• Title/Summary/Keyword: odor threshold

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Effect of Bad Breath on Olfactory Identification Ability and on Olfactory Detection Threshold for CH3SH (구취가 후각인지도 및 methyl mercaptan에 대한후각감지역치에 미치는 영향)

  • Do, Young-Hwan;Choi, Jae-Kap;Ahn, Hyoung-Joon
    • Journal of Oral Medicine and Pain
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    • v.26 no.4
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    • pp.309-318
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    • 2001
  • The purposes of the study were (1) to evaluate the olfactory identification ability in those who have bad breath, (2) to determine the olfactory detection threshold for methyl mercaptan in normal subjects and those who have bad breath, and (3) to evaluate the effect of oral hygiene care on the olfactory detection threshold for methyl mercaptan. Sixteen male subjects with bad breath (male odor group), 9 male subjects without bad breath (male non-odor group), and 10 female subjects without bad breath (female non-odor group) were included for the study. Olfactory identification ability was assessed by administrating the Cross-Cultural Smell Identification Test (CC-SIT), and the olfactory detection threshold for methyl mercaptan was measured by two-alternative forced-choice single-staircase detection threshold procedure in a double-blinded condition. The geometric mean of the last four staircase reversal points of a total of seven reversals is used as the threshold. For the male odor group, after 1 month of intensive oral hygiene care for reducing oral volatile sulfur compounds (VSC) concentration, the olfactory detection threshold for methyl mercaptan was measured again and compared to the initial value. The ANOVA was used to test the group difference of olfactory threshold and olfactory identification ability and the paired t-test was used to test the difference of olfactory threshold between before and after reduction of oral VSC in male odor group. The results were as follows : 1. There was no significant difference in olfactory identification ability among those who have bad breath and normal male or female subjects. 2. The olfactory detection threshold for methyl mercaptan was about 8.4 ppb in normal male and female. 3. There was a tendency that male subjects with bad breath showed a higher olfactory detection threshold for methyl mercaptan when compared to those of no bad breath. 4. The olfactory detection threshold for methyl mercaptan returned to a normal level after 1 month of intensive oral hygiene care for reducing oral VSC.

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Development of feasible program of exchange period for chemical cartridge in the workplace (II) - Method of using odor threshold (작업장에서 사용 가능한 방독마스크 정화통 교체주기 프로그램의 개발(II) - 냄새 서한도(odor threshold)를 이용하는 방법)

  • Han, Don-Hee;Kang, Min-Sun;Yi, Gwang Yong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.2
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    • pp.102-112
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    • 2009
  • The greatest concern of vapor/gas respirators is when to exchange chemical cartridges, but it is very difficult to estimate the breakthrough time of them in the workplace spot due to so many factors influencing on breakthrough. There needs to study on estimating cartridge exchange period available practically in the spot, even if it is not precise. In the previous study, authors suggested the method on estimating service-life of chemical cartridges using cartridges discarded after use. This followed study was to estimate exchange period for chemical cartridges using comparison of concentrations between Korean Occupational Exposure Limits (KOELs) and odor thresholds of chemicals. Chemicals were divided into four groups, I, II, III and IV groups. Group I chemicals are relatively safe if cartridges are just or slightly delayed exchanged when smelling since odor thresholds were less than 0.5 times KOELs. Odor threshold of Group II chemicals are 0.5~2.0 times KOELs and potentially hazardous if cartridges are exchanged when smelling. Those chemicals should be conducted program on estimating service-life of cartridges, which was just previously published (J Kor Soc Occup Environ Hyg 2008;18(3) 204-215). Group III chemicals (odor thresholds are more than 2.0 times KOELs) and Group IV chemicals (odorless or no data for smelling) must be performed the above mentioned program before cartridges. Even if this method on cartridge exchange using odor threshold is practically widely used in the workplace spot in the present, program on estimating service-life of cartridges is recommended for all chemicals to reduce potentially hazards.

Research on Odor Analysis Technology to Secure the Reliability of Air Quality Improvement in Air Conditioners (에어컨디셔너 공기질 개선의 신뢰도 확보를 위한 냄새 분석 기술 연구)

  • Kang, Seok-Hyun;Huh, Pil-Ho;Ahn, Young-Chull
    • Journal of Environmental Science International
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    • v.30 no.1
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    • pp.45-55
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    • 2021
  • In this study, the odor of the parts and the odor of the surrounding environment were classified and verified. In order to increase the reliability of odor quantitative/qualitative analysis, the selection criteria for 5 sensory evaluators were established, and the n-Butanol control solution for each odor intensity was periodically trained to recognize the odor intensity before sensory evaluation. In addition, although various odor thresholds have been used through several studies, verification of whether the odor intensity value obtained through GC/MSD analysis is similar to the degree to which a person directly smells and feels it. It is important to select the odor threshold that has the best correlation with the odor intensity calculated by the person smelling the odor. Finally, sampling and measuring flowing airflow and temporary odors such as odor component analysis was experimentally difficult due to limited collection space and differences in concentration of generated components. In this study, a quantitative analysis was made possible by using the low temperature concentration (cooling) trap method. Through this, it was confirmed that the correlation with the actual odor intensity was not caused by the product itself, but by the environmental factor discharged from the product after creating the odor environment.

Determination of Malodor-causing Chemicals Produced by Microorganisms Inside Automobile (차량 내 미생물에 의해 생성되는 악취유발 화학물질의 분석)

  • Park, SangJun;Kim, EuiYong
    • KSBB Journal
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    • v.29 no.2
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    • pp.118-123
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    • 2014
  • It was confirmed that malodor connected with an air-conditioner in an automobile is caused by microbial volatile organic compounds (MVOCs) produced by microorganisms getting into an air-conditioner when it is operating. Chemicals such as hydrogen sulfide, dimethyl sulfide, nbutyric acid, n-valeric acid, iso-valeric acid, n-octanol and toluene were detected above the odor threshold inside the automobile. The characteristics of a funky odor in the air blown into the automobile were due to detected sulfur compounds (hydrogen sulfide and dimethyl sulfide). Dimethyl sulfide was produced by microorganisms such as Aspergillus versicolor, Methylobacterium aquaticum, Herbaspirillum sp. and Acidovorax sp. In addition, the characteristics of a sour odor in the air blown into the automobile were due to detected organic acids (n-butyric acid, n-valeric acid and iso-valeric acid). N-valeric acid and iso-valeric acid were generated from Aspergillus versicolor, while iso-valeric acid was produced by Methylobacterium aquaticum. In addition, the odor intensity of the air blown into the automobile was affected by the concentration of detected sulfur compounds and organic acids. On the other hand, it is estimated that chemicals such as hydrogen sulfide, n-octanol and n-butyric acid detected in the air blown into the automobile were produced by non-identified species of microorganisms.

A Fundamental Experiment of Odor Unit Estimation for Water-body Diffuse Odor (수체발산 악취물질 악취단위 산정에 관한 기초실험)

  • 김학민;이범진;김선태
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.115-116
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    • 1999
  • 대기 중으로 발산되어 인간의 감각기관을 자극함으로써 불쾌감을 유발하고 집중력을 저하시키는 등 일상생활에 좋지 않은 영향을 주는 악취를 객관적으로 평가하기 위해 취기를 감지할 수 있는 최저농도를 평가하는 감지역취(Threshold)의 결정, 냄새가 얼마나 강한가를 평가하는 악취강도(Odor Intensity) 측정, 냄새의 종류를 판단하는 냄새 질(Odor Quality) 판정 등 악취의 성질을 표현하는 여러 방법이 사용되고 있다.(중략)

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A Comparative Study of Odors between Air Dilution Sensory Test and Instrumental Detection Method Using Industrial and Food Waste Samples (공기희석관능법과 기기분석법에 기초한 악취감지기술의 연계성 비교: 산단지역 및 음식물 부패시료를 중심으로)

  • Park, S.Y.;Kim, K.H.
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.420-429
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    • 2007
  • In this study, we attempted to evaluate the relationship between air dilution sensory test and instrumental detection method for individual odorous compound. For the purpose of our comparative study, we conducted the analysis of malodor on total of 46 samples collected from both industrial and food waste sectors using the two independent approaches. The results of instrumental analyses were explained after modification to several parameters such as: the sum of odor concentration (SOC), sum of odor quotient (SOQ) and sum of odor intensity (SOI). When we compared dilution ratio values (DRV) of threshold limit (TL) with the modified instrumental data sets, pearson coefficient of SOC, SOQ, and SOI were 0.556 (p=5.83E-05), 0.911 (p=9.64E-19) and 0.847 (p=8.93E-14), respectively. The results of this study thus suggest that the DRV of TL sensitively reflects odor strength measured intuitive.

Emission Characteristics of Odors and Odorants Released from Grilling Mackerel and Pork Belly by Different Cooking Tools

  • Kim, Hyun-Jeong;Yu, Mee-Seon;Yang, Sung-Bong
    • Journal of Environmental Science International
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    • v.23 no.10
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    • pp.1763-1773
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    • 2014
  • It is known that mackerel and pork belly release a strong odor in the process of roasting. We evaluated a dilution factor of odor arising during roasting mackerel or pork belly and the relative odor strength using several cooking tools and analyzed compounds causing odors with gas chromatograph/mass detector. Roasting pans used were grill with lid, electric grill without lid and general roasting pan, and a grill with lid can attach the activated carbon charcoal deodorant at the inside of lid. And all electric grills have a drip tray under the heater. We investigated characteristics of odor emission depending on the presence of water and deodorants in these cooking tools. Study has shown that roasting mackerel produces approximately 36 time more odors than roasting pork belly, and the reduced odor emission when roast with water. And it shows the reduced deodorant effect when cooked with water after attaching activated carbon charcoal in the cooking pan. Major odor causing compounds arising when cooking mackerel and pork belly were aldehydes with high boiling point such as octyl aldehyde with a low odor threshold value.

Emission Characteristics of Odor Compounds in a Charcoal Production Kiln (숯가마 배가스 중 악취물질의 배출특성)

  • Park, Seong-Kyu;Choi, Sang-Jin;Hwang, Ui-Hyun;Lee, Jeong-Joo;Kim, Daekuen
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.4
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    • pp.319-326
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    • 2014
  • Exhaust gas emitted as a result of the incomplete combustion of biomass in charcoal kilns includes odor compounds as well as other air pollutants such as particulate matters, sulfur and nitrogen oxides, and carbon monoxide. A number of offensive odor compounds affect quality of life. In this study, odor emissions were investigated from biomass burning in a pilot-scale charcoal kiln and a commercial-scale kiln. Complex odor from emission source reached up to 10,000 dilutions to threshold during the study period. Combustion fume was found to contain reduced sulfur compounds, aldehydes, and volatile organic compounds. Hydrogen sulfide and methyl mercaptan were the major odorants which highly contributed to the offensive odor.

A Study on Dispersion Characteristics of Odor from Hanwoo and Dairy Farms (한우 및 젖소농장 발생 악취의 확산특성 연구)

  • Kim, Doo-Hwan;Ha, Duck-Min;Lee, Jae-Young;Kim, Hee-Ho;Song, Jun-Ik
    • Journal of Animal Environmental Science
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    • v.21 no.1
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    • pp.1-8
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    • 2015
  • This study was conducted to investigate the dispersion prediction of odor from Hanwoo and dairy farms. Gaussian Plume model used in considering of farm size, wind velocity, atmospheric stability and threshold odor unit to prediction of odor dispersion based on the survey on current state of odor emission and control from 9 site of Hanwoo and 9 site of dairy farms. Farm size, wind velocity and atmospheric stability were affected the distance of odor dispersion, showed longer distance in cases of large farm, low wind velocity and stable atmospheric condition. We will suggestion the adjusted distance of odor dispersion according to farm size was estimated to 50~100 m in Hanwoo farm and 50~150 m in dairy farm when apply the 3OU, 5 m/s wind velocity and stable atmospheric condition.

A Study on Dispersion Characteristics of Odor from Swine Farms (양돈장 발생 악취의 확산특성 연구)

  • Kim, Doo-Hwan;Ha, Duck-Min;Lee, In-Bok;Choi, Dong-Yun;Song, Jun-Ik
    • Journal of Animal Environmental Science
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    • v.20 no.2
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    • pp.41-48
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    • 2014
  • This study was conducted to investigate the dispersion prediction of odor from swine farms in Korea. Gaussian Plume model used in considering of farm size, wind velocity, atmospheric stability and threshold odor unit to prediction of odor dispersion based on the survey on current state of odor emission and control from 48 site of swine farms. Farm size, wind velocity and atmospheric stability were affected the distance of odor dispersion, showed longer distance in cases of large farm, low wind velocity and stable atmospheric condition. We will suggestion the adjusted distance of odor dispersion according to farm size was estimated to 180 m in small farm and 320 m in large farm when apply the 3 OU, 5 m/s wind velocity and stable atmospheric condition.