News & Comment

In October 2021, hydrogen sulfide (H₂S), a toxic odorous gas, was measured in Carson, California at concentrations reaching 7000 parts per billion (ppb), exceeding California’s 30 ppb acute air quality standard. Thousands of residents complained of malodors and headaches. We responded to community concerns by launching a rapid survey assessing symptoms. We recruited participants through door-to-door outreach, community events, and social media. During the emergency’s first week, 75% of the 108 total respondents experienced headaches, 72% experienced dizziness, and 63% experienced difficulty sleeping. About 60% of respondents (n = 63, no response = 7) noted the odor worsening their mental health. When adjusting for age, sex, and smoking, participants <2 km from the highest H₂S concentrations reported higher prevalence of agitation (PD = 0.23, 95% CI: 0.03, 0.42) and headaches (PR = 0.14, 95% CI: −0.04, 1.31) compared to participants farther away. Malodors are underprioritized in environmental justice communities, despite H₂S’s effects on mental and physical health.

The use of aligned exposure science terminology is crucial for ease of comparison and appropriate interpretation of exposure information, regulatory reports, and scientific publications. Sometimes the use of different terminology in different contexts and areas of exposure science results in diverging interpretations of the same descriptor. During the development of the European strategy for exposure science, the need was identified to agree on a defined terminology requiring an evaluation of the commonly used terms, synonymous uses, and their relationships between each other. This paper presents the first steps in compiling the most important exposure-related terms from existing guidance documents and publications for exposure and risk assessment and adapting them to be useful for different contexts and areas. This initial step is intended to trigger discussion on terminology among exposure scientists around the globe and across regulatory and methodological silos. The glossary itself is intended as a living document to be hosted by the International Society for Exposure Science.