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"Predict'Air, a new air quality indicator"

Validate the relevance of a health exposure indicator, the Oxidative Potential of atmospheric particles.

Air pollution is a major public health concern. Current PM10 and PM2.5 indicators, based on particle mass, do not adequately describe the short-term health impact. Gaëlle Uzu, IRD research director at the Institute of Environmental Geosciences (UGA, CNRS, IRD, G-INP) proposes a complementary indicator, the Oxidative Potential.

Particle pollution

Air quality is a major public health issue. Epidemiological studies have established that chronic diseases resulting from air pollution are mainly due to particles. Current European regulations use the mass concentration of particulate matter (PM) as an indicator and health warning tool and do not integrate the major determinants of the toxicity of particles (composition, size, solubility, specific surface, chemical speciation). However, most of the mass of ambient particles is made up of components of low toxicity while harmful substances represent only a very small percentage of the mass. Isn't a new indicator representative of the health impact necessary to alert us?

→ In France, the impact of poor air quality is estimated at 40,000 premature deaths per year in 2020.*

A complementary health metric

The Predict'air Chair is involved in research aimed at demonstrating the relevance of the Oxidative Potential (OP) of particles as a new indicator of health exposure. The objective is to propose the OP as a new regulatory measure of air quality in Europe.  This new metric would allow us to consider only pollutants with an impact on health.

G. Uzu proposes, with the Station of the Future, to develop a project around automatic measurements in quasi-real time of the Oxidizing Potential and other chemical measurements on line. 

The contribution of the station will be to demonstrate the feasibility of this concept in Grenoble, a city with a complex topography impacted by winter pollution episodes.

The station of the future

It is necessary to complete the first studies carried out which aimed to show the relationship between the values of the oxidizing potential of particles in the air and the effects on health.

More specifically, the Predict'air Chair with the Station of the Future wishes to support the development of laboratory measurements, as well as the science consolidating the relationships between Oxidative Potential, sources of particulate emissions and health impact.

The Station of the Future implements a novel platform of equipment to :

  • take into account health exposure in the measurement of air quality
  • identify in real time the sources responsible for air quality
  • study the impact of current regulations and propose scenarios

For that, Gaëlle Uzu's team proposes to:

  • Deploy and operate in parallel different on-line measurement devices at the Grenoble-Les Frênes air quality reference measurement station.
  • To develop a new method of processing online data from several instruments, in order to attribute to each source of particles emitted in the atmosphere its share of health impact.
  • Cross-reference the data with epidemiological studies in the Grenoble basin and in La Paz, Bolivia, where the IGE manages an atmospheric observatory.

To go further

But what is the Oxidative Potential? 

It is a metric defined as the capacity of particles to induce the formation of oxidizing species in the pulmonary environment and thus to cause oxidation reactions leading to deleterious effects for the organism. This measure integrates the properties of the particles (size, chemical composition, active surface...) related to the oxidative stress that they can generate in the respiratory system.

Indeed, in vitro process studies have shown that the health effects of atmospheric particles are mainly attributed to their inflammatory potential via the oxidizing species they carry, such as metals and organic molecules.

The diseases triggered differ according to the specific mixtures of the different pollution sources, the duration of exposure and the susceptibility of the individuals. But the common origin of these respiratory diseases is attributed to pulmonary oxidative stress generated by exposure to particles. At the biological level, oxidative stress can be defined by an uncontrolled excess of radicals derived from oxygen, (also called free radicals) or nitrogen. This excess can damage cells, induce an inflammatory response, and more generally upset the metabolic balance of cells. This biological mechanism is at the origin of many cardio-respiratory pathologies that occur when we are exposed to air pollution such as asthma, bronchitis or certain cancers. This stress is expressed if the production of oxidizing species exceeds the antioxidant mechanisms supposed to limit their presence.

What the Air Liquide Foundation is doing

Since 2019, the Foundation has financed the Predict'Air project with 420,000€. A monitoring committee including the Air Liquide Foundation and the sponsors meets annually to follow the progress of the research.

Gaëlle Uzu interview: Can we control the air we breathe? (french podcast)


"Air pollution, and in particular the number of particles, has direct impacts on health but it is not yet well established which characteristic is preponderant between chemical composition, size or oxidizing power. This project will provide a lot of comparative data that is essential to be able to better understand the mechanisms involved and thus define future air quality measurement stations. "

Martine Carré, Scientific Director in Analytical Sciences, International Fellow

Fondation Université Grenoble Alpes