Occupational asphyxiation by unknown compound(s): environmental and toxicological approach

Area of Science:

• Occupational Health and Safety
• Environmental Toxicology
• Forensic Science

Background:

• Routine truck-tank washing operations can pose significant, unrecognized chemical hazards.
• Accidental deaths within confined spaces, like tanker trucks, require thorough investigation to determine the causative agent.

Observation:

• Five workers were found unresponsive in an empty tanker; four died at the scene, and one succumbed later in the hospital.
• Initial investigations lacked identification of the specific fatal compound, necessitating a comprehensive environmental and toxicological assessment.

Findings:

• Environmental analysis identified hydrogen sulfide (H2S) fumes, originating from previously transported liquid sulfur, as the cause of the fatalities.
• Toxicological examination of post-mortem samples revealed elevated thiosulfate concentrations, a key metabolite of H2S, in various tissues.
• Cluster analysis of thiosulfate distribution aided in reconstructing the timeline of death.

Implications:

• This case highlights the critical importance of identifying and mitigating H2S exposure risks in industrial settings.
• The study validates the combined use of environmental monitoring, toxicological analysis of metabolites, and autopsy findings for diagnosing fatal gas asphyxiation.
• Accurate determination of death in such incidents can be enhanced by analyzing metabolite distribution patterns.