Why urban pollution harms health?

EL MUNDO 

http://www.elmundo.es/blogs/elmundo/elporquedelascosas/2015/02/08/por-que-la-contaminacion-urbana-hace.html

SUM UP

Madrid, either in winter or summer, except when strong winds for days, this tucked under a 'beret' yellowing of contamination.

The capital suffers to be a cold city in winter as a result of a longstanding policy of using diesel oil. Diesel, a product of oil refining, little is sold. To help sell the various authorities assigned low taxes, so the price was, at times, half that of gasoline. It is still cheaper than this.

These 10 years or so, the authorities were concerned that bothered visible pollution and dirtying the cities, forcing refineries to better filter diesel, eliminating combustion PM10. But authorized diesel oils size PM2.5 particulate (particulate matter of 2.5 microns or less). 

This occurs not only from vehicles. Madrid has a huge amount of heating boilers that run on diesel.

OPINION

Nowadays, there are a lot of vehicles that are harmful  for the environement, i know there are people who don't care about the planet because of they aren't green. But we have gone to a limit we hadn't expect, the levels of pollution that we have also are dangerous for us.

I'm ashame that we can't neither protect ourselves of us. It's a pity we will destroy our plantet.

VOCABULARY
CO2= Dióxido de Carbono.