Assessment of volatile organic compounds and particulate matter in a dental clinic and health risks to clinic personnel.

This study was conducted to assess (1) levels of volatile organic compounds (VOCs) and particulate matter (PM) in a dental clinic in southern Taiwan and (2) dental care personnel's health risks associated with due to chronic exposure to VOCs. An automatic, continuous sampling system and a multi-gas monitor were employed to quantify the air pollutants, along with environmental comfort factors, including temperature, CO2, and relative humidity at six sampling sites in the clinic over eight days. Specific VOC compounds were identified and their concentrations were quantified. Both non-carcinogenic and carcinogenic VOC compounds were assessed based on the US Environmental Protection Agency's Principles of Health Risk Assessment in terms of whether those indoor air pollutants increased health risks for the full-time dental care professionals at the clinic. Increased levels of VOCs were recorded during business hours and exceeded limits recommended by the Taiwan Environmental Protection Agency. A total of 68 VOC compounds were identified in the study area. Methylene methacrylate (2.8 ppm) and acetone (0.176 ppm) were the only two non-carcinogenic compounds that posed increased risks for human health, yielding hazard indexes of 16.4 and 4.1, respectively. None of the carcinogenic compounds increased cancer risk. All detected PM10 levels ranged from 20 to 150 µg/m(3), which met the Taiwan EPA and international limits. The average PM10 level during business hours was significantly higher than that during non-business hours (P = 0.04). Improved ventilation capacity in the air conditioning system was recommended to reduce VOCs and PM levels.

Using a composite material containing waste tire powder and polypropylene fiber cut end to recover spilled oil.

The superior oil absorption capacity of recycled polypropylene (PP) fiber and waste tire powder were used to recover spilled engine oil. We used ASTM F726-99 method to evaluate oil adsorbing capability of PP fiber and found it to have a large, rapid oil sorption capacity. However, its lack of elasticity dramatically limited that capacity after repeated use. Tire powder, which absorbs less oil more slowly, is more elastic than PP fiber and can be used repeatedly up to a hundred times without losing its oil adsorption capability. We combined PP fiber and tire powder to develop a composite material capable of recovering greater amounts of oil than any of its components. This composite can be use repeatedly for at least 100 times. Thus, the material cost for recovering 1 ton of spilled oil is about USD $0.03, making it very competitive on the market.

The effects of preventive intervention for betel nut chewing in school.

PURPOSE: This study was to explore the effect of preventive health education intervention in the knowledge, attitude, practice of betel nut chewing, and self-efficacy of anti-betel nut chewing for adolescent students. METHODS: One hundred eighty-six indigenous samples were recruited, and divided into experimental and control groups. The experimental group underwent fourteen-week classes regarding the prevention of betel nut chewing. Both groups took post-tests immediately after intervention in order to evaluate the instant effect of the teaching program. The follow-up (post-post-test) evaluated the instant improvement at the 28th week (14 weeks after the end of the class). RESULTS: There was no difference in knowledge of the hazards of betel nut chewing among pre-tests, post-tests, and post-post-test in the experimental group. The attitude, practice of betel nut chewing and self-efficacy of anti-betel nut chewing aspects was significantly different among pre-tests, post-tests, and post-post-test after intervention. There was a significantly immediate and instant improvement after health education intervention. CONCLUSION: Health education enables students to better resist the use of betel nuts. This study confirmed the importance of health education programs in dealing with the health risks of betel nut chewing for the risk group students.

Changes in immunological and hematological parameters of female residents exposed to volatile organic compounds in the city of Kaohsiung, Taiwan.

The objective of this study was to assess the effects, if any, of volatile organic compounds (VOCs) in the ambient air of Kaohsiung, Taiwan, on certain hematological and immunological parameters of 153 female study participants. The major source of VOCs was vehicle emissions. The participants were selected from three areas, each area at a different distance from a freeway. Results indicated that total concentrations of VOCs and a subgroup of 25 VOCs (VOC25) ranged from 250 to 335 ppb and 89 to 113 ppb, respectively. The distribution of VOC concentrations did not correlate with distance from the freeway. The participants living in the area with higher VOC concentrations had significantly higher abnormalities of white blood cells (WBC) and hemoglobin (Hb). In addition, IgG and IgA counts were significantly lower for the participants in the area with higher VOCs than for participants in the area with lower VOCs. This finding indicates that VOCs in ambient air may suppress immunological variables.

Distribution of volatile organic compounds in ambient air of Kaohsiung, Taiwan.

Automobile emissions have created a major hydrocarbon pollution problem in the ambient air of Taiwan. The aim of this study was to determine the volatile organic compounds (VOCs) in the ambient air of Kaohsiung, Taiwan. The spatial distribution, temporal variation, and correlations of VOCs at three study sites, selected based on traffic densities and distances from a freeway, were discussed. Sixty-four hydrocarbons were identified in the ambient air. Among all of the VOC species, acetone, aromatic and aliphatic compounds constituted the major constituents. Higher concentrations of VOCs existed further away from major arteries as compared to those found near the freeway. Therefore, the distance from the freeway may not be a sufficient index for reflecting actual air quality in the study area. Weather conditions, wind speed and direction did not affect the distribution of VOC concentrations in the three study sites. Other factors, such as the height and density of buildings, traffic conditions or commercial activities, might affect the distribution of VOCs.

Discovering meaningful information from large amounts of environment and health data to reduce uncertainties in formulating environmental policies.

This study uses knowledge discovery concepts to analyze large amounts of data step by step for the purpose of assisting in the formulation of environmental policy. We performed data cleansing and extracting from existing nation-wide databases, and used regression and classification techniques to analyze the data. The current water hardness in Kaohsiung, Taiwan contributes to the prevention of cardiovascular disease (CVD) but exacerbates the development of renal stones (RS). However, to focus on water hardness alone to control RS would not be cost effective at all, because the existing database parameters do not adequately allow for a clear understanding of RS. Analysis of huge amounts of data can most often turn up the most reliable and convincing results and the use of existing databases can be cost-effective.

Impact of a short-term community-based cleanliness campaign on the sources of dengue vectors: an entomological and human behavior study.

In June 2002, a considerable number of cases of dengue fever/dengue hemorrhage fever were reported in South Taiwan. To effectively reduce the sources of dengue vectors, the government conducted a weeklong community-based cleanliness campaign. The study reported here was designed to evaluate the effectiveness of the campaign. The sources of dengue vectors were evaluated according to changes in the ovitrap index. This index significantly decreased from 66.7 percent before the campaign to 39.3 percent three months later. Human knowledge and behavior were investigated by a survey questionnaire. Although the respondents had sufficient knowledge about dengue as well as its transmission and prevention, only 57.4 percent knew that the dengue vector breeds in clean water. After the campaign, this percentage significantly increased, to 88.4 percent, and the percentage of those properly handling artificial containers also significantly increased. On the basis of these findings, the authors conclude that short-term community-based cleanliness educational programs may change behavior to eliminate container habitats of the dengue vectors and in turn reduce the ovitrap index. This control strategy is a feasible alternative to rapidly reduce sources of dengue vector in urban areas, especially at the onset of a new epidemic.

Assessment of a natural wetland for use in wastewater remediation.

An environmental study was conducted to assess various aspects of the water and sediment quality of a natural wetland to determine its feasibility for advanced wastewater treatment in Louisiana. Nitrate (NO(3)), nitrite (NO(2)), ammonia (NH(4)), total Kjeldahl nitrogen (TKN), total phosphorus, chloride, total organic carbon, pH, trace metals, fecal coliform, dissolved oxygen (DO), and biochemical oxygen demand (BOD) were monitored. Productivity of a dominant shrub, Iva frutescens, in the wetland was also assessed. Research results indicated that gradients of chloride and salinity concentrations showed a broad mixing of the discharged fresh water into the more saline natural brackish waters. This provided an ideal pattern for nutrient assimilation by the receiving marsh. NH(4) was reduced in the range of 50-100% when all combinations of sources and outflows were considered. For total phosphorus and TKN, reduction ranged from 0-95.1% and 11.2-89.7%, respectively. Some nutrient concentrations in the effluent outlet, NO(3) in particular, were lower than background concentrations found in the reference wetland. Sediment and water showed no significant deficiency or toxicity problems for the major nutrients and metals analyzed. The secondary effluent discharges had little demonstrable negative impact on the wetland during the study period from 1995 to 1996.

The differences of dengue vectors and human behavior between families with and without members having dengue fever/dengue hemorrhagic fever.

Dengue vectors, human knowledge and behavior have been reported to play an important role in the transmission of dengue. This study was designed to understand the differences of dengue vectors and the behavior between families with (target group) and without (control group) members having dengue fever/dengue hemorrhagic fever. Population density of dengue vectors were determined by ovitrap index. The living conditions, knowledge, and behavior related to dengue were investigated by questionnaire survey. Long-term ovitrap indices obtained in the target group was significantly higher than those obtained in the control. Most of the respondents had sufficient knowledge about the transmission and prevention of dengue. However, only low percentages of the families frequently cleaned water-filled containers and ditches around their residence, especially in the target group. These findings indicate that higher indices of dengue vectors and dengue-related behavior are important in the transmission of indigenous dengue.

Investigation of management models in elite athlete injuries.

This cross-sectional study investigated management models among elite athletes participating in sports including baseball, basketball, soccer, volleyball, tennis, softball, football, handball, track and field, swimming, judo, tae-kwon-do, gymnastics, archery, and weight lifting at the Tsoying National Sport Training Center. Data were collected by questionnaire. Of the 393 athletes investigated, 56% were male and 44% were female, with an average age of 20.9 years and average length of athletic experience of 9.8 years. At the time of the survey, 74.8% had sporting injuries and were being treated with Chinese and/or Western medicine. Among injured athletes, 14.5% chose Western treatment, 8.1% chose Chinese medicine, and 75.4% received combined treatment. There were various reasons for choosing the management model. Most athletes had ordinary self-recognition of sports injury prevention. Their qualified ability for sports injury prevention was 70%. This ability was significantly correlated with age, education, and sports experience. Within Taiwan's current medical and social environment, elite athletes prefer a combination of Eastern and Western treatments for sports injuries. Each of the medical approaches are widely accepted by elite athletes and their coaches. Doctors trained in Western medicine should learn these alternative treatment methods and apply them effectively in athletes, so that a better medical network can be established.

Developing a safety and health training model for petrochemical workers.

The production processes of the petrochemical industry expose workers to high potential hazards. Our previous study showed that hazard recognition was closely related to worker safety and health training activities. The purpose of this study was to establish and validate a safety and health training model. It is expected that the training model will help workers to recognize hazards, thereby lowering their operating risks. The training model, which included a complete training course and follow-up scoring using a questionnaire, was applied to three groups of subjects for comparison. Group A had joined our study previously and took the training course again at this time. Group B had also joined our previous study but did not take this training course. Group C was new to our study and took this training course for the first time. Groups A and C (who took the training course) had higher cognition and attitude scores than group B (who did not take the training course). The training course was a significant factor that positively influenced both cognition and attitude scores among managers and workers. The training course was more significant for managers while the duration of education was more significant for workers.

Betel nut chewing: the prevalence and the intergenerational effect of parental behavior on adolescent students.

PURPOSE: To explore the betel nut chewing prevalence among students, analyze the probability and the odds ratio of ex-chewers and current chewers, as well as the correlation between parental behavior characteristics and those of adolescents chewing betel nut. METHODS: A cross-sectional survey was designed and 10,288 Taiwanese students answered the questionnaires in 2002. A structured questionnaire included information about betel nut chewing behavior among the adolescent students, sociodemographic data, and the betel nut chewing practice among parents or classmates. Samples were randomly chosen from each cluster of different types of schools in various areas. Three different grade levels of the first, second, and third grade (ages 16-18 years) were selected. Frequency distribution was used to analyze the prevalence among adolescent students, and Chi-square tests were used to compare the differences of betel nut chewing behavior among genders and the effect of parental behavior and socioeconomic factors. Logistic regression was used to analyze the odds ratio of the prevalence of adolescent students' betel nut chewing in the different types of schools and by gender. RESULTS: When the parents' marriage was not successful, or was of a lower social status, a higher incidence of adolescent betel nut chewing was observed. It was easy to experience betel nut chewing in adolescence if either parent chewed betel nut. The prevalence of betel nut chewing among male students was higher than female students and among vocational school students than general school students. The odds ratio of agricultural school students to general school students was highest of all the ex-chewers and current chewers from different types of schools. CONCLUSIONS: Betel nut chewing behavior is related to the effect of parental behavior on adolescent students. Apparently, it is indicated that there is a significant intergenerational effect of the parent's behavior on their children's behavior.

Betel nut chewing and related factors in adolescent students in Taiwan.

OBJECTIVE: To investigate the prevalence of betel nut chewing and related factors among adolescent students in general, manufacturing, commercial, agricultural and medical technology schools in Taiwan. To make suggestions regarding how health authorities can reduce the number of students taking up the habit. MATERIALS AND METHODS: A cross-sectional survey was designed, and 10,288 students answered the questionnaire. RESULTS: Significantly more male than female students were betel nut chewers. The less urbanized areas were also associated with a higher prevalence of the habit. The prevalence of the habit grew with increasing age. By analysing betel nut chewing behaviour, it was found that most students started chewing betel nuts because of curiosity, and most obtained betel nuts from their friends and classmates. Betel nut chewing behaviour is definitely related to peer pressure. Most betel nut chewers did not realize that withdrawal could lead to physiological reactions, and they were ignorant of any risk to health even though they were compulsive betel nut chewers. The health-harming behaviours of both smoking and drinking were found in many betel nut chewers, particularly smoking. CONCLUSION: This study confirmed the need for a health education programme dealing with the health risks of betel nut chewing for students at risk. The health authorities could also develop a programme for betel nut chewing among Taiwan's adolescent students, emphasizing the dangers of this habit.

A community-based surveillance on determinants of rodent infestation.

Rodent infestation is an important factor in the transmission of infectious diseases of public health importance. From October to November 1998, surveillance stations were established in 110 boroughs of Kaohsiung City in southern Taiwan. Boroughs were chosen by random sampling 10 boroughs from each of 11 districts (464 boroughs) in the city. The extent of rodent infestation was determined by cage trapping. The possibility of applying a community-based control program was evaluated by investigating associated demographic and environmental factors as well as related knowledge, attitudes, and behaviors. A total of 90 rodents were trapped in 41% of the 110 boroughs. Using univariate analyses, 17 factors were significantly associated with rodent infestation. A lack of knowledge that rodent control relies on community cooperation was the most important factor among the seven variables associated with the extent of rodent infestation (OR 3.1) by logistic multiple regression. This revealed the importance of community cooperation in controlling rodent infestation. Moreover, improvement of environmental hygiene associated with garbage problems, such as cleanliness of storage rooms and closets, and the hygiene of empty space and resource recycling stations should not be ignored.

Building collapse and human deaths resulting from the Chi-Chi Earthquake in Taiwan, September 1999.

In this study, the authors attempted to determine factors associated with earthquake deaths in the great Chi-Chi Earthquake that occurred on September 21, 1999, in Taiwan. An isoseismal map was used to identify life-threatening hazards. The vertical peak ground acceleration of ground motion intensity was deemed the most appropriate index for the evaluation of building collapse and mortality. Mortality increased with the increase in earthquake intensity, and building collapse, approaching the epicenter. The greatest number of collapsed buildings and human deaths occurred between the Chelungpu Fault and the Shuantun Fault. Individuals 65 yr of age and older were the most vulnerable to the impact. The authors' findings suggest that improvements in earthquake-resistant building design and construction, as well as improved medical rescue for the elderly, could reduce the level of exposure to earthquake hazards.

Measuring the efficiency of dental departments in medical centers: a nonparametric analysis approach.

Data envelopment analysis (DEA), a cross-sectional study design based on secondary data analysis, was used to evaluate the relative operational efficiency of 16 dental departments in medical centers in Taiwan in 1999. The results indicated that 68.7% of all dental departments in medical centers had poor performance in terms of overall efficiency and scale efficiency. All relatively efficient dental departments were in private medical centers. Half of these dental departments were unable to fully utilize available medical resources. 75.0% of public medical centers did not take full advantage of medical resources at their disposal. In the returns to scale, 56.3% of dental departments in medical centers exhibited increasing returns to scale, due to the insufficient scale influencing overall hospital operational efficiency. Public medical centers accounted for 77.8% of the institutions affected. The scale of dental departments in private medical centers was more appropriate than those in public medical centers. In the sensitivity analysis, the numbers of residents, interns, and published papers were used to assess teaching and research. Greater emphasis on teaching and research in medical centers has a large effect on the relative inefficiency of hospital operation. Dental departments in private medical centers had a higher mean overall efficiency score than those in public medical centers, and the overall efficiency of dental departments in non-university hospitals was greater than those in university hospitals. There was no information to evaluate the long-term efficiency of each dental department in all hospitals. A different combination of input and output variables, using common multipliers for efficiency value measurements in DEA, may help establish different pioneering dental departments in hospitals.