>>14861>What is the physics or chemistry behind vegetables and fruit grown close to city streets in comparison to rural streets? What do you mean? It's exactly the same lol
>The city can "keep" contaminations better than rural areas?Well you have to consider the dwelling time of a given pollutor. In a city you have a lot of pollutors on a small area, perpetually.
On a highway you have less pollutors at nights because less people are commuting and trucks are sleeping, plus people on the highway move faster through the area, wheras in a city it's usually stop and go, and acceleration costs more gas and thus produces more dirt than going straight at a constant speed like the autobahn. Some people going very fast might burn a lot of gas, but I out of a first impulse I would say a truck passing a crop field on a highway will leave less dirt along the 300 meter of field (plus higher dispersion because more room) than when it's moving the same distance in a city where the 300m might be two turns around a block, plus traffic lights and brake-accelerate cycles.
Then of course in cities you have all those areas where there might have been industry so the soil is already contaminated, or people using certain spots as designated trash dumps, all the dog and cat shit, trash everywhere (incl. smoking residues), and so on. There was a reason the plague could spread so well in cities.