- Two new studies are reporting the possibility that exposure to specific environmental factors increases the risk of developing MS in children and teens.
- One study, based on individuals’ residences, found a possible link between air pollutants and pediatric MS, and the other study, based on questionnaires, found a possible link between certain household chemicals (such as pest and weed control products) and pediatric MS.
- Both studies warrant further research to confirm the findings and determine whether these exposures actually cause MS in some children, and if so, why. The findings do not mean that everyone who develops MS in childhood has been exposed to these factors, or that everyone exposed to these factors will develop MS.
- Studies like these, which involve hundreds of children and adolescents with MS, are made possible by the infrastructure of the U.S. Network of Pediatric MS Centers, which was launched with funding from the National MS Society, and to which the Society continues to provide funding to facilitate research. Recently, the Network completed a study of risk factors related to the development of pediatric MS, leading to these reports among other publications.
- The teams published their findings in Annals of Clinical and Translational Neurology; links to the papers are available below and can be read without a subscription.
Although the cause of multiple sclerosis is not yet known, more is being learned about environmental and genetic factors that are related to the risk of developing this disease. There is no single risk factor that provokes MS, but several factors are believed to contribute to the overall risk. In contrast to adult MS, pediatric MS appears to have a narrower window of onset. The U.S. Network of Pediatric MS Centers
was launched with Society funding in 2006 to set the standard for pediatric MS care, educate the medical community about this underserved population, and create the framework to conduct critical research. Since 2013, the Society has committed $5.8 million to support the Network to provide essential infrastructure to facilitate research. Recently, the Network completed a study of risk factors that are related to the development of pediatric MS, leading to these reports among other publications
Urban air quality:
For this study, investigators looked at 290 people who developed MS in childhood, and 442 controls without MS. The team gathered information on pollutants from the Environmental Protection Agency (EPA), which tracks six air pollutants, as well as the management/release of potentially harmful industrial chemicals. Researchers looked at pollutant exposure in participants’ county of residence, as well as their proximity to sites releasing industrial chemicals.
The results show that four pollutants (fine particulate matter, carbon monoxide, sulfur dioxide, and lead air emissions) were significantly associated with an increased risk of pediatric MS for participants who lived within 20 miles of an MS center (possibly indicating an increased risk in more urban settings). Seventy-five percent of all participants resided within five miles of a site releasing potentially harmful chemicals, but the total amount of chemicals released was higher for sites near people who developed MS.
The authors note that the findings indicate that the risk of developing pediatric MS increased in more urban settings with increased levels of air pollution, and commented that pollutants might stimulate the immune response that gets misdirected against the brain and spinal cord in MS. Further study is necessary to determine whether exposure to pollutants can actually cause pediatric MS, and how this interaction might trigger the disease.
The team (Amy Lavery, MD, Children’s Hospital of Philadelphia, and colleagues) published its findings in Annals of Clinical and Translational Neurology
(2018; 5(10): 1146–1153
, available via open access). This study was funded by the National Institutes of Health.
Household chemical exposures:
For this study, investigators with the U.S. Network of Pediatric MS Centers looked at parents’ responses to a comprehensive environmental questionnaire that asked about the exposure and timing of exposure to household chemicals such as synthetic fresheners, pest control agents, weed control agents, and paint. Questionnaires were completed for 312 children with MS and 490 children without the disease.
The results suggest links between the risk of developing pediatric MS and several chemicals, including rodent-killing agents, weed control products, and plant/tree insect or disease control products.
These findings need to be confirmed, and further study needs to determine whether these exposures actually can cause pediatric MS, and also if specific ingredients are contributing to increased risk of pediatric MS. The researchers also note that the findings should be interpreted with caution, since genetic and environmental factors together contribute to development of MS.
The team (Soe Mar, MD, Washington University in St. Louis, and colleagues at the U.S. Network of Pediatric MS Centers) published their findings in Annals of Clinical and Translational Neurology
(Published online October 9, 2018
, available via open access). This study was funded by the National MS Society and National Institutes of Health.
Note: The findings from both of these studies do not mean that everyone who develops MS in childhood has been exposed to these factors, or that everyone exposed to these factors will develop MS. However, they offer new leads that may help provide a deeper understanding of what triggers MS, how those triggers lead to the development of the disease, and how to protect against it.
Read more about pediatric MS
Read more about MS risk factors