The effect of organic dust exposure on long-term change in lung function: a systematic review and meta-analysis

Abstract

Lung function is a predictor of morbidity and mortality, and the chronic nature of lung function decline allows for preventive initiatives. Proinflammatory constituents of organic dust are considered a possible cause of compromised respiratory health. The aim of this systematic review was to reveal the impact of organic dust exposure on long-term change in lung function. The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Predefined criteria concerned study design: longitudinal, ≥1 year follow-up, ≥50 exposed; exposure measures: organic dust, measured or estimated, in different occupational settings; and outcome measures: change in lung function measured by spirometry. Based on these criteria, 1580 potentially relevant publications were narrowed down to 20 included publications. Quality was evaluated and discussed based on six objectively defined criteria. Overall, 14 studies found some type of association between exposure to organic dust and long-term change in lung function. However, the results were inconsistent and no specific work exposure showed more clear associations to change in lung function. Meta-analysis revealed an overall small significant excess loss in forced expiratory volume in the 1st s for exposed compared with controls of 4.92 mL/year (95% CI 0.14 to 9.69). No significant association was seen overall for forced vital capacity. 12 studies revealed a significant exposure-response relation between organic dust and change in lung function. The results were inconsistent across varying study design and different exposure measures and outcomes. We therefore conclude that there is limited evidence of a causal association between general exposure to organic dust and long-term excess decline in lung function.

Endotoxin and particulate matter emitted by livestock farms and respiratory health effects in neighboring residents

“…A clear decline in lung function after short term exposure to organic dust, specifically endotoxin, has been firmly established in experimental and occupational studies (Castellan et al, 1987;Michel et al, 2002;Möller et al, 2012;Smid et al, 1994). Evidence with respect to long-term exposure and accelerated lung function decline is limited (Bolund et al, 2017). In our study population, we did not observe a clear decrease in lung function in relation to long-term endotoxin exposure.…”

COPD, airflow limitation and chronic bronchitis in farmers: a systematic review and meta-analysis

“…Thirdly, results may depend on study designs and on methods of population sampling. For example, several cross-sectional studies found that farming jobs exposing workers to organic dusts were associated with increased prevalence of COPD,15 16 whereas a recent meta-analysis including only longitudinal studies concluded that there was limited evidence for a causal association between occupational exposure to organic dust and decline of lung function 17. In addition, many studies did not include a control group of subjects unexposed to any agricultural environment, which may also lead to some bias.…”

Risicomodellering veehouderij en gezondheid (RVG) : modellering van regionale endotoxineconcentraties en relaties met gezondheidseffecten

“…Een andere systematisch literatuuronderzoek naar het lange-termijn effect van hogere endotoxineconcentraties op de longfunctie liet slechts beperkt bewijs zien van een dergelijk effect. 36 Dit lijkt consistent met de ruimtelijke analyses voor de VGO populatie, zoals die eerder zijn gepubliceerd en specifiek voor de associaties met endotoxine zijn opgenomen in deze studie. 37 De literatuurstudie geeft wel aanwijzing voor korte-termijneffecten op de longfunctie en voor associaties met luchtwegklachten.…”