Young children living in two categories of families - the richest and the poorest - are the most exposed, in France, to fine particles. The former live more often in large cities, where air pollution is concentrated, while the poorest households live in the most polluted places in these urban areas, notes a study published Thursday by the Directorate of Research, Studies , evaluation and statistics (Drees) at the Ministry of Health.
But not all of these children are equal when it comes to the consequences of this exposure to particles, the study shows. According to the Drees, 10% of children concentrate most of the health effects detectable in the event of an increase in pollution. Babies from low-income families are the most vulnerable, particularly because their general health at birth is poorer. For example, they are more likely to have a low birth weight and to be born prematurely, two factors favoring the occurrence of respiratory pathologies.
» READ ALSO - Air pollution still kills 1,200 children and adolescents per year in Europe
Regardless of these findings, being exposed, during the first year of life, to peaks in pollution increases the risk of emergency hospitalization for bronchiolitis and asthma, as well as the consumption of anti-asthma medications. The scientists show this phenomenon by means of a semi-experimental analysis taking into account thermal inversion, a meteorological phenomenon resulting in the accumulation of atmospheric pollutants (fine particles, but also nitrogen dioxide and carbon monoxide).
Around 11,000 children under the age of three are urgently admitted to hospital for asthma each year; 28,000 are for bronchiolitis. The Drees deduces that around 2,000 hospitalizations for bronchiolitis and 1,800 hospitalizations for asthma, as well as 6,100 deliveries of anti-asthma drugs, could be avoided by protecting "children under 1 year of age from a fortnight of significant increase in their exposure to major air pollutants.
The consequences of air pollution on emergency admissions for bronchiolitis are particularly marked in the Paris region. But the children most affected by additional pollution also live in cities with fewer than 200,000 inhabitants, suggesting that "even in areas where exposure levels are lower, variations in air pollution cause effects harmful”. Another hypothesis made by the researchers: background overexposure to pollution could weaken the respiratory tract in the long term and make them more sensitive to occasional peaks. This would explain why children from the wealthiest families are slightly over-represented (along with those from low-income families) in the group of children most affected by pollution.