Physical and chemical trigger factors in environmental intolerance

Area of Science:

• Environmental Health
• Toxicology
• Epidemiology

Background:

• Environmental intolerance (EI) is characterized by reactions to environmental exposures below established hazardous thresholds.
• Prevalence of symptom attribution to chemical and physical sources was examined across different EI types.

Purpose of the Study:

• To determine the prevalence of symptom attribution to environmental sources in individuals with self-reported EI.
• To compare symptom attribution patterns between different EI groups and a general population referent group.

Main Methods:

• Utilized cross-sectional data from the Västerbotten Environmental Health Study (n=3406).
• Identified individuals with self-reported EI to chemicals, buildings, electromagnetic fields, sounds, and multiple EIs.
• Employed the Environmental-Symptom Attribution Scale to quantify symptom attribution to 40 environmental exposures.

Main Results:

• Most EI groups, excluding building-related intolerance (BRI), reported more symptoms from expected sources than referents.
• Individuals with chemical and sound intolerance reported symptoms linked to building-related factors.
• Electromagnetic hypersensitivity (EHS) individuals reported symptoms from chemical triggers.

Conclusions:

• Individuals with BRI react to fewer, more specific triggers compared to other EI groups.
• It is crucial to inquire about diverse environmental sources, as some EI groups attribute symptoms to multiple triggers beyond their primary intolerance.
• Findings highlight the complex nature of symptom attribution in environmental intolerance.