Respiratory symptoms and asthma among workers exposed to paper dust: A cohort study

Abstract

The aim of the present cohort study was to investigate whether exposure to paper dust causes increased risk for respiratory symptoms or asthma. The cohort included all workers at a soft paper mill who had worked there for more than 1 year 1960-1986 (n = 1,697). Randomly selected inhabitants of the mill town (n = 781) were used as unexposed referents. Both groups were investigated using a postal questionnaire. From the paper mill cohort, workers with high cumulative exposure (n = 313), with medium cumulative exposure (n = 321), and with low cumulative exposure (n = 338) to paper dust were selected. In the 1960s and 1970s, the dust levels were between 5 and 10 mg/m3. After adjustment for smoking and gender, paper dust exposure resulted in elevated prevalence ratios for chronic cough, chronic phlegm, wheeze, and breathlessness. The prevalence ratios ranged from 1.3 to 2.5. No significantly increased risk of asthma was found among the exposed, incidence rate ratio 1.4 (95% confidence interval 0.93-1.8). Among the exposed, there was an insignificantly increasing incidence rate ratio, 1.0, 1.4, 2.1, with increasing cumulative exposure. In conclusion, an increased risk for respiratory symptoms was observed among workers exposed to paper dust, but the study does not permit any definite conclusions regarding asthma and paper dust exposure.

Occurrence of self-reported asthma among Swedish bakers

“…Davies et a1 (19) reposted an incidence of 2% during the first year of exposure among laboratory animals. TorCn et a1 (20) measured the incidence of self-reported, but not physiciandiagnosed asthma among paper mill workers. The incidence rate ranged from 1.1 per 1000 person-years among the low-exposed workers to 1.5 among the mediumexposed and to 2.3 among high-exposed.…”

Challenges for the new century in the epidemiology of adult asthma

“…When risk factors for rare diseases such as adult-onset asthma are analyzed, specific diagnostic methods are to be preferred (20). The question about self-reported physician-diagnosed asthma has been very useful (21), especially in combination with a report of the year of onset (5,(22)(23)(24). It is a specific, inexpensive, and simple way of diagnosing asthma (21).…”

Airflow limitation and changes in pulmonary function among bleachery workers

“…While paper mill workers, selected as the internal control group, did not experience gassing events, they were exposed to paper dust, which has been previously shown to be associated with lower respiratory symptoms and impaired lung function [1,36]. Thus, the ability to detect an effect of gassings may have been reduced.…”