Serum pneumoproteins in tunnel construction workers

Air particulate matter pollution and circulating surfactant protein: A systemic review and meta-analysis

OBJECTIVE

Air particulate matter (PM) pollution is associated with the alterations in circulating pulmonary damage proteins. But there are not consistent results among the epidemiological studies. The aim of this study is to investigate the alteration of surfactant protein (SP) from PM exposure.

METHODS

We conducted a comprehensive meta-analysis by searching the databases of PubMed, Medline, EMBASE, Web of Science and CNKI before October 2020 which reported PM pollutants and surfactant protein in the population. The sources of heterogeneity were assessed by subgroup (smoking, particulate matter with different aerodynamic diameter, exposure duration) analysis. We also used the publication bias tests for the comprehensive assessment.

RESULTS

This meta-analysis consisted of 10 studies with 1985 subjects. The results showed that the combined standardized mean difference (SMD) value was 0.05, 95% confidence interval (CI) was -0.07 to 0.17 for serum SP-A and -0.81 (95% CI: -1.41 to -0.21) for circulating SP-D. Among smokers, the combined SMD value of SP-A were 0.29 (95% CI: 0.05 to 0.52). We did not find the correlation between publication year of SP-A and SP-D and study heterogeneity.

CONCLUSIONS

Circulating SP-D was significantly decreased by air particulate matter. Serum SP-A was significantly increased by PM exposure among smokers. Circulating surfactant protein may be considered as a biomarker for respiratory injury caused by air particulate matter.

Investigation of the health effects on workers exposed to respirable crystalline silica during outdoor and underground construction projects

Chronic exposure of workers to powder containing crystalline silica (Silicon dioxide; SiO2) can lead to chronic lung diseases (lung cancer, silicosis, etc.). Aim of this study was to evaluate the exposure of Greek construction workers to SiO2 and describe their pulmonary function. The study involved 86 outdoor and underground workers. Medical and professional history was obtained, and breath samples were collected at morning hours through a mask for the determination of SiO2 levels. Pulmonary function tests, radiological examination and evaluation of radiographs were also performed. Pulmonary function examination showed that the majority of the workers were within normal range (61.4%) while the rest were diagnosed with mild (26.5%) and more severe impairment (7.24%). Working conditions (underground-outdoor) were statistically significantly related to the categorization of pulmonary function (P=0.038). During radiological examination, the type of working activity/ conditions (underground-outdoor) were statistically significantly related to the categorization of these findings (P=0.044). Of the 69 employees, 52 did not present findings (75.4%) and 5 were diagnosed with findings specific to occupational diseases (7.23%). Environmental exposure to respirable crystalline silica (RCS) was detected at 0.0125 mg/m3 in the workplace, which is not beyond the legal limits. Underground workers with more than 15 years of exposure to SiO2 are more likely to present chronic silicosis compared to the workers of outdoor activities.

Respiratory health and inflammatory markers - Exposure to respirable dust and quartz and chemical binders in Swedish iron foundries

Purpose

To study the relationship between respirable dust, quartz and chemical binders in Swedish iron foundries and respiratory symptoms, lung function (as forced expiratory volume FEV₁ and vital capacity FVC), fraction of exhaled nitric oxide (FENO) and levels of club cell secretory protein 16 (CC16) and CRP.

Methods

Personal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Full shift sampling and examination were performed on the second or third day of a working week after a work free weekend, with additional sampling on the fourth or fifth day. Logistic, linear and mixed model analyses were performed including, gender, age, smoking, infections, sampling day, body mass index (BMI) and chemical binders as covariates.

Results

The adjusted average respirable quartz and dust concentrations were 0.038 and 0.66 mg/m³, respectively. Statistically significant increases in levels of CC16 were associated with exposure to chemical binders (p = 0.05; p = 0.01) in the regression analysis of quartz and respirable dust, respectively. Non-significant exposure-responses were identified for cumulative quartz and the symptoms asthma and breathlessness. For cumulative chemical years, non-significant exposure–response were observed for all but two symptoms. FENO also exhibited a non significant exposure-response for both quartz and respirable dust. No exposure-response was determined for FEV₁ or FVC, CRP and respirable dust and quartz.

Conclusions

Our findings suggest that early markers of pulmonary effect, such as increased levels of CC16 and FENO, are more strongly associated with chemical binder exposure than respirable quartz and dust in foundry environments.

Biomarkers of endothelial activation and thrombosis in tunnel construction workers exposed to airborne contaminants

OBJECTIVES

The aims were to study biomarkers of systemic inflammation, platelet/endothelial activation and thrombosis in tunnel construction workers (TCW).

METHODS

Biomarkers and blood fatty acids were measured in blood of 90 TCW and 50 referents before (baseline) and towards the end (follow-up) of a 12 days work period. They had been absent from work for 9 days at baseline. Air samples were collected by personal sampling.

RESULTS

Personal thoracic air samples showed geometric mean (GM) particulate matter and α-quartz concentrations of 604 and 74 µg/m³, respectively. The arithmetic mean (AM) concentration of elemental carbon was 51 µg/m³. The GM (and 95% confidence interval) concentration of the pro-inflammatory cytokine TNF-α decreased from 2.2 (2.0-2.4) at baseline to 2.0 pg/mL (1.8-2.2) (p = 0.02) at follow-up among the TCW. Also the platelet activation biomarkers P-selectin and CD40L decreased significantly [25.4 (24.1-26.6) to 24.4 (22.9-26.0)] ng/mL, p = 0.04 and 125 (114-137) to 105 (96-115) pg/mL, p < 0.001, respectively. ICAM-1 concentrations increased from 249 (238-260) to 254 (243-266) ng/mL (p = 0.02). No significant alterations were observed among the referents when assessed by paired sample t test. Unbeneficial alterations in blood fatty acid composition were observed between baseline and follow-up, mainly among referents.

CONCLUSIONS

TCW had slightly reduced systemic inflammation and platelet activation although highly exposed to particulate matter, α-quarz and diesel exhaust, which might be due to increased physical activity during the exposure period. The slightly increased ICAM-1 may indicate monocyte recruitment to the lungs. The diet was substantially altered towards a less beneficial fatty acid profile.