The air quality is officially “good”, 400ft above Paris in a balloon at rush hour. From that height you can see the ring road and many of the city’s 37 bridges blocked with traffic, the commuting trains coming in, and – on the first cold day of winter – water vapour rising from several power stations as thousands of central heating systems fire up .
A yellowish haze has formed on the horizon as air pressure builds, but the pollution from Paris’s transport, construction sites and power stations is minimal compared to that of Beijing or New Delhi at this time of year.
Paris measures its air pollution from 20 official sites, one of which is a large helium-filled balloon tethered to the ground with a small measuring device strapped to its base. At 9am at ground level, it registers 66,500 particles in a single litre of air; 400ft up, however, it reads 78,000. The most it has recorded is more than 6m in November 2013 when the city’s fumes were trapped for days in a particular weather pattern.
Then, says Jean-Baptiste Bernard, a senior scientist at France’s national research station ( LPC2E ) in Orleans, it was not possible to see the Eiffel Tower from just 400 yards away. But even 6m particles a litre is nothing compared to what developing countries regularly suffer. At this time of year, he says, Chinese and Indian cities are likely to be 12 times as bad. This week Beijing was put on red alert as pollution levels from thousands of cars and factories rose to their highest levels in more than a year.
“Pollution at altitude is worse than at ground level. It is dominated [in Paris] by very small carbon particles. It is worst in spring. Paris, like London gets two or three incidents a year when particulate pollution can spike. When it reached 6m per litre in 2013 it was the equivalent of smoking 6-8 cigarettes,” he said.
Paris, which like London regularly exceeds EU pollution limits for some pollutants, such as NO2 gas, has begun “days without cars” and other measures to reduce traffic during the spikes of pollution which it experiences a year. When an alternate licence-plate system was introduced in September, it reduced NO2 levels by 10-40% in the city centre, said Bernard. It now plans to greatly increase cycling and reduce traffic with more public transport.
“This year it has not been too bad because of the wind and the rain. The real issue is not the spikes at peak times but the air we breathe all the year. It’s the everyday pollution which is the problem,” said a spokeswoman for Airparif, the independent monitoring organisation which works for the city of Paris.
“We need to reduce the number of diesels. We have a problem with heating systems, especially in the suburbs where people burn wood. In the spring there is a lot of pollution blown in from farms applying fertiliser,” said Bernard.
Bernard, one of France’s leading particle researchers, increasingly finds air pollution crossing national boundaries. Indian air now is affecting weather on a regional scale in the east European countries, he says. “There is a strong pollution effect in the eastern Mediterranean from India. This is climate change on a regional scale. New Delhi’s pollution spreads far. China’s pollution has been detected thousands of miles away.”
But there is conflicting evidence, he says, on how far that air pollution is linked to global warming. Some pollutants allow heat to escape, but others reflect the heat back to the ground, increasing warming and leading to the “heat island” effect.
Concern is growing that “short-lived climate pollutants”, like ozone, methane and black carbon emitted largely from diesels, are potential warming agents with dangerous impacts on human health and food production.
Black carbon, says the World Health Organisation, is largely soot, much of it emitted from diesel motors. “It is a primary component of particulate matter in air pollution that is the major environmental cause of premature death globally. It has a warming impact on climate 460-1,500 times stronger than CO2,” said a spokeswoman at a health summit in Paris this week.
“Equally, methane, a powerful greenhouse gas, is emitted largely from landfill sites,” she said. “People are beginning to understand that there is a direct link between air pollution and climate change, and that if they address air pollution they will also reduce climate change and improve health quickly. It’s a win-win situation.”
The top of this list is dominated by the ultra-miasmic cities of India and Pakistan and shaded at the top by Delhi. On an average day, the residents of the Indian capital breathe air fouled by fine particles at a concentration of 153µg/m3. This is close to three times the Beijing mean and 15 times the 
A vast swathe of humanity is unknowingly breathing poison on a daily basis. The implication is profound, because without knowing the air is bad, nothing will be done to fix it.
Respro® Masks are reusable 
Respro® Bulletin Board 