientist
19 October 2019 | New Scientist | 27
It isn’t necessarily good just because it is green 24 August, p 6 From Hugh McAdams, Glasgow, UK You report on CityTrees – moss walls from Berlin-based firm Green City Solutions. Glasgow installed two on busy streets in 2017. I calculate that they removed less than 0.02 per cent of the city’s pollutants each year. They have now disappeared. As Scully notes, researchers at the Netherlands Organisation for Applied Scientific Research found that eight moss walls installed in Amsterdam failed to reduce the concentration of pollutants. The makers of the trees don’t make any outlandish claims – so why have 50 been installed in European cities, costing about $60,000 each?
How well do wind tunnels simulate mountain air? 14 September, p 14 From Sandy Henderson, Dunblane, Stirling, UK Chelsea Whyte reports that wind-tunnel experiments on bar-headed geese show their blood cools in low-oxygen conditions, simulating those they face crossing the Himalayas. Cooler blood can carry more oxygen. Did the researchers recreate the low pressure and temperature that the birds would encounter 7000 metres up? At low pressure, it is harder for the wings to transfer heat to the passing air and cool the blood. That might be
balanced in real life by the greater temperature gradient at altitude. The editor writes: The experiment didn’t mimic pressure or temperature at high altitudes, just oxygen levels. But if the birds’ blood running cold makes them more efficient at sealevel pressures, the effect is likely to be even stronger at altitude.
I am not so happy with Ola Rosling’s cheery statistics 7 September, p 46 From Arne Maus, Nesoddtangen, Norway I agree with Ola Rosling that we should base our views on facts, but I see problems with the statistics he presents. One graph shows the risk of dying in a plane crash as one per 10 billion passenger miles. No flights are 1 mile long and most of the risk is at take-off and landing. It would be better to give the risk per flight. Another states that the fraction of Earth’s surface in protected reserves increased from 0.03 per cent in 1900 to 14.7 per cent in 2016. This says only that certain nations are trying to save some of their land. Pristine forests and nature are clearly suffering as the Amazon, parts of Indonesia and elsewhere are burned to make way for farmland. ❚
For the record ❚ The photograph we used to illustrate our report on climate change increasing the risk of heavy rainfall and storm surges in coastal areas was of Mytholmroyd, West Yorkshire, UK, which has flooded but is around 90 metres above sea level and a 70-kilometre walk from the coast (28 September, p 18).
Want to get in touch?
Send letters to New Scientist, 25 Bedford Street, London WC2E 9ES or [email protected]; see terms at newscientist.com/letters
25 years ago, New Scientist was celebrating a milestone in eradicating the scourge of polio IT WAS a rare example of a straight-up good news story. “Polio has been eradicated in the western hemisphere, officials at the Pan American Health Organization declared last week,” we wrote in our 8 October 1994 issue. Polio is a viral disease that is typically transmitted by the ingestion of faecal matter, often through infected water supplies. If the virus enters the central nervous system, it can cause muscle weakness and paralysis, and sometimes death or long-term disabilities. Effective polio vaccines were first developed in the 1950s, but a coordinated global fight to eradicate the disease began in earnest in 1988. The disease was officially eliminated in China, Australia and 34 other western Pacific countries in 2000. Europe was declared polio-free in 2002. “The last known polio case in the Americas was a Peruvian boy called Luis Fermin who contracted the virus in August 1991,” we wrote. Models suggested that if the virus were still circulating there, at least one case of polio-induced paralysis would have occurred in the following three years. There had been none. Other animals can’t carry polio, so once the world’s human population is finally purged of it, there will be no reservoir from which the natural virus can emerge to reinfect us. Afghanistan and Pakistan are the last remaining regions with wild polio cases; there are fewer than 100 a year. Will the scourge of polio now vanish from human memory? Probably not. For a start, there is an attenuated strain present in the popular and effective trivalent oral polio vaccine itself. This strain can persist in the environment and regain the ability to cause polio. Such a strain was probably responsible last month for the first cases of polio recorded in the Philippines since the virus was declared eradicated there in 2000. We discussed one ingenious solution to this problem in March 2017, when we reported on some nifty gene editing that resulted in a live vaccine with a lower risk of mutating into a virulent form. More worrying, perhaps, is that a team of researchers in 2002 built the polio virus from scratch in the lab, using nothing more than genetic sequence information from public databases and readily available technology. The price of liberty from polio will be eternal vigilance. Simon Ings
To find more from the archives, visit newscientist.com/old-scientist
19 October 2019 | New Scientist | 27