Kazukiyo Kumagai

A Novel Methodology to Evaluate Health Impacts Caused by VOC Exposures Using Real-Time VOC and Holter Monitors

While various volatile organic compounds (VOCs) are known to show neurotoxic effects, the detailed mechanisms of the action of VOCs on the autonomic nervous system are not fully understood, partially because objective and quantitative measures to indicate neural abnormalities are still under development. Nevertheless, heart rate variability (HRV) has been recently proposed as an indicative measure of the autonomic effects. In this study, we used HRV as an indicative measure of the autonomic effrects to relate their values to the personal concentrations of VOCs measured by a real-time VOC monitor. The measurements were conducted for 24 hours on seven healthy subjects under usual daily life conditions. The results showed HF powers were significantly decreased for six subjects when the changes of total volatile organic compound (TVOC) concentrations were large, indicating a suppression of parasympathetic nervous activity induced by the exposure to VOCs. The present study indicated these real-time monitoring was useful to characterize the trends of VOC exposures and their effects on autonomic nervous system.

Field validation of an active sampling cartridge as a passive sampler for long-term carbonyl monitoring

Abstract A carbonyl sampler originally designed for the active sampling method (Sep-Pak XPoSure) was used for long-term passive sampling, and its applicability as a passive sampler was examined through field experiments. The uptake rates of passive sampling were determined experimentally from collocated passive and active samplings for various sampling periods. The obtained uptake rates of formaldehyde, acetaldehyde, and acetone were 1.48, 1.23, and 1.08 mL/min, respectively. These uptake rates were consistent for a wide range of the sampling term (12 hr–2 weeks). Uptake rates of each carbonyl were proportional to the diffusion coefficients of each. Therefore, the ratios of diffusion coefficients were used to calculate the uptake rates of carbonyls for which the rates were not determined experimentally. Lower limits of determination were 2.16–17.5 μg/m3 for 2-week sampling. It was confirmed that 2-week monitoring of carbonyl concentrations up to 118–229 μg/m3 was possible. Relative standard deviations of the passive method generated from the repeatability test were 2–12.3% error for five samplings, and the recovery efficiencies were larger than 90%. Thus, the passive sampler was found to be highly suitable for long-term monitoring of carbonyl compounds.

A Device-Independent Evaluation of Carbonyl Emissions from Heated Electronic Cigarette Solvents

Objectives To investigate how the two main electronic (e-) cigarette solvents—propylene glycol (PG) and glycerol (GL)—modulate the formation of toxic volatile carbonyl compounds under precisely controlled temperatures in the absence of nicotine and flavor additives. Methods PG, GL, PG:GL = 1:1 (wt/wt) mixture, and two commercial e-cigarette liquids were vaporized in a stainless steel, tubular reactor in flowing air ranging up to 318°C to simulate e-cigarette vaping. Aerosols were collected and analyzed to quantify the amount of volatile carbonyls produced with each of the five e-liquids. Results Significant amounts of formaldehyde and acetaldehyde were detected at reactor temperatures ≥215°C for both PG and GL. Acrolein was observed only in e-liquids containing GL when reactor temperatures exceeded 270°C. At 318°C, 2.03±0.80 μg of formaldehyde, 2.35±0.87 μg of acetaldehyde, and a trace amount of acetone were generated per milligram of PG; at the same temperature, 21.1±3.80 μg of formaldehyde, 2.40±0.99 μg of acetaldehyde, and 0.80±0.50 μg of acrolein were detected per milligram of GL. Conclusions We developed a device-independent test method to investigate carbonyl emissions from different e-cigarette liquids under precisely controlled temperatures. PG and GL were identified to be the main sources of toxic carbonyl compounds from e-cigarette use. GL produced much more formaldehyde than PG. Besides formaldehyde and acetaldehyde, measurable amounts of acrolein were also detected at ≥270°C but only when GL was present in the e-liquid. At 215°C, the estimated daily exposure to formaldehyde from e-cigarettes, exceeded United States Environmental Protection Agency (USEPA) and California Office of Environmental Health Hazard Assessment (OEHHA) acceptable limits, which emphasized the need to further examine the potential cancer and non-cancer health risks associated with e-cigarette use.

Observation‐based metrics for residential dampness and mold with dose‐response relationships to health: a review

An important proportion of respiratory illness is considered attributable to residential dampness or mold (D/M). Developing health-protective D/M guidelines has been challenging, in part because unhealthy levels of indoor D/M cannot be defined using available microbiological measurements. This review paper explores reported multilevel, observation-based (eg visual or olfactory) D/M metrics for potential in defining unhealthy levels of residential D/M. For many of the 33 multilevel residential D/M metrics identified, health risks generally increased as observed D/M increased. Although some metrics seemed too complex for practical use, simple metrics had among the strongest associations with health outcomes. Available findings suggest the feasibility of setting observation-based D/M thresholds to trigger remedial action, using further improved D/M metrics without microbiological measurements (at least until the actual dampness-related agents that cause illness are better quantified). Additional data would allow setting health-protective D/M thresholds more precisely. Also, metrics could better reflect hidden D/M by more strongly emphasizing mold odor, which has demonstrated strong associations with health effects.

Broad range observation of particle deposition on greased and non-greased impaction surfaces using a line-sensing optical microscope

Abstract A computer-automated optical microscope combined with a line-sensing camera was used to capture the entire range of a particle deposit downstream of an individual acceleration nozzle in a hi-volume Andersen sampler. To investigate the particle bounce and reentrainment, particles collected on collocated greased and non-greased Teflon plates on the inlet stage (d a >7 μm ) were observed by an automated particle counting, locating and sizing method. The result confirmed reproducible collection characteristics among nozzles even though application of the grease increased collection efficiency and altered the size distribution of collected particles to the larger side. In these experiments, assuming spherical particles with uniform density, approximately 65% of particle mass and 50% by number were lost from non-greased plates at 54% RH, while 45% by mass and 25% by number were underestimated at 84% RH. The spatial investigation showed that particles were densely deposited around the center of deposition on greased plates while on non-greased plates they were dispersedly distributed. Particle dispersions on the smooth impaction plate were due to bounce and/or reentrainment of small particles especially with d PA μm .

In-situ Real-Time Monitoring of Volatile Organic Compound Exposure and Heart Rate Variability for Patients with Multiple Chemical Sensitivity

In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health 2010, 7, 4127–4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

Investigation of association between indoor environmental factors and child health problems in Japan – Design of survey and outcome from preliminary cross-sectional questionnaire

In Japan, there is an increase in allergic diseases such as asthma, respiratory symptom, particularly prevailing among the young generation. The reasons why the prevalence is increasing are still not yet well understood. However, it is deemed that indoor environmental factors are one of the essential sources. Therefore, an epidemiology type of survey was investigated on the 4th and 5th grade school children in Japan. The survey was divided into three phases. Phase 1 was a preliminary cross-sectional questionnaire of the prevalence of health problems. Phase 2 was a cross-sectional questionnaire survey on housing characteristics and health. Phase 3 was a field measurement for case control. This paper describes the study protocol and the outcomes from Phase 1. The prevalence of current allergic symptoms was 49.9%. Asthma and rhinitis of the children were 12.5% and 33.3%, respectively. The prevalence of several allergic symptoms among boys was significantly higher than in girls. It indicated that the environmental factors such as pollen, indoor house dust and dust mites could influence allergic symptoms. This survey reveals the ratio of children allergic symptoms in Japan and the possibility of the association between adverse health effect and indoor environmental factors.

Case Study: Formaldehyde Exposure During Simulated Use of a Hair Straightening Product

Case Study Michelle Stewart a , Trevor Bausman a , Kazukiyo Kumagai b & Mark Nicas a a School of Public Health , University of California , Berkeley , Berkeley , California b California Department of Public Health, Division of Environmental and Occupational Disease Control , Environmental Health Laboratory Branch , Richmond , California Accepted author version posted online: 30 Apr 2013.Published online: 14 Jun 2013.M any hairstylists use hair straightening products that may potentially expose them and their clients to formaldehyde. One popular hair straightening product, Brazilian Blowout Acai Professional Smoothing Hair Solution, contains methylene glycol, a hydrated form of formaldehyde, and a small amount of nonhydrated (free) formaldehyde. This pilot study simulated product use procedures in a test chamber and measured associated formaldehyde concentrations in air via integrative sampling and a direct-reading instrument. Two different chamber air exchange rates (one and four per hour) were used. Breathing zone formaldehyde concentrations during some treatment steps exceeded the federal Occupational Safety and Health Administration (OSHA) 15-min time-weighted average (TWA) exposure limit of 2 ppm and, during all steps, exceeded the National Institute for Occupational Safety and Health (NIOSH) recommended ceiling limit of 0.1 ppm and the ACGIH R

First- and second-hand smoke dispersion analysis from e-cigarettes using a computer-simulated person with a respiratory tract model

The purpose of this study was to investigate, in the human respiratory tract, the flow patterns and adsorption flux (deposition flux) distributions of volatile organic compounds (VOCs) generated by the use of electronic cigarettes (e-cigarettes) through the application of a three-dimensional computational fluid dynamics (CFD) analysis. Two types of human respiratory tract models, which give detailed respiratory tract geometries were reproduced in this study using computed tomography data, for the CFD analysis of inhalation exposure. Complicated flow patterns, nonuniform distributions of VOC concentrations, and heterogeneous adsorption flux distributions were determined within the human respiratory tract models, and individual specificity was confirmed. The CFD simulation results of adsorption flux distributions on the epithelium tissue surfaces of airways denoted the probability distributions of inhalation exposure in respiratory tracts, and high adsorption flux sites representing ‘hot spots’ were delineated for tissue doses of VOCs generated from smoking e-cigarettes. Furthermore, dispersion and diffusion of VOCs in an indoor environment due to exhalation of the vapour phase of e-cigarette emissions were analysed by using a computer-simulated person with a numerical respiratory tract model through an integrated and contiguous analysis of inhalation and exhalation modes during e-cigarette smoking.

A Study on Indoor Air Quality of Urban Residential Buildings in China

abstract The purpose of this survey was to examine the actual conditions of residential indoor air quality in urban areas in China. In this survey, the concentrations of about 16 volatile organic compounds (VOCs) and two carbonyl compounds were measured at 75 apartments in seven Chinese cities, viz., Urumqi, Harbin, Beijing, Shanghai, Changsha, Chongqing, and Kunming. In this paper, the measurement results for six VOCs and two carbonyl compound concentrations are summarized. It was found that the average concentrations of benzene, toluene, and formaldehyde were relatively high.