If a chemical in the air were linked to 12,000 premature deaths a year in Europe, 48,000 new cases of heart disease, and the chronic sleep disruption of 20 million people, there would be a directive, a commissioner and a summit. Those are the European Environment Agency’s figures for traffic noise. There is a directive. Nobody enforces it.

Noise is the environmental hazard we have decided to live with, in the way that cities once lived with coal smoke. One in five Europeans is exposed to road noise above the level the World Health Organization considers harmful to health, which is 53 decibels averaged over a day, roughly the sound of a busy office. In Paris, Rome and Athens, the figure is closer to one in two. The body does not habituate; the stress response to a passing truck at 3 a.m. fires whether or not you wake.

The E.U.’s Environmental Noise Directive, adopted in 2002, requires large cities to map their noise and draw up action plans every five years. Most do the mapping. Fewer do the planning. Almost none set binding limits, because the directive does not require them to, and because the main sources of urban noise — cars, lorries and motorbikes — are protected by a politics that treats the right to be loud as a right to move.

The remedies are not exotic. Lowering speed limits in cities to 30 kilometers an hour cuts noise by about 3 decibels, which the ear perceives as a 40 percent reduction; Paris, Brussels and Bilbao have done it and the sky did not fall. Low-noise asphalt, about 10 percent dearer than the standard kind, cuts another 3 to 5 decibels. Noise cameras, which photograph the plates of vehicles exceeding a threshold, are being rolled out in French cities; the fine is 135 euros. Enforcing existing rules on modified exhausts, already illegal everywhere, would help more than any of these.

What stands in the way is not cost but attention. Noise does not stain buildings or show up in blood tests. Its victims mostly do not know they are victims; they know they are tired and that their blood pressure is a little high.

The Commission is reviewing the noise directive next year. It should add what the 2002 version left out: binding limits, aligned with the W.H.O. guidelines, phased in over a decade, with consequences for cities that miss them. It should fund noise cameras the way it funds speed cameras.

Europe cleaned its air, slowly and against resistance, when it decided that breathing was not a luxury. Sleep is not one either.

Olivier Brandt is a contributing writer for The Continental Times Opinion section.