Objectives
Pleural plaques are biomarkers of previous asbestos exposure [1-2] which are typically apparent 15 to 25 years after exposure.
However,
the prevalence of plaques in the United Kingdom is currently unknown: there have been no large-scale population-based prospective surveys to answer this question.
There is broad consensus that plaques are asymptomatic and not associated with functional impairment per se [4].
It is also accepted that pleural plaques do not undergo malignant degeneration [1].
However,
there is the known tendency for some plaques to increase in...
Materials and Methods
Over six months during 2011-12,
consecutive patients,
aged over 40 years,
referred for volumetric CT - for varied clinical indications - were invited to participate.
The study was approved by the local Ethics Committee and full informed consent was given by all participants.
The study subjects completed a questionnaire regarding potential sources of i) occupational,
ii) incidental,
iii) co-habitational and iv) residential exposure to asbestos.
CT studies were examined for pleural plaques blinded to the clinical /occupational data.
Patients with and without plaques were randomly...
Results
195 patients (M=107) were recruited.
Plaques were observed in 18 out of 195 (9.2%) subjects; all were male.
The prevalence of plaques among the male group studied was 16.8% (18/107) and increased with age (0% of men aged 40-49 compared with 71.5% aged 80-89). 73% of men with plaques versus 27% without plaques had worked in the construction industry ≥20 years previously.
After coding,
reported levels of exposure were similar between plaque and non-plaque groups (means=1.93 vs 1.8 [respectively]).
Three men with plaques had worked...
Conclusions
The prevalence of pleural plaques on CT is high among older British men.
Our results confirm an association with known occupational exposures but also suggest a potential exposure from cryptic sources,
given the similar rates of reported exposure in both plaque and non-plaque groups.