Occupational airborne exposure in relation to Chronic Obstructive Pulmonary Disease (COPD) and lung function in individuals without childhood wheezing illness: A 50-year cohort study

Abstract

Background: Evidence from longitudinal population-based studies relating occupational exposure to the full range of different forms of airborne pollutants and lung function and airway obstruction is limited.Objective: To relate self-reported COPD and lung function impairment to occupational exposure to different forms of airborne chemical pollutants in individuals who did not have childhood wheeze.Methods: A prospective cohort study was randomly selected in 1964 at age 10-15 years and followed up in 1989, 1995, 2001 and 2014 (aged 58-64) by spirometry and respiratory questionnaire. Occupational histories were recorded in 2014 and occupational exposures assigned using an airborne chemical job exposure matrix. The risk of COPD and lung function impairment was analyzed in subjects, who did not have childhood wheeze, using logistic and linear regression and linear mixed effects models.Results: 237 subjects without childhood wheeze (mean age 60.6 years, 47% male) were analyzed.There was no association between any respiratory outcomes and exposure to gases, fibers, mists or mineral dusts and no consistent associations with exposure to fumes. Reduced FEV1 was associated with longer duration (years) of exposure to any of the six main pollutant forms -vapors, gases, dusts, fumes, fibers and mists (VGDFFiM) with evidence of a dose-response relationship (p-trend=0.004). Exposure to biological dusts was associated with self-reported COPD and [-17.38, -0.84] respectively). Exposure to vapors was associated with self-reported COPD and FEV1<LLN (adjOR 6.46 [1.18, 35.37] and 4.82 [1.32, 17.63]). Longitudinal analysis demonstrated reduced FEV1 and FEF25-75% associated with exposure to biological dusts or vapors.3 Conclusions: People with no history of childhood wheezing who have been occupationally exposed to biological dusts or vapors or had longer duration of lifetime exposure to any VGDFFiM are at a higher risk of reduced lung function at age 58-64 years. Occupational exposure to biological dusts or vapors also increased the risk of self-reported COPD.

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

“…The summary characteristics of the 12 population-based cohort studies1 2 23–32 are presented in table 1 and the data on lung function decline are presented in online supplemental material table S1. The duration of follow-up in the studies ranged from 4.5 to 25 years, sample sizes ranged from 237 to 17 833, and the mean age at baseline ranged from 33.9 to 60.6 years.…”

“…The studies used different exposure assessment methods. Most of the studies used JEMs to assess exposures,1 2 23 24 28–32 however only three studies were based on self-report 25–27. Exposure metrics (eg, ever/never, low/high, cumulative) were assigned by lifetime work history calendars,1 23 29 30 32 current job titles2 24 28 31 and any jobs at baseline or follow-up 25–27.…”

A nationwide follow-up study of occupational organic dust exposure and risk of chronic obstructive pulmonary disease (COPD)

“…An exposure-response relation between wood dust exposure and lung function decline was found for women, but not for men, in a follow-up study of Danish woodworkers 28. Additionally, Tagiyeva et al found that longer lifetime exposure to biological dust increased the risk of reduced lung function over 50 years compared with shorter exposure duration29 and Alif et al found that fixed airflow obstruction was associated with ever (but not cumulative) biological dust exposure in non-asthmatics 30. However, in line with the current findings,31 neither cumulative biological dust nor cumulative endotoxin exposure was found to be associated with longitudinal decline in lung function among 1134 Danish farming students and controls 31.…”

Causal Effects of Body Mass Index on Airflow Obstruction and Forced Mid-Expiratory Flow: A Mendelian Randomization Study Taking Interactions and Age-Specific Instruments Into Consideration Toward a Life Course Perspective

“…This study relied on FEV1, FVC and BMI measured at a single time point in almost 500,000 participants, and supported a causal effect of BMI (2). The causal effect of BMI on other LF parameters relevant to asthma and COPD such as FEV1/FVC, the physiological parameter used to define AO, and FEF2575 (27)(28)(29)(30), has not been investigated using an MR approach.…”