Air pollution and childhood obesity. Scientists see a connection

Obesity in children can have negative health consequences in adulthood. It is a disease that requires treatment (and not just an unsightly problem) – it has been included in the list of the International Classification of Diseases. According to a report by the World Health Organization (WHO), 32 percent of Polish children aged 7-9 were overweight and obese. This is the 8th place among the surveyed countries in Europe. Now, scientists have proven that the factor that can affect obesity in children is, among other things, air quality. It is also worth recalling that a few months ago, doctors recognized smog as the official cause of the 11-year-old’s illness. It was the first such diagnosis in Poland.

Air pollution and obesity in children

The study was published in the journal “Environmental Pollution”. Researchers analyzed data from over 46,000 people. Catalan children aged 2-17 who changed their place of residence once in 2011-2018. It turned out that moving children to places with more air pollution was also associated with an increase in their body mass index. This study proves the importance of actions related to the reduction of air pollution, among others, precisely because of the negative impact on children’s health. In addition to other activities, it can be one of the elements of preventing overweight and obesity in the youngest.

The course of a study on the relationship between obesity and air quality

Scientists from the Instituto de Salud Global Barcelona (ISGLOBAL) together with other researchers from the Institut Universitari d’Investigacio en Atencio Primaria in Barcelona conducted a large-scale natural experiment. Experts in the areas where the children lived checked the level of air pollution before and after the move, examining the annual levels of nitrogen dioxide and suspended particulate matter with a diameter of no more than 10 micrometers (PM10) and with a diameter of no more than 2.5 micrometers (PM 2, 5). On the other hand, in primary health care centers, children’s body weight was measured during routine examinations, thanks to which it was possible to determine its possible increase. For their analysis, the researchers used the children’s body mass index (BMI) calculations before and 180 days after the move.

How does air pollution affect children’s weight?

Moving to places where the air was more polluted was associated with a small increase in body weight among children. Researchers noted this effect in all places where the air was polluted. The tendency to increase BMI because of this was stronger in preschool children, as well as children attending primary school. On the other hand, when children and their families moved to less polluted areas – this was not associated with a change in BMI. The researchers did not observe any relationship between the socioeconomic status of the family and the body weight of the children during the study.

And although children from polluted areas had a small increase in body mass index, the researchers emphasize that this study could still be of great importance for public health on a global scale. This is because 56 percent of the population now lives in urban areas that are more polluted.

Why does smog affect weight gain in children?

The biological mechanisms linking air pollution to weight gain are not yet fully understood. This relationship may be related to, among others:

• hormonal disorders,

• oxidative stress,

• metabolic changes,

• decreased lung function

• inflammation of adipose tissue (due to pollution).

Increased car traffic can also contribute to weight gain, which means that children go outside less often, which reduces their physical activity. Scientists remind that obesity and overweight in children are affected by the interaction of many factors, including genetic, psychological and social factors, but also lifestyle. And although, as it turns out, environmental pollution also plays a role, it is difficult to study its impact. It is not yet clear whether the relationship between air pollution and childhood obesity is causal (whether air pollution directly causes obesity or overweight) or is influenced by other related factors.