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PubMedDate not supplied

Exposure to emissions from gasoline within automobile cabins.

Gasoline is emitted from automobiles as uncombusted fuel and via evaporation. Volatile organic compounds (VOC) from gasoline are at higher levels in roadway air than in the surrounding ambient atmosphere and penetrate into automobile cabins, thereby exposing commuters to higher levels than they would experience in other microenvironments. Measurements of VOC concentrations and carbon monoxide were made within automobiles during idling, while driving on a suburban route in New Jersey, and on a commute to New York City. Concentrations of VOC from gasoline were determined to be elevated above the ambient background levels in all microenvironments while VOC without a gasoline source were not. The variability of VOC concentrations with location within the automobile was determined to be smaller than inter-day variability during idling studies. VOC and carbon monoxide levels within the automobile cabin differed among the different routes examined. The levels were related to traffic density and were inversely related to driving speed and wind speed. Overall, daily VOC exposure for gasoline-derived compounds during winter commuting in New Jersey was estimated to range between 5 and 20% and constituted between 15 and 40% of an individual's daily exposure based on comparison to urban and suburban settings, respectively. VOC exposure during commuting in Southern California was estimated to range between 15 and 60%.

Air↗
PubMed2006

Stress management using UMTS cellular phones: a controlled trial.

One of the best strategies for dealing with stress is learning how to relax. However, relaxing is difficult to achieve in typical real world situations. For this study, we developed a specific protocol based on mobile narratives - multimedia narratives experienced on UMTS/3G phones - to help workers in reducing commuting stress. In a controlled trial 33 commuters were randomly divided between three conditions: Mobile narratives (MN); New age music and videos (NA); no treatment (CT). In two consecutive days the MN and NA samples experienced during their commute trip 2 x 2 6-minute multimedia experiences on a Motorola A925 3G phone provided by the "TRE" Italian UMTS carrier: the MN sample experienced a mobile narrative based on the exploration of a desert beach; the NA sample experienced a commercial new age video with similar visual contents. The trials showed the efficacy of mobile narratives in reducing the level of stress experienced during a commute trip. No effects were found in the other groups. These results suggest that 3G mobile handsets may be used as relaxation tool if backed by a specific therapeutic protocol and meaningful narratives.

Adult↗
PubMedDate not supplied

Exposure to volatile organic compounds in the passenger compartment of automobiles during periods of normal and malfunctioning operation.

In-vehicle exposures to selected gasoline-derived volatile organic compounds (VOCs) and formaldehyde were examined on 113 commutes through suburban New Jersey and on 33 New Jersey/New York commutes using measurements taken in two vehicles driven in tandem during 1991-1992. Overall median exposures to VOCs were lowest on the suburban commute, slightly higher on the New Jersey Turnpike, and highest in transit through the Lincoln Tunnel. Median in-vehicle concentrations of benzene, ethylbenzene, m- and p-xylene, and o-xylene were 14 microg/m3, 6.8 microg/m3, 36 microg/m3, and 15 microg/m3, respectively. For a motorist who commutes 93.2 min daily (6.5% of the day), this corresponds to 12.1%, 10.8%, 14.9%, and 14.7% of the total daily exposures to these compounds. One vehicle, with a carbureted engine, developed malfunctions which caused gasoline emissions within the engine compartment during driving. Resultant gasoline-derived VOC concentrations in this vehicle measured much higher than in the properly maintained, fuel-injected vehicle, particularly for the low ventilation extreme. The highest in-vehicle benzene concentration measured during these malfunctions was 45.2 microg/m3. The air concentration in the vehicle driven in tandem was a factor of 25 less (1.8 microg/m3). A motorist who drives for the average daily period of 93.2 min/day in this malfunctioning automobile will have a benzene exposure of 2.8 (microg/m3)day, compared to 0.1 (microg/m3)day in the properly functioning vehicle.

Adult↗
PubMed1995

The urban household pattern of daytime population change.

"A matrix representation of places of residence and places of commuting destination in a metropolis, is coupled with evidence regarding spatio-temporal change in average household size. This approach allows the average number of persons per household who commute to be hierarchically ordered in a square matrix which shows attributes associated with a well-known class of matrices. Based on these attributes it is shown that any given spatial distribution of households implies a bounded range of vectors representing the spatial distribution of commuters.... The proposed methodology is applied to thirty four subareas throughout the city of Saskatoon, Saskatchewan."

Americas↗
PubMed1997

Density and the journey to work.

"This paper evaluates the influence of residential density on commuting behavior across U.S. cities while controlling for available opportunities, the technology of transportation infrastructure, and individual socio-economic and demographic characteristics. The measures of metropolitan and local density are addressed separately.... Regressions are conducted to predict commuting time, speed, and distance, by mode of travel on a cross-section of individuals nationally and city by city. The results indicate that residential density in the area around the tripmaker's home is an important factor: the higher the density the lower the speed and the shorter the distance.... The paper suggests a threshold density at which the decrease in distance is overtaken by the congestion effects resulting in a residential density between 7,500 and 10,000 persons per square mile (neither the highest nor lowest) with the shortest duration auto commutes."

Americas↗
PubMed1998

Preparation of enzyme calibration materials.

Standardisation in clinical enzymology needs not only reference methods but also reference materials. While single-enzyme reference enzymes have been developed, a multienzyme certified reference material (MECRM) available in high amount remains to be produced. To transfer trueness from the value of the reference system to patients' results, validated enzyme calibrators (EC) are also needed. Both the MECRM and the ECs must exhibit the same catalytic properties as the corresponding enzymes in human plasma. Moreover, commutability of these materials with patients' samples must be experimentally tested for one or a set of methods defined by an analytical specificity equal to that of the reference method. Various experimental studies have shown that the commutability of an enzyme material depends on the source of enzyme and its purification process, the matrix (including cofactors, effectors, additives, stabilisers... ) and the mode of processing of the final material. To promote intermethod calibration in clinical enzymology, a collaborative programme between the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), Institute for Reference Materials and Measurements (IRMM, Geel, Belgium) and IFCC corporate members is in progress for the development of a MECRM containing amylase, ALT, AST, ALP, CK, GGT, LDH, and lipase and exhibiting a wide and defined commutability.

Calibration↗
PubMed2003

Preliminary measurements of aromatic VOCs in public transportation modes in Guangzhou, China.

This study examined the exposure level of aromatic volatile organic compounds (VOCs) in public transportation modes in Guangzhou, China. A total of 40 VOC samples were conducted in four popular public commuting modes (subway, taxis, non-air-conditioned buses and air-conditioned buses) while traversing in urban areas of Guangzhou. Traffic-related VOCs (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene) were collected on adsorbent tubes and analyzed by thermal desorption (TD) and gas chromatography/mass-selective detector (GC/MSD) technique. The results indicate that commuter exposure to VOCs is greatly influenced by the choice of public transport. For the benzene measured, the mean exposure level in taxis (33.6 microg/m(3)) was the highest and was followed by air-conditioned buses (13.5 microg/m(3)) and non-air-conditioned buses (11.3 microg/m(3)). The exposure level in the subway (7.6 microg/m(3)) is clearly lower than that in roadway transports. The inter-microenvironment variations of other target compounds were similar to that of benzene. The target VOCs were well correlated to each other in all the measured transports. The concentration profile of the measured transport was also investigated and was found to be similar to each other. Based on the experiment results, the average B/T/E/X found in this study was about (1.0/4.3/0.7/1.4). In this study, the VOC levels measured in evening peak hours were only slightly higher than those in afternoon non-peak hours. This is due to the insignificant change of traffic volume on the measured routes between these two set times. The out-dated vehicle emission controls and slow-moving traffic conditions may be the major reasons leading elevated in-vehicle exposure level in some public commuting journeys.

Air Pollutants↗
PubMed2003

Energy-related emissions from telework.

Telework is a growing phenomenon that is thought to save energy and air emissions. This paper applies a systems model to telework and nontelework scenarios in order to quantify greenhouse gas and other air emissions from transportation, heating, cooling, lighting, and electronic and electrical equipment use both at the company and the home office. Using United States data, a WWW-based, scalable decision-support tool was created to evaluate the environmental impacts of teleworkers. For a typical case reflecting United States teleworker patterns, the analysis found that telework has the potential to reduce air emissions. However, Monte Carlo simulation employed to perform a probabilistic analysis over a set of likely parameters has revealed that telework may not affect equally the emissions of all types of pollutants. It may decrease CO2, NOx, SO2, PM10, and CO but not N2O and CH4 emissions. Therefore, the scope and goal of telework programs must be defined early in the implementation process. Work-related transportation (commuting) impacts could be reduced as a result of telework; however, home-related impacts due to an employee spending additional time at home could potentially offset these reductions. Company office-related impacts may not be reduced unless the office space is shared with other employees during telework days or eliminated entirely. In states with high telework potential (California, Georgia, Illinois, New York, Texas), telework could save emissions, but it would depend on commuting and climatic patterns and the electricity mix. Environmentally beneficial telework programs are found to depend mainly on commuting patterns, induced energy usage, and characteristics of the office and home space and equipment use.

Air Pollutants↗
PubMed2000

The effect of physical activity on breast cancer risk: a cohort study of 30,548 women.

BACKGROUND: In epidemiological studies abundant physical activity has been related to decreased breast cancer risk, though the results have been inconsistent. The purpose of this paper was to study the association of physical activity at leisure and commuting to work and incidence of breast cancer. METHODS: The study cohort consisted of 30,548 female participants of the Finnish adult health behaviour survey, based on annual random samples of Finns aged 15-64, collected in 1978-1993. By the end of 1995, 332 breast cancer cases had been diagnosed in the cohort. Relative risks of breast cancer were adjusted for age at survey, body mass index (BMI), education, length of follow-up, parity and age at first birth using Poisson regression models. RESULTS: Compared to women exercising less than once a week, the adjusted relative risk of breast cancer for women exercising once a week was 0.80 (95% confidence interval (CI): 0.58-1.10), for women exercising 2-3 times per week 0.92 (95% CI: 0.78-1.22) and for women exercising daily 1.01 (95% CI: 0.72-1.42). Women who reported commuting, walking or bicycling to work 30 min or more daily had slightly lower adjusted risk of breast cancer (RR: 0.87, 95% CI: 0.62-1.24) than women working at home, being unemployed or driving a car to working place. CONCLUSION: Although a small protective effect of regular physical activity for breast cancer incidence was found in physical activity when commuting to work, the role of the physical activity in breast cancer prevention is still an open question.

Adolescent↗
PubMedDate not supplied

Concentrations of volatile organic compounds in the passenger side and the back seat of automobiles.

The in-vehicle volatile organic compound (VOC) concentrations during commutes have previously been measured in only one single interior sampling location, considering a sample collected in the single interior location as representative of overall VOC concentrations within an automobile. The present study evaluated if the potential differences in VOC concentrations occur in the automobiles' interior during idling and commuting under different driving conditions associated with the use of air cleaning devices (ACDs) and interior fan. The experiments were conducted under the low ventilation condition with the windows and the vent closed and the fan off. The difference of VOC concentrations between passenger side and back seat during idling was small. The variability of VOC concentrations with location inside automobiles while commuting was not significant at p < 0.05, regardless of the use of ACDs and/or the interior fan, while inter-vehicle variability was significant at p < 0.05. In addition, currently available ACDs equipped with activated carbon filters in Korea were ineffective at removing VOCs from the interior of automobiles. The concentrations of the two lightest ones of the target compounds, benzene and toluene, were significantly higher inside two vehicles than in the roadway air at p < 0.05, while the in-vehicle and roadway concentrations of the other target compounds did not differ significantly at p < 0.05 for both vehicles. The concentrations of all target VOCs, except benzene, were significantly higher (p < 0.05) in the interior of older car than of newer car. Median in-vehicle concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, and o-xylene were 38.3, 107, 9.2, 7.8, 16.9, and 10.7 micrograms/m3, respectively.

Air Pollution, Indoor↗
PubMed2004

Active living and injury risk.

The purpose of this study was to get reliable insight into injury risk in various commuting and lifestyle activities, as well as recreational and competitive sports. A cohort of 3 657 persons was randomly selected from the 15- to 74-year-old Finnish population. Ninety-two percent (n = 3 363) of the subjects accepted to participate the one-year follow-up, record all their physical activities that lasted 15 min or more, and register all acute and overuse injuries that occurred during these activities. To collect the information, the study subjects were interviewed by phone by the trained personnel of the Statistics Finland three times in four-month intervals. The individual injury risk per exposure time was relatively low, ranging from 0.19 to 1.5 per 1 000 hours of participation, in commuting and lifestyle activities including walking and cycling to work, gardening, home repair, hunting and fishing, and, in sports such as golf, dancing, swimming, walking, and rowing. The risk was clearly higher in squash, orienteering, and contact and team sports, such as judo, wrestling, karate, rinkball, floorball, basketball, soccer, ice hockey, volleyball, and Finnish baseball ranging from 6.6 to 18.3 per 1 000 hours of participation. However, the highest absolute number of injuries occurred in low-risk activities, such as gardening, walking, home-repair, and cycling, because they are performed so often. In conclusion, individual injury risk per exposure hours is relatively low in commuting and lifestyle activities compared to many recreational and competitive sports. However, at a population level, these low-to-moderate intensity activities are widely practised producing a rather high absolute number of injuries, and thus, preventive efforts are needed in these activities, too.

Activities of Daily Living↗
PubMed2002

Traces, ideals, and arithmetic means.

This article grew out of recent work of Dykema, Figiel, Weiss, and Wodzicki (Commutator structure of operator ideals) which inter alia characterizes commutator ideals in terms of arithmetic means. In this paper we study ideals that are arithmetically mean (am) stable, am-closed, am-open, soft-edged and soft-complemented. We show that many of the ideals in the literature possess such properties. We apply these notions to prove that for all the ideals considered, the linear codimension of their commutator space (the "number of traces on the ideal") is either 0, 1, or infinity. We identify the largest ideal which supports a unique nonsingular trace as the intersection of certain Lorentz ideals. An application to elementary operators is given. We study properties of arithmetic mean operations on ideals, e.g., we prove that the am-closure of a sum of ideals is the sum of their am-closures. We obtain cancellation properties for arithmetic means: for principal ideals, a necessary and sufficient condition for first order cancellations is the regularity of the generator; for second order cancellations, sufficient conditions are that the generator satisfies the exponential Delta(2)-condition or is regular. We construct an example where second order cancellation fails, thus settling an open question. We also consider cancellation properties for inclusions. And we find and use lattice properties of ideals associated with the existence of "gaps."

Journal Article↗
PubMed1992

Vehicle occupant exposure to carbon monoxide.

This paper focuses on the auto commuting micro-environment and presents typical carbon monoxide (CO) concentrations to which auto commuters in central Riyadh, Saudi Arabia were exposed. Two test vehicles traveling over four main arterial roadways were monitored for inside and outside CO levels during eighty peak and off-peak hours extending over an eight-month period. The relative importance of several variables which explained the variability in CO concentrations inside autos was also assessed. It was found that during peak hours auto commuters were exposed to mean CO levels that ranged from 30 to 40 ppm over trips that typically took between 25 to 40 minutes. The mean ratio of inside to outside CO levels was 0.84. Results of variance component analyses indicated that the most important variables affecting CO concentrations inside autos were, in addition to the smoking of vehicle occupants, traffic volume, vehicle speed, period of day and wind velocity. An increase in traffic volume from 1,000 to 5,000 vehicles per hour (vph) increased mean CO level exposure by 71 percent. An increase in vehicle speed from 14 to 55 km/h reduced mean CO exposure by 36 percent. The number of traffic interruptions had a moderate effect on mean concentrations of CO inside vehicles.

Air Pollutants↗
PubMed2004

Teen at work: the burden of a double shift on daily activities.

The purpose of this study was to the evaluate time spent by working and nonworking adolescents on daily activities (work, home duties, school, transportation, other activities, leisure, sleep, and naps). Twenty-seven students, 8 male workers, 8 female workers, 5 male nonworkers, and 6 female nonworkers, ages 14-18 yrs participated in the study. They attended evening classes Monday-Friday (19:00-22:30h) in a public school in the city of São Paulo, Brazil. The students answered a comprehensive questionnaire on the characterization of their life, work, and health conditions. Simultaneously, they wore actigraphs (Ambulatory Monitoring, Inc.) and completed a diary of their daily activities (time spent at work, on home duties, commuting, leisure, other activities) for a minimum of 10 to a maximum of 17 consecutive days. The means of the variables were tested for differences by a two-factor (work and sex) ANOVA and Student-t test applied to pair-wise samples (weekdays and weekends). The average duration during weekdays of working time was 7 h 09 min and home duties 0 h 48 min. As for commuting time, there was a work effect [F(1,23) = 4.9; p = 0.04]; mean commuting time was 2 h 22 min for workers (males and females) and 1 h 25 min for nonworkers. There was a significant difference between workers and nonworkers [F(1,23) = 4.6; p = 0.04] regarding extra-cirricular class activities; workers spent a mean of 3 min/day on them as opposed to 1 h 14 min by nonworkers. The average daily time spent on leisure activities by workers was 6h 31 min; whereas, for nonworkers it was 7h 38min. Time spent in school amounted to 2h 47min for workers in comparison to 3h 22min by nonworkers. There was a significant work effect upon sleep [F(1,23)= 10.0; p <0.01]. The work effect upon nighttime sleep duration was significant [F(1,23)= 16.7; p <0.01]. Male workers showed a mean night sleep of 6 h 57 min and female workers 07h 15min. The average nighttime sleep duration for nonworkers was 9 h 06 min. There was a significant interactive effect between work and sex [F(1,23)= 5.6; p=0.03] for naps. Female workers showed took shortest nap on average (36 min; SD = 26 min), and female nonworkers the longest naps (1 h 45min; SD= 35min). Study and employment exert significant impact on the life and activities of high school students. Work affects sleep and nap duration plus the amount of time spent in school and other extra-curricular activities.

Activities of Daily Living↗
PubMed2003

Effect of air pollution on peak expiratory flow rate variability.

Exposure to air pollution affects pulmonary functions adversely. Effect of exposure to pollution on diurnal variation of peak flow was assessed in healthy students. Three hundred healthy age-matched nonsmoker students were studied. They were categorized into two groups on the basis of their residence: commuters and living on campus. Peak expiratory flow (PEF) recordings were made twice daily for 2 days with the Pink City Flow Meter. The measurement was then used to calculate for each subject the amplitude percentage mean, which is an index for expressing PEF variability for epidemiological purposes (Higgins BG, Britton JR, Chinns Jones TD, Jenkinson D, Burnery PG, Tattersfield AE. Distribution of peak expiratory flow variability in a population sample. Am Rev Respir Dis 1989; 140:1368-1372). Air pollution parameters were quantified by measurement of sulfur dioxide (SO2), oxides of nitrogen (NO2), carbon monoxide (CO), and respirable suspended particulate matter (RSPM) in the ambient air at the campus and on the roadside. The mean values of PEF variability (amplitude percent mean) in the students living on campus and in the commuters were 5.7 +/- 3.2 and 11 +/- 3.6, respectively (P < .05). Among the commuters, maximum number of subjects showed amplitude percentage mean PEFR at the higher end of variability distribution, as compared to the students living on campus, among whom the majority of subjects fell in the lower ranges of variability distribution. The ambient air quality parameters, namely SO2, NO2, CO, and RSPM were significantly lower on the campus. It can be concluded that long-term periodic exposure to air pollution can lead to increased PEF variability even in healthy subjects. Measurement of PEF variability may prove to be a simple test to measure effect of air pollution in healthy subjects.

Air Pollution↗
PubMed2006

Physical activity and the incidence of type 2 diabetes in the Shanghai women's health study.

BACKGROUND: Leisure-time physical activity (LPA) has been associated with a reduced risk of type 2 diabetes. However, the potential effect of other types of physical activity on type 2 diabetes is still uncertain. The aim of this study was to examine the effect of occupational, commuting, daily living, and LPA on the incidence of type 2 diabetes in a cohort of middle-aged women. METHODS: We prospectively followed 70,658 women who had no prior history of diabetes at study recruitment for 4.6 years. Participants completed in-person interviews at baseline that collected information on diabetes risk factors including physical activity habits. Anthropometric measurements were taken by trained interviewers. Multivariate-adjusted hazard ratios were estimated by levels of occupational, commuting, daily living, and LPA. RESULTS: We documented 1973 incident cases of diabetes during 326,625 person-years of follow-up. LPA and daily living physical activity (DPA) were associated with a moderately reduced risk of type 2 diabetes. The relative risk for type 2 diabetes associated with LPA and DPA categories were 1.00, 0.89, 1.05, and 0.83, (P trend = 0.12) and 1.00, 0.98, 0.95, and 0.88, (P trend = 0.06) respectively. LPA was associated with lower risk of type 2 diabetes in employed participants (P trend = 0.09) while DPA was mainly associated with a reduction in risk in non-employed participants (P trend <0.01). While occupational physical activity was not associated with type 2 diabetes risk in this population, commuting to work was associated with a reduction in risk. A combination of DPA and LPA was associated with a reduced risk of type 2 diabetes. CONCLUSIONS: This study suggests that physical activity, either from leisure-time exercise or daily activity reduces the risk of type 2 diabetes in women, supporting the current health promotion efforts encouraging both exercise and non-exercise activity levels.

Activities of Daily Living↗
PubMed1997

Fatal railway injuries in Cape Town, South Africa.

To describe the features of railway-related deaths in Cape Town, South Africa, we reviewed demographic, autopsy, and accident report data on all such deaths between 1 April 1992 and 30 September 1994. Of the 379 railway-related deaths, 27 were among pedestrians or commuters who were hit by a train while crossing the track, 38 were among commuters who fell from moving trains, 32 were suicides, 43 were the result of criminal violence on trains or at railway stations, and 38 were due to other causes. Most railway fatalities were among men between the ages of 25 and 44 years. About half of all railway fatalities occurred at peak commuting times, with high levels of violence (often robbery related) recorded during the evening peak. A blood alcohol concentration > 0.1 g/100 ml was found in 35% of the people who died from crossing the track or falling from moving trains. Fatal railway injury is characterized by extensive disruption of more than one body region. The high levels of fatal railway injury make a strong case for a range of injury control interventions, including ticket control, surveillance, law enforcement, and safety engineering.

Accidents↗
PubMed2006

Different forms of physical activity and cardiovascular risk factors among 24-64-year-old men and women in Finland.

BACKGROUND: There is convincing evidence that regular physical activity reduces risk factors for cardiovascular diseases (CVD) among men. However, only a few studies have been conducted among women. Most previous studies have focused on the effects of leisure-time physical activity on cardiovascular risk factors, without considering the impact of occupational or commuting physical activity. DESIGN: Four independent cross-sectional surveys were carried out at 5-year intervals within the framework of the FINMONICA studies in 1982, 1987, 1992 and 1997. METHODS: An independent random sample was drawn from the national population register for each survey. The samples were stratified by sex and 10-year age categories according to the WHO MONICA protocol. The survey consisted of a self-administered questionnaire. RESULTS: Not only leisure-time physical activity, but also commuting activity was directly associated with high-density lipoprotein (HDL)-cholesterol and was inversely related to body mass index (BMI) and waist circumference among both men and women. High occupational physical activity was related to high HDL-cholesterol levels and high total serum cholesterol levels in both sexes and to lower BMI, waist circumference and diastolic blood pressure (DBP) in men. High leisure-time physical activity was associated with reduced DBP among both men and women, whereas high occupational physical activity was related to lower DBP only among men. CONCLUSION: Not only leisure-time physical activity but also commuting activity is associated with reduced levels of some cardiovascular risk factors. All forms of physical activity should be promoted to reduce CVD in the population.

Adult↗