Ever and cumulative occupational exposure and lung function decline in longitudinal population-based studies: a systematic review and meta-analysis

Pulmonary function assessment among conventional and organic cotton farmers exposed to pesticides in the Central-West region of Burkina Faso

BACKGROUND

Respiratory diseases have been associated with the exposure of populations to some environmental pollutants such as pesticides. To assess effects of pesticides on farmers' respiratory health, this study aimed to evaluate the pulmonary function of cotton farmers exposed to synthetic and natural pesticides in the Central-West region of Burkina Faso.

METHODS

A cross-sectional study was conducted from June to July 2022 among 281 conventional and 189 organic cotton farmers. After collecting information on pesticide use conditions, pulmonary function tests (PFTs) were performed on each farmer according to the American Thoracic Society/European Respiratory Society guidelines, in order to assess chronic respiratory effects among cotton producers. Binary logistic regression was used to assess factors associated with the occurrence of ventilatory changes.

RESULTS

Both conventional and organic cotton farmers reported similar chronic respiratory symptoms in different proportions. The main reported were rhinitis (54.45% conventional vs. 34.92% organic), chest pains (41.28% conventional vs. 23.81% organic), cough (33.45% conventional, 24.34% organic), breathlessness (31.67% conventional, 4.23% organic) (p<0.05). 16.18% and 27.50% of conventional male and female cotton farmers, respectively, had a restrictive defect. Among organic cotton farmers, 15.85% and 18.69%, respectively, of males and females had a restrictive defect. Furthermore, a significant increase in the predicted average percentage of FEV1/FVC ratio was observed among organic cotton farmers after salbutamol's use (p = 0.039). The type of cultivated cotton was not associated with ventilatory changes neither in the univariate analysis, nor in the multivariate analysis. Other factors such as farmers' age, BMI and insecticides use frequency per year were also important. Farmers who used insecticides more than 6 times per season had an increased risk of developing an obstructive defect (OR = 1.603; 95%CI: 0.484-5.309) compared to those who used them 6 times or less.

CONCLUSION

Chronic respiratory signs and ventilatory impairments were found among conventional and, to our knowledge, for the first time among organic cotton producers. However, these health effects were more prevalent among conventional cotton farmers than organic ones.

Worse pulmonary function in association with cumulative exposure to nanomaterials. Hints of a mediation effect via pulmonary inflammation

BACKGROUND

Today, nanomaterials are broadly used in a wide range of industrial applications. Such large utilization and the limited knowledge on to the possible health effects have raised concerns about potential consequences on human health and safety, beyond the environmental burden. Given that inhalation is the main exposure route, workers exposed to nanomaterials might be at risk of occurrence of respiratory morbidity and/or reduced pulmonary function. However, epidemiological evidence regarding the association between cumulative exposure to nanomaterials and respiratory health is still scarce. This study focused on the association between cumulative exposure to nanomaterials and pulmonary function among 136 workers enrolled in the framework of the European multicentric NanoExplore project.

RESULTS

Our findings suggest that, independently of lifelong tobacco smoking, ethnicity, age, sex, body mass index and physical activity habits, 10-year cumulative exposure to nanomaterials is associated to worse FEV1 and FEF25 - 75%, which might be consistent with the involvement of both large and small airway components and early signs of airflow obstruction. We further explored the hypothesis of a mediating effect via airway inflammation, assessed by interleukin (IL-)10, IL-1β and Tumor Necrosis Factor alpha (TNF-α), all quantified in the Exhaled Breath Condensate of workers. The mediation analysis results suggest that IL-10, TNF-α and their ratio (i.e., anti-pro inflammatory ratio) may fully mediate the negative association between cumulative exposure to nanomaterials and the FEV1/FVC ratio. This pattern was not observed for other pulmonary function parameters.

CONCLUSIONS

Safeguarding the respiratory health of workers exposed to nanomaterials should be of primary importance. The observed association between cumulative exposure to nanomaterials and worse pulmonary function parameters underscores the importance of implementing adequate protective measures in the nanocomposite sector. The mitigation of harmful exposures may ensure that workers can continue to contribute productively to their workplaces while preserving their respiratory health over time.

Longitudinal changes in lung function following post-9/11 military deployment in symptomatic veterans

RATIONALE

Exposure to burn pit smoke, desert and combat dust, and diesel exhaust during military deployment to Southwest Asia and Afghanistan (SWA) can cause deployment-related respiratory diseases (DRRDs) and may confer risk for worsening lung function after return.

METHODS

Study subjects were SWA-deployed veterans who underwent occupational lung disease evaluation (n = 219). We assessed differences in lung function by deployment exposures and DRRD diagnoses. We used linear mixed models to assess changes in lung function over time.

RESULTS

Most symptomatic veterans reported high intensity deployment exposure to diesel exhaust and burn pit particulates but had normal post-deployment spirometry. The most common DRRDs were deployment-related distal lung disease involving small airways (DDLD, 41%), deployment-related asthma (DRA, 13%), or both DRA/DDLD (24%). Those with both DDLD/DRA had the lowest estimated mean spirometry measurements five years following first deployment. Among those with DDLD alone, spirometry measurements declined annually, adjusting for age, sex, height, weight, family history of lung disease, and smoking. In this group, the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio declined 0.2% per year. Those with more intense inhalational exposure had more abnormal lung function. We found significantly lower estimated FVC and total lung capacity five years following deployment among active duty participants (n = 173) compared to those in the reserves (n = 26).

CONCLUSIONS

More intense inhalational exposures were linked with lower post-deployment lung function. Those with distal lung disease (DDLD) experienced significant longitudinal decline in FEV1/FVC ratio, but other DRRD diagnosis groups did not.

[Pesticide exposure and chronic respiratory diseases]

INTRODUCTION

Pesticides are used worldwide, mainly in agriculture as a means of controlling pests and protecting crops. That said, the entire world population is ultimately subject to pesticide exposure (consumption of fruits and vegetables, living near treated fields…), with varying degrees of toxicity involved.

STATE OF THE ART

In recent decades, epidemiological studies have contributed to the identification of chemical pesticide families with detrimental effects on human health: cognitive disorders, Parkinson's disease, prostate cancer… and impairment in respiratory functioning. Current scientific evidence points to the implication of the active substances in insecticides, herbicides and fungicides in chronic respiratory diseases, two examples being chronic obstructive pulmonary disease (COPD) in exposed workers, and asthmatic wheezing in children during prenatal or postnatal exposure.

PERSPECTIVES

The safety of individuals exposed to pesticides is of key importance in public health. Further epidemiological investigations are needed to identify the chemical families affecting certain populations.

CONCLUSIONS

The scientific literature suggests strong links between pesticide exposure and respiratory health. Whether it be environmental or occupational, pesticide exposure can lead to respiratory disorders and symptoms of varying severity.

Assessment of pulmonary function and respiratory symptoms among INDIAN textile sizing mill workers

BACKGROUND

Textile-sizing mill workers are exposed to various hazards in the sizing units during their working hours and are at risk of acquiring lung impairments due to the usage of sizing chemicals in the sizing process.

OBJECTIVE

The main aim of this study is to assess the influence of cotton dust and sizing agents on lung function and breathing difficulties among Indian textile sizing mill workers.

METHODS

This cross-sectional study was carried out at a textile-sizing mill from August 2022 to September 2022. A modified questionnaire based American Thoracic Society's standard was used to assess respiratory symptoms among sizing mill workers and the pulmonary function test was conducted Spirometry. The chi-square test was used to find the difference between respiratory symptoms and the t-test was used to find the difference between spirometric parameters.

RESULTS

Textile sizing mill workers showed significant (P <  0.0001) decline in peak expiratory flow rate, forced vital capacity (FVC), ratio of FEV1 and forced vital capacity, and forced expiratory volume in 1 s (FEV1). There was an association between symptoms and duration of exposure to pulmonary abnormality. Sizing mill workers showed a significant decline in lung functions and an increase in pulmonary symptoms. As the service duration of exposure in terms of years increased, respiratory symptoms increased and spirometric abnormality also increased.

CONCLUSION

This study confirms that sizing agents such as polyvinyl alcohol (PVA), emulsifier, wax, carboxymethyl cellulose (CMC), and starch used in sizing mills are also responsible for respiratory illness and lung impairment among textile workers.

Benzene Exposure and Lung Cancer Risk: A Systematic Review and Meta-Analysis of Human Studies

Lung cancer is a leading cause of death with nearly 1.8 million deaths estimated worldwide in 2020. Although benzene is classified as a human carcinogen (Group 1) on the basis of its association with acute myeloid/non-lymphocytic leukaemia, there is still limited evidence that it may influence lung cancer risk. This study examined the potential link between benzene exposure and risk of lung cancer using a systematic review of epidemiological studies and meta-analysis. We searched through PubMed, Web of Science and Scopus databases up to 10 February 2023 to identify all articles on the association between benzene exposure and lung cancer (incidence or prevalence) and/or mortality. We extracted the risk estimates of the highest and the lowest reported categories of benzene exposure and conducted a meta-analysis using a random-effects model. Heterogeneity and publication bias were analysed using an I2 test and funnel plots asymmetry, respectively. Twenty-one studies were included in the final analysis, with a total of 10,750 lung cancer cases and 2899 lung cancer deaths. Overall, risk estimates of lung cancer prevalence and mortality in association with benzene exposure were 1.20 (n = 14; 95% CI 1.05-1.37) and 1.15 (n = 13; 95% CI 1.02-1.30), respectively. In all cases, heterogeneity was quite large, while no significant publication bias was observed. When only studies that adjusted for smoking habit were selected, the risk for lung cancer increased by up to 34% (n = 9; 95% CI 1.10-1.64). Our data, which show a strong association between benzene exposure and lung cancer risk, may have important public health implications. However, further studies are needed to identify the lung cancer risk associated with benzene exposure considering different smoking conditions.

Association between exposure to external airborne agents and autoimmune disease

The etiology of autoimmune disease pathogeneses remains obscure, and the impact of general environmental or occupational exposure to external airborne agents (EAA) on autoimmune diseases remains understudied. This study was conducted to elucidate the association between exposure to EAA and the risk of autoimmune diseases according to exposure type. From the NHIS-NSC (2002-2019), 17,984,963 person-years were included in the data analysis. Autoimmune diseases were categorized based on the InterLymph classification. We estimated the incidence and rate ratio of autoimmune diseases according to the EAA exposure. Association between exposure and autoimmune diseases was investigated using logistic regression analysis, adjusted for potential confounders. Of the 1,082,879 participants, 86,376 (8.0%) were diagnosed with autoimmune diseases. Among these, 208 (14.1%) experienced severe exposure to EAA. Total EAA exposure was significantly associated with any autoimmune disease (OR: 1.29, 95% CI: 1.11-1.49) and organ-specific diseases (OR: 1.28, 95% CI: 1.08-1.53). Inorganic dust exposure was associated with organ-specific diseases (OR, 1.38; 95% CI: 1.01-1.81). Exposure to other dust was significantly associated with any autoimmune disease (OR: 1.35, 95% CI: 1.10-1.66), connective tissue diseases (OR: 1.43, 95% CI: 1.03-1.99), and organ-specific diseases (OR: 1.28, 95% CI: 1.00-1.65). Exposure to EAA was predominantly related to psoriasis, rheumatoid arthritis (RA), and type 1 diabetes (T1DM). We found that exposure to EAA is a potential risk factor for autoimmune diseases, especially psoriasis, RA, and T1DM. Our findings provide insight into the role of exposure to severe airborne agents in the pathogenesis of autoimmune diseases.

The association of forced expiratory volume in one second with occupational exposures in a longitudinal study of adults in a rural community in Iowa

PURPOSE

The Keokuk County Rural Health Study (KCRHS) is a longitudinal population-based study conducted in rural Iowa. A prior analysis of enrollment data identified an association of airflow obstruction with occupational exposures only among cigarette smokers. The current study used spirometry data from all three rounds to investigate whether level of forced expiratory volume in one second (FEV1) and longitudinal change in FEV1 were associated with occupational vapor-gas, dust, and fumes (VGDF) exposures, and whether these associations were modified by smoking.

METHODS

This study sample comprised 1071 adult KCRHS participants with longitudinal data. A job-exposure matrix (JEM) was applied to participants' lifetime work histories to assign exposures to occupational VGDF. Mixed regression models of pre-bronchodilator FEV1 (millimeters, ml) were fit to test for associations with occupational exposures while adjusting for potential confounders.

RESULTS

Mineral dust had the most consistent association with change in FEV1, including ever/never ( - 6.3 ml/year) and nearly every level of duration, intensity, and cumulative exposure. Because 92% of participants with mineral dust also had organic dust exposure, the results for mineral dust may be due to a combination of the two. An association of FEV1 level with fumes was observed for high intensity ( - 91.4 ml) among all participants, and limited to cigarette smokers with results of  - 104.6 ml ever/never exposed,  - 170.3 ml high duration, and  - 172.4 ml high cumulative.

CONCLUSION

The current findings suggest that mineral dust, possibly in combination with organic dust, and fumes exposure, especially among cigarette smokers, were risk factors for adverse FEV1 results.