Analysis finds link between cumulative occupational exposure and declining lung capacity

Analysis finds link between cumulative occupational exposure and declining lung capacity

Occupational exposure to gases, dusts, vapors and aromatic solvents used in paints, varnishes and adhesives is associated with declining lung capacity beyond normal aging, finds a pooled data analysis of available evidence published online in the journal Occupational and Environmental Medicine.

Regular screening is needed for workers in these environments to ward off serious respiratory illnesses, the researchers advise.

Lung capacity is measured by how much air a person can forcibly exhale in 1 second; Forced expiratory volume, FEV1 for short.

A gradual decline in FEV1 is a natural consequence of aging, but is associated with increased susceptibility to respiratory disease, and when this decline is accelerated, it is associated with an increased risk of cardiovascular disease and death, the researchers say.

Previously published research suggests that some occupational exposures may accelerate the decline in FEV1 and forced vital capacity (FVC) - the amount of air forcibly exhaled during a deep breath. But most of these studies were short-term and the results were inconclusive.

To address these knowledge gaps, researchers set out to pool available evidence on the potential links between any workplace exposure and declining lung capacity in long-term, population-based studies.

They searched research databases for relevant studies published in English up to September 2021. All studies included occupational exposure to a broad range of emissions and airborne particles, as well as declining lung capacity, tracked for at least one year and defined as the annual loss of FEV1, FVC, or the ratio of both.

Exposures included: biological dust; mineral dust; Combination of vapors, gases, dusts and smoke (VGDF); fungicides; herbicides; insecticides; aromatic solvents; chlorinated solvents; metals; fibers; or fog.

The final analysis included 12 studies with observation periods ranging from 4.5 to 25 years. The number of participants ranged from 237 to 17,833; Their average age was between 33 and 60 years.

Pooled data analysis of the study results showed that any exposure to gases/vapours, VGDF and aromatic solvents was strongly associated with decreasing FEV1, while cumulative workplace exposure for these three categories of substances suggested a similar trend.

Any exposure to fungicides and cumulative exposure to biological dust, fungicides and insecticides were also associated with decreasing FEV1, but in relation to specific variables such as age, gender and smoking.

No statistically significant association was observed between exposure to mineral dust, herbicides, metals and FEV1 decline.

The methodological quality of all included studies was rated as good overall, but the number included in the final analysis was small, the researchers admit, highlighting other limitations that make it difficult to draw definitive conclusions.

Pulmonary function definitions were not consistent across studies; Several methods have been used to assess occupational exposure; and pre-existing congenital or occupational asthma was not taken into account. Exposure categories were only loosely defined, and researchers were unable to identify the components involved or the duration of exposure.

Despite these limitations, the researchers still advise: “Regular occupational health monitoring and pulmonary function testing in exposed occupations will help to detect respiratory diseases early, control exposure and protect against further disease progression.”

Source:

BMJ

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