Mobile monitoring along a street canyon and stationary forest air monitoring of formaldehyde by means of a micro gas analysis system

A micro-gas analysis system (μGAS) was developed for mobile monitoring and continuous measurements of atmospheric HCHO. HCHO gas was trapped into an absorbing/reaction solution continuously using a microchannel scrubber in which the microchannels were patterned in a honeycomb structure to form a wide absorbing area with a thin absorbing solution layer. Fluorescence was monitored after reaction of the collected HCHO with 2,4-pentanedione (PD) in the presence of acetic acid/ammonium acetate. The system was portable, battery-driven, highly sensitive (limit of detection = 0.01 ppbv) and had good time resolution (response time 50 s). The results revealed that the PD chemistry was subject to interference from O3. The mechanism of this interference was investigated and the problem was addressed by incorporating a wet denuder. Mobile monitoring was performed along traffic roads, and elevated HCHO levels in a street canyon were evident upon mapping of the obtained data. The system was also applied to stationary monitoring in a forest in which HCHO formed naturally via reaction of biogenic compounds with oxidants. Concentrations of a few ppbv-HCHO and several-tens of ppbv of O3 were then simultaneously monitored with the μGAS in forest air monitoring campaigns. The obtained 1 h average data were compared with those obtained by 1 h impinger collection and offsite GC-MS analysis after derivatization with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBOA). From the obtained data in the forest, daily variations of chemical HCHO production and loss are discussed

Effect of Environmental Change while Climbing Mt. Daisen on Forced Vital Capacity and Forced Expiratory Volume % in Young Women

The aim of the present study was to clarify the effects of environmental change while climbing Mt. Daisen on forced vital capacity and forced expiratory volume % in young women in summer. Seven healthy Japanese women (age: 22.6 ± 4.2 years) volunteered to climb Mt. Daisen (1,709m), located in Tottori prefecture, in August. Participants\u27 expiratory forced vital capacity (FVC), forced expiratory volume % (FEV_%) and arterial oxygen saturation (SpO_2) were measured at 4 points (Ground: 10m, Rest point: 780m, Summit: 1,709m, Goal point: 780m). The measurements were conducted soon after the subjects\u27 arrival at each point. The degree of dyspnea sensation was measured at Ground, Rest point, Goal point and at each station. There were no significant changes in FVC. FEV_% at the summit was significantly lower than at the Ground and Rest point. No significant differences were found in SpO_2 at each measuring point. The degree of dyspnea sensation at each station soon after the subjects\u27 arrival was significantly higher than those at the Rest point. The results of this study indicated mild airway contraction induced by stresses on the respiratory system from increasing exercise intensity during an ascent of Mt. Daisen

Identification of Gas Emanated from Human Skin: Methane, Ethylene, and Ethane

We investigated whether methane, ethylene and ethane gas can be detected in gas emanating from human skin, which is called skin gas. Skin gas was collected with a homemade stainless-steel trap system, which was cooled with liquid nitrogen, and analyzed with a gas chromatograph fitted with a flame ionization detector (FID). Skin-gas samples were obtained by covering a hand for 30 min with a polyfluorovinyl bag in which pure helium gas was introduced. The bag, the trap system and GC were set up online to avoid any contamination by air. Methane, ethylene and ethane in skin gas were successfully collected at an average amount emanated for 30 min (from ten subjects) of 150 ± 63, 20 ± 11 and 17 ± 8 [mean ± SD] pg/cm2, respectively.This work was partly supported by the Regional Science Promotion Program, Japan Science and Technology Agency

Breath Hydrogen Produced by Ingestion of Commercial Hydrogen Water and Milk

Objective To compare how and to what extent ingestion of hydrogen water and milk increase breath hydrogen in adults. Methods Five subjects without specific diseases, ingested distilled or hydrogen water and milk as a reference material that could increase breath hydrogen. Their end-alveolar breath hydrogen was measured. Results Ingestion of hydrogen water rapidly increased breath hydrogen to the maximal level of approximately 40 ppm 10–15 min after ingestion and thereafter rapidly decreased to the baseline level, whereas ingestion of the same amount of distilled water did not change breath hydrogen (p < 0.001). Ingestion of hydrogen water increased both hydrogen peaks and the area under the curve (AUC) of breath hydrogen in a dose-dependent manner. Ingestion of milk showed a delayed and sustained increase of breath hydrogen in subjects with milk intolerance for up to 540 min. Ingestion of hydrogen water produced breath hydrogen at AUC levels of 2 to 9 ppm hour, whereas milk increased breath hydrogen to AUC levels of 164 ppm hour for 540 min after drinking. Conclusion Hydrogen water caused a rapid increase in breath hydrogen in a dose-dependent manner; however, the rise in breath hydrogen was not sustained compared with milk