A cross-shift study of lung function, exhaled nitric oxide and inflammatory markers in blood in Norwegian cement production workers

Twenty-Four week Taichi training improves pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus

This study evaluated the effect of 24-week Taichi training and Taichi plus resistance band training on pulmonary diffusion capacity and glycemic control in patients with Type 2 diabetes mellitus (T2DM). Forty-eight patients with T2DM were randomly divided into three groups: Group A-Taichi training: practiced Taichi 60 min/day, 6 days/week for 24 weeks; Group B-Taichi plus resistance band training: practiced 60-min Taichi 4 days/week plus 60-min resistance band training 2 days/week for 24 weeks; and Group C-controls: maintaining their daily lifestyles. Stepwise multiple regression analysis was applied to predict diffusion capacity of the lungs for carbon monoxide (DLCO) by fasting blood glucose, insulin, glycosylated hemoglobin (HbA1c), tumour necrosis factor alpha (TNF-α), von Willebrand Factor (vWF), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), endothelial nitric oxide synthase (eNOS), nitric oxide (NO), endothelin-1 (ET-1), vascular endothelial growth factor, and prostaglandin I-2. Taichi with or without resistance band training significantly improved DLCO, increased insulin sensitivity, eNOS and NO, and reduced fasting blood glucose, insulin, HbA1c, TNF-α, vWF, IL-6, ICAM-1, and ET-1. There was no change in any of these variables in the control group. DLCO was significantly predicted (R2 = 0.82) by insulin sensitivity (standard-β = 0.415, P<0.001), eNOS (standard-β = 0.128, P = 0.017), TNF-α (standard-β = -0.259, P = 0.001), vWF (standard-β = -0.201, P = 0.007), and IL-6 (standard-β = -0.175, P = 0.032) in patients with T2DM. The impact of insulin sensitivity was the most important predictor for the variation of DLCO based on the multiple regression modeling. This study demonstrates that 24-week Taichi training and Taichi plus resistance band training effectively improve pulmonary diffusion capacity and blood glycemic control in patients with T2DM. Variation of DLCO is explained by improved insulin sensitivity and endothelial function, and reduced inflammatory markers, including TNF-α, vWF, and IL-6.

A Cross Sectional Study of Respiratory and Allergy Status in Dairy Workers

INTRODUCTION

Workers on dairy farms face exposures to organic dusts and endotoxin. At the same time, a number of studies of farmers have reported a lower prevalence of asthma in farmworkers compared to persons without farm contact. The "hygiene hypothesis" suggests that early life exposures on farms could be protective against allergic disease and asthma. Such protective relationships are less well studied in adult farm workers.

METHODS

A cross-sectional analysis of respiratory function and allergy status was performed in a sample of dairy farm workers (n = 42) and community controls (n = 40). Measures of respiratory status (spirometry, exhaled nitric oxide FeNO, self-reported symptoms) and levels of total and bovine-specific IgE were compared between the groups.

RESULTS

Prevalence of self-reported asthma and most respiratory symptoms was similar in the two groups, with the exception of increased report of dyspnea among dairy workers. In the dairy workers, level of lung function was not reduced and FeNO was not increased. In unadjusted and adjusted models, dairy work was not associated with reduced lung function or increased airway inflammation. Mean IgE levels did not differ significantly between workers and controls, but elevated bovine-specific IgE was detected only among dairy workers, with an apparent association between elevated bovine IgE and increased FeNO.

CONCLUSION

While dairy workers did not demonstrate increased asthma prevalence compared to controls, sensitization to bovine antigen in several workers appeared to be associated with airway inflammation. Occupational health programs for dairy workers should consider the risk of animal allergy as part of respiratory health protection efforts.

Structural and functional alterations of subjects with cement dust exposure: A longitudinal quantitative computed tomography-based study

Cement dust exposure (CDE) can be a risk factor for pulmonary disease, causing changes in segmental airways and parenchymal lungs. This study investigates longitudinal alterations in quantitative computed tomography (CT)-based metrics due to CDE. We obtained CT-based airway structural and lung functional metrics from CDE subjects with baseline CT and follow-up CT scans performed three years later. From the CT, we extracted wall thickness (WT) and bifurcation angle (θ) at total lung capacity (TLC) and functional residual capacity (FRC), respectively. We also computed air volume (V_air), tissue volume (V_tissue), global lung shape, percentage of emphysema (Emph%), and more. Clinical measures were used to associate with CT-based metrics. Three years after their baseline, the pulmonary function tests of CDE subjects were similar or improved, but there were significant alterations in the CT-based structural and functional metrics. The follow-up CT scans showed changes in θ at most of the central airways; increased WT at the subgroup bronchi; smaller V_air at TLC at all except the right upper and lower lobes; smaller V_tissue at all lobes in TLC and FRC except for the upper lobes in FRC; smaller global lung shape; and greater Emph% at the right upper and lower lobes. CT-based structural and functional variables are more sensitive to the early identification of CDE subjects, while most clinical lung function changes were not noticeable. We speculate that the significant long-term changes in CT are uniquely observed in CDE subjects, different from smoking-induced structural changes.

Physicochemical characterization of particulate matter in a cement production plant

Employees working in cement production plants are exposed to airborne particulate matter (PM) which may lead to lung function impairments and airway symptoms. The PM consists of raw materials, clinker and additives which vary depending on cement blend. The aim of this work was to characterize the thoracic fraction of PM with regard to size, phase composition and mixing state. Both stationary and personal impactors were used to collect size-fractionated samples in a cement production plant in Norway. Stationary samples were measured with aerosol particle counters and collected with a 13-stage cascade impactor, which were stationed at three locations of the cement production plant: at the raw meal mill, clinker conveyor belt and cement mill. Sioutas cascade impactors, and thoracic and respirable dust samplers were used in parallel for personal sampling. Additionally, particles for electron microscopy were collected with the stationary cascade impactor for size-fractionated single particle characterization. Gravimetric measurements and element compositions of the samples from the stationary impactors show that the PM mass is dominated by calcium-rich particles of size >1 μm. The size distribution results of stationary and personal impactors were similar. Characterization of single particles reveals that limestone is the dominating material in the raw meal mill, whereas clinker and limestone dominate at the clinker conveyor belt and at the cement mill. The element composition of clinker PM did not change with particle size. The PM collected on impactor stages with aerodynamic diameter cut-offs below 0.56 μm was dominated by soot and volatile secondary particles at the three locations. The number of ultrafine particles of the cement related compounds was low. Air concentrations of PM in personal respirable and thoracic samples ranged from 0.14-10 mg m^-3 to 0.37-9.5 mg m^-3, respectively. Considerable local variations exist, both in composition and air concentration of the PM.

Quantitative computed tomography imaging-based classification of cement dust-exposed subjects with an artificial neural network technique

BACKGROUND AND OBJECTIVE

Cement dust exposure is likely to affect the structural and functional alterations in segmental airways and parenchymal lungs. This study develops an artificial neural network (ANN) model for identifying cement dust-exposed (CDE) subjects using quantitative computed tomography-based airway structural and functional features.

METHODS

We obtained the airway features in five central and five sub-grouped segmental regions and the lung features in five lobar regions and one total lung region from 311 CDE and 298 non-CDE (NCDE) subjects. The five-fold cross-validation method was adopted to train the following classification models:ANN, support vector machine (SVM), logistic regression (LR), and decision tree (DT). For all the classification models, linear discriminant analysis (LDA) and genetic algorithm (GA) were applied for dimensional reduction and hyperparameterization, respectively. The ANN model without LDA was also optimized by the GA method to observe the effect of the dimensional reduction.

RESULTS

The genetically optimized ANN model without the LDA method was the best in terms of the classification accuracy. The accuracy, sensitivity, and specificity of the GA-ANN model with four layers were greater than those of the other classification models (i.e., ANN, SVM, LR, and DT using LDA and GA methods) in the five-fold cross-validation. The average values of accuracy, sensitivity, and specificity for the five-fold cross-validation were 97.0%, 98.7%, and 98.6%, respectively.

CONCLUSIONS

We demonstrated herein that a quantitative computed tomography-based ANN model could more effectively detect CDE subjects when compared to their counterpart models. By employing the model, the CDE subjects may be identified early for therapeutic intervention.

Environmental and Occupational Short-Term Exposure to Airborne Particles and FEV1 and FVC in Healthy Adults: A Systematic Review and Meta-Analysis

Background: No study has compared the respiratory effects of environmental and occupational particulate exposure in healthy adults. Methods: We estimated, by a systematic review and meta-analysis, the associations between short term exposures to fine particles (PM_2.5 and PM₄) and certain parameters of lung function (FEV₁ and FVC) in healthy adults. Results: In total, 33 and 14 studies were included in the qualitative synthesis and meta-analyses, respectively. In environmental studies, a 10 µg/m³ increase in PM_2.5 was associated with an FEV₁ reduction of 7.63 mL (95% CI: −10.62 to −4.63 mL). In occupational studies, an increase of 10 µg/m³ in PM₄ was associated with an FEV₁ reduction of 0.87 mL (95% CI: −1.36 to −0.37 mL). Similar results were observed with FVC. Conclusions: Both occupational and environmental short-term exposures to fine particles are associated with reductions in FEV₁ and FVC in healthy adults.

A comparative study of chest CT findings regarding the effects of regional dust exposure on patients with COPD living in urban areas and rural areas near cement plants

Background

The clinical and radiological presentation of chronic obstructive pulmonary disease (COPD) is heterogenous depending on the characterized sources of inflammation. This study aimed to evaluate COPD phenotypes associated with specific dust exposure.

Methods

This study was designed to compare the characteristics, clinical outcomes and radiological findings between two prospective COPD cohorts representing two distinguishing regions in the Republic of Korea; COPD in Dusty Area (CODA) and the Korean Obstructive Lung Disease (KOLD) cohort. A total of 733 participants (n = 186 for CODA, and n = 547 for KOLD) were included finally. A multivariate analysis to compare lung function and computed tomography (CT) measurements of both cohort studies after adjusting for age, sex, education, body mass index, smoking status, and pack-year, Charlson comorbidity index, and frequency of exacerbation were performed by entering the level of FEV1(%), biomass exposure and COPD medication into the model in stepwise.

Results

The mean wall area (MWA, %) became significantly lower in COPD patients in KOLD from urban and metropolitan area than those in CODA cohort from cement dust area (mean ± standard deviation [SD]; 70.2 ± 1.21% in CODA vs. 66.8 ± 0.88% in KOLD, p = 0.028) after including FEV1 in the model. COPD subjects in KOLD cohort had higher CT-emphysema index (EI, 6.07 ± 3.06 in CODA vs. 20.0 ± 2.21 in KOLD, p < 0.001, respectively). The difference in the EI (%) was consistently significant even after further adjustment of FEV1 (6.12 ± 2.88% in CODA vs. 17.3 ± 2.10% in KOLD, p = 0.002, respectively). However, there was no difference in the ratio of mean lung density (MLD) between the two cohorts (p = 0.077). Additional adjustment for biomass parameters and medication for COPD did not alter the statistical significance after entering into the analysis with COPD medication.

Conclusions

Higher MWA and lower EI were observed in COPD patients from the region with dust exposure. These results suggest that the imaging phenotype of COPD is influenced by specific environmental exposure.

Quantitative CT-based structural alterations of segmental airways in cement dust-exposed subjects

Background

Dust exposure has been reported as a risk factor of pulmonary disease, leading to alterations of segmental airways and parenchymal lungs. This study aims to investigate alterations of quantitative computed tomography (QCT)-based airway structural and functional metrics due to cement-dust exposure.

Methods

To reduce confounding factors, subjects with normal spirometry without fibrosis, asthma and pneumonia histories were only selected, and a propensity score matching was applied to match age, sex, height, smoking status, and pack-years. Thus, from a larger data set (N = 609), only 41 cement dust-exposed subjects were compared with 164 non-cement dust-exposed subjects. QCT imaging metrics of airway hydraulic diameter (D_h), wall thickness (WT), and bifurcation angle (θ) were extracted at total lung capacity (TLC) and functional residual capacity (FRC), along with their deformation ratios between TLC and FRC.

Results

In TLC scan, dust-exposed subjects showed a decrease of D_h (airway narrowing) especially at lower-lobes (p < 0.05), an increase of WT (wall thickening) at all segmental airways (p < 0.05), and an alteration of θ at most of the central airways (p < 0.001) compared with non-dust-exposed subjects. Furthermore, dust-exposed subjects had smaller deformation ratios of WT at the segmental airways (p < 0.05) and θ at the right main bronchi and left main bronchi (p < 0.01), indicating airway stiffness.

Conclusions

Dust-exposed subjects with normal spirometry demonstrated airway narrowing at lower-lobes, wall thickening at all segmental airways, a different bifurcation angle at central airways, and a loss of airway wall elasticity at lower-lobes. The airway structural alterations may indicate different airway pathophysiology due to cement dusts.

Dietary patterns in relation to inflammation in shift workers

INTRODUCTION

Rotational shift work has a considerable effect on immune function and cause inflammation. In addition, it may lead to unhealthy dietary intake. No earlier study has examined the association between dietary patterns and inflammation in rotational shift workers. Therefore, this study was conducted to investigate the association between dietary patterns and circulating proinflammatory cytokines among shift workers.

METHODS

This cross-sectional study was conducted among 257 male shift workers. Dietary intake of participants was examined using the semiquantitative Food Frequency Questionnaire. Serum concentrations of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and high sensitivity C-reactive protein (hs-CRP) were measured using suitable commercial kits.

RESULTS

Three main dietary patterns included green vegetables, yellow vegetables and cruciferous vegetables (VEG), liquid oils and mayonnaise, fast food and eggs (LFE), as well as tea and coffee, refined grains and spice (TRS). Subjects with the highest adherence to VEG dietary pattern had a significantly lower concentration of IL-6 (p<0.01) and TNF-α (p<0.001) as compared with those with the lowest adherence. On the other hand, a significant negative association was found between LFE dietary pattern and serum concentrations of IL-6 (p=0.01) and TNF-α (p=0.02). However, no significant association was found between adherence to VEG (p=0.34) or LFE (p=0.99) dietary patterns and levels of hs-CRP and between adherence to TRS dietary pattern and any of the inflammatory cytokines.

CONCLUSION

Adherence to VEG and LFE dietary patterns was inversely and directly associated to serum IL-6 and TNF-α concentrations in shift workers, respectively. However, no significant association was found between adherence to these two dietary patterns and serum hs-CRP concentrations and between TRS dietary pattern and any of the inflammatory cytokines.

Dust Exposure, Fractional Exhaled Nitric Oxide and Respiratory Symptoms among Volcanic Rock Miners in Kilimanjaro, Tanzania

Volcanic rock for use as building material is mined extensively in the North Eastern Region of Tanzania. Dust emitted from the rock may contain harmful elements such as crystalline silica, arsenic (As), cobalt (Co), boron (B) and mercury (Hg) which might contribute to severity and onset of health symptoms.

Association between exposure in the cement production industry and non-malignant respiratory effects: a systematic review

OBJECTIVES

Based on findings from a systematic literature search, we present and discuss the evidence for an association between exposure to cement dust and non-malignant respiratory effects in cement production workers.

DESIGN AND SETTING

Systematic literature searches (MEDLINE and Embase) were performed. Outcomes were restricted to respiratory symptoms, lung function indices, asthma, chronic bronchitis, chronic obstructive pulmonary disease, pneumoconiosis, induced sputum or fraction of exhaled nitric oxide (FeNO) measurements.

PARTICIPANTS

The studies included exposed cement production workers and non-exposed or low-exposed referents.

PRIMARY AND SECONDARY OUTCOMES

The searches yielded 594 references, and 26 articles were included. Cross-sectional studies show reduced lung function levels at or above 4.5 mg/m³ of total dust and 2.2 mg/m³ of respiratory dust. ORs for symptoms ranged from 1.2 to 4.8, while FEV₁/FVC was 1-6% lower in exposed than in controls. Cohort studies reported a high yearly decline in FEV₁/FVC ranging from 0.8% to 1.7% for exposed workers. 1 longitudinal study reported airflow limitation at levels of exposure comparable to ∼1 mg/m³ respirable and 3.7-5.4 mg/m³ total dust. A dose-response relationship between exposure and decline in lung function has only been shown in 1 cohort. 2 studies have detected small increases in FeNO levels during a work shift; 1 study reported signs of airway inflammation in induced sputum, whereas another did not detect an increase in hospitalisation rates.

CONCLUSIONS

Lack of power, adjustment for possible confounders and other methodological issues are limitations of many of the included studies. Hence, no firm conclusions can be drawn. There are few longitudinal data, but recent studies report a dose-response relationship between cement production dust exposure and declining lung function indicating a causal relationship, and underlining the need to reduce exposure among workers in this industry.

Military small arms fire in association with acute decrements in lung function

OBJECTIVE

After introduction of unleaded ammunition, Norwegian Armed Forces received reports of acute respiratory symptoms in soldiers after exposure to fumes from firing the standard weapon, HK416. The aim of the present study was to examine lung function before and after exposure to fumes from HK416 in a double-blinded standardised study design using three different types of ammunition.

METHODS

Fifty-four healthy, non-smoking male volunteers (19-62 years) fired the weapons for 60 min with either leaded, unleaded or 'modified' unleaded ammunition. Gaseous and particulate emissions were monitored. Spirometry and exhaled nitric oxide (eNO) were performed within 14 days before (T0), shortly after (T1) and 24 hours after (T2) shooting. Methacholine provocation and diffusing capacity of carbon monoxide (DLCO) were carried out at T0 and T2.

RESULTS

The mean forced expiratory volume in 1 s on a group level was significantly reduced both at T1 and T2 compared with T0, with means and 95% CI of 226 mL (158 to 294 mL) and 285 mL (218 to 351 mL), respectively. The same significant pattern was seen for DLCO, forced vital capacity and eNO. The methacholine test indicated a slight increase in bronchial hyper-reactivity. However, there were no significant differences between types of ammunition used.

CONCLUSION

Exposure to fumes from military weapons might be a respiratory hazard for soldiers who do live-fire training regularly or are in a closed combat environment.

Lung function and dust in climbing halls: two pilot studies

In climbing halls, high levels of dust are found because magnesia powder is used to dry hands. Concerns have been raised about possible health effects after reports from asthmatics experiencing worsening of symptoms while or after climbing. We investigated acute and sub-acute effects of climbing in dusty halls on lung function in two pilot studies. The first study examined 109 climbers before and after a climbing activity that lasted at least 1 h. In the second study, 25 climbers from different age classes participated in a 2-day climbing competition. Of these, 24 agreed to take part in our investigation, but only 22 provided valid lung function tests on both days. The climbers underwent lung function tests before the first round of the competition (in the morning), after the second round approximately 3 h later and in the morning of the second day before the competition started again. In the first study, we found acute effects, a decline in lung function immediately after the exposure, likely due to protective reflexes of the bronchial muscles and stronger declines in persons with higher exhaled nitric oxide (NO) pre-climbing. In the second study, we also expected sub-acute effects on the next day due to inflammation. On the first day of the competition (second study), dust levels at a central monitor increased over time in a linear manner. Most of the dust was in the size range between 2.5 and 10 μm and dust levels of particulate matter (PM10) reached 0.5 mg/m3. There was a decline in lung function over 24 h in persons with higher exhaled NO levels pre-exposure. All spirometric parameters were affected though the effects were not statistically significant in all cases. Younger age classes started earlier in the morning. Because of the increasing trend in dust levels we expected stronger effects with higher numbers but for the acute effects the reverse was true, possibly because younger climbers use magnesia more or with less experience thus causing higher individual exposure. No differences by age or by time of the first climb were observed for the 24-h lung function change.

Multi-element analysis of airborne particulate matter from different work tasks during subsea tunnel rehabilitation work

Tunnel rehabilitation work involves exposure to various air contaminants, including airborne particulate matter (APM). Little is known on the contents of different chemical components of APM generated during tunnel work. The objective of the present study was to characterize exposure to APM and various elements for different job categories in different size fractions of APM during a subsea tunnel rehabilitation project carried out in Western Norway. Personal as well as stationary samples of inhalable, thoracic and respirable dust were collected from workers divided into 11 different job categories based on work operations performed, and air concentrations of a range of elements were determined using high-resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). Overall, APM concentrations were low, but with some measurements exceeding the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for inhalable particles, and considerable proportions of respirable and especially inhalable APM exceeding 10% of the TLVs. For most elements, air concentrations measured were quite low, in the ng/m(3) range, except for the major crustal elements Si, Fe, Al, and Mg, which were found to be in the µg/m(3) range. Asphalt millers overall had the highest exposure levels for APM and most measured elements; for instance, mean concentrations of V, Rb, and Mn were 380, 210, and 2000 ng/m(3) in inhalable and 33, 44, and 310 ng/m(3) in respirable APM. Mounting PVC membrane seemed to generate elevated levels of Cr, Zn, Sn, Pb, Sb, As, Mn, Fe, and Ni, whereas typical bedrock elements were elevated during drilling activities compared to the low exposed categories lead car drivers, foremen/surveyors, drivers of heavy-duty vehicles, and electricians. Overall, stationary samples contained lower amounts of dust and elemental constituents compared to personal samples. Elemental air concentrations were highly variable with occasional elevated values for APM and certain elements, particularly Cr and Zn.

Airway inflammation and ammonia exposure among female Palestinian hairdressers: a cross-sectional study

OBJECTIVES

Little is known about the working conditions and airway inflammation in hairdressers in Palestine. We aimed to investigate if hairdressers in Palestine have a higher level of airway inflammation as compared to a control group. We also assessed the hairdressers' physical working conditions and exposure to ammonia gases at the hair salons. Lastly, we investigated the association between ammonia levels and inflammation markers in the airways and the blood.

METHODS

Our study participants were 33 non-smoking hairdressers (aged 19-50 years) and 35 non-smoking control subjects (aged 18-49 years). Both groups answered a questionnaire on respiratory symptoms, and performed lung function and exhaled nitric oxide (eNO) tests. Blood and sputum samples were collected from all participants and air concentration levels of ammonia were measured in 13 salons.

RESULTS

Hairdressers had a higher level of sputum neutrophil count (absolute numbers/mg sputum (median (25th-75th centiles)) compared to controls, 376 (183-980) and 182 (96-358), respectively. Hairdressers also had significantly elevated eNO and blood C reactive protein (CRP) levels compared to the control subjects, controlled for age and body mass index. Exposure measurements showed that the hairdressers in salons with scarce ventilation were exposed to ammonia concentration, ranging from 3 to 61 mg/m(3).

CONCLUSIONS

Compared to unexposed controls, the hairdressers had signs of neutrophilic airway inflammation, higher eNO levels and higher CRP. The hairdressers were exposed to high concentrations of ammonia from hairdressing chemicals and their working conditions were unsatisfactory.

Exposure to thoracic aerosol in a prospective lung function study of cement production workers

INTRODUCTION

An exposure study was conducted as part of a multi-national longitudinal study of lung function in cement production workers.

AIM

To examine exposure to thoracic aerosol among cement production workers during a 4-year follow-up period.

METHODS

Personal shift measurements of thoracic aerosol were conducted among the cement production workers within seven job types, 22 plants, and eight European countries (including Turkey) in 2007, 2009, and 2011. The thoracic sub-fraction was chosen as the most relevant aerosol fraction related to obstructive dynamic lung function changes. Production factors, job type, and respirator use were recorded by questionnaire. The exposure data were log-transformed before mixed models analysis and results were presented by geometric mean (GMadj) exposure levels adjusted for plant or job type, worker, and season as random effects.

RESULTS

A total of 6111 thoracic aerosol samples were collected from 2534 workers. Repeated measurements were obtained from 1690 of these workers. The GMadj thoracic aerosol levels varied between job types from 0.20 to 1.2mg m(-3). The highest exposure levels were observed for production, cleaning, and maintenance workers (0.79-1.2mg m(-3)) and could reach levels where the risk of lung function loss may be increased. The lowest levels were found for administrative personnel (0.20mg m(-3)) serving tasks in the production areas. Office work was not monitored. GMadj exposure levels between plants ranged from 0.19 to 2.0mg m(-3). The time of year/season contributed significantly to the total variance, but not year of sampling. Production characteristics explained 63% of the variance explained by plant. Workers in plants with the highest number of employees (212-483 per plant) were exposed at a level more than twice as high as those in plants with fewer employees. Other production factors such as cement production, bag filling, and tidiness were significant, but explained less of the exposure variability. These determinants factors can be useful in qualitative exposure assessment and exposure prevention in the cement production industry. Respirator use was minor at exposure levels <0.5mg m(-3) but more common at higher levels.

CONCLUSION

Production, cleaning, and maintenance work were the job types with highest exposure to thoracic aerosol in cement production plants. However, plant had an even larger effect on exposure levels than job type. The number of employees was the most important factor explaining differences between plants. Exposure reached levels where the risk of lung function loss may be increased. No significant differences in exposure between sampling campaigns were observed during the 4-year study period.

The impact of reduced dust exposure on respiratory health among cement workers: an ecological study

OBJECTIVES

To compare total dust exposure, prevalence of chronic respiratory symptoms, lung function, and chronic obstructive pulmonary disease (COPD) among Tanzanian cement workers before (2002) and after (2010-2011) establishment of dust-control measures.

METHODS

Personal total dust-exposure measurements, questionnaire assessment for chronic respiratory symptoms, and spirometry were conducted in both examination periods.

RESULTS

Total dust exposure was lower in 2010-2011 than in 2002. The prevalence of most chronic respiratory symptoms and COPD was lower in 2010 than in 2002. Forced expiratory volume in 1 second (FEV1), percentage predicted FEV1, and percentage predicted forced vital capacity were higher among cement workers in 2010 than in 2002.

CONCLUSIONS

There was reduced total dust exposure level, lower prevalence of chronic respiratory symptoms and COPD, and higher lung function among cement workers in 2010 than in 2002.

Fractional exhaled nitric oxide among cement factory workers: a cross sectional study

BACKGROUND

It has been suggested that dust exposure causes airway inflammation among cement factory workers. However, there is limited information on the mechanisms of this effect. We explored any associations between total dust exposure and fractional exhaled nitric oxide (FENO) as a marker of airway eosinophilic inflammation among cement production workers in Tanzania. We also examined possible differences in FENO concentration between workers in different parts of the production line.

METHODOLOGY

We examined 127 cement workers and 28 controls from a mineral water factory. An electrochemistry-based NIOX MINO device was used to examine FENO concentration. Personal total dust was collected from the breathing zone of the study participants using 37 mm cellulose acetate filters placed in three-piece plastic cassettes. Interviews on workers' background information were conducted in the Swahili language.

RESULTS

We found equal concentrations of FENO among exposed workers and controls (geometric mean (GM)=16 ppb). The GM for total dust among the exposed workers and controls was 5.0 and 0.6 mg/m(3), respectively. The FENO concentrations did not differ between the exposed workers with high (GM≥5 mg/m(3)) and low (GM<5 mg/m(3)) total dust exposure. There was no significant difference in FENO concentration between workers in the two main stages of the cement production process.

CONCLUSIONS

We did not find any difference in FENO concentration between dust-exposed cement workers and controls, and there were similar FENO concentrations among workers in the two main stages of cement production.

Plasma and exhaled breath condensate nitrite-nitrate level in relation to environmental exposures in adults in the EGEA study

This study evaluated the associations between biological markers in the nitrate-nitrite-NO pathway and four environmental exposures among subjects examined in the second survey (2003-2007) of the French Epidemiological study on Genetics and Environment of Asthma (EGEA). Total nitrite and nitrate (NO(2)(-) /NO(3)(-)) levels were measured both in plasma and in exhaled breath condensate (EBC) in 949 adults. Smoking, diet and exposure to chlorine products were assessed using standardized questionnaires. Exposure to air pollutants was estimated by using geostatistical models. All estimates were obtained with generalized estimating equations for linear regression models. Median levels of NO(2)(-)/NO(3)(-) were 36.3 μM (1st-3rd quartile: 25.7, 51.1) in plasma and 2.0 μmol/mg proteins (1st-3rd quartile 0.9, 3.9) in EBC. After adjustment for asthma, age, sex and menopausal status, plasma NO(2)(-)/NO(3)(-) level increased with leafy vegetable consumption (above versus below median=0.04 (95%CI: 0.001, 0.07)) and decreased in smokers (versus non/ex-smokers=-0.08 (95%CI: -0.11, -0.04). EBC NO(2)(-)/NO(3)(-) level decreased in smokers (-0.08 (95%CI: -0.16, -0.001)) and with exposure to ambient O(3) concentration (above versus below median=-0.10 (95%CI: -0.17, -0.03)). Cured meat, chlorine products, PM(10) and NO(2) concentrations were not associated with NO(2)(-)/NO(3)(-) levels. Results suggest that potential modifiable environmental and behavioral risk factors may modify NO(2)(-)/NO(3)(-) levels in plasma and EBC according to the route of exposure.