• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7407-7411
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• 2014

The incidence of urban female breast cancer has been continuously increasing over the past decade with unknown etiology. One hypothesis for this increase is carcinogen exposure from tobacco. Therefore, the objective of this study was to investigate the risk of urban female breast cancer from tobacco smoke exposure. The matched case control study was conducted among Thai females, aged 17-76 years and living in Bangkok or its surrounding areas. A total of 444 pairs of cases and controls were recruited from the Thai National Cancer Institute. Cases were newly diagnosed and histologically confirmed as breast cancer while controls were selected from healthy women who visited a patient, matched by age ${\pm}5$ years. After obtaining informed consent, tobacco smoke exposure data and information on other potential risk factors were collected by interview. The analysis was performed by conditional logistic regression, and presented with odds ratio (ORs) and 95% confidence intervals(CI). From all subjects, 3.8% of cases and 3.4% of controls were active smokers while 11.0% of cases and 6.1% of controls were passive smokers. The highest to lowest sources of passive tobacco smoke were from spouses (40.8%), the workplace (36.8%) and public areas (26.3%), respectively. After adjusting for other potential risk factors or confounders, females with frequent low-dose passive smoke exposure (${\leq}7$ hours per week) from a spouse or workplace had adjusted odds ratio 3.77 (95%CI=1.11-12.82) and 4.02 (95%CI=1.04-15.50) higher risk of breast cancer compared with non-smokers, respectively. However, this study did not find any association of breast cancer risk in high dose passive tobacco smoke exposure, or a dose response relationship in cumulative passive tobacco smoke exposure per week, or in the active smoker group. In conclusion, passive smoke exposure may be one important risk factor of urban female breast cancer, particularly, from a spouse or workplace. This risk factor highlights the importance of avoiding tobacco smoke exposure as a key measure for breast cancer prevention and control.

• 대한의생명과학회지
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• 제12권4호
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• pp.375-383
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• 2006

The physiological responses following stress are different in individual or personality. We performed this study to clarify gender differences in influences of noise stress on physiological factors. 70 healthy subjects, which was divided man (n=30) and woman (n=40) groups, were exposed to 85 decibels of excavator noise for 15 minutes. Cardiac factors such as heart rate (HR), systolic and diastolic blood pressures (SBP and DBP, respectively), and heart rate-systolic pressure product (RPP) were determined. Transcranial Doppler ultrasound (TCD) was used to measure mean blood flow velocity (Vm), pulsatility index (PI), and resistance index (RI) in the middle, anterior and posterior cerebral arteries (MCA, ACA and PCA, respectively) before and during noise exposure. Cortisol level and hematological variables were also measured before (baseline) and immediately after the end of noise exposure. In the both groups HR, SBP, and RPP significantly decreased during noise exposure (P<0.05) but not significantly different between two groups (P>0.05). Vms of three cerebral arteries in man group decreased, whereas Vm of PCA in woman group fell during noise exposure (P<0.05). Vm, PI and RI in MCA and ACA during noise exposure were low in man group compared with woman group (P<0.05). Vm of PCA was low, whereas PI and RI of PCA were high in man group compared with woman group during noise exposure (P<0.05). Total leukocyte and red blood cell (RBC) counts slightly decreased during noise exposure but not significant (P>0.05). Levels in hematological variables decreased but not significant changed following noise exposure. Decreased rate of total leukocyte in man group was higher (P<0.05). Cortisol levels in the both groups decreased immediately after the end of noise exposure, while the decreased rate in man group was greater than that in woman group (p<0.05). These findings indicate that a transient exposure to experimental excavator noise may cause decreased changes in cardiac factors, cerebral hemodynamics and cortisol levels and the changes may be greater in men than in women.

• 한국환경보건학회지
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• 제45권1호
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• pp.71-81
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• 2019

Objectives: The lung injuries by exposure to the humidifier disinfectants (HDs) were reported in 2011, Korea. For the HD victims, environmental exposure level and clinical diagnosis were conducted to determine the levels of damage by HDs. Methods: The exposure assessment to the HDs from 1st to 4th questionnaire surveys were carried out for 5,245 victims. And the affecting factors of exposure levels were analyzed by characterizing exposure and demographic information. By using of exposure concentration and cumulative time, exposure levels were classified and compared by percentage of clinical diagnosis classes. The high exposure and low clinical diagnosis rating groups, and low exposure and high clinical diagnosis rating groups were analyzed to overcome the limitation of past exposure assessment such as recall bias. Results: Among the all applicants damaged by the humidifier disinfectants, survivors were 4,028 and the dead were 1,217. And male and female were 2,675, and 2,547, respectively. In case of occurrence age of lung disease, under 10 years was majority age group (1,536) and followed by thirties (917). Pregnant women and fetuses were 339 and 439, respectively. And the damages by exposure to the HDs were concentrated on these susceptible populations in groups with low exposure and high clinical diagnosis rating. On the other hand, the groups classified by high exposure and low clinical diagnosis rating were shown different characterization. Conclusions: The questionnaire survey on past exposure may be uncertain due to recall bias. However, the relationship between classified exposure levels and clinical diagnosis ratings might be shown positive correlation if the exposure assessment errors were analyzed and controlled.

• 한국산업보건학회지
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• 제25권4호
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• pp.525-533
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• 2015

Objectives: Alongside smoking, occupational exposure is an important risk factor for chronic obstructive pulmonary disease. The purpose of this study was to evaluate factors associated with occupational pulmonary function decline that can be used to create guidelines for the health management of shipyard workers Materials: This study analyzed spirometry from 10,597 male shipbuilding workers. Functional decline in spirometry was defined as FEV1/FVC <70% and logistic regression for work duration and occupational hazard exposure was performed Results: Among the subjects, 4.2% showed an obstructive pattern in pulmonary function. The odds ratios for hazard exposure were 1.67(indirect) and 3.54(direct), and for work duration 1.97(10-18 years), 2.29(19-27), and 5.02(28+). After adjusting for smoking and work-related factors, the odds ratios for work durations of over 10 years were 1.73(10-18 years), 1.99(19-27), and 4.09(28+), but for hazards exposure was 1.71(direct) alone after adjustment. Conclusions: Occupational COPD is insidious and chronic, and thus long-term hazard exposed(especially over 10 years) shipyard workers with functional decline in spirometry need to prevent and manage COPD. This study is important for establishing guidelines to manage hazard exposure among shipyard workers and prevent COPD.

• Asian Pacific Journal of Cancer Prevention
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• 제17권sup1호
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• pp.43-47
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• 2016

Second-hand tobacco smoke (SHS) exposure at home, especially among children, is a serious issue in Viet Nam. During the past decade, much effort has been taken for tobacco control in the country, including various prgorammes aiming to reduce SHS exposure among adults and children. This article analysed trends and factors associated with SHS exposure at home among school children aged 13-15 in Viet Nam, using the Global Youth Tobacco Surveys conducted in 2007 and 2014. Descriptive and inferential statistical methods with logistic regression were applied. Overall, there was a significant reduction in the level of exposure, from 58.5% (95%CI: 57.6-59.3) in 2007 to 47.1% (95%CI: 45.4-48.8) in 2014. Of the associated factors, having one or both parents smoking was significantly associated with the highest odds of SHS exposure at home (OR=5.0; 95%CI: 4.2-6.1). Conversely, having a mother with a college or higher education level was found to be a protective factor (OR=0.5; 95%CI: 0.3-0.8).

• Safety and Health at Work
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• 제11권2호
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• pp.199-206
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• 2020

Background: In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar. Methods: A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss. Results: In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss. Conclusion: Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

• Composites Research
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• 제22권5호
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• pp.37-42
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• 2009

온도, 수분 및 자외선과 같은 자연환경을 모사할 수 있는 가속노화시험장치를 적용하여 복합적인 환경인자에 노출된 탄소섬유/에폭시 복합재의 열분석 특성과 화학구조분석을 수행하였다. 복합적인 환경인자의 최대 노출시간은 3000시간으로 노출시간에 따른 복합재의 열분석 특성과 화학구조는 Modulated DSE와 FTIR을 통해 조사하였다. Modulated DSC 시험을 통한 연우-결과에 따르면 노출시간이 증가할수록 복합재 내에 치밀한 망사 구조가 형성되어 유리전이온도는 증가함을 알 수 있었다. 또한 노출시간이 증가할수록 복합재의 특성에 영향을 미치는 물리시효가 발생하여 엔탈피 완화현상을 나타내는 흡열 피크가 관찰되었다. 아울러 FTIR 시험을 통해 관찰된 피크의 위치는 노출시간에 큰 영향을 받지 않지만 피크의 세기는 노출시간이 증가할수록 에폭시기에 발생되는 경화 반응으로 인해 점차 감소함을 알 수 있었다.

• 한국환경보건학회지
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• 제41권4호
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• pp.231-240
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• 2015

Objectives: Blood mercury levels among adults living in certain areas of the Gyeongsang Provinces have been shown to be very high (Kunwee County $29.6{\mu}g/L$, Yeongcheon-city $26.7{\mu}g/L$). The purpose of this project was to determine mercury exposure levels in schoolchildren and factors related with their mercury levels in high mercury exposure areas identifyed by the 2007 Korea National Environmental Health Survey. Methods: From June to September 2010, 1,097 students from grades 3 to 6 at 19 elementary schools participated in this study, including 294 students from 10 elementary schools in Kunwee County, 529 students from Yeongcheon City, 122 students from two elementary schools in Pohang City, North Gyeongsang Province, and 152 students from two elementary schools in Ulsan Metropolitan City. Biological samples from schoolchildren, including whole blood, urine and hair, were collected to measure total mercury at the time of a health check up. Information about children was collected by questionnaire. Total mercury concentrations in blood were measured using the Direct Mercury Analyzer 80 with the gold-amalgam collection method. Results: The mean mercury levels were $2.70{\mu}g/L$ in 1,091 blood samples, $2.25{\mu}g/g-creat.$ in 820 urine samples and $1.03{\mu}g/g$ in 1,064 hair samples. Blood mercury levels in the schoolchildren was slightly higher than the result of $2.4{\mu}g/L$ from a 2006 survey of elementary school children on exposure and health effects of mercury by the National Institute of Environmental Research. However, 0.3% and 4.5% of participants exceeded the reference level of blood mercury by CHBMII ($15{\mu}g/L$) and the US EPA ($5.8{\mu}g/L$), respectively. The reference level of urine by CHBMII ($20{\mu}g/L$) was exceeded by 0.4% of participants. As factors, residence period in the study areas, residence type, father's education level and income all showed significant associations with mercury level in the biological samples. The number of dental amalgam sides showed an association with urine mercury. Fish intake preference and fish intake frequency were important factors in mercury levels. In particular, intake of shark meat and recent intake of shark meat were associated with higher mercury levels. In this regard, participation in the performance of an ancestral rite showed a relation with higher mercury levels. Conclusion: The intake of shark meat was very important factor to high mercury exposure level. It is recommended to monitor and manage students with high mercury exposures who exceeded CHBM II and EPA guidelines, and include blood mercury testing in the Children's Health check up for this province.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.203-216
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• 1999

This paper describes a set of multi-pathway models for estimating health risk to lead. The models link concentrations of an environmental contaminant (lead) in air, water and food to human exposure through inhalation, ingestion, and dietary routes. Exposure is used as the foundation for predicting risk of health detriment within the population. The process of estimating exposure using often limited data and extrapolating to a large diverse population requires many assumption, inferences, and simplification. This paper is divided into four section. The first section provides lead contaminant levels on obtaining environmental concentration of air, tap water, and foods. The second section provides a discussion of exposure parameters and uncertainty associated predicting human health risk of contaminants. The third and fourth section illustrate lifetime average daily exposure (LADE) and excess cancer risk (ECR) based on exposure parameters. The relationship between concentration of lead in an environmental medium and human exposure is determined with pathway exposure factors (PEFs). The calculation of LADE and ECR is carried out using Monte-Carlo simulation with probability density function of exposure parameters. Examination of the result reveals that, for lead exposure, ingestion (food) is the dominant route of exposure rather than inhalation (air), and ingestion (tap eater).

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3391-3396
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• 2014

Background: Vitamin D has been suggested as one of the critical factors for female reproductive health with protective activities against different cancers but there are conflicting facts regarding its role on breast cancer without any clear data on premenopausal cases. This study aimed to evaluate the role of vitamin D from dietary sources and sunlight exposure on the incidence of premenopausal breast cancer. Materials and Methods: We conducted a case control study on 60 newly diagnosed premenopausal breast cancer patients and 116 normal women who lived in Sabzevar and surrounding villages in Razavi, Khorasan, a rural and conservative area of Iran. Results: The mean concentrations of 25-OH vitamin D in cases and controls were $15.2{\pm}8.15$ vs $15.5{\pm}7/45ng/ml$, both well below normal values elsewhere. In fact 50% of analyzed individuals showed very severe or severe vitamin D deficiency and the rest (25%) were detected in suboptimal levels. Although the lack of vitamin D and calcium supplementation increased slightly the risk of premenopausal breast cancer (p=0.009, OR=1.115, CI 95%=1.049-1.187), higher prevalence of weekly egg consumption (86.66% vs 96.55%, p=0.023, OR=0.232, CI 95% 0.065-0.806) showed a slight protective role. The last but the most important risk factor was lack of sunlight exposure because the breast cancer patients had total body coverage from sun (p=0.007, OR=10.131, CI 98% 0.314-78.102). Conclusion: This study pointed out the role of vitamin D and other possible risk factors on the development and growth of breast tumors in this special geographical region. Although this study has revealed the interactions between hormonal and environmental factors in this province of Iran, understanding the deficiency pattern and its contribution to other lifestyle factors elsewhere is also necessary.