nightmare in the kitchen (and indoors)
[Série 3/3] More fine particles with roast chicken or waffles than driving on the ring road? Fine particle pollution does not only concern the outside air or that of the Lyon metro. In our homes they are also there and do not only come from outside sources. Cigarettes, candles and Armenian paper may no longer be your friends.
Fine particle pollution in Lyon
Another catchy article title? Yes, but at least you’re here. So now stay a little longer.
You are unlikely to develop lung cancer while baking waffles in your kitchen. On the other hand, you may not imagine that this exposes you to a potentially greater concentration of fine particles than during your car or metro journey a little earlier in the day. And yet, you would surely have imagined the opposite.
Air pollution is often associated with that outside, of the city or its environment. The air inside your home is not always very clean. Take a look at our (your) small experiments.
More fine particles with roast chicken or waffles than driving on the ring road?
Yes it’s possible. Besides, we’re not the ones saying it, if you still don’t believe us:
“We can be at 150 μg/m3 pay a roast chicken in the oven in his kitchen when we spent 20 minutes in the car with lower levels of fine particle concentration. »
Atmo Auvergne-Rhône-Alpes
Indeed, to operate its oven or cook food in a frying pan can produce a high concentration of fine particles. On the site of the Captotheque, the measurement project open to the public by Atmo Auvergne-Rhône-Alpes, there are measurements taken indoors. And especially in the kitchen. The concentration levels of fine particles are sometimes very high and somewhat unsuspected (for us anyway).
Here is a measurement made by one of the members of the Captothequeduring a frying pan. We exceed 1000 μg/m3 for PM10, when the WHO recommendation for one-hour exposure is set at 45 μg/m3. For the other sizes of fine particles, the levels are also very high.
Even chosen here, with this other experimenter, during the realization and the waffle baking :
Cooking can generate a lot of fine particles
This is a somewhat disturbing finding. Some measurements taken during cooking on the pole or in the oven by users of the Captothèque show levels that are sometimes higher than those we encountered during our outdoor journeys by metro or car.
The cooking of “fries for the aperitif” made by this user shows it:
Even when the concentration of fine particles does not pierce the ceiling. Like here, during a frying session:
The levels are at times higher than those encountered during our drive between Perrache and the Tête d’Or park.
During our measurements carried out in our homes, we did not encounter any problematic concentration levels. In particular, we carried out measurements during baking. The level of concentration is roughly equivalent to that of the room in normal times.
But for others, that’s not always the case, like this user:
So is cooking dangerous?
Obviously, the conclusion is not that a roast chicken in the process of cooking would be more harmful to your health than sitting in traffic jams.
As Atmo Auvergne-Rhône-Alpes reminds us:
“Concentration levels must always be put into perspective with respect to exposure time.”
A peak, even high, will have less impact (if it lasts a short time or if our exposure time is low) than an average level of concentration and background pollution experienced daily.
In addition, the concentration of fine particles in your interior will also emit dependent sources. As seen above with the examples of baking, the concentration levels between users can differ radically. The type of equipment and the dispersal capacity of the house also play a big role in the level of concentration.
Finally, in our homes, ventilation and the ability to disperse can be easier and more effective than at the back of the very underground Vieux Lyon metro station.
“The worst indoors is smoking”
The cigarette emitting fine particles? Again, not really a surprise. But with a fine particle sensor in your hands, you become more aware of the level of concentration generated. We did a little test by lighting a cigarette indoors. Then, we launched our sensor and here is the result:
At the start of the measurement (when the curves are still green), the cigarette is not lit. From the start of combustion, the concentration of fine particles, in particular the smallest ones (PM1), rises sharply. We see in particular that nearly 20 minutes later, the levels are still very high.
Just like the cigarette, light a armenia paper in your home won’t really clean your air. On the other hand, it will load it with fine particles.
In this user we reached 700 μg/m3 for PM10.
Here too, we see that it takes some time, a good twenty minutes on average, for the levels of concentration, with ventilation of the room, to become acceptable again.
“Indoor pollution is often overlooked. In particular that coming from activity in the kitchen, certain cooking methods or cigarette smoke.
Thomas Coudon, researcher at the Léon Bérard center for the fight against cancer in Lyon
Atmo Auvergne-Rhône-Alpes even adds a layer:
“We see that apart from industrial sources for outdoor air, the worst source of fine particle pollution is indoor smoking”
Atmo Auvergne-Rhône-Alpes
Remember that air pollution (fine particles and other sources) is responsible for premature deaths. Between 2015 and 2017, a study was conducted in Lyon by theInsermthe CNRSI‘inrah, Grenoble Alpes University and Atmo Auvergne Rhône-Alpes. It concluded that nearly 500 people died prematurely due to fine particles. For the air pollution levels of several metropolises, France was condemned in 2019 by the Court of Justice of the European Union (CUEJ).
The golden rule against indoor pollution: ventilation
Ventilation. This is the conclusion recalled by Atmo Auvergne-Rhône-Alpes. A known rule but that the measurements made over time by the experimenters of the Captothèque become.
“We see that it takes at least 20 minutes of aeration to return to acceptable concentration levels. »
A rule confirmed by Thomas Coudon:
“We don’t always pay attention to dispersion at home, inside”.
Should we then open our windows in all circumstances? In the midst of a fine particle pollution peak or Sirocco, opening your windows could increase the concentration of fine particles in your interior.
Apart from these times, Atmo Auvergne-Rhône-Alpes advises: it is generally preferable to ventilate its interior rooms to avoid the phenomenon of concentration and allow a better dispersion of the particles.
During our fine particle sensor loan session, we did not have the opportunity to take measurements by doing Household chores in our homes or in some poorly ventilated rooms. Household activity can in fact cause an increase in the level of concentration in resuspending fine particles for example. A chamber closed overnight may also exhibit relatively high concentration levels due to low dispersion.
Now, if you feel like it, it’s up to you! How to do ? The explanations are here ⬇️
How did we measure the concentration of fine particles in Lyon?
The three journalists from Rue89Lyon had three sensors provided by Atmo Auvergne-Rhône-Alpes. Sensors to measure the concentration of fine particles in the air, of three different sizes: PM 1, PM2.5 and PM10 (from the finest to the largest). These sensors are accessible to all, as part of the project Atmo Rhône-Alpes Captotheque. On simple request, you can borrow a sensor free of charge and take your own measurements.
We carried out various measurements during outdoor and indoor sessions (metro and homes). In particular, we have made two recording sessions on identical routes carried out with different modes of transport (the bicycle for Laurent Burlet, the metro for Laure Solé and the car for Bertrand Enjalbal):
- a journey of Golden-headed Parakeet, performed on April 15 from 8:30 a.m.
- a journey of Parilly (metro D) to place BellecourApril 28 from 8:30 a.m.
The choice of a simple logical follow-up: a variety of environments (park, ring road, city centre, quays, etc.) and routes that can be practically identically carried out by all modes of transport. We made these trips at the same time by bike, metro and car.
These measures present several limits. We did not repeat the measurements on these same routes by varying the times of the day or the week. In addition, they are made in motion to stick as close as possible to the movements of the public. However, fine particle pollution is analyzed with regard to the average concentration over time, these measurements are not intended to determine the usual concentration levels of the places crossed. We wanted to illustrate in particular the sources of pollution and the differences in concentration between the means of transport.
The thresholds used in the gradation of the graphs presented here (from the Atmo Captotheque) are those of the WHO. These are therefore not the regulatory thresholds, used in particular by the prefecture in the event of the implementation of alternating traffic during pollution peaks (with an alert threshold set at 50 μg/m3 for PM10 for example). The thresholds are lower here and are the latest published by the WHO. Those from which the organization believes there is an impact on health.
> Rue89Lyon would like to thank the Atmo Auvergne-Rhône-Alpes and Captothèque team for their availability, monitoring and analysis of the measurements taken as part of this experiment