Chemical Evaluation of ethanol intake that makes a bad influence on human performance in maneuvering aircrafts is essential in air accident investigations. However ethanol within human body becomes too low to detect at a rapid rate due to decrease in ethanol concentration by metabolism. What is worse, postmortem ethanol production by microbial activity is a significant problem which makes it impossible to evaluate whether or not there is an ethanol intake in fetal air accidents.
This study, the liquid chromatography tandem mass spectrometric condition (LC/MS/MS) using a pentafluorophenyl column was established for serotonin metabolites, 5-hydroxytryptophol (5-HTOL) and 5-hydroxyindole acetic acid (5-HIAA), the ratio of which is employed as an alcohol biomarker not influenced by microbial ethanol formation. Each limit of detection of 5-HTOL and 5-HIAA without any chemical derivatization was 1ng/mL and 10ng/mL in aqueous solution in this condition. The cut-off value ([5-HTOL]/[5-HIAA] = 0.015) measured by the LC/MS/MS method developed above allowed for identification of human urinary samples to ethanol intake (0.5g/kg body weight) .
Carbon monoxide (CO) is formed by the incomplete combustion of carbon-containing materials such as aviation fuels. Exposure to exhaust fumes from aircraft engines can lead to CO poisoning. This study determined environmental CO concentrations on flight line at Japan Air Self-Defense Force Air Bases (AB). In addition, we considered factors which increase CO concentration using multiple regression analysis.
We conducted CO measurements at downwind from aircraft on flight line and in bunker using controlled-potential electrolysis method. This survey was performed at Naha AB (subtropical zone), Hamamatsu AB (temperate zone), Misawa AB (temperate zone) and Chitose AB (subarctic zone). Surveyed aircraft types were T-4, F-15 and F-2. Each aircraft was fueled either JetA-1+ or JP-4. The number of aircrafts on flight line was 1 to 3.
When single aircraft was operating on flight line, the highest CO concentrations in T-4 and F-15 were 60.8 ppm (JetA-1+, Chitose AB) and 2.3 ppm (JetA-1+, Naha AB), respectively. In case of multiple aircrafts, CO concentration of JetA-1 fueled T-4 at Chitose AB indicated maximum value among all measurements, that is 61.2 ppm. The maximum CO level in bunker was 2.2 ppm (JetA-1+ fueled F-15 at Chitose AB). These values did not exceed occupational health standards.
Multiple regression analysis revealed that aircraft type, wind direction, ambient temperature and the number of aircrafts were significant contributing factors of CO concentration, whereas fuel type and humidity had no significance.
We conclude that CO concentration on flight line and in bunker has little effect on human health.