Association of respiratory symptoms with body mass index and occupational exposure comparing sexes and subjects with and without asthma: follow-up of a Norwegian population study (the Telemark study)

BACKGROUND

Occupational exposure and increased body mass index (BMI) are associated with respiratory symptoms. This study investigated whether the association of a respiratory burden score with changes in BMI as well as changes in occupational exposure to vapours, gas, dust and fumes (VGDF) varied in subjects with and without asthma and in both sexes over a 5-year period.

METHODS

In a 5-year follow-up of a population-based study, 6350 subjects completed a postal questionnaire in 2013 and 2018. A respiratory burden score based on self-reported respiratory symptoms, BMI and frequency of occupational exposure to VGDF were calculated at both times. The association between change in respiratory burden score and change in BMI or VGDF exposure was assessed using stratified regression models.

RESULTS

Changes in respiratory burden score and BMI were associated with a β-coefficient of 0.05 (95% CI 0.04 to 0.07). This association did not vary significantly by sex, with 0.05 (0.03 to 0.07) for women and 0.06 (0.04 to 0.09) for men. The association was stronger among those with asthma (0.12; 0.06 to 0.18) compared with those without asthma (0.05; 0.03 to 0.06) (p=0.011). The association of change in respiratory burden score with change in VGDF exposure gave a β-coefficient of 0.15 (0.05 to 0.19). This association was somewhat greater for men versus women, with coefficients of 0.18 (0.12 to 0.24) and 0.13 (0.07 to 0.19), respectively (p=0.064). The estimate was similar among subjects with asthma (0.18; -0.02 to 0.38) and those without asthma (0.15; 0.11 to 0.19).

CONCLUSIONS

Increased BMI and exposure to VGDF were associated with increased respiratory burden scores. The change due to increased BMI was not affected by sex, but subjects with asthma had a significantly larger change than those without. Increased frequency of VGDF exposure was associated with increased respiratory burden score but without statistically significant differences with respect to sex or asthma status.

Occupational Asthma: The Knowledge Needs for a Better Management

The management of occupational asthma (OA) may be influenced by several factors and removal from exposure is the main tertiary prevention approach, but it is not always feasible without personal and socioeconomic consequences. Reducing the delay between the onset of suggestive symptoms of OA and the diagnosis of OA is associated with a better prognosis. Workers' education to increase awareness to trigger agents and a medical surveillance program directed especially at at-risk workers could be helpful in reducing this latency time. An early identification of workers who develop rhinitis and conjunctivitis which often precede the onset of asthma symptoms could be important for an early identification of OA. This is particularly important for cases of asthma caused by high-molecular-weight sensitizers and in the early years of employment. The availability of financial support and compensation measures for workers with OA may influence the latency time before diagnosis and, consequently, may influence the OA outcomes. In conclusion, there is a need for high-quality cohort studies that will increase knowledge about risk factor that may influence the timing of diagnosis of OA. This knowledge will be useful for implementation of future surveillance and screening programs in workplaces.

Influence of asthma and obesity on respiratory symptoms, work ability and lung function: findings from a cross-sectional Norwegian population study

Background

Although asthma and obesity are each associated with adverse respiratory outcomes, a possible interaction between them is less studied. This study assessed the extent to which asthma and overweight/obese status were independently associated with respiratory symptoms, lung function, Work Ability Score (WAS) and sick leave; and whether there was an interaction between asthma and body mass index (BMI) ≥25 kg/m² regarding these outcomes.

Methods

In a cross-sectional study, 626 participants with physician-diagnosed asthma and 691 without asthma were examined. All participants completed a questionnaire and performed spirometry. The association of outcome variables with asthma and BMI category were assessed using regression models adjusted for age, sex, smoking status and education.

Results

Asthma was associated with reduced WAS (OR=1.9 (95% CI 1.4 to 2.5)), increased sick leave in the last 12 months (OR=1.4 (95% CI 1.1 to 1.8)) and increased symptom score (OR=7.3 (95% CI 5.5 to 9.7)). Obesity was associated with an increased symptom score (OR=1.7 (95% CI 1.2 to 2.4)). Asthma was associated with reduced prebronchodilator and postbronchodilator forced expiratory volume in 1 s (FEV₁) (β=−6.6 (95% CI −8.2 to −5.1) and −5.2 (95% CI −6.7 to −3.4), respectively) and prebronchodilator forced vital capacity (FVC) (β=−2.3 (95% CI −3.6 to −0.96)). Obesity was associated with reduced prebronchodilator and postbronchodilator FEV₁ (β=−2.9 (95% CI −5.1 to −0.7) and −2.8 (95% CI −4.9 to −0.7), respectively) and FVC (−5.2 (95% CI −7.0 to −3.4) and −4.2 (95% CI −6.1 to −2.3), respectively). The only significant interaction was between asthma and overweight status for prebronchodilator FVC (β=−3.6 (95% CI −6.6 to −0.6)).

Conclusions

Asthma and obesity had independent associations with increased symptom scores, reduced prebronchodilator and postbronchodilator FEV₁ and reduced prebronchodilator FVC. Reduced WAS and higher odds of sick leave in the last 12 months were associated with asthma, but not with increased BMI. Besides a possible association with reduced FVC, we found no interactions between asthma and increased BMI.

Possible risk factors for poor asthma control assessed in a cross-sectional population-based study from Telemark, Norway

This cross-sectional study of the general population of Telemark County, Norway, aimed to identify risk factors associated with poor asthma control as defined by the Asthma Control Test (ACT), and to determine the proportions of patients with poorly controlled asthma who had undergone spirometry, used asthma medication, or been examined by a pulmonary physician. In 2014–2015, the study recruited 326 subjects aged 16–50 years who had self-reported physician-diagnosed asthma and presence of respiratory symptoms during the previous 12 months. The clinical outcome measures were body mass index (BMI), forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁), fractional exhaled nitric oxide (FeNO), immunoglobulin E (IgE) in serum and serum C-reactive protein (CRP). An ACT score ≤ 19 was defined as poorly controlled asthma. Overall, 113 subjects (35%) reported poor asthma control. The odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with poorly controlled asthma were: self-reported occupational exposure to vapor, gas, dust, or fumes during the previous 12 months (OR 2.0; 95% CI 1.1–3.6), body mass index ≥ 30 kg/m² (OR 2.2; 95% CI 1.2–4.1), female sex (OR 2.6; 95% CI 1.5–4.7), current smoking (OR 2.8; 95% CI 1.5–5.3), and past smoking (OR 2.3; 95% CI 1.3–4.0). Poor asthma control was also associated with reduced FEV₁ after bronchodilation (β –3.6; 95% CI –7.0 to –0.2). Moreover, 13% of the participants with poor asthma control reported no use of asthma medication, 51% had not been assessed by a pulmonary physician, and 20% had never undergone spirometry. Because these data are cross-sectional, further studies assessing possible risk factors in general and objectively measured occupational exposure in particular are needed. However, our results suggest that there is room for improvement with regards to use of spirometry and pulmonary physician referrals when a patient’s asthma is inadequately controlled.

Lifestyle, sick leave and work ability among Norwegian employees with asthma-A population-based cross-sectional survey conducted in Telemark County, Norway

Objective

To investigate whether physician-diagnosed asthma modifies the associations between multiple lifestyle factors, sick leave and work ability in a general working population.

Methods

A cross-sectional study was conducted in Telemark County, Norway, in 2013. A sample of 16 099 respondents completed a self-administered questionnaire. We obtained complete data on lifestyle, work ability and sick leave for 10 355 employed persons aged 18–50 years. We modelled sick leave and work ability using multiple logistic regression, and introduced interaction terms to investigate whether associations with lifestyle factors were modified by asthma status.

Results

Several lifestyle risk factors and a multiple lifestyle risk index were associated with sick leave and reduced work ability score among persons both with and without physician-diagnosed asthma. A stronger association between lifestyle and sick leave among persons with asthma was confirmed by including interaction terms in the analysis: moderate lifestyle risk score * asthma OR = 1.4 (95% CI 1.02–2.1); high lifestyle risk score * asthma OR = 1.6 (95% CI 1.1–2.3); very high lifestyle risk score * asthma OR = 1.6 (95% CI 0.97–2.7); obesity * asthma OR = 1.5 (95% CI 1.02–2.1); past smoking * asthma OR = 1.4 (95% CI 1.01–1.9); and current smoking * asthma OR = 1.4 (95% CI 1.03–2.0).

There was no significant difference in the association between lifestyle and work ability score among respondents with and without asthma.

Conclusions

In the present study, we found that physician-diagnosed asthma modified the association between lifestyle risk factors and sick leave. Asthma status did not significantly modify these associations with reduced work ability score. The results indicate that lifestyle changes could be of particular importance for employees with asthma.

Self-reported traffic-related air pollution and respiratory symptoms among adults in an area with modest levels of traffic

Health effects of traffic-related air pollution (TRAP) concentrations in densely populated areas are previously described. However, there is still a lack of knowledge of the health effects of moderate TRAP levels. The aim of the current study, a population-based survey including 16 099 adults (response rate 33%), was to assess the relationship between TRAP estimates and respiratory symptoms in an area with modest levels of traffic; Telemark County, Norway. Respondents reported respiratory symptoms the past 12 months and two TRAP exposure estimates: amount of traffic outside their bedroom window and time spent by foot daily along a moderate to heavy traffic road. Females reported on average more symptoms than males. Significant relationships between traffic outside their bedroom window and number of symptoms were only found among females, with the strongest associations among female occasional smokers (incidence rate ratio [IRR], 1.75, 95% confidence interval (CI) [1.16–2.62] for moderate or heavy traffic compared to no traffic). Significant relationship between time spent daily by foot along a moderate to heavy traffic road and number of symptoms was found among male daily smokers (IRR 1.09, 95% CI [1.04–1.15] per hour increase). Associations between traffic outside bedroom window and each respiratory symptom were found. Significant associations were primarily detected among females, both among smokers and non-smokers. Significant associations between time spent by foot daily along a moderate to heavy traffic road (per hour) and nocturnal dyspnoea (odds ratio (OR) 1.20, 95% CI [1.05–1.38]), nocturnal chest tightness (OR 1.13 [1.00–1.28]) and wheezing (OR 1.14 [1.02–1.29]) were found among daily smokers, primarily men. Overall, we found significant associations between self-reported TRAP exposures and respiratory symptoms. Differences between genders and smoking status were identified. The findings indicate an association between TRAP and respiratory symptoms even in populations exposed to modest levels of TRAP.

Influence of Obesity on Work Ability, Respiratory Symptoms, and Lung Function in Adults with Asthma

BACKGROUND

Asthma is defined by variable respiratory symptoms and lung function, and may influence work ability. Similarly, obesity may contribute to respiratory symptoms, affect lung function, and reduce work ability. Thus, assessment of the influence of obesity on work ability, respiratory symptoms, and lung function in adults with asthma is needed.

OBJECTIVES

We hypothesized that patients with obesity and asthma have more respiratory symptoms and reduced work ability and lung function compared with normal-weight patients with asthma.

METHODS

We examined 626 participants with physician-diagnosed asthma, aged 18-52 years, recruited from a cross-sectional general population study using a comprehensive questionnaire including work ability score, the asthma control test (ACT), height and weight, and spirometry with reversibility testing.

RESULTS

Participants with a body mass index (BMI) ≥30 kg/m2 (i.e., obese) had a higher symptom score (OR 1.78, 95% CI 1.14-2.80), current use of asthma medication (1.60, 1.05-2.46), and incidence of ACT scores ≤19 (poor asthma control) (1.81, 1.03-3.18) than participants with BMI ≤24.9 kg/m2 (i.e., normal weight). Post-bronchodilator forced vital capacity (FVC) as a percentage of predicted (β coefficient -4.5) and pre-bronchodilator forced expiratory volume in 1 s as a percentage of predicted (FEV1) (β coefficient -4.6) were negatively associated with BMI ≥30 kg/m2. We found no statistically significant association of BMI >30 kg/m2 (compared to BMI <24.9 kg/m2) with sick leave (1.21, 0.75-1.70) or reduced work ability (1.23, 0.74-2.04).

CONCLUSIONS

There were indications that patients with obesity had a higher symptom burden, poorer asthma control, higher consumption of asthma medication, and reduced lung function, in particular for FVC, compared with normal-weight patients.

Lifestyle and work ability in a general working population in Norway: a cross-sectional study

OBJECTIVES

The aim of this study was to investigate the association between multiple lifestyle-related risk factors (unhealthy diet, low leisure-time physical activity, overweight/obesity and smoking) and self-rated work ability in a general working population.

SETTING

Population-based cross-sectional study, in Telemark County, Norway, 2013.

PARTICIPANTS

A random sample of 50 000 subjects was invited to answer a self-administered questionnaire and 16 099 responded. Complete data on lifestyle and work ability were obtained for 10 355 participants aged 18-50 years all engaged in paid work during the preceding 12 months.

OUTCOME MEASURE

Work ability was assessed using the Work Ability Score (WAS)-the first question in the Work Ability Index. To study the association between multiple lifestyle risk factors and work ability, a lifestyle risk index was constructed and relationships examined using multiple logistic regression analysis.

RESULTS

Low work ability was more likely among subjects with an unhealthy diet (ORadj 1.3, 95% CI 1.02 to 1.5), inactive persons (ORadj 1.4, 95% CI 1.2 to 1.6), obese respondents (ORadj 1.5, 95% CI 1.3 to 1.7) and former and current smokers (ORadj 1.2, 95% CI 1.1 to 1.4 and 1.3, 95% CI 1.2 to 1.5, respectively). An additive relationship was observed between the lifestyle risk index and the likelihood of decreased work ability (moderate-risk score: ORadj 1.3; 95% CI 1.1 to 1.6; high-risk score: ORadj 1.9; 95% CI 1.6 to 2.2; very high risk score: ORadj 2.4; 95% CI 1.9 to 3.0). The overall population attributable fraction (PAF) of low work ability based on the overall risk index was 38%, while the PAFs of physical activity, smoking, body mass index and diet were 16%, 11%, 11% and 6%, respectively.

CONCLUSIONS

Lifestyle risk factors were associated with low work ability. An additive relationship was observed. The findings are considered relevant to occupational intervention programmes aimed at prevention and improvement of decreased work ability.

Exposure to second-hand tobacco smoke and respiratory symptoms in non-smoking adults: cross-sectional data from the general population of Telemark, Norway

Background

In Norway, data on the association between second-hand tobacco smoke (SHS) exposure at home and respiratory symptoms in adults are limited.

Methods

We assessed the association between self-reported exposure to SHS and the prevalence of respiratory symptoms among never-smokers aged 16 to 50 years from the general population who were included in a cross-sectional population-based study in Telemark County, Norway. Logistic regression analysis was used to estimate the odds ratios of symptoms among 8850 never-smokers who provided an affirmative response to questions regarding SHS; 504 (5.7%) of these reported that they lived in a home with daily or occasional indoor smoking.

Results

Productive cough and nocturnal dyspnoea were statistically associated with daily SHS exposure (ORs 1.5 [95% CI 1.04–2.0] and 1.8 [1.2–2.7], respectively). In analyses stratified by gender, nocturnal dyspnoea was associated with SHS among women (OR 1.8 [1.1–3.1]), but not among men (OR 0.93 [0.49–1.8]). Symptoms were not associated with occasional SHS exposure in the entire group, but infrequent exposure among men only was associated with increased prevalence of chronic cough; (OR 1.6; [1.04–2.6]) and was negatively associated with wheeze; (OR 0.44 [0.21–0.92)].

Conclusions

Daily SHS exposure in private homes was associated with productive cough and nocturnal dyspnoea. Our results suggest that preventive measures may be needed to reduce the respiratory effects of SHS at home.

Trial registration

ClinicalTrials.gov Identifier: NCT02073708 Registered February 27. 2014.

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.

Association of respiratory symptoms and asthma with occupational exposures: findings from a population-based cross-sectional survey in Telemark, Norway

OBJECTIVES

The aim of this study was to estimate the prevalence of respiratory symptoms and physician-diagnosed asthma and assess the impact of current occupational exposure.

DESIGN

Cross-sectional analyses of the prevalence of self-reported respiratory health and association with current occupational exposure in a random sample of the general population in Telemark County, Norway.

SETTINGS

In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16-50, in Telemark, Norway. The overall response rate was 33%, comprising 16 099 responders.

OUTCOME MEASURES

The prevalence for respiratory symptoms and asthma, and OR of respiratory symptoms and asthma for occupational groups and exposures were calculated. Occupational exposures were assessed using self-reported exposure and an asthma-specific job-exposure matrix (JEM).

RESULTS

The prevalence of physician-diagnosed asthma was 11.5%. For the occupational groups, the category with agriculture/fishery workers and craft/related trade workers was associated with wheezing and asthma attack in the past 12 months, showing OR 1.3 (1.1 to 1.6) and 1.9 (1.2 to 2.8), respectively. The group including technicians and associated professionals was also associated with wheezing OR 1.2 (1.0 to 1.3) and asthma attack OR 1.4 (1.1 to 1.9). The JEM data show that exposure to flour was associated with wheezing OR 3.2 (1.4 to 7.3) and woken with dyspnoea OR 3.5 (1.3 to 9.5), whereas exposures to diisocyanates, welding/soldering fumes and exposure to vehicle/motor exhaust were associated with dyspnoea OR 2.9 (1.5 to 5.7), 3.2 (1.6 to 6.4) and 1.4 (1.0 to 1.8), respectively.

CONCLUSIONS

The observed prevalence of physician-diagnosed asthma was 11.5%. The 'manual' occupations were associated with respiratory symptoms. Occupational exposure to flour, diisocyanates, welding/soldering fumes and vehicle/motor exhaust was associated with respiratory symptoms in the past 12 months and use of asthma medication. However, prospective data are needed to confirm the observed associations.

Multiple subcutaneous granulomas and severe rhinitis after intradermal deposition of epoxy: a case report

Background

We present an unusual case of subcutaneous granulomas that also highlights the importance of assessing possible associations between exposure and symptoms early in the diagnostic approach to prevent further adverse health effects. Granulomas of the skin are seen in association with several diseases and after foreign body penetration of soft tissue, but have not been described after contact with epoxy. Epoxy resins are commonly used in paints and other protective coatings, including flooring materials.

Case presentation

We report a case of granulomatous inflammation in a 58-year-old man after accidental intradermal deposition of unhardened epoxy. Multiple subcutaneous nodules were present on his right forearm, from hand to elbow, for a period of 6 months after the incident. Biopsies and histological analysis showed a granulomatous inflammation without necrosis. Microscopic analysis of the biopsies did not show mycobacterium tuberculosis, other bacteria, or fungal elements. Standard patch testing was negative. The nodules disappeared gradually, but intense pruritus remained. The patient returned to exposure and developed severe work related rhinitis.

Conclusions

This case report describes an unusual case of multiple subcutaneous granulomas after a small injury with an epoxy-contaminated tool. Initially no association between the granulomas and exposure was established and the patient returned to work and epoxy exposure. He subsequently developed severe work related rhinitis. The case highlights the challenges of establishing an association between exposure and dermal reactions and that exposure should be reduced or avoided when sensitisation to allergens may have occurred.

Non-response in a cross-sectional study of respiratory health in Norway

OBJECTIVES

Declining participation in epidemiological studies has been reported in recent decades and may lead to biased prevalence estimates and selection bias. The aim of the study was to identify possible causes and effects of non-response in a population-based study of respiratory health in Norway.

DESIGN

The Telemark study is a longitudinal study that began with a cross-sectional survey in 2013.

SETTING

In 2013, a random sample of 50,000 inhabitants aged 16-50 years, living in Telemark county, received a validated postal questionnaire. The response rate was 33%. In this study, a random sample of 700 non-responders was contacted first by telephone and then by mail.

OUTCOME MEASURES

Response rates, prevalence and OR of asthma and respiratory symptoms based on exposure to vapours, gas, dust or fumes (VGDF) and smoking. Causes of non-response.

RESULTS

A total of 260 non-responders (37%) participated. Non-response was associated with younger age, male sex, living in a rural area and past smoking. The prevalence was similar for responders and non-responders for physician-diagnosed asthma and several respiratory symptoms. The prevalence of chronic cough and use of asthma medication was overestimated in the Telemark study, and adjusted prevalence estimates were 17.4% and 5%, respectively. Current smoking was identified as a risk factor for respiratory symptoms among responders and non-responders, while occupational VGDF exposure was a risk factor only among responders. The Breslow-Day test detected heterogeneity between productive cough and occupational VGDF exposure among responders.

CONCLUSIONS

The Telemark study provided valid estimates for physician-diagnosed asthma and several respiratory symptoms, while it was necessary to adjust prevalence estimates for chronic cough and use of asthma medication. Reminder letters had little effect on risk factor associations. Selection bias should be considered in future investigations of the relationship between respiratory outcomes and exposures.

Exposure to thoracic dust, airway symptoms and lung function in cement production workers

Cement dust exposure has previously been associated with airway symptoms and ventilatory impairment. The aim of the present study was to examine lung function and airway symptoms among employees in different jobs and at different levels of exposure to thoracic dust in the cement production industry. At the start of a 4-yr prospective cohort study in 2007, exposure to cement dust, symptoms and lung function were recorded cross-sectionally in 4,265 employees in 24 European cement plants. Bronchial exposure was assessed by 2,670 full-shift dust samples with cyclones collecting the thoracic aerosol fraction. A job exposure matrix was constructed by grouping dust concentrations according to job type and plant. Elevated odds ratios for symptoms and airflow limitation (range 1.2-2.6 in the highest quartile), but not for chronic bronchitis, were found in the higher quartiles of exposure compared with the lowest quartile. Forced expiratory volume in 1 s (FEV(1)) showed an exposure-response relationship with a 270-mL deficit of FEV(1) (95% CI 190-300 mL) in the highest compared with the lowest exposure level. The results support the hypothesis that exposure to dust in cement production may lead to respiratory symptoms and airway obstruction.

Respiratory symptoms and ventilatory function in workers exposed to portland cement dust

The healthy worker effect and incomplete exposure information have been problems in former studies regarding the association between exposure to Portland cement dust and respiratory effects. We included former workers and made an individual estimation of particle exposure to reduce the selection bias in this controlled cross-sectional study on the effects of cement dust exposure on respiratory symptoms and ventilatory function in long-term exposed Norwegian cement plant workers. A total of 119 workers from the largest cement plant in Norway and 50 workers from a nearby control plant, born 1918 to 1938, performed spirometry and gave information on respiratory symptoms in 1998 and 1999. The prevalence of symptoms and mean pulmonary function indices were similar for exposed workers and controls. There was no dose-response-related increase in symptoms or decrease in lung function indices. The estimated power to detect a true difference between forced expiratory volume in one second (FEV1) in the two groups of 0.3l was 0.90, assuming 95% significance level. The prevalence of chronic obstructive pulmonary disease was 14.3% in the exposed group and 14.0% among the controls. These findings do not support the hypothesis that cement dust exposure has a negative impact on lung function or gives an increase in respiratory symptoms.