Measuring Air Quality: A Tech Approach

Understanding the quality of the air we breathe is essential for a sustainable future. With our innovative air quality monitoring kit, connected to a computer, we can collect and analyze data in real time. This hands-on approach allows students to explore the impact of human activity on the environment and develop solutions for healthier cities.

Here are the real-time results from our sensors:

Air pollutants are numerous. They can be classified into several categories:

chemical
physical
biological

Chemical polluants

Physical polluants

Biological Polluants

Meteorology

Air quality is closely linked to meteorological phenomena. Meteorology influences the transformation, dispersion, accumulation and deposition of pollution.

Temperatures affect the volatility of compounds, dispersion (by convection) and emissions of pollutants (increased sources in cold periods).
Solar radiation alone can transform certain compounds into others. This is the case with ozone, which is formed from nitrogen oxides and COV under the action of solar radiation

Under normal conditions, the temperature decreases with altitude. The warmer air on the ground naturally carries with it the pollutants emitted on the ground. The concentrations of these pollutants decrease and disperse at higher altitudes.
Under certain conditions, this temperature gradient is broken and colder air is present on the ground. Natural convection no longer takes place and the pollutants accumulate.

Wind moves air masses and the pollutants they contain. It can transport pollution or, on the contrary, disperse pollutants.

Precipitation ‘leaches’ pollutants from the atmosphere by washing them down to the ground, reducing their concentration in the air. On the other hand, it can transfer pollutants into the soil or water.

Qualité de l’air

The index is constructed by integrating 5 different pollutants:

– fine particles (PM10)
– fine particles (PM2.5),
– nitrogen dioxide (NO2),
– ozone (O3),
– sulphur dioxide (SO2).

All these polluants have impacts on our health and our environment.

origin of NO2 ( dioxyde d’azote)

Nitrogen oxides are mainly emitted during combustion processes. The main sources are transport, industry, agriculture, energy conversion and heating. Some industrial processes, such as nitric acid production, fertiliser manufacture and surface treatment, introduce nitrogen oxides into the atmosphere.
Natural sources include thunderstorms, volcanic eruptions, forest fires and bacterial activity.

Inside enclosed spaces (houses , offices, vehicle cabins…) combustion appliances (heating, cooking, hot water production) are the main emitters of nitrogen oxides. Cigarette smoke, which results from combustion, also contains them.

Effects

origin of CO ( carbon monoxide)

Carbon monoxide comes from incomplete combustion. It is largely emitted by road traffic and residential/tertiary heating.

The main sources of carbon monoxide in the home are malfunctioning combustion appliances:
Boilers and water heaters damaged
Used stoves and cookers
Old, cracked chimneys, barbecues …

effects

origin of VOC ( Volatil Organic Compounds) , ethanol….

A volatile organic compound (VOC) contains at least one carbon atom associated with other atoms. VOCs are made up of a number of species, including volatile hydrocarbons and other compounds in the vapour state in the atmosphere, such as ethanol and benzene ….

VOCs are produced by industrial processes:

chemicals, metal degreasing, paint, printing, glues and adhesives, rubber, cleaning products, perfumes and cosmetics, etc.

oil refining, production of alcoholic beverages, bread, etc.
industrial combustion, etc.

VOCs are also emitted naturally: forests, Mediterranean vegetation, cultivated areas, fermentations, etc.

origin of PM10; PM2,5; PM1

Suspended particles are very varied: salts (nitrates, sulphates, carbonates, chlorides, etc.), organic carbon compounds (PAHs, oxides, organic matter, etc.), trace elements (heavy metals, etc.) and even elemental carbon. They can be distinguished by their diameter :
-PM10: particles with a diameter of less than 10 µm (microns)
-PM 2.5: particles with a diameter of less than 2.5 µm
-PM 1: particles with a diameter of less than 1 µm

Human activities, particularly combustion, such as road traffic, heating, the burning of fossil fuels, waste incineration and thermal power stations, as well as numerous industrial processes (quarries, cement works, steelworks, foundries, fine chemicals, etc.) generate large quantities of dust. Agriculture and the construction and public works sector also contribute to the resuspension of fine particles in the atmosphere.
Dust also comes from natural sources (forest fires, soil erosion, Saharan dust, volcanic eruptions, pollen, spores, etc.). ( source : atmo.fr)

In enclosed spaces, the presence of particles results both from indoor sources and from transfers with the outside world. Combustion sources include cigarettes, fireplaces, wood or gas stoves, gas cookers, gas water heaters, food cooking (frying, sautéing, roasting), candles, incense sticks, etc. Some activities also contribute (DIY, housework), as do construction, furnishing and decorative items.