History Of Occupational Dust Exposure Research Articles

Chronic pulmonary mucormycosis caused by rhizopus microsporus mimics lung carcinoma in an immunocompetent adult: A case report

Pulmonary mucormycosis is a rare but life-threatening invasive fungal infection that mostly affects immunocompromised patients. This disease usually develops acutely and progresses rapidly, often leading to a poor clinical prognosis. Chronic pulmonary mucormycosis is highly unusual in immunocompetent patients. A 43-year-old man, who was a house improvement worker with a long history of occupational dust exposure, presented with an irritating cough that had lasted for two months. The patient was previously in good health, without dysglycemia or any known immunodeficiencies. Chest computed tomography revealed a mass in the left lower lobe, measuring approximately 6 cm in diameter, which was suspected to be primary lung carcinoma complicated with obstructive pneumonia. Thoracoscopic-assisted left lower lobectomy was performed, and metagenomic next-generation sequencing detection, along with special pathological staining of surgical specimens, suggested Rhizopus microsporus infection. Postoperatively, the patient's respiratory symptoms were relieved, and no signs of recurrence were found during the six-month follow-up. This article reports a rare case of chronic pulmonary mucormycosis caused by Rhizopus microsporus in a middle-aged male without dysglycemia or immunodeficiency. The patient's surgical outcome was excellent, reaffirming that surgery remains the cornerstone of pulmonary mucormycosis treatment.

A mixed-methods study on impact of silicosis on tuberculosis treatment outcomes and need for TB-silicosis collaborative activities in India

Globally, silicosis and tuberculosis (TB) have been targeted for elimination by 2030. The study’s objectives were to determine the association of silicosis with unfavorable TB treatment outcomes, as well as to explore experts’ perspectives on improving treatment outcomes among silico-tuberculosis patients. A retrospective cohort study evaluated TB treatment outcomes in Khambhat block, the western part of India, between 138 patients with silico-tuberculosis and 2610 TB patients without silicosis in February–March 2022. ‘Unfavorable TB treatment outcomes’ was defined as a patient stopping treatment for at least one month, a positive sputum smear at the end of treatment, or, a patient dying while on treatment. During April–July 2022, fifteen in-depth interviews with experts in the field of silicosis/tuberculosis were audio-recorded, transcribed, and analyzed to generate codes (thematic analysis). On multivariable logistic regression analysis, patients with silico-tuberculosis had a 2.3 (95% CI 1.6–3.4) times higher odds of unfavorable treatment outcomes. The experts recommended collaborative TB-silicosis activities for improving treatment outcomes of patients with silico-tuberculosis. I conclude from the study’s findings that silicosis is associated with unfavorable TB treatment outcomes in this study setting. All patients with silicosis should be screened for TB and treated according to national TB program guidelines. All patients with TB who have a history of occupational dust exposure should be evaluated for silicosis and provided appropriate pulmonary/vocational rehabilitation.

Association between Occupational and Radiological Factors and Nontuberculous Mycobacteria Lung Infection in Workers with Prior Dust Exposure.

This retrospective cross-sectional study was conducted to identify the factors that promote the risk of nontuberculous mycobacteria (NTM) lung infection in subjects with prior occupational dust exposure. All consecutive patients with a history of occupational dust exposure whose expectorated sputum, bronchial wash, or bronchial lavage was subjected to acid-fast Bacilli culture in a tertiary hospital between 2011 and 2016 were identified. The patients who were infected with NTM were identified according to the bacteriological criteria of the American Thoracic Society (ATS) and The Infectious Diseases Society of America (IDSA) statement. Pneumoconiosis-associated radiological findings were graded according to the International Labor Organization guidelines. Of the 1392 patients with prior dust exposure, NTM was isolated from 82. Logistic regression analysis showed that risk factors for NTM lung infection were a history of pulmonary tuberculosis (adjusted odds ratio [aOR] = 1.82, 95% confidence intervals [CI] = 1.03–3.16). Moreover, the unadjusted odds ratios (ORs) were higher when both small-opacity profusion and the large-opacity grades increased. Even after adjustment, the ORs for the A, B, and C large-opacity grades were 2.32 (95% CI = 1.01–4.99), 2.68 (95% CI = 1.35–5.24), and 7.58 (95% CI = 3.02–17.95). Previous tuberculosis, bronchiectasis, and especially extensive small-opacity profusion, and high large-opacity grade associated significantly with NTM lung infection in dust-exposed workers.

EBUS-TBNA Cytology Specimens are Predictive of Occupational Dust Exposure in Patients With Bilateral Mediastinal and Hilar Lymphadenopathy.

The aim of this study was to describe the cytological features of patients with significant occupational dust exposure presenting with benign bilateral mediastinal and hilar lymphadenopathy (BHL). A retrospective cohort study including patients undergoing EBUS-TBNA for investigation of benign BHL. Patient characteristics, dust exposure history, radiology, and cytology samples from EBUS-TBNA were assessed. EBUS-TBNA cytology in patients with exposure showed a significant increase in the presence of birefringent fibers (60.7% vs 19.2%, P = 0.001) and intracellular carbon pigment (75.0% vs 28.9%, P = 0.001) compared with patients without exposure. The presence of these two features together yielded a sensitivity of 53.6% and a specificity of 88.5%. In patients with BHL and a history of occupational dust exposure, the presence of birefringent fibers and intracellular carbon pigment in EBUS-TBNA cytology samples may assist in a diagnosis of lymphadenopathy due to occupational dust exposure.

Urinary polycyclic aromatic hydrocarbon metabolites and adult asthma: a case-control study

Polycyclic aromatic hydrocarbons (PAHs) exposure was reported to be associated with childhood asthma. However, the quantitative relationship between PAHs exposure and adult asthma and possible inflammatory pathways are less clear. We aimed to investigate potential associations between urinary PAHs metabolites and adult asthma. We enrolled 507 adult asthma cases and 536 matched controls. The concentrations of 12 urinary PAHs metabolites and plasma cytokines of interleukin (IL)-9 and eotaxin were measured. Potential associations between urinary PAHs metabolites and adult asthma were analyzed by logistic regression. The relationships between urinary PAHs metabolites and plasma cytokines were determined by generalized linear regression. After adjusted for covariates, each 1-unit-increase in natural log-transformed concentrations of 2-hydroxyfluorene (2-OHFLU), 4- hydroxyphenanthrene (4-OHPHE), 1-OHPHE, 2-OHPHE, 1-Hydroxypyrene (1-OHPYR) and ∑OH-PAHs were significantly associated with elevated risk of adult asthma with odds ratios of 2.04, 2.38, 2.04, 1.26, 2.35 and 1.34, respectively. And the associations were more pronounced in the subjects who were female, younger than 45 years, smoker and had history of occupational dust exposure. No associations were observed between urinary PAHs metabolites levels and expressions of IL-9 and eotaxin. Our results demonstrated that elevated urinary PAHs metabolites levels were associated with increased risk of asthma in adults.

Interactions between single nucleotide polymorphism of SERPINA1 gene and smoking in association with COPD: a case-control study.

BackgroundSERPINA1 gene has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD), while smoking is a known risk factor for COPD. Little is known on the effect of SERPINA1 gene and its interaction with smoking in the Chinese population. In this study, the effect of SERPINA1 gene polymorphisms on COPD risk and its interaction with smoking status has been investigated.MethodA total of 120 COPD patients and 481 healthy controls were recruited at The Armed Police Corps Hospital. Data on demographic variables, smoking status, history of occupational dust exposure, and allergies were collected. Genotyping for single nucleotide polymorphism’s (SNP) rs1243160, rs2854254, and rs8004738 was performed in all participants.ResultsSNP rs8004738 genotype was associated with a significantly higher risk for COPD (odds ratio (OR) =1.835, 95% confidence interval (CI): 1.002–3.360), whereas SNPs rs1243160 and rs2854254 did not exhibit such an association. Smoking habit also significantly increased the risk for COPD (OR =2.306, 95% CI: 1.537–3.459). On stepwise logistic regression analysis, advanced age, smoking, and SNP rs8004738 variant were associated with increased risk for COPD, while female gender and higher educational status decreased the risk. On additive interaction analysis, a significant interactive effect of SNP rs8004738 and smoking was observed in this population (relative excess risk due to interaction =0.478; attributable proportion due to interaction (AP) =0.123; S=1.197).ConclusionSNP rs8004738 of SERPINA1 gene significantly interacted with smoking status and was associated with a higher risk for COPD in the Chinese population.

Anthracofibrosis, Bronchial Stenosis With Overlying Anthracotic Mucosa: Possibly a New Occupational Lung Disorder: A Series of Seven Cases From One UK Hospital

Anthracofibrosis, which was recently defined as bronchial stenosis with overlying anthracotic mucosa, has been infrequently reported in Asia as a complication of tuberculosis (TB). It has not been reported in the United Kingdom or the United States, or, to our knowledge, in non-Asian patients. We have identified seven cases of patients presenting to a single teaching hospital in the northwest of England over a 13-year period. Only one patient had a history of TB, but six of the seven patients had a history of occupational dust exposure, including one patient with pneumoconiosis. It is possible that anthracofibrosis is an exaggerated endobronchial form of the much more common condition of anthracosis in coal miners and other workers who have been exposed to mineral dusts. Our study suggests that this is essentially a benign condition, although it may progress very slowly, leading to gradually progressive bronchial stenosis. The diagnosis is important because most patients have clinical, radiologic, and bronchoscopic changes that are highly suspicious of malignancy.

Byssinosis in Guangzhou, China.

To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton. All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer. The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure. It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis.

Occupational exposures and chronic respiratory symptoms. A population-based study.

Data from a random sample of 8,515 white adults residing in 6 cities in the eastern and midwestern United States were used to examine the relationships between occupational exposures to dust or to gases and fumes and chronic respiratory symptoms; 31% of the population had a history of occupational dust exposure and 30% reported exposure to gas or fumes. After adjusting for smoking habits, age, gender, and city of residence, subjects with either occupational exposure had significantly elevated prevalences of chronic cough, chronic phlegm, persistent wheeze, and breathlessness. The adjusted relative odds of chronic respiratory symptoms for subjects exposed to dust ranged from 1.32 to 1.60. Subjects with gas or fume exposure had relative odds of symptoms between 1.27 and 1.43 when compared with unexposed subjects. Occupational dust exposure was associated with a higher prevalence of chronic obstructive pulmonary disease as defined by an FEV1/FVC ratio of less than 0.6, when comparing exposed and unexposed participants (OR = 1.53, 95% Cl = 1.17-2.08). Gas or fume exposure was associated with a small, but not significant, increase in COPD prevalence. Significant trends were noted for wheeze and phlegm with increasing duration of dust exposure. Although 36% of exposed subjects reported exposure to both dust and fumes, there was no evidence of a multiplicative interaction between the effects of the individual exposures. Smoking was a significant independent predictor of symptoms, but did not appear to modify the effect of dust or fumes on symptom reporting. These data, obtained in random samples of general populations, demonstrate that chronic respiratory symptoms and disease can be independently associated with occupational exposures.

Mineral particles, mineral fibers, and lung cancer

The total fibrous and nonfibrous mineral content of the lung has been analyzed in a series of 14 men with lung cancer but no history of occupational dust exposure, and in a series of 14 control men matched for age, smoking history, and general occupational class. The lung cancer patients had an average of 525 ± 369 × 106 exogenous mineral particles and 17.4 ± 19.6 × 106 exogenous mineral fibers/g dry lung, while the controls had averages of 261 ± 175 mineral particles and 4.7 ± 3.2 × 106 mineral fibers/g dry lung. These differences are statistically significant for both particles and fibers. Kaolinite, talc, mica, feldspars, and crystalline silica comprised the majority of particles of both groups. Approximately 90% of the particles were smaller than 2 μm in diameter and approximately 60% smaller than 1 μm; the mean particle size in the cancer group was 1.1 ± 0.2 μm and in the control group 1.3 ± 0.2 μm. In both groups, patients who had smoked more than 35 pack years had greater numbers of particles than patients who had smoked less than 35 pack years. It is concluded that, in this study, lungs from patients with lung cancer had statistically greater numbers of mineral particles and fibers than lungs from controls, and that smoking influences total long-term retention of particles from all sources.