An investigation of deaths in a confined space of an artesian well, Nuea Khlong district, Krabi province, May 2023

Abstract

Background: On 7 May 2023 at 12:05, the Situation Awareness Team (SAT), Office of Disease Prevention and Control, Region 11 Nakhon Si Thammarat (ODPC11) was informed by the Krabi Provincial Public Health Office that on May 5, 2023, 3 people died after dredging mud in one artesian well in, Nuea Khlong District, Krabi Province. The Joint Investigation Team (JIT) ODPC 11, Nakhon Si Thammarat Province, in collaboration with Koh Lanta Hospital, Krabi Hospital, Nuea Khlong Hospital and Krabi provincial public health office Investigated the incident on 9 – 10 May 2023. The objectives were to verify the diagnosis, describe the events in confined spaces, explore potentially dangerous environments, and provide control measures to prevent injuries and fatalities from working in confined spaces.

Methods: This study was a descriptive study. We reviewed medical records and forensic records data to confirm the number of victims and death in the hospital where treatment was performed. We also interviewed stakeholders and studied the environment at the incident scene and also surveyed and measured gases including oxygen, carbon monoxide, hydrogen sulfide, and methane at different depths in the incident well and nearby wells. The data were analyzed using descriptive statistics (frequency). The oxygen and other toxic gas levels were measured as % by volume and parts per million (ppm).

Results: We found five people exposed to the well and three of them died. The first and the second deaths were the rescuers; the third death was a victim who entered the well. Three of them did not wear personal protection equipment for working in a confined space. One victim was identified as death from hypoxia; while two rescuers died from drowning. In addition, two rescue volunteers who went down to help the first and the second deaths, did not experience any symptoms. The level of oxygen was detected below the standard level, whereas no other toxic gases were found in the wells after 4 days. The causes of deaths in confined spaces were likely due to lack of personal protective equipment, delayed assistance caused by lack of rescue equipment, and unclear identification of the scene. The rescue volunteer teams in the area were not ready and had limited knowledge and skills to help victims from working in confined spaces.

Recommendations: preventive measures including risk assessment before working in confined spaces should be emphasized. Health education and sufficient personal protective equipment should be promoted for the operators and rescuers.