A new study is adding to long-running scientific and public debates about the health effects of everyday electromagnetic exposure, reporting a link between certain types of radiation and a higher risk of central nervous system tumors in children.

The research, published in Environmental Research, examined children’s exposure to extremely low frequency magnetic fields (ELF-MF) in urban homes and its association with central nervous system (CNS) tumors. ELF-MF is a form of non-ionizing electromagnetic radiation commonly produced by power lines, electrical substations, household wiring and many plugged-in electronic devices.

The study focused on families in Mexico City, one of the world’s largest metropolitan areas, where dense infrastructure and heavy electricity use can increase background electromagnetic exposure. Researchers measured magnetic field levels inside children’s bedrooms and collected information on device use and other environmental factors.

According to the findings, children exposed to residential ELF-MF levels above 0.4 microtesla (μT) in their bedrooms showed a statistically significant increase in the risk of developing CNS tumors compared with children exposed to lower levels. CNS tumors include a range of cancers affecting the brain and spinal cord, which are among the most serious pediatric cancers.

The researchers also observed a link between prolonged use of digital tablets and higher CNS tumor risk, particularly among children aged 6 to 10. The increased risk was noted for tablet use both with and without an internet connection, suggesting that the device itself and its electrical components — rather than wireless signals alone — may contribute to exposure.

In addition, the study estimated that more than 5% of children in Mexico City are exposed to ELF-MF levels above 0.3 μT at home. This proportion is higher than the estimated global average, highlighting how exposure can vary widely depending on local infrastructure, housing conditions and proximity to electrical systems.

Scientists say the results are noteworthy because ELF-MF exposure is nearly universal in modern societies. Power lines, transformers, home wiring, and a growing array of personal electronics all generate low-frequency magnetic fields. While these fields are non-ionizing and lack the energy to directly damage DNA in the way that ionizing radiation can, some researchers have long questioned whether chronic, low-level exposure could still influence biological processes.

The new study does not prove that electromagnetic radiation directly causes tumors. It identifies an association, meaning the two factors occur together more often than expected by chance. Other variables — such as socioeconomic conditions, housing quality, environmental pollutants or genetic predispositions — could also play roles.

Even so, the findings contribute to a body of research that has periodically raised concerns about ELF-MF and childhood cancers. International health agencies have previously classified extremely low frequency magnetic fields as “possibly carcinogenic,” a category used when evidence is limited but credible enough to warrant caution and further study.

Public health experts often emphasize that risk levels, if present, are likely to be small for any individual child. However, because exposure is so widespread, even a modest increase in risk could have population-level implications.

The study also draws attention to sources of exposure that families may overlook. While many people associate electromagnetic fields mainly with high-voltage power lines, indoor sources can also contribute. Charging cables, extension cords, appliances near beds, and the habit of using devices close to the body for long periods can all affect personal exposure levels.

Researchers say the findings underline the need for more large-scale, long-term studies that track children’s exposure over time and account for multiple environmental influences. Improved measurement methods and standardized exposure guidelines could also help clarify risks.

For now, some scientists suggest simple precautionary steps for concerned families, such as keeping beds away from major electrical sources, avoiding unnecessary device use close to the body, and not placing charging electronics directly next to sleeping areas.

As cities become more electrified and children begin using digital devices at ever younger ages, understanding how everyday electromagnetic environments interact with human health is likely to remain an important research priority.