Decades of Contaminated Drinking Water in Sweden Linked to 40% Increase in Childhood Asthma Risk

Lund University study finds very high prenatal PFAS exposure from contaminated water in Sweden significantly increases childhood asthma risk by age 12.

By: AXL Media

Published: Apr 10, 2026, 4:00 AM EDT

Source: Information for this report was sourced from Lund University

The Toxic Legacy of Firefighting Foam in Ronneby

The municipality of Ronneby, Sweden, serves as the epicenter of a major environmental health study following the 2013 discovery of extreme PFAS contamination in the local water supply. For over 30 years, firefighting foam used during drills at the nearby F17 regiment leached into the groundwater, exposing approximately one-third of the town's residents. Because perfluoroalkyl and polyfluoroalkyl substances (PFAS) are highly persistent and capable of crossing the placenta, thousands of children were exposed to these "forever chemicals" before birth. Researchers at Lund University utilized this tragic real-world scenario to investigate the long-term respiratory consequences for children born during the height of the contamination between 2006 and 2013.

Mapping High Intensity Prenatal Exposure

To determine the level of fetal exposure, the research team analyzed the residential addresses of 11,488 mothers during the five years preceding each child's birth. Participants were categorized into four groups ranging from a control group in non-contaminated areas to a "very high exposure" group consisting of 194 children whose mothers lived at heavily contaminated addresses for all five years. This granular mapping allowed scientists to differentiate between background environmental levels and the extreme concentrations found in Ronneby’s water, which were hundreds of times higher than those seen in the general population. The children were then followed through Swedish national health registries until they reached 12 years of age.

A Significant Spike in Pediatric Asthma Incidence

The study’s findings, published in PLOS Medicine, indicate a stark dose-response relationship between PFAS levels and respiratory health. While children exposed to intermediate levels of the chemicals showed no significant increase in asthma, those in the "very high" category faced a 40% greater risk of developing the condition. Specifically, 27% of children in the highest exposure group were diagnosed with asthma by age 12, compared to only 16% in the low-exposure control group. According to lead researcher Annelise Blomberg, this substantial increase highlights a previously unrecognized public health consequence of industrial water contamination that may have lasting effects on lung maturation.