Indeed, the quality of our indoor air is paramount, while we spend about 80% of our time in closed places. So the reflection and suggestions on how to improve air quality at home will not be redundant.
The concept of indoor pollution conventionally refers to non-industrial interior environments in enclosed environments such as dwellings, public establishments, places of care and education, office buildings, health and medical-social establishments or methods of transportation. Urban dwellers spend more than 80% of their time inside these confined spaces, so exposure to air pollutants is primarily associated with indoor environments, particularly habitat (about 50% of the time).
The indoor environment is a dynamic universe characterized by pollution from outside and pollution of internal origin, related to the building and the occupants. Indoor pollution is diverse, marked by biological, physical and chemical pollutants. Every day we eat a kilogram of food, we drink two kilograms (liters) of water, and we breathe an average of twelve thousand liters of air.
Indoor pollution is a growing concern for several reasons. First, for a number of years, to reduce energy consumption, buildings are increasingly isolated, which greatly reduces air infiltration. In addition, the renewal of air is sometimes insufficient to evacuate indoor pollutants (lack of ventilation, malfunction and/or inadequate maintenance of ventilation systems). The buildings can be occupied by sensitive populations: this is the case of children, the elderly, and subjects with asthma or suffering from chronic respiratory or cardiovascular pathologies, for example. Finally, the health aspects associated with different indoor pollutants are better recognized; although it is still difficult to assess the health effects of associations or interactions of several pollutants.
The Question of the Quality of the Air
If the outside air is polluted, indoor air is often of poorer quality: prolonged exposure to harmful products, persistent humidity … The degradation of indoor air quality (at home but also at the office, school, shops, transportation …) has become a prominent public health concern, too often neglected.
Thus, according to a Harris Interactive opinion poll conducted in late 2013, in Europe as in the United States, 9 out of 10 inhabitants consider the quality of the air in their homes to be good even though they do not know how to evaluate it. in general, the indoor air quality is worse than outside: 2 to 5 times higher according to the US Environmental Protection Agency (EPA).
The effects of indoor pollution on health are only partially known, and it is only recently (the 1970s) that the French began to worry about its quality, hence the concern for asbestos (prohibited in 1997), carbon monoxide and lead paints.
Contrary to what one might think, the quality of the indoor air is not necessarily better than that of the outside air. A problem is all the more important for public health that we have the habit of spending about 80% of our time locked inside a building, whatever it is.
In 2014, NAFSA (National Agency for Food Safety, Environment, and Labor) estimated that the number of premature deaths caused by the most well-known indoor air pollutants was almost 20,000 per year. The air we breathe inside our homes may indeed be of lower quality than the one we breathe on the outside. The fault of some specific pollutants that emanate from the materials we use for the construction, decoration or furnishing of our homes. Also responsible, some of our activities: smoking, DIY, cleaning, etc.
*** Biological pollutants
Infectious agents (bacteria, viruses, toxins) come from living beings or can proliferate in some poorly maintained equipment (ventilation, etc.) Mold can lead to infections such as nosocomial invasive aspergillosis. Allergens come from pets, plants, molds, insects, and mites.
*** Chemical pollutants
It is very often found in indoor air. Chemical pollutants are among the list of those found abundantly in the air we breathe at home:
– Carbon monoxide (CO) is a colorless, odorless and deadly gas with a high concentration. Heating or hot-water heating appliances are disengaged when they are old or poorly adjusted. The symptoms of intoxication are headache, dizziness, blurred vision, nausea, weakness of the legs, drowsiness, syncope…
– Volatile organic compounds (VOCs) – such as formaldehyde, benzene or organic solvents – released by paints, perfumes or felts. Some are carcinogenic. Volatile organic compounds or VOCs (formaldehyde, organic solvents, glycol ethers, hydrocarbons …): they are found in new or recently renovated buildings. They can be released by many materials: glues, paints, cleaning products, chemical perfumes, felts, but also so-called “natural” materials such as treated wood. Most are carcinogenic.
– Semi-volatile organic compounds (SVOC) – such as phthalates and bisphenols – are found in biocides or coatings. Lead in old paintings causes anemia and irreversible damage to the central nervous system. Phthalates contained in plastic, they cause reproductive disorders.
– Cigarette smoke, pesticides – insecticides, for example – etc. Let’s go back to tobacco smoke. Tobacco smoke contains more than 3,000 dangerous substances. It causes irritation of the eyes and respiratory tract, may cause seizures in asthmatics, cancer by active or passive smoking, etc. Hence the importance of airing if someone smokes in the room. Or better, to smoke outside. As a reminder, it is anyway forbidden to smoke in public places today.
*** Other indoor air pollution agents
We must add to them some living organisms evolving in our houses and which can also be sources of pollution. Mold spores can cause infections. And allergens are regularly emitted by plants, insects, mites or pets.
*** Particles and fibers
Dust, for its part, may be composed of various contaminants such as pollen or spores. Suspended in the air, they can be inhaled by the inhabitants of the house, especially during certain activities such as DIY or cleaning.
Dust contains particles, the smallest of which can be inhaled. It also contains smoke, soot, pollen, spores, and allergens. Fibers are particles emitted by certain materials (cellulose, hemp, sisal, asbestos, glass wool, rock …). Some activities such as DIY, cooking or cleaning emit significant amounts of particles and fibers that remain suspended in the air.
Asbestos is infamous because it is very carcinogenic.
*** Radioactive gases
Finally, a pollutant may be less known: radon, a natural radioactive gas, colorless and odorless. It can accumulate in homes and even more in poorly ventilated cellars. Attention therefore in the granite basement regions such as Brittany or the Massif Central.
Radon is a natural radioactive gas contained in soil and rock all over the world, at varying concentrations depending on the nature of the soil and the degree of containment of the site.
It is not perceptible (painless, colorless) and nevertheless dangerous, indeed, radon is a definite pulmonary carcinogen for humans and belongs to group I in the classification of the International Center for Research on Cancer (CIR). As such, “exposure to radon is one of the major risk factors in environmental health and this gas is significantly involved in the occurrence of a particularly common and serious disease: lung cancer,” says Hajo Zeeb, Professor Epidemiology and Zhanat Carr, Researcher at the World Health Organization (WHO).
In France, domestic radon is the second leading cause of lung cancer deaths after smoking.
It can accumulate in rooms where the renewal of air is very low (cellars, etc.)
This risk mainly concerns the regions with granitic or volcanic subsoil (Brittany, Massif Central, Corsica).
*** Moisture, indirect pollution
As for humidity, if it is not intrinsically considered as polluting, it can be at the origin of degradation of the quality of the indoor air. Cooking, drying clothes, shower, mobile auxiliary heating and even breathing: the sources of moisture at home are numerous. However, it is not recommended to live in a dwelling that is too humid, because the humidity favors the development of mites and molds, for example, but also the release of VOC by degradation of the glues on the furniture.
The sources of moisture are not lacking: shower, cooking, washing, drying (up to 1 kg of water vapor for laundry) toilets, human metabolism (an adult produces about 55g of water vapor per hour), water damage…
Of course, moisture is not directly polluting, but it promotes the proliferation of molds and mites. Moisture also degrades the glue on particle board, which releases formaldehyde.
According to the Observatory of Indoor Air Quality (OIAQ), 15% of households have visible fungal infections, micro-organisms that can induce various respiratory diseases such as allergies, infections or toxic-infections. the occupants.
However, a study led by Stéphane Moularat of the Scientific and Technical Center for Building Construction (SCBC) found that thyme essential oil and garlic extract, natural biocides, have been shown to be effective against fungal and bacterial overgrowth wood.
The Health and Economic Costs of Indoor Air Pollution
According to a study by NAFSA in April 2014 entitled “Exploratory study of the socio-economic cost of indoor air pollutants”, indoor air pollution would kill nearly 20,000 French people a year.
Kidney cancer caused by the inhalation of trichloroethylene; leukemia attributable to exposure to benzene; lung cancers related to radon or passive smoking; carbon monoxide poisoning, cardiovascular diseases caused by particulate respiration, etc. : the cost of this mortality and the decline in the quality of life of sick people amounts to 18 billion euros, to which are added the loss of days worked, and costs of care, and those related to research, about 20 billion euros.
Note that this is a low estimate for which scientists have retained only six pollutants for this first study: benzene, trichloroethylene, carbon monoxide, radon, particulates, and passive smoking.
The effects on our health can be immediate or long-term (chronic diseases or serious diseases). They depend on the nature of the pollutant and the quantities inhaled, the age of the subject, his vulnerability, his habits.
According to the Observatory of Indoor Air Quality, the French lose on average 9 months of life expectancy because of the polluted air in their homes, up to 13 months in the most polluted countries according to the WHO.
When the effects are immediate, they can result in discomfort, discomfort: irritation (eyes, nose, throat, etc.), uncomfortable odor, nausea, cough, asthma attacks, intoxications, suffocation … It should be noted that dust, because of its irritating power, amplifies the harmfulness of other pollutants.
Long-term effects are less obvious: they occur long after exposure and it is difficult to determine their causes. Low intensity but prolonged exposure to pollutants can result in serious diseases: cancers, respiratory diseases (asthma or various disorders), aggravation of cardiovascular diseases … In France, the number of allergic people has doubled between 1980 and 2000 and 3.5 million people suffer from asthma.
How to Improve Air Quality at Home?
According to the Harris Interactive opinion survey, most residents say they feel uninformed about the quality of the air in their homes, how to measure it and how to improve it. Here are some tips for reducing indoor air pollution.
Choose products that contain as few pollutants as possible from the moment of purchase. Some information has been put in place to help you:
* The VOC label (mandatory for all products sold in France by September 2013): indicates the level of emissions of volatile organic compounds, from a scale of A + (very low emissions) to C (strong emissions).
* Eco-labels: preferably buy products bearing the European Ecolabel
* The pictograms: they are there to alert you of possible dangers (flammable, toxic product, etc.)
– Read the instructions carefully before using a product, and observe the recommended doses and safety instructions.
– Install reliable and efficient appliances (heating, ventilation, etc.) and always ensure proper maintenance.
– Beware of mixtures of products (DIY, maintenance …) that can cause dangerous emanations. For example, bleach, mixed with an acid (such as a descaling agent), releases chlorine, an irritant gas. Odor products (paints, glues, perfumes, cosmetics, deodorants) all release VOCs, so do not overdo it. Ditto for scented candles and incense, whose combustion releases carbon monoxide, very toxic.
– Evacuate moisture: in case of infiltration or capillary rise in the walls, it is necessary to improve the water tightness of your house.
– For ventilation, choose your VMC with the help of a professional, because the right choice depends on the context of each dwelling. It must be cleaned regularly to avoid clogging and remain effective.
– Warning! A home cleaned with toxic products is not necessarily a healthy home!
– Unfortunately, green plants do not significantly cleanse indoor air.
The best solution is to prevent pollution.
In Conclusion: Health Issues
The health impacts of indoor pollution are many, of varying nature and severity: they range from simple nuisances (feelings of discomfort, discomfort or confinement, olfactory nuisance, various non-specific symptoms, ENT, ocular, cutaneous or respiratory, headaches, tiredness, malaise, difficulty concentrating, etc.) but which can have an impact on absenteeism and productivity, up to diseases such as poisoning (oxycarbonates, lead poisoning, etc.), infections (legionellosis , viruses, tuberculosis, etc.), respiratory allergies (rhinitis, asthma, dermatitis, etc.) sometimes favored by the humidity of buildings. But also indoor pollution has risks more or less long term: chronic respiratory diseases, cardiovascular, tumoral, neurological, etc.
Air pollution is now recognized as the main environmental risk for health in the world. It would be responsible in 2012, according to the World Health Organization, for seven million annual deaths worldwide (representing one in eight deaths), including 4.3 million for indoor pollution. Every European citizen is deprived on average of 8.6 months of life. Air pollution has been classified as a certain carcinogen for humans by the International Agency for Research on Cancer, such as outdoor air particles and exhaust effluents from diesel engines. Epidemiological studies show a strong causal link between fine particles (PM2.5) and cardiovascular and respiratory mortality.
Chronic particulate pollution (PM2.5) causes atherosclerosis, adverse pregnancy outcomes and respiratory illness in children. Long-term exposure to ozone affects respiratory mortality and death in people with chronic conditions. An increase in mortality, hospitalizations, and respiratory disorders is found with exposure to nitrogen dioxide. Exceeding WHO’s guideline value for PM2.5 translates into 19,000 premature deaths each year (including 2,900 for the nine French cities), including 15,000 cardiovascular deaths (1,500 of which occurred in nine cities). French) – European study APHEKOM (2012). In the most polluted cities in Europe, it is almost two years of life expectancy that could be earned if pollution could be reduced to the concentrations advocated by WHO (average life expectancy at thirty years for the nine French cities from 3.6 to 7.5 months).
According to the Health Observatory of Ile-de-France, living near roads with high traffic density would be responsible for 16% of new cases of asthma in children and 16 to 29% of exacerbations of respiratory symptoms (asthma attacks, hospitalizations).
Allergic diseases related to the air or food environment concern 25 to 30% of the French population and have a strong socio-economic impact (cost, absenteeism, quality of life). Their prevalence has doubled in twenty years in developed countries.
In its 2014 report on the health impact of exposure of the general population to pollens, NAFSA indicates that in epidemiological surveys carried out in France from 1994 to 2006, the prevalence of allergic rhinitis is estimated at most 7% in children aged 6 to 7, 20% in children 9 to 11 years old (with an awareness of nearly 27% of children with at least one aeroallergen), 18% among adolescents aged 13 to 14, 31 to 34% in adults. NAFSA specifies that certain chemical pollutants can modulate the allergic reaction by acting directly on the sensitized subjects, or by acting on the pollen grains, in particular on their wall and on their protein content.