Ozone smog may increase the risk of MS in children: Study
Every unit increase in exposure raised the likelihood of diagnosis by 10%
Written by |
Children exposed to higher levels of ozone may face an increased risk of developing pediatric-onset MS. (Photo from iStock)
- Exposure to ground-level ozone significantly increases the risk of childhood-onset multiple sclerosis (MS).
- Each unit increase in ozone raised MS likelihood by ~10% in the three years before symptoms appear.
- Reducing ozone exposure in youth is a potential public health strategy for MS prevention.
Exposure to higher levels of ground-level ozone may significantly increase the risk that children and teens will develop multiple sclerosis (MS), a new Italian study suggests.
Researchers found that for every unit increase in ozone levels in the three years preceding the first MS symptoms, the likelihood of a child or adolescent developing the autoimmune disease rose by approximately 10%.
The findings add to a growing body of evidence linking environmental pollutants to the onset of MS. While researchers are still untangling the exact causes of the disease, this study suggests that ground-level ozone, a common air pollutant, could be a key environmental trigger during the critical years of childhood development.
“These results support the hypothesis that [ozone] exposure may be a contributing risk factor for MS,” researchers wrote, noting that as global ozone levels trend upward, reducing exposure in youth could become a vital public health strategy for MS prevention.
The findings were described in a study, “Ozone pollution as a possible trigger for multiple sclerosis in young people: the PEDIGREE study,” published in the Journal of Neurology.
Investigating environmental triggers in pediatric-onset MS
MS is marked by an immune response that damages the brain and spinal cord. The exact causes are not fully understood, but environmental factors such as long-term exposure to air pollution are believed to play a role.
While air pollution has been linked to an increased risk of MS in adults, less is known about its impact on children and adolescents. To learn more, a group of Italian researchers compared air pollutant exposure data from people with pediatric-onset MS (POMS) with those of healthy children and adolescents.
The research was part of the PEDIGREE study, which is investigating genetic and environmental factors associated with POMS in the Italian population. Environmental exposure data were collected from 2020 to 2023 using the PEQ-IT questionnaire, which collects comprehensive information on events and lifestyle-related exposures from both parents and children.
Spatial information on air pollutants of interest, including ozone, was obtained from the European Monitoring and Evaluation Program (EMEP) database, a scientifically based, policy-driven program that aims to reduce air emissions from various sources. Data on air pollutant exposure were available for 113 POMS patients and 117 controls.
Participants with POMS experienced the first signs of MS at a mean age of 14.2 years, and were 16.8 years at the time of the questionnaire. Compared with controls, patients more commonly had at least one parent who smoked (76.3% vs. 61.3%), and fewer of their mothers had high education levels (30% vs. 50.5%).
Results showed that the average ozone levels in Italy increased over the years. Ozone is a gas formed from oxygen that protects against ultraviolet radiation when present in higher layers of the atmosphere. However, ground-level ozone is considered a potentially harmful air pollutant.
The data showed that in all three years preceding MS onset, kids with MS had been exposed to significantly higher levels of ozone than controls. Initial statistical analyses demonstrated that higher ozone exposure was associated with an 8%-9% higher likelihood of developing POMS.
This association persisted after adjustment for age at disease onset, gender, sun exposure, parental smoking habits, and mother’s education. In this analysis, each unit increase in ozone exposure in the year preceding MS onset was associated with an 11% higher risk of MS, while the risk was 10% and 9% higher in the second and third years before the first symptoms emerged, respectively.
While the mechanisms behind this association were not explored, the scientists said that ozone may contribute to brain inflammation and generate reactive oxygen molecules that damage cells.
Additionally, being a girl and having a mother with less education were independently associated with a higher risk of developing the disease.
No significant association was observed between POMS and exposure to other air pollutants, including nitric oxide and nitrogen dioxide, two outdoor air pollutants produced by vehicle emissions and fossil fuel combustion. Exposure to atmospheric particulate matter (solid particles and liquid droplets) was also not linked to a higher risk of developing POMS.
“These results are consistent with previously reported data showing an association between high levels of [ozone] and an increased risk of developing [POMS], particularly in genetically predisposed individuals,” the researchers concluded.
Leave a comment
Fill in the required fields to post. Your email address will not be published.