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Dutch Town Lays Air-Purifying Concrete
eldavojohn writes "In an effort to combat air pollution, a Dutch town has paved some of its streets with air-purifying concrete. It contains a titanium dioxide-based additive that utilizes sunlight to turn car exhaust into harmless nitrates. It was shown to do this in a lab and now the scientists are interested in just how much this will affect the air quality around the road. They will sample the air quality by a normal road and by this newly paved one."
Because the purifying concrete offsets the pollution incurred from mining the titanium to create the concrete? Am I wrong in thinking I knew an old lady who swallowed a fly? Someone weigh in on this please. Thanks :P
My humor is probably your flamebait
All passive filters I know require replacement because they get clogged, or the active elements eventually decay. Beyond making jokes about swapping the church bricks five years from now, TFA was a bit light on the details. Does anyone know how does this works, from a chemical perspective?
Web2.0: I love when people Flickr my cuil and digg my boingboing until my google is reddit and I start to yahoo
This sounds like a great idea if it works, but surely producing concrete is a far from 'green' process. I wonder how long the concrete has to be in place to neutralise the polluting effect of manufacturing it in the first place.
But we are producing concrete anyway, so we'll still be ahead as long as this process does not produce more pollution than the pollution from standard concrete + whatever it absorbs.
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
not to mention all the side products that are produced, msot of which i am willing to bet havenot even been identified, much less studied
J Environ Qual. 2008 Feb 11;37(2):291-5. Print 2008 Mar-Apr.Click here to read Links
When does nitrate become a risk for humans?
Powlson DS, Addiscott TM, Benjamin N, Cassman KG, de Kok TM, van Grinsven H, L'Hirondel JL, Avery AA, van Kessel C.
Soil Science Dep, Rothamsted Research, Harpenden, Herts, UK.
Is nitrate harmful to humans? Are the current limits for nitrate concentration in drinking water justified by science? There is substantial disagreement among scientists over the interpretation of evidence on the issue. There are two main health issues: the linkage between nitrate and (i) infant methaemoglobinaemia, also known as blue baby syndrome, and (ii) cancers of the digestive tract. The evidence for nitrate as a cause of these serious diseases remains controversial. On one hand there is evidence that shows there is no clear association between nitrate in drinking water and the two main health issues with which it has been linked, and there is even evidence emerging of a possible benefit of nitrate in cardiovascular health. There is also evidence of nitrate intake giving protection against infections such as gastroenteritis. Some scientists suggest that there is sufficient evidence for increasing the permitted concentration of nitrate in drinking water without increasing risks to human health. However, subgroups within a population may be more susceptible than others to the adverse health effects of nitrate. Moreover, individuals with increased rates of endogenous formation of carcinogenic N-nitroso compounds are likely to be susceptible to the development of cancers in the digestive system. Given the lack of consensus, there is an urgent need for a comprehensive, independent study to determine whether the current nitrate limit for drinking water is scientifically justified or whether it could safely
Maybe we could do even better.
Hmm, since we're being green anyway, lets eliminate some of the cars--then perhaps we could make the concrete softer to walk on.
We could use some other color but grey--yuck. Maybe green to represent the fact that it purifies the air.
Being softer, it would be nice if it had some kind of self-patching mechanism...
As long as it's going to be self-patching, let's get really sci-fi and have it create itself using some kind of a system involving materials from underneath itself in some kind of a synthesis process.
Damn, I'm thinking way too far ahead--our science will never get to the point where it can do this stuff. Guess I'll have to be happy with air-purifying concrete.
What do you suggest paving the road with? Grass? Good intentions?
Comment of the year
Anything is harmful in the wrong place and in the wrong concentrations. Nitrates are, for example harmful to fish in high concentrations.
Most systems have processes that are limited by the supply of some resource. Ocean ecosystems are nitrogen limited, whereas fresh water systems tend to be phosphorous limited. Thus if the nitrates are washed off into fresh water, they'll cause relatively little immediate damage unless the concentrations are high enough to be toxic. However, if that nitrate is carried downstream to the ocean, the plume of nitrogen rich water entering the ocean can cause blooms of organisms that use up so much oxygen that fin fish suffocate. This happens where the Mississippi enters the gulf.
So, how and where something like this is used makes a difference. If you imagine all the US cities along the Mississippi and its tributaries using it, and if there is a mechanism by which the nitrates make it into the rivers, then this could make the situation in the Gulf much worse. If you use it in a coastal city and only the runoff from that city affects the local ocean, the amount of nitrogen entering the ocean might or might not have any measurable effect.
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The nitrates can't run off into the oceans, because Holland is below sea level.
At the bottom of the
a) Not all of Holland is below sea level, 75% of it is above sea level.
b) Nitrates can still pollute the ground water then diffuse into the ocean and rivers