Short-Term Carbon Monoxide Exposure during Field Travel and Occupational-health Vulnerability among Medical Outreach Attendees in Guatemala: An Exploratory Descriptive Field Study

Aims: The present study characterise occupational and healthcare vulnerability among adults attending mobile medical outreach sites in Guatemala and to describe short-term carbon monoxide (CO) concentrations encountered by the research team during field travel. Study Design: An exploratory descriptive field study with two parallel components analysed independently. Place and Duration of Study: Communities in the Chimaltenango and Tecpán areas of Guatemala, 19-24 June 2026. Methodology: A convenience sample of 100 adults completed a 10-item Spanish-language questionnaire on occupation, work schedule, income, physical job demands, illness-related work behaviour, healthcare-seeking behaviour and self-rated health. Separately, a Lascar EL-USB-CO data logger measured CO concentrations every 30 seconds during transportation and routine field activities. Field notes recorded traffic, ventilation, smoke, cooking, construction and other contextual factors. Survey data were summarised as counts and percentages; CO time-series data were interpreted descriptively against the field notes. Results: Seventy-six per cent of respondents worked at least five days per week, 88% described their work as physically demanding at least sometimes, 70% had worked while ill and 73% reported that health problems had made work difficult at least sometimes. CO concentrations were near baseline for much of the observation period, but brief peaks occurred during bus travel and near traffic, smoke, cooking, construction or limited ventilation. The highest recorded 30-second value was approximately 207 ppm. Conclusion: The findings identify a plausible intersection among transportation dependence, intermittent combustion-related exposure and limited economic capacity to stop working when ill. Because the monitoring and survey components were not linked at the participant level, the study does not support causal exposure-health inferences. Future studies should use calibrated multi-pollutant instruments, standardised activity logs, participant-level measurements and health-relevant time-weighted averages.