Respiratory symptoms and lung function in taxi drivers and manual workers

The aim of this study, was to determine the prevalence of some respiratory symptoms and possible diseases among taxi drivers and manual workers. This prospective study was performed on 165 Pakistani male drivers, (mean age: 34.5±7.8 years) and 165 Pakistani male manual workers not exposed to dust or fumes, without occupational exposure to driving employed in the Water and Electricity Department and recruited as controls (mean age: 34.6±7.6 years and mean height and weight 169.8±6.0 cm and 71.9±10.9 kg). The data on chronic respiratory symptoms showed that taxi drivers had higher prevalence of symptoms than manual workers, being significantly greater for asthma (RR=1.72; 95% CI=1.00–2.88,P=0.037); allergic rhinitis (RR=2.41; 95% CI=1.46–3.94,P=0.0006); dyspnea (RR=2.13; 95% CI=1.22–3.71,P=0.009); and nasal catarrh (RR=2.19; 95% CI=1.22–3.91,P=0.0106). Thirty percent of taxi drivers and 27% of manual workers were smokers, there was no significant differences in the prevalence of chronic respiratory symptoms between smokers and non-smokers. Lung function parameters in the taxi drivers were significantly lower than in manual workers group (P<0.0001) except PEF parameter. When comparing the measured mean values of lung function parameters in the drivers among smokers and nonsmokers, there was no significant differences between smokers and nonsmokers. Also, a comparison of ventilatory capacity of paired predicted values with measured normal values showed statistically significant differences between predicted and measured values for taxi drivers and manual workers for FVC, FEV₁, FEF_25–75 and PEF parameters except for FEV₁/FVC test in manual workers. In conclusion, the results of the present study provide evidence regarding effects of such as carbon monoxide, nitrogen dioxide, sulfur dioxide and gases exposures on taxi drivers and long-term driving, which may be associated with the development of chronic respiratory symptoms and lung function impairment.     

Pneumoproteins and markers of inflammation and platelet activation in the blood of grain dust exposed workers

Abstract

Purpose: To investigate if blood biomarkers could indicate early signs of lung damage or cardiovascular risk due to exposure to grain dust.

Materials and methods: Pneumoproteins and markers of inflammation and platelet activation were analysed in blood samples of 102 grain elevator and compound feed mill workers. Differences between exposed (n?=?67) and controls (n?=?35), and associations with exposure measurements and respiratory health were investigated by multiple linear regression analyses.

Results: Concentrations of CC-16 and IL-6 were higher in exposed workers compared with controls (p?<?0.001 for both), whereas fibrinogen was lower (p?=?0.005). Concentrations of CRP, TNF-α, sCD40L and sP-selectin were similar in both groups. Serum CC-16 was significantly higher in workers with farm childhood, regardless of exposure. The impact of farm childhood on CC-16 interacted with smoking. None of the biomarkers were associated with exposure measurements or any of the tested respiratory health parameters.

Conclusion: Dust exposure induced inflammatory and anti-inflammatory reactions, but did not induce systemic inflammation and had no effect on platelet activation. No cause–effect relationship could be established in spite of relatively high exposure levels, particularly to endotoxin. Whether increased serum CC-16 is an early sign of lung damage or a reversible defense reaction remains unclear.     

Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices

Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km² along an elevation gradient of 500 m by tag-encoded 454 pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, and geographic and climatic parameters) and biotic (wheat cultivar and previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity values of fungal communities. In addition, elevation and soil CaCO₃ concentrations shaped the alpha diversity, whereas wheat cultivar, cropping history, and the number of freezing days per year shaped the taxonomic beta diversity of these communities.     

Occupational exposure and respiratory health of workers at small scale industries

Certain occupations like welding, painting, and vehicle repairing are associated with regular exposure to dust, exhausts, fuels, fumes, PM, and vapors of welding, solvents, and paint. Many studies have proved a reduction in lung functions due to exposure to these agents. The present study aims to assess and compare respiratory symptoms and pulmonary functions among exposed and non-exposed persons as well as suggests controls respectively. A cross-sectional case study was carried out among small scale industry workers having matched demographic and anthropometric parameters. Medical Research Council (MRC) questionnaire and Micro Direct computerized automated spirometer were used for recording respiratory ailments and pulmonary function tests (PFT) respectively. The percentages of mechanics, welders and painters were 40.9, 31.8, and 27.3 respectively. The highest reported respiratory symptom was chest tightness and whistling among exposed (22.7%) and unexposed (10%). Among study exposed cases, the occupational exposure was found as often (22.7%), sometimes (68.2%) and never (9.1%) while the reported use of airway protection (masks) was very low. Overall respiratory health of the exposed versus controls was reported as excellent (54.5% vs 73.4%), good (27.3% vs 23.3%) and average (18.2% vs 3.3%) respectively. The exposed group on contrary to control one has decreased mean values for FEV1 (3.12 vs 3.50), FVC (4.12 vs 4.43), FEV1/ FVC % (79.60 vs 80.79) and PEF (414.77 vs 523.16). The present study reveals that exposed workers are at increased risk of developing respiratory symptoms and decreased pulmonary functions as compared to unexposed. Such exposure research studies are instrumental in health status evaluation of workers. However, this area has been neglected by the researchers in Saudi Arabia. It is, thus, strongly recommended to carry out prospective studies to substantiate the study results including large sample size, background pollutants concentrations and biological monitoring. Control strategies should be adopted to reduce the vapor concentration in the ambient air, protect and promote respiratory health of workers.     

Field survey of circadian rhythm in PEF of electronics workers suffering from colophony-induced asthma

Twenty-two British electronics workers suffering from occupationally-induced asthma due to their exposure to colophony fumes self-recorded their peak expiratory flow (PEF) every 1-2 hr throughout the waking span for at least two weeks, both during work and vacation periods. Data were analyzed by a two-step procedure using the statistical techniques of Single and Population Mean Cosinor analyses. The objective endpoints of mesor (24-hr mean), amplitude (measure of 24-hr rhythmic variation) and acrophase (peak time along the scale of 24 hr) for the time-spans of the work-week (Monday-Friday), weekend after work (Saturday-Sunday) and vacation weekdays and vacation weekends were compared. The PEF data of four workers who participated in the study for nearly one year also were evaluated for seasonal variation. A statistically significant difference (P less than 0.04) was detected in the PEF amplitude between work and vacation weeks; the difference in the PEF mesor and acrophase between work-weekdays and work-weekends achieved near or statistical significance (P = 0.07 and 0.05, respectively). The at-work amplitude was higher and the acrophase earlier timed. There was no statistically significant difference between work-week and weekend-after-work PEF mesors. Winter PEF mesors were significantly lower than summer ones in the four subjects self-measuring their bronchial patency over the year. Overall, the findings indicate that data obtained through employee surveys, using lightweight portable and inexpensive PEF Wright meters and analyzed by statistical analyses used in the field of biological rhythm research, yield objective evidence of occupationally associated decrements in pulmonary function resulting from colophony fume exposure.     

Effects of extremely low frequency electromagnetic field on the health of workers in automotive industry

Objective. To observe the effects of extremely low frequency electromagnetic fields (ELF-EMFs) in automotive industry on occupational workers. Methods. A total of 704 workers were investigated, and 374 workers were chosen and divided into two groups (control group and exposure group) according to the inclusive criteria, namely male with age 20–40 years old and ≥ 2 years of exposure. The intensities of ELF-EMFs and noise were detected with EFA-300 Field Analyzer (Narda company, Pfullingen, Germany) and AWA5610D integrating sound level meter (Hangzhou Aihua Instruments Co., Ltd, Hangzhou, China), respectively. Survey data were collected by questionnaire, and the physical check-up was done in hospital. All the data were input into SPSS17.0 software (SPSS Inc, Chicago, USA), and the appropriate statistic analyses were carried out. Results. The intensity of EMFs in exposure group was significantly higher than that in control group (p < 0.05), while the noise in two workplaces showed no difference (p>0.05). The survey data collected by questionnaires showed that the symptoms of loss of hair in exposure group were significantly different as compared with that in control group (p < 0.05). The check-up parameters of cardiovascular, liver and hematology system showed significant differences between the two groups (p < 0.05). Conclusions. Survey and check-up data suggest that exposure to ELF-EMFs might have effects on the nervous, cardiovascular, liver, and hematology system of workers.     

Prognostic significance of low serum levels of Clara cell phospholipid-binding protein in occupational aluminium neurotoxicity

The relationship between respiratory and neurological effects of exposure to aluminium (Al) was investigated in a group of foundry workers exposed to Al at concentrations below the threshold limit value (TLV) binding in Poland (2.0 mg Al2O3 m(-3)). Neurological and neurophysiological parameters indicated subclinical effects of Al exposure on the nervous system. The measurement of serum anti-inflammatory Clara cell protein (CC16) was employed as a peripheral marker of the lung epithelium function. There was a strong inverse relationship between serum Al (Al-S) and CC16 concentrations (p = 0.006). The lowest CC16 concentrations were found in serum of workers characterised by subjective symptoms of the central nervous system (CNS) and abnormal results of neurophysiological examinations (EEG and VEP). Low serum CC16 concentrations and enhanced Al and iron (Fe) levels were also observed in the younger age group of workers with the subjective CNS symptoms and abnormal VEP results, which suggests that Fe is implicated in strengthening of the neurotoxic Al potential. The results of our study support the hypothesis that subclinical neurological symptoms (especially abnormal VEP) are most likely associated with internalisation of Al ions with lipid fractions of the lung epithelium, which in turn may help Al ions overcome the blood-brain barrier. Low serum CC16 concentrations (<10 microg L(-1)) were noted in workers with the abnormal results of neurological (CNS) and neurophysiological (EEG and VEP) examinations as well as with Al body burden manifested by urinary excretion (Al-U) below 60 microg L(-1) and Al-S concentration of 2 microg L(-1). This concentration may be considered as a threshold allowable biological concentration of aluminium.     

Impact of the Spanish Smoking Law on Exposure to Second-Hand Smoke and Respiratory Health in Hospitality Workers: A Cohort Study

Background

A smoke-free law came into effect in Spain on 1st January 2006, affecting all enclosed workplaces except hospitality venues, whose proprietors can choose among totally a smoke-free policy, a partial restriction with designated smoking areas, or no restriction on smoking on the premises. We aimed to evaluate the impact of the law among hospitality workers by assessing second-hand smoke (SHS) exposure and the frequency of respiratory symptoms before and one year after the ban.

Methods and Finding

We formed a baseline cohort of 431 hospitality workers in Spain and 45 workers in Portugal and Andorra. Of them, 318 (66.8%) were successfully followed up 12 months after the ban, and 137 nonsmokers were included in this analysis. We obtained self-reported exposure to SHS and the presence of respiratory symptoms, and collected saliva samples for cotinine measurement. Salivary cotinine decreased by 55.6% after the ban among nonsmoker workers in venues where smoking was totally prohibited (from median of 1.6 ng/ml before to 0.5 ng/ml, p<0.01). Cotinine concentration decreased by 27.6% (p = 0.068) among workers in venues with designated smoking areas, and by 10.7% (p = 0.475) among workers in venues where smoking was allowed. In Portugal and Andorra, no differences between cotinine concentration were found before (1.2 ng/ml) and after the ban (1.2 ng/ml). In Spain, reported respiratory symptom declined significantly (by 71.9%; p<0.05) among workers in venues that became smoke-free. After adjustment for potential confounders, salivary cotinine and respiratory symptoms decreased significantly among workers in Spanish hospitality venues where smoking was totally banned.

Conclusions

Among nonsmoker hospitality workers in bars and restaurants where smoking was allowed, exposure to SHS after the ban remained similar to pre-law levels. The partial restrictions on smoking in Spanish hospitality venues do not sufficiently protect hospitality workers against SHS or its consequences for respiratory health.     

Increased levels of urinary biomarkers of lipid peroxidation products among workers occupationally exposed to diesel engine exhaust

Diesel engine exhaust (DEE) was found to induce lipid peroxidation (LPO) in animal exposure studies. LPO is a class of oxidative stress and can be reflected by detecting the levels of its production, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and etheno-DNA adducts including 1,N⁶-etheno-2′-deoxyadenosine (?dA) and 3,N⁴-etheno-2′-deoxycytidine (?dC). However, the impact of DEE exposure on LPO has not been explored in humans. In this study, we evaluated urinary MDA, 4-HNE, ?dA, and ?dC levels as biomarkers of LPO among 108 workers with exclusive exposure to DEE and 109 non-DEE-exposed workers. Results showed that increased levels of urinary MDA and ?dA were observed in subjects occupationally exposed to DEE before and after age, body mass index (BMI), smoking status, and alcohol use were adjusted (all p?p?p?相似文献   

Determination of isocyanate biomarkers in construction site workers

4,4′-Methylenediphenyl diisocyanate (MDI) is the most important isocyanate in the manufacture of polyurethanes, dyes, pigments and adhesives. High concentrations of isocyanates are a potent respiratory irritant. Therefore, it is important to develop methods to monitor exposure to such compounds. We monitored biological samples from 40 non-exposed and 45 exposed construction site workers. 4,4′-Methylenedianiline (MDA) and N-acetyl-4,4′-MDA (AcMDA) were determined from untreated urine (U-MDA, U-AcMDA) and MDA was analysed from acid-treated urine (U-MDA-tot). Haemoglobin (Hb) adducts of MDA (Hb-MDA) were determined in all workers. The levels of biomarkers decreased in the following order: U-MDA-tot>U-AcMDA>U-MDA>Hb-MDA. The same order was found for the percentage of samples, which were found positive in exposed workers: 100%, 91%, 91%, 27%. The urine levels U-MDA-tot correlate with U-MDA, U-AcMDA and Hb-MDA with r=0.79, 0.86 and 0.39, respectively (Spearman rank order, p<0.01). U-AcMDA correlates with U-MDA and Hb-MDA with r=0.77 and 0.47, respectively (p<0.01). U-MDA correlates with Hb-MDA (r=0.38, p<0.05). The levels in the controls were significantly lower than in the exposed workers for all compounds (Mann–Whitney test, p<0.01). The median isocyanate-specific IgE-level was higher in the exposed workers, but the difference was statistically not significant. The change of the biomarker levels was compared in a group of workers (n=20), which were analysed prior to isocyanate exposure and after the exposure for ～4–7 months. All urine MDA metabolites and the Hb-adduct levels increased significantly (Wilcoxon sign test, p<0.01). Total IgE increased significantly after the exposure with isocyanate activity (p<0.01). With the present work it could be shown that outdoor workers are exposed to a similar extent as workers from a MDI factory.     

A mite survey in the dumpsters for urban solid rubbish

Summary The presence of house dust mites and storage mites in dumpsters was investigated in 3 different areas of Venice hinterland. The aim of this study was to find a relationship between some reported respiratory symptoms among 6 workers who were responsible for moving the dumpsters to the truck and the bio-aerosol released from such operation. These symptoms were closely related to the work and after allergological evaluation we found sensitisation to house dust mites in all 6 employees. The mine exposure in the workplace was assessed by a standardized sampling and analysis of dust obtained after brushing the inside surfaces of dumpsters. In 50% of the specimens (10/20) we found mites belonging to the following families: Pyroglyphidae (Dermatophagoides spp.), Acaridae (Acarus siro) and a lower amount of Cheyletidae (Cheyletus spp.). An indirect test (guanine test) was also performed and gave positivity in 16 dust samples (80%). The insides of dumpsters showed to be an optimal environment for mites survival and reproduction because of cracks and grooves on the walls, the high humidity level and the presence of mould. These mites probably come from dwelling places and other environments (markets, slaughters-houses, farms, etc.). This suggests that mites allergens can be released during rubbish discharging from the dumpsters and represent a possible risk for the employees.     

Airborne Fungi in a Bakery and the Prevalence of Respiratory Dysfunction among Workers

Concentrations of fungi in different sections of a bakery in Delhi were studied for two years (May 1989–April 1991). Andersen Volumetric and Burkard Personal Slide samplers, were used to collect samples at 10 day intervals. Aspergilli/penicillia, smuts and Cladosporium spp. predominated, contributing about 90% of the total fungi. Aspergillus flavus was characteristic in the storage section and Aspergillus niger in the packing section. In general, concentrations inside the bakery were higher than in the outdoor air. Aspergillus flavus, Aspergillus niger, Alternaria spp. and ustilaginales were predominant in the summer months, whereas Cladosporium spp., Penicillium citrinum and Penicillium chrysogenum were prevalent in winter. The seasonal differences observed in the first year were seen again in the second year. A survey of the prevalence of respiratory dysfunction among the bakery workers (n=279) revealed that 40.1% of the workers were suffering from respiratory disorders and 8.2% had a family history of respiratory disorders. The prevalence of various symptoms was: cough with phlegm, 37.5%; cough without phlegm, 16.1%; breathlessness/wheeze, 34.7%; rhinitis, 53.6%; conjunctivitis, 20.5%; eczema, 16.1%. Age, period of association with the job and smoking habits significantly influence the incidence of breathlessness, rhinitis and cough (p<0.05). Thirtynine individuals reported their symptoms to be work related, of which 35 reported aggravation of symptoms during work hours.     

Incidence of anaphylaxis in the emergency department of a general hospital in Milan

Objective: To evaluate incidence and causes of anaphylactic reactions in the emergency room (E.R.) of a general hospital in Milan during a 2-year period. Methods: We retrospectively studied the computerized records of patients discharged from an E.R. with a diagnosis of anaphylactic reaction. Anaphylaxis was established on the presence of at least two cutaneous, respiratory, gastrointestinal or cardiovascular system symptoms. Results: During 1997 and 1998, out of 38 685 patients referred to the E.R., 13 had severe anaphylaxis with loss of consciousness (LOC) and 127 had anaphylactic symptoms, without LOC. Of the 13 patients with LOC, a possible cause was identified in 12 (five foods, six drugs, one hair dye). In the other 127 patients anaphylaxis was related to foods in 49 cases (38.5%), drugs in 44 (34.6%), unknown causes in 29 (22.8%), hymenoptera stings in two (1.5%), and other causes in three (2.3%). Conclusion: The incidence of anaphylactic reactions was 0.4% and mainly affected females and atopic subjects. Foods, particularly fruits and vegetables, appeared to be the most important cause; other important causes were non steroidal antiinflammatory drugs and β-lactam antibiotics.     

Clearance of technetium-99m-DTPA and HRCT findings in the evaluation of patients with Idiopathic Pulmonary Fibrosis

Background

Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF) results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients.

Methods

We studied 36 subjects (PEF range 80–570 l/min). All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique) or a forced maximal expiration to residual volume (FVC technique). Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer.

Results

The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p < 0.0001). The mean PEF recorded with the turbine spirometer was 5.5% lower than the Wright meter reading. The Fleisch spirometer result was 19.5% lower than the Wright reading. However, adjustment of the Wrights measurements from the traditional Wright's scale to the new EU Peak Flow scale produced results that were only 7.2% higher than the Fleisch pneumotachograph measurements.

Conclusion

Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.     

Bartonella henselae in eastern Poland: the relationship between tick infection rates and the serological response of individuals occupationally exposed to tick bites

To explore the potential role of Ixodes ricinus as the presumed vector of Bartonella henselae in eastern Poland, ticks collected in various geographic locations were examined for the presence of B. henselae, and the results were matched against the prevalence of anti‐B. henselae antibodies in individuals occupationally exposed to tick bites. The presence of Bartonella DNA was investigated by PCR in a total of 1,603 unfed Ixodes ricinus ticks. The presence of IgG antibodies against B. henselae was investigated in serum samples from 332 people occupationally exposed to tick bites (94 farmers and 238 forestry workers). The total prevalence of B. henselae in ticks was 1.7%; the infection rates in males (3.1%) and females (2.7%) were nearly ten times greater than in nymphs (0.3%). The prevalence of seropositive results in the risk group (30.4%), farmers (27.7%) and forestry workers (31.5%), was significantly greater compared to the control group (8.9%). The results showed a weak positive correlation between the degree of infection of ticks and humans living in the same geographic region. The lack of a direct relationship indicates that exposure to tick bites is only one of the factors contributing to the significant preponderance of a seropositive response to B. henselae in the forestry workers and farmers over the control group. Other factors must be considered, such as contact with cats, which are popular domestic animals in Polish villages, and exposure to cat fleas.     

The influence of visual display terminal use on the physical and mental conditions of administrative staff in Japan

Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.     

Psychosocial Work Characteristics Predicting Daytime Sleepiness in Day and Shift Workers

Characteristics of work organization other than working time arrangements may contribute importantly to daytime sleepiness. The present study was designed to identify the psychosocial factors at work that predict daytime sleepiness in a sample of day and shift workers. Participants working at a pulp and chemical factory completed an annual questionnaire regarding psychosocial factors at work using the U.S. National Institute for Occupational Safety and Health Generic Job Stress Questionnaire (i.e., quantitative workload, variance in workload, job control, support from supervisor, coworkers, or family/friends, job satisfaction, and depressive symptoms), as well as daytime sleepiness (through the Epworth Sleepiness Scale [ESS]) and sleep disturbances for three years starting in 2002 (response rates, 94.6–99.0%). The present analysis included 55 day workers (11 women) and 57 shift workers (all men) who participated in all three years of the study, worked under the same work schedule throughout the study period, and had no missing data on any of the daytime sleep items. A repeated‐measures analysis of covariance (ANCOVA) was used to test the effects of work schedule (day vs. shift work) and psychosocial factors at work in 2002 on the ESS scores in subsequent years, with sleep duration, insomnia symptoms, chronic diseases, and sleepiness levels at baseline as covariates. Given significant and near‐significant interactions of work schedules with psychosocial factor or study year, the ANCOVA, with the factors of psychosocial work characteristics and study year, was performed by type of work schedule. The results indicated a significant main effect of psychosocial work characteristics (p=0.010, partial ?²=0.14) and an almost significant main effect of study year (p=0.067, partial ?²=0.06) and interaction between psychosocial work characteristics and study year (p=0.085, partial ?²=0.06) for variance in workload among the day work group. The day workers reporting high variance in workload in 2002 exhibited significantly higher ESS scores in 2003 and 2004 than did those reporting low variance in workload. The ANCOVA for the shift work group showed a main effect of psychosocial work characteristics for job satisfaction (p=0.026, partial ?²=0.10) and depressive symptoms (p=0.094, partial ?²=0.06) with the interaction between psychosocial work characteristics and study year for job satisfaction (p=0.172, partial ?²=0.04) and depressive symptoms (p=0.035, partial ?²=0.07). The shift workers with low job satisfaction and high symptoms of depression in 2002 showed significantly greater ESS scores in 2003 and/or 2004 than did those with opposite characteristics. These results may suggest a potential predictive value of variance in workload for day workers as well as job satisfaction and depressive symptoms for shift workers with respect to daytime sleepiness. The present findings may imply that redesigning these aspects of work environment would be of help in managing daytime sleepiness.     

Respiratory profiles of grain handlers and sedentary workers.

During 1978, grain handlers employed at three large inland grain terminals were studied along with an equal number of office workers matched for sex, age and smoking history. Respiratory symptoms and spirometric abnormalities were no more frequent in 16 grain handlers who were non-smokers than in their controls. However, 20 grain handlers who were smokers complained significantly more (P less than 0.01) of grade 1 dyspnea and had significantly lower ratios of forced expiratory volume in the first second to forced vital capacity (P less than 0.05) than their controls. Only 3% of the grain handlers were sensitive to grain dust, and 18% were found to be atopic but to have good lung function. A family history of asthma or allergic rhinitis was no more frequent in the grain handlers than in the control subjects. We conclude that the combination of cigarette smoking and exposure to grain dust causes a deterioration in lung function.     

Synergistic Impaired Effect between Smoking and Manganese Dust Exposure on Pulmonary Ventilation Function in Guangxi Manganese-Exposed Workers Healthy Cohort (GXMEWHC)

PurposeThe aims of this study were to investigate the effects of manganese (Mn) dust exposure on lung functions and evaluate the potential synergistic effect between smoking and Mn dust exposure among refinery workers.MethodsA retrospective study including 1658 workers in a ferromanganese refinery was conducted, with subjects who were from the Guangxi manganese-exposed workers healthy cohort (GXMEWHC). Based on the Mn manganese cumulative exposure index (Mn-CEI), all subjects were divided into the low exposure group (n = 682) and the high exposure group (n = 976). A pulmonary function test was performed using an electronic spirometer, including the values and percentages of FVC, FEV₁, FEV₁/FVC, MMEF, PEFR, MVV, respectively.ResultsNo significant effect of Mn dust exposure on the pulmonary function was found in the female workers (all p>0.05). However, there was an obvious decrease in the male workers in the high exposure group compared with those in the low exposure group (FVC -60 ml, FEV₁ -120 ml, MMEF -260 ml/s, MVV -5.06 L, all p<0.05). In the high exposure group, the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively. In particular, among the exposed subjects smokers had a statistically significant decrease in lung function compared with non-smokers and the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively (p<0.05). Partial correlation analysis showed that there was also negative correlation between Mn-CEI and decreased changes in MMEF (r = -0.159, p = 0.018) and also MMEF% predicted (r = -0.163, p = 0.015).ConclusionsMn dust can impair the pulmonary ventilation function of male workers but not females, and individual smoking habits and manganese exposure had a synergistic effect on the lung function decrease.     

Proteomic analysis of plasma proteins of workers exposed to benzene

In this study, we analyzed the proteins in plasma of workers exposed to benzene by two-dimensional gel electrophoresis, in the hope of finding a specific protein suitable for the biomonitoring of benzene exposure. Comet assays were also carried out to evaluate lymphocytes DNA damage. Fifty workers from a printing company and 38 matched unexposed healthy subjects were enrolled in the study. DNA damage was found to be significantly higher in the exposed workers than in the controls. The tail moments of the two groups were 2.07 +/- 0.35 and 1.48 +/- 0.41, respectively (P < 0.0001). The mean values of trans, trans-muconic acid (t,t-MA) in workers exposed to benzene and in unexposed subjects were 1.011 +/- 0.249 and 0.026 +/- 0.028 mg/g creatinine, respectively. Protein profiles were significantly different (P < 0.05) in the two groups, as identified by matrix-assisted laser desorption ionization/time of flight (MALDI-TOF) mass spectrometry and confirmed by Western blot. T cell receptor beta chain (TCR beta), FK506-binding protein (FKBP51) and matrix metalloproteinase-13 (MMP13) were found to be up-regulated in the benzene-exposed workers. In addition, the correlation between TCR beta and the tail moments of lymphocytes was statistically significant (r-value, 0.428). We conclude that TCR beta in plasma could be used for the early detection of exposure to benzene.