Thoracic dust exposure is associated with lung function decline in cement production workers

Health effects of informal precarious workers in occupational environments with high exposure to pollutants

The aim is to investigate and describe the health conditions of workers who are employed in precarious work settings in Mexico. Specifically, the study aims to provide insight on the health status of workers who are vulnerable due to the informal nature of their employment. Through the evaluation of three different scenarios of precarious employment (n = 110), including workers in mercury miner (workers A), brick-kilns (workers B), and quarries workers (workers C). The study analyzes clinical parameters to determine the workers' renal health condition and assesses their pulmonary function using spirometry. Multivariate analyses and Spearman correlation are performed to determine the contribution of length of service to workers' health parameters. Workers B have the highest incidence of clinical health alterations, with the highest BMI and prediabetes/diabetes index, albumin creatinine ratio, and eGFR. Moreover, pulmonary function parameters show a decrease in %FEV1/FVC in workers B and C compared to workers A, while workers A demonstrate a more significant decrease in %FEV1. Additionally, a negative correlation is observed between the length of service in precarious work settings and lung parameters (r = -0.538, p < 0.001). In conclusion, this study highlights the need to address the issue of precarious employment in Mexico by improving working conditions, access to healthcare and promoting social protection for workers, which can reduce the number of work-related illnesses and deaths and ensure the safety and health of workers.

Evidence of seasonal changes in airborne particulate matter concentration and occupation-specific variations in pulmonary function and haematological parameters among some workers in Enugu Southeast Nigeria: a randomized cross-sectional observational study

Background

Upsurge in cardiopulmonary dysfunctions in Enugu, Nigeria, involved mainly cement workers, automobile spray painters, woodworkers, and Cleaners and was worsened in the dry season, suggesting the need for an occupation-specific characterization of the disease features and seasonal evaluation of air quality for prevention and management.

Methods

We conducted a randomized cross-sectional study of eighty consenting participants (in Achara Layout, Enugu), comprising 20 cement workers (39.50 ± 14.95 years), 20 automobile spray painters (40.75 ± 9.85 years), 20 woodworkers (52.20 ± 9.77 years), and 20 cleaners (42.30 ± 9.06 years). The air quality, some haematological (fibrinogen-Fc, and C-reactive protein-CRP), and cardiopulmonary parameters were measured and analyzed using ANCOVA, at p < 0.05.

Results

The dry season particulate matter (PM) in ambient air exceeded the WHO standards in the New layout [PM₁₀ = 541.17 ± 258.72 µg/m³; PM_2.5 = 72.92 ± 25.81 µg/m³] and the University campus [PM₁₀ = 244 ± 74.79 µg/m³; PM_2.5 = 30.33 ± 16.10 µg/m³], but the former was twice higher. The PM differed significantly (p < 0.05) across the sites. Forced expiratory volume at the first second (FEV₁) (F = 6.128; p = 0.001), and Peak expiratory flow rate (PEFR) (F = 5.523; p = 0.002), differed significantly across the groups. FEV₁/FVC% was < 70% in cement workers (55.33%) and woodworkers (61.79%), unlike, automobile spray painters (72.22%) and cleaners (70.66%). FEV₁ and work duration were significantly and negatively related in cement workers (r = -0.46; r2 = 0.2116; p = 0.041 one-tailed). CRP (normal range ≤ 3.0 mg/L) and Fc (normal range—1.5–3.0 g/L) varied in cement workers (3.32 ± 0.93 mg/L versus 3.01 ± 0.85 g/L), automobile spray painters (2.90 ± 1.19 mg/L versus 2.54 ± 0.99 mg/L), woodworkers (2.79 ± 1.10 mg/L versus 2.37 ± 0.92 g/L) and cleaners (3.06 ± 0.82 mg/L versus 2.54 ± 0.70 g/L).

Conclusion(s)

Poor air quality was evident at the study sites, especially in the dry season. Cement workers and automobile spray painters showed significant risks of obstructive pulmonary diseases while woodworkers had restrictive lung diseases. Cement workers and cleaners recorded the highest risk of coronary heart disease (CRP ≥ 3.0 mg/L). The similarity in Fc and CRP trends suggests a role for the inflammation-sensitive proteins in the determination of cardiovascular risk in cement workers and cleaners. Therefore, there are occupation-specific disease endpoints of public health concern that likewise warrant specific preventive and management approaches among the workers.

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.

Characterization and Hazard Identification of Respirable Cement and Concrete Dust from Construction Activities

Construction is an important segment of the economy that employs millions of people. Construction dust is an occupational health hazard to millions of construction workers worldwide. The hazards associated with respirable dust depend upon its particulate size distribution and chemical composition, as these determine the deposition pattern in the respiratory tract and reactivity, respectively. This study presents characterization of the size and composition of the dust from two key construction materials-cast cement and poured concrete. The dust was generated by cutting the cured cement and concrete blocks using an 18" hand-held circular saw as used in highway and building construction. Transmission electron microscopy, scanning electron microscopy, dynamic light scattering, and laser diffraction were performed for the size analysis of the particles. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used for chemical analysis. X-ray diffraction was used for phase identification. Electron diffraction patterns were obtained to assess the crystallinity of individual particles. They confirm the crystallinity of particles of different size and shapes. With a particle size range between 0.5 μm and 10 μm, greater than 90% of particles fell below 2.5 μm, presenting a respirable health concern. Crystalline compounds including the metals Al, Ca, Fe, Mg, Na, and K were detected. The concrete particles were most enriched in crystalline silica with a concentration of more than 30% by weight. The presence of metals and high crystalline silica content pose a serious health concern to construction workers.

Pulmonary functionality among workers of a Central Italy waste-to-energy plant: a retrospective study

Background

We are observing a growing trend towards the use of waste incineration in waste-to-energy (WTE) plants in Italy. Various authors started to investigate their potential health effects, but without univocal outcomes. The aim of this study is to assess whether or not main pulmonary function indexes could be decreased in a group of workers employed in a municipal solid WTE plant located in Central Italy, and if there’s a correlation between the levels of exposure to airborne pollutants and alterations in the pulmonary apparatus.

Methods

The study was conducted with a retrospective cohort approach. We reviewed data from clinical records of 58 waste-to-energy plant workers undergoing annual health surveillance in the period 2010–2015. We considered the exposure to airborne dust and the main parameters of respiratory function (FVC, FEV1, Tiffeneau Index and FEF 25–75%) at time zero and after a period of 5 years. We divided our study population into two groups: low (< 1 mg/m3) and high (> 1 mg/m3) exposure. We estimated odds ratios (OR) with 95% confidence interval (95% CI) adjusted for potential confounders.

Results

We observed a decrease in lung function parameters both in high and in low exposure group after a five-years exposure period. FEV1, FEV1/VC ratio and FEF 25–75% were worst in more exposed group, even if this difference resulted not significant at Wilcoxon test.

Conclusions

Active employee in WTE plants is associated to a non-significant worsening in the main parameters of lung function after 5 years exposure. Clinical significant of these variations need to be assessed.

Cement plant emissions and health effects in the general population: a systematic review

Adverse health effects of cement plant exposure have been found in occupational contexts but are less defined for the general population living near plants. We aimed to summarize the evidence on the health effects of people exposed to ambient air pollution by cement plants. A systematic review using Embase, PubMed and Web of Science was performed. We included only non-occupational studies with a comparison group that focused on adverse health outcomes and biomarkers of internal dose or subclinical effect associated with cement plant exposure. Selection of articles was performed by two authors independently. Of 1491 articles identified by the initial search, 24 were included: 17 of them were included in the analysis of adverse health outcomes and 9 in the analysis of biomarkers of internal dose or subclinical effects. The studies were very heterogeneous in study design, measure of cement plant exposure, outcome detection, measure of association and adjustment for confounding. Almost all the studies found positive associations between cement plant exposure and respiratory diseases and symptoms. An excess risk of cancer incidence and mortality in both children and adults mainly concerning respiratory tract cancers was also reported in some studies. Higher values of heavy metals and of a biomarker of renal toxicity were found in the exposed compared to unexposed populations. In conclusion, there is some evidence for a possible role of cement plant exposure on health adverse effects, although many studies had serious or critical risk of bias and overall level of certainty was low.

Prevalence of lung function impairment among Greek cement production workers: a cross-sectional study

Greece is a significant cement producing country. The aim of this study was to investigate the prevalence and risk factors of lung function impairment among Greek cement workers. One hundred thirty- seven cement production workers participated in this study. In addition, 110 employees not exposed to cement dust comprised the control group. The concentration of cement total dust at workplace varied from 1.1 to 11.6 mg/m³. In only one of the measurements, the Threshold Limit Level of 10 mg/m³ has been exceeded. Cement production workers presented a higher prevalence of FEV1<80% in comparison to controls (13.9% vs. 2.7%; Chi-Square Test; p=0.002). Multivariate analysis has shown that cement production workers have recorded an almost 5 fold risk of low lung function, as expressed by FEV1<80%, in comparison to the reference population OR=4.92; 95% C.I.=1.22-12.62). Current smoking was associated with an almost 4- fold increased risk of FEV1<80% (OR=3.91;95% C.I.=1.32-11.56). In conclusion, we found a high prevalence of impaired lung function among Greek cement production workers, despite the fact that total and inhalable dust levels were below the occupational exposure limits.

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.