Jet fuel and liver function

The impact of occupational exposure to jet fuel on antipyrine elimination was studied in 91 fuel-filing attendants. The mean antipyrine clearance was enhanced to 68.4 (SD 19.5) ml/min during exposure to jet fuel compared to 57.9 (SD 18.1) ml/min after an exposure-free period of two to four weeks. The corresponding values for 47 office workers (referents) were 62.7 (SD 22.2) ml/min and 56.4 (SD 22.3) ml/min. The median jet fuel concentration in the breathing zone of the fuel-filling attendants was 31 (range 1-1 020) mg/m3. No known inducing factor could be identified in the work environment of the office workers. No difference in the concentration of aspartate aminotransferase and alkaline phosphatase in serum was found either within or between the groups. Our study indicates that jet fuel, which is a mixture of aliphatic and aromatic organic solvents resembling gasoline and white spirit, is an inducer of hepatic drug metabolism in man.     

接触苯的氨基和硝基化合物工人安替比林及灭滴灵代谢活性的改变

61名接触二硝基氯苯、硝基氯苯、二硝基甲苯及二氨基甲苯工人唾液安替比林和灭滴灵清除率明显低于对照组(62人)。表明肝微粒体酶活性被抑制。吸烟和饮酒者两药清除率增高,似可认为吸烟和饮酒是微粒体酶活性的诱导因素。血清GPT及MAO未见明显变化。血清铜蓝蛋白显著下降,而血清脂质过氧化产物MDA明显增高。作者认为,无损伤药物清除率试验以及血清铜蓝蛋白和血清MDA可望作为对接触工人进行医学监护的敏感指标。     

Smoking, body weight, and CHD mortality in diverse populations

Background. It is well documented that smokers tend to be leaner than nonsmokers. It is also clearly established that smoking is detrimental to health. The question that immediately comes to mind, therefore, is whether the possible weight-controlling aspects of the smoking habit offset the harm induced by smoking.Methods. In this report, we present an analysis of 21 observational studies that examine the relationship between smoking status and BMI. With few exceptions, smokers are leaner than nonsmokers.Results. The average differences between smokers and nonsmokers are 0.97 kg/m² for men (95% CI = 0.82–1.13) and 1.38 kg/m² for women (95% CI = 1.19–1.58). However, considering the relationship of both BMI and smoking to coronary heart disease (CHD) mortality, adjusting for age, we find that 15.9 kg/m² BMI units is required for men and 15.8 kg/m² is required for women to offset the detrimental effect of smoking. This weight differential is 42 kg (93 lb) for a woman 163 cm (64 in.) tall.Conclusion. Our results demonstrate that the risk of CHD death among smokers is not reduced sufficiently by the lower BMIs to justify the habit. It is unquestionably better to quit smoking and gain weight than to continue to smoke.     

Antipyrine clearance during experimental and occupational exposure to toluene.

Exposure to toluene vapour enhances hepatic microsomal enzyme function in animals as assessed by the metabolism of the test drug antipyrine. Thirty six printing trade workers with long term occupational exposure to a mixture of organic solvents and 39 matched controls were randomly allocated into four groups. Eighteen printers and 21 controls were exposed to 100 ppm of toluene during 6.5 hours in an exposure chamber. The remaining 18 printers and 18 controls were exposed to 0 ppm of toluene under similar conditions. The salivary clearance of antipyrine was measured immediately after the stay in the exposure chamber to investigate a possible acute change in liver function and was repeated two weeks later, shortly before the summer vacation. Antipyrine clearance was measured again at the end of the summer vacation-four weeks after exposure. To study a possible effect of chronic exposure on antipyrine clearance 12 printing trade workers with 17 years (median) of occupational exposure to toluene vapour at concentrations of about 100 ppm were investigated before and four weeks after cessation of exposure. No difference in antipyrine clearance was found either within the groups or between the groups at any of the measurements.     

Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Prague using personal monitoring

Objective: Exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) were assessed in Prague, Czech Republic, to determine the range and degree of personal exposure by means of personal monitoring over a 24-h period. Design: Self-reported nonsmokers were randomly selected from a representative sample of the population of Prague. Housewives were recruited into one group, primarily for assessment exposures in the home, and office workers were recruited into a second group for assessment of the contribution from the workplace. Methods: A total of 238 randomly selected nonsmoking subjects collected air samples near their breathing zone by wearing personal monitors for 24 h. Samples collected were analyzed for RSP, nicotine, 3-ethenylpyridine, and ETS particles (using ultraviolet absorbance, fluorescence, and solanesol measurements). Saliva cotinine analyses were also undertaken to confirm the nonsmoking status of the subjects. Results: The most highly exposed subjects in this study were office workers both living and working with smokers. Median time-weighted average exposure concentrations of 60 μg m⁻³ RSP, 16 μg m⁻³ ETS particles, and 1.6 μg m⁻³ nicotine were determined for these subjects, who also had the highest median saliva cotinine level of 2.4 ng ml⁻¹. Housewives living in nonsmoking households were the least exposed subjects in this study, showing levels of 32 μg m⁻³ RSP, 0.17 μg m⁻³ ETS particles, and 0.15 μg m⁻³ nicotine. As based upon median levels of ETS particles and nicotine, no group would potentially inhale or be exposed to more than 10 cigarette equivalents per year (CE/y) and the least exposed would inhale less than 1 CE/y. The most highly exposed (90th percentile levels) nonsmokers in this study, who both worked and lived with smokers, would potentially inhale up to 29 CE/y. Overall, the workplace was estimated to contribute between 45% and 49% of the annual exposure to nicotine and ETS particles, respectively. On the basis of determined saliva cotinine concentrations, a misclassification rate of between 1.7% and 2.5% was calculated. Conclusions: Highest exposures were apparent for office workers both working and living in smoking environments, and our findings suggest a significant contribution to overall ETS particle and nicotine levels from the workplace where smoking takes place. Overall, the rates at which subjects were determined to have misclassified their smoking status in this study were the lowest observed in any of the European cities investigated to date. Clearly, a more sensitive method of analysis for cotinine in body fluids is needed for more accurate determination of the levels expected for nonsmokers. Received: 19 November 1997 / Accepted: 26 February 1998     

Support for and Observance of Worksite Smoking Restriction Policies—A Study of Municipal Employees at a City Office in Japan

Background. While various types of smoking restrictions have been introduced in Japanese workplaces, it is not clear what restriction policies workers find acceptable. This study examined the relationship between the extent of worksite smoking restriction and worker attitudes toward these policies.Methods. Municipal employees randomly selected from a city office were surveyed using a self-administered questionnaire concerning support for and smokers' observance of their present smoking restriction. A total of 2857 (88.6%) workers responded.Results. More than 60% of respondents regarded a work-area ban with a designated smoking space as the most desirable policy. Among subjects who were aware of the current policies in their workplaces, positive support was highest for a total ban (73.9%) and decreased as the extent of the restriction became milder (P for trend <0.001). In contrast, an inverse relation was found for negative support (P for trend <0.001). These trends were observed among both nonsmokers and smokers. Smokers subject to a work-area ban observed the policy more faithfully than those subject to milder policies.Conclusions. Policies prohibiting smoking in work areas were favorably accepted by municipal employees, irrespective of smoking status. These results should encourage Japanese workplaces to adopt work-area bans, through which nonsmokers are effectively protected from environmental tobacco smoke.     

Traffic-related Occupational Exposures to PM2.5, CO,and VOCs in Trujillo,Peru

Abstract

A traffic-related exposure study was conducted among 58 workers (drivers, vendors, traffic police, and gas station attendants) and 10 office workers as controls in Trujillo, Peru, in July 2002. PM_2.5 was collected, carbon monoxide (CO) was measured, volatile organic compounds (VOCs) were sampled and analyzed. Newspaper vendors had the highest full-shift CO exposures (mean ± SD: 11.4 ± 8.9 ppm), while office workers had the lowest (2.0 ± 1.7 ppm). Bus drivers had the highest full-shift PM_2.5 exposures (161±8.9 pg/m³), while gas station attendants (64 ± 26.5 pg/m³) and office workers (65 ± 8.5 μg/m³) were the lowest. Full-shift benzene/toluene/ethylbenzene/xylene exposures (BTEX) among gas station attendants (111/254/43/214 μg/m³) were much higher than those among van and taxi drivers. Several of the traffic-related occupational exposures studied were elevated and are of occupational health concern.     

Workplace Secondhand Smoke Exposure in the U.S. Trucking Industry

Background

Although the smoking rate in the United States is declining because of an increase of smoke-free laws, among blue-collar workers it remains higher than that among many other occupational groups.

Objectives

We evaluated the factors influencing workplace secondhand smoke (SHS) exposures in the U.S. unionized trucking industry.

Methods

From 2003 through 2005, we measured workplace SHS exposure among 203 nonsmoking and 61 smoking workers in 25 trucking terminals. Workers in several job groups wore personal vapor-phase nicotine samplers on their lapels for two consecutive work shifts and completed a workplace SHS exposure questionnaire at the end of the personal sampling.

Results

Median nicotine level was 0.87 μg/m³ for nonsmokers and 5.96 μg/m³ for smokers. As expected, smokers experienced higher SHS exposure duration and intensity than did nonsmokers. For nonsmokers, multiple regression analyses indicated that self-reported exposure duration combined with intensity, lack of a smoking policy as reported by workers, having a nondriver job, and lower educational level were independently associated with elevated personal nicotine levels (model R² = 0.52). Nondriver job and amount of active smoking were associated with elevated personal nicotine level in smokers, but self-reported exposure, lack of a smoking policy, and lower educational level were not.

Conclusions

Despite movements toward smoke-free laws, this population of blue-collar workers was still exposed to workplace SHS as recently as 2005. The perceived (reported by the workers), rather than the official (reported by the terminal managers), smoking policy was associated with measured SHS exposure levels among the nonsmokers. Job duties and educational level might also be important predictors of workplace SHS exposure.     

Occupational risks of zoonotic infections in Dutch forestry workers and muskrat catchers

Lyme borreliosis (LymeB), Hemorrhagic fever with renal syndrome (HemoFRS), Lymphocytic choriomeningitis (LymphoCM), Tick-borne encephalitis (TickBE), Q Fever (QFever), and Weil's leptospirosis (Lepto) are known to be occupational diseases for rural outdoor workers. We investigated the occupational infection risks for these diseases in greater detail. Antibodies to these agents were assessed in 312 forestry workers and muskrat catchers, and in 356 matched office workers. Three levels of occupational exposure were distinguished: high for active forestry workers, low for supervisory forestry staff and muskrat catchers and zero for office workers. At high exposure the prevalence odds ratios (with 95% CI between brackets) were: LymeB 15 (5.5–42), HemoFRS 11 (1.3–501), LymphoCM 5.4 (1.0–50), TickBE 1.0 (0.3–3.0), QFever 1.0 (0.4–2.1), and Lepto 0 (0.0–33). No significant risk of infection was found at low exposure. Part of the present group had also been studied in 1989 and 1990. Within this cohort the conversion rates to Borrelia burgdorferi have been estimated for the periods 1989–1990 and 1990–1993 as 0.23 and 0.066 year^-1, respectively, and the reversion rate as 0.44 year^-1. The corresponding values for HemoFRS were 0.031, 0.018 and 1.42 year^-1. Active forestry workers in the Netherlands are at high risk of infection by LymeB, HemoFRS and LymphoCM. Prevalence of antibodies to LymeB and HemoFRS appeared to reflect the levels of these infection hazards in recent history.     

Induction of microsomal drug metabolism in man and in the rat by exposure to petroleum.

To determine the effect of petroleum exposure on the activity of hepatic mixed function oxidase enzymes, salivary elimination kinetics of antipyrine were determined in 19 petrol station attendants and compared with 19 controls. Antipyrine half life in petrol station attendants was shorter than in controls. Microsomal preparations (10 000 x g supernatants) were prepared from six male Porton rats exposed to petrol vapour (5 ppm at an air flow rate of 41/min for eight hours a day for three weeks) and six control rats maintained under the same conditions without exposure to petrol vapour. The rates of oxidative metabolism of antipyrine, aminopyrine, ethylmorphine, aniline, and benzo(a)pyrene were all increased by more than 45% in the petrol-exposed rats. The results indicate that petrol vapour is a moderately potent inducer of mixed function oxidase activity in rats, and that occupational exposure to petroleum may result in enhanced microsomal drug metabolism.     

Comparative study of effect of inorganic lead and cadmium on blood δ-aminolevulinate dehydratase in man

Lauwerys, R. R., Buchet, J.-P., and Roels, H. A. (1973).British Journal of Industrial Medicine,30, 359-364. Comparative study of effect of inorganic lead and cadmium on blood δ-aminolevulinate dehydratase in man. δ-Aminolevulinate dehydratase (ALA¹-D) of red blood cells, lead concentration in blood (Pb-B) and in urine (Pb-U), cadmium concentration in blood (Cd-B) and in urine (Cd-U), and ALA in urine (ALA-U) were measured in 77 workers occupationally exposed to cadmium, and in 73 control workers.

An excellent negative correlation was found between log ALA-D and Pb-B (r = - 0·660) or Pb-U (r = - 0·501), but no significant correlation was found between Cd-B and log ALA-D activity.

Unlike ALA-D, ALA-U is not correlated with Pb and Pb-U in the `normal' range of Pb concentration investigated. Mean ALA-D activity in smokers is lower than in nonsmokers, and this is probably related to the fact that a higher mean Pb-B concentration is found in smokers than in nonsmokers.

It is clear from this investigation that in the general population, and even in Cd-exposed workers, Cd has no significant effect on ALA-D. Moreover, all the available evidence indicates that ALA-D activity of erythrocytes is a very sensitive and specific parameter of lead in blood.

     

Comparative Toxicokinetics of Explosive Compounds in Sheepshead Minnows

Juvenile sheepshead minnows Cyprinodon variegatus were exposed to the explosive compounds 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro−1,3,5,7-tetranitro−1,3,5,7-tetrazocine (HMX) and to the TNT transformation products 2-aminodinitrotoluene (2-ADNT) and 2,4-diaminonitrotoluene (2,4-DANT) in five separate water-only experiments. A one-compartment model was used to characterize uptake (k_u) and elimination (k_e) rate constants and to estimate bioconcentration factors (BCFs). The compounds investigated in this study are weakly hydrophobic. Kinetically derived BCFs (9.6, 13.1, 0.5, 1.7, and 0.5 ml g^–1 for TNT, 2-ADNT, 2,4-DANT, RDX, and HMX, respectively) confirmed the expected low bioaccumulative potential of those compounds and the positive relationship between log BCF and log K_ow (1.6, 2.0, 0.8, 0.9, and 0.2 for TNT, 2-ADNT, 2,4-DANT, RDX, and HMX, respectively). The uptake clearance (k_u) was relatively slow for all compounds (7.3, 12.6, 1.3, 0.15, and 0.06 ml g^–1h^–1 for TNT, 2-ADNT, 2,4-DANT, RDX, and HMX, respectively), and overall, it decreased with decreasing compound hydrophobicity. Elimination was extremely fast for the nitroaromatic compounds (0.77, 0.96, and 2.74 h⁻¹ for TNT, 2-ADNT, and 2,4-DANT, respectively), thus resulting in very short biological half-lives (<1 hour), but it was much slower for the cyclonitramines (0.09 h^–1 for RDX and 0.12 h⁻¹ for HMX). Although ADNTs were present in fish exposed to TNT, the parent compound was the dominant compound in tissues during the uptake and elimination exposures. The rates of metabolite formation (0.06 h^–1) and elimination (0.16 h^–1) were much slower than the rate of elimination of the parent compound (0.80 h^–1). Because of the fast elimination rate of TNT and its transformation products and the exceedingly low bioaccumulative potential of RDX and HMX, exposure conditions likely associated with the presence of explosives in aquatic systems are unlikely to pose unacceptable risks to fish.     

Measured exposures by personal monitoring for respirable suspended particles and environmental tobacco smoke of housewives and office workers resident in Bremen, Germany

Objective : Exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) were assessed in Bremen, Germany, as part of a European air quality study. The range and level of personal exposures were assessed for housewives and office workers. Design : Nonsmokers were randomly selected from a representative sample of the population of Bremen. Housewives were recruited into one group primarily for assessment of exposures in the home and office workers, into a second group for assessment of the contribution of the workplace to overall exposure. Methods : A total of 190 subjects collected air samples from areas close to their breathing zone by wearing personal monitors for 24 h. Samples collected were analysed for RSP, ultraviolet-absorbing particulate matter (UVPM), fluorescing particulate matter (FPM), solanesol-related particulate matter (SolPM), nicotine and 3-ethenylpyridine (3-EP). Saliva cotinine levels for all subjects were also established. Results : Overall the levels found were quite low, with the majority of results being below the limit of quantification. Workers both living and working with smokers were exposed to the highest 24-h median quantities of RSP (789 μg) and ETS particles (128 μg) measured by FPM. The highest nicotine levels, based on median 24-h time-weighted average concentrations, were experienced by office workers working with smokers (0.69 μg m⁻³). These workers were also found to have␣the highest median cotinine levels (1.6 ng ml⁻¹). Conclusions: The most highly exposed workers, both living and working with smokers, would potentially inhale over 20 cigarette equivalents (CE) per annum as based on the upper decile levels. Housewives living with smokers could inhale up to 11 CE per annum as based on the upper decile levels. Locations outside the workplace, including the home, contribute most to overall RSP and ETS particle exposure. Consideration should be given to extending the personal monitoring period in cities where levels appear to be quite low. Received: 9 May 1997 / Accepted: 17 October 1997     

Rheological and immunological findings in dockers with vibration-induced white fingers

Summary The aim of the present study was to characterize theological and immunological features involved in the pathogenesis of vibration-induced white fingers (VWF). Plasma viscosity, at two shear rates (580 s^–1 and 1164 s^–1), levels of immunoglobulins (IgG, IgM, IgA), circulating immune complexes, rheumatoid factor, antinuclear antibodies, fibronectin, fibrinogen, hemoglobin and erythrocyte sedimentation rate were analysed in 30 male dockers with VWF and in 30 healthy male referents unexposed for hand-arm vibrations. Decreased plasma viscosity was observed among the men with VWF, although formal significance (P < 0.05) was only obtained at shear rate 580 s^–1. The decrease was mainly seen among smokers. In the study there were no significant differences between the VWF group and the referents with regard to immunoglobulin levels, autoantibodies and other plasma proteins. From the study it is concluded that workers with VWF may have a decreased plasma viscosity. The biological relevance of this observation is uncertain and deserves further study.     

Uptake,metabolism and elimination of cyclohexanone in humans

The metabolism and toxicokinetics of cyclohexanone (CH-one), an important solvent and chemical intermediate, have been studied in volunteers during and after 8-h exposures to CH-one vapour at a concentration of 101, 207 and 406 mg · m^–3. The pulmonary ventilation in these experiments was typically 11 1 · min^–1 and retention in the respiratory tract was 58%. After exposure to CH-one, 207 mg · m^–3, the metabolic yields of cyclohexanol (CH-ol), 1,2- and 1,4-cyclohexanediol (CH-diol) as determined in urine by a gas chromatographic method involving hydrolysis of glucuronide conjugate were 1.0% ±0.3%, 39% ± 5% and 18% ± 2% (n = 8), respectively. Peak excretion of CH-ol was achieved at the end of the exposure period, after which it decayed rapidly. Elimination of 1,2- and 1,4-CH-diol reached maximum values a few hours following exposure, with subsequent elimination half-times of 16 ± 2 and 18 ± 4 h, respectively. Repeated exposure to CH-one vapour (around 200 mg · m^–3) for five consecutive days (8 h/day) resulted in cumulative excretion of CH-diols. The permeation rate of CH-one liquid through the skin was 0.037–0.069 mg · cm^–2 · h^–1 (n = 3), indicating that the contribution of percutaneous absorption to total CH-one occupational intake is of minor importance. CH-diols are recommended as biomarkers of exposure to CH-one.     

Blood Lead Survey of Children,Pregnant Women,Professional Drivers,Street Workers,and Office Workers in Trujillo,Peru

In this pilot study, conducted in summer 2002, the authors measured blood lead levels (BLLs) for 118 subjects in the city of Trujillo, Peru, where leaded gasoline is in the process of being phased out. Subjects included bus drivers, combi (minivan) drivers, street vendors, newspaper vendors, traffic police, taxi drivers, gas station attendants, children living both near and distant from gas stations, pregnant women, and office workers (controls). The highest BLLs were 9.2 μg/dl and 9.3 μg/dl from a child who lived near a gas station and from a traffic policeman, respectively; however, all BLLs were below the U.S. Centers for Disease Control and Prevention's advisory level of concern (10 μg/dl). Office workers (n = 8) and pregnant women (n = 36) had significantly lower BLLs (geometric mean ± standard deviation = 2.1 ± 0.7 μg/dl, p < 0.022; and 2.5 ± 1.1 μg/dl, p < 0.008, respectively) than total traffic-exposed workers (n = 48; 3.2 ± 1.8 μg/dl). BLLs of children living near gas stations (n = 17; 3.7 ± 2.2 μg/dl) were marginally higher (p = 0.07) than for children not living near gas stations (n = 9; 2.9 ± 1.1 μg/dl). The study was limited by small sample size and the fact that the data were based on a convenience sample not fully representative of the cohorts studied. Nevertheless, the authors' findings suggest that leaded gasoline use in Trujillo continues to affect BLLs in traffic-exposed populations.     

Bioconcentration of 5,5′,6 -trichlorobiphenyl and pentachlorophenol in the midge,Chironomus riparius,as measured by a pharmacokinetic model

A two compartment pharmacokinetic model was developed which describes the uptake and elimination of 5,5,6-trichlorobiphenyl (TCB) and pentachlorophenol (PCP) in the midge, Chironomus riparius. C. riparius were exposed to nominal TCB (2 g L^–1) and PCP (9 g L^–1) concentrations during a 16 h static uptake phase. Depuration was determined over approximately 45 h using a flowthrough system without feeding. The uptake clearance (P) was 330±61 ml g^–1 midge h^–1 for TCB and 55±4 ml g^–1 midge h^–1 for PCP, while measured bioconcentration factors (BCF) were 35,900 and 458 for TCB and PCP, respectively. Overall, the clearance-volume-based pharmacokinetic model predicted BCF values that were consistent with published values as well as with BCF values obtained from the octanol-water partition coefficient (K_OW).     

Smoking Bans in the Home and Car: Do Those Who Really Need Them Have Them?

Background. This paper addresses the question of whether individuals who are most in need of household and car smoking bans, such as individuals with children living at home or who have many friends who smoke, are the ones who have them.Method. A representative sample of 6985 California adults ages 18 and older participated in telephone interviews.Results. Overall, 76% of adults report having home smoking bans and 66% have car smoking bans. Being a smoker or African American, not having children in the home, having more friends who smoke, and lower household income were associated with lower prevalence of both home and car smoking bans (P < 0.01). In multivariate analyses, nonsmokers were 7.9 (95% CI = 3.56, 17.31) times more likely to have a home smoking ban when none of their friends were smokers compared to when most of their friends were smokers. Among smokers, there was an interaction between having children at home and the proportion of friends who smoke. Only 27 to 55% of smokers had home smoking bans unless most of their friends were smokers, then the odds of having a ban were 6.1 (95% CI = 2.76, 13.68) times higher for smokers with children (67% with home bans) than for smokers without children at home (25% with home bans).Conclusions. Efforts to increase home and car smoking bans for nonsmokers who have friends who smoke and smokers with children living at home are needed.     

Shared office space and the risk of the common cold

The common cold persists as a major economic and public health problem worldwide. Despite its long-established ubiquity, little is yet certain about the determinants of indoor environment in spreading of the infection, and even less about the role of indoor air quality as a mediator. The effect of sharing an office with one or more colleagues on the risk of the common cold was studied in a modern, mechanically ventilated, 8 story office building in central Helsinki. Data on respiratory infections and the relevant personal and environmental determinants were collected in a self-administered questionnaire (response rate 71.0%). The study population, one person from each office on floors 3 to 8, consisted of 893 workers, 493 males (49.2%) and 454 females (50.8%). In logistic regression analysis the adjusted odds ratio (OR) for more than two episodes of common cold during the past 12 months in subjects with one or more office colleagues vs those working alone was 1.35 (95% CI 1.00–1.82). Among all workers higher risk also emerged for those with young children (OR 1.46, 1.05–2.04) or a history of hay fever (OR 2.07, 1.47–2.92). Females (OR 1.25, 0.95–1.66) and all under 40 years of age (OR 1.15, 0.86–1.55) had non-significantly increased risk, while smokers did not differ essentially from non-smokers (OR 1.05, 0.76–1.42). The results suggest that sharing office space increases the risk of the common cold, although the primary mode of transmission — airborne, direct or indirect contact-remains controversial.     

Soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 concentrations, and leukocyte count in smokers

The leukocyte count and concentrations of_sICAM-1 and_sVCAM-1 in smokers were investigated. The subjects were 96 persons (31 smokers and 65 nonsmokers) hospitalized for a complete health checkup examination. There were no differences between the two groups for background factors (age (nonsmokers, 56.2 ± 9.2 vs smokers, 52.6 ± 11.3)gender ratio (m/f)(nonsmokers, 47/18 vs smokers, 24/7) and drinker ratio (+/-) (nonsmokers, 45/20 vs smokers, 26/5)). For smokers, the average number of cigarettes smoked daily, smoking period(ys) and Brinkman Index were 21.4 ± 10.4, 26.2± 14.5 and 584.2 ± 476.9, respectively. In smokers, total leukocyte count (l μ 1) (6371.0 ± 1303.4 vs 5063.1 ± 1279.1,_p<0.0001), and_sICAM-1 concentration (ng/ml) (202.6 ± 64.0 vs 163.0 ± 60.8,_p<0.01) were higher than those in nonsmokers. No significant difference in the_sVCAM-1 concentration was shown between the two groups. Items showing large correlation coefficients with the number of cigarettes smoked daily were the total leukocyte count (r = 0.45,_p<0.0001) and_sICAM-1 (r = 0.36,_p<0.0001). In smokers,_sICAM-1 showed correlation with the total leukocyte count (r = 0.42,_p<0.05) . We conclude diat the leukocyte count and_sICAM-1 concentration in healthy smokers are higher than those in nonsmokers.