Evaluation of occupational exposure to wood dust among sawmill workers within the Gert Sibande District Municipality, South Africa

Abstract

Introduction and objective: Wood dust is regarded as one of the human carcinogen based on an increased risk of nasal and sinonasal cancer. This study was conducted in two sawmills to measure and determine the time-weighted average (TWA) exposure level to wood dust, and compare the results with the South African occupational exposure limit (OEL).

Material and methods: Personal and area respirable and total inhalable wood dust samples were collected using calibrated Giliair-3 personal air sampling pump (Sensidyne, USA). Data was analysed using Microsoft Office Excel 2019 Analysis Tool Pak for a summary of descriptive statistics. Both the geometric means and standard deviation as well as the minimum and maximum values were calculated.

Results: The geometric mean = GM (geometric standard deviation = GSD) for personal respirable wood dust exposure at sawmill A was 0.9(4.8) mg/m³ while at sawmill B - 0.57(0.75) mg/m³. The GM(GSD) for personal total inhalable wood dust exposure at sawmill A was 0.37(0.94) mg/m³ while at sawmill B - 1.19(16.91) mg/m³. Besides that, the GM(GSD) for area respirable wood dust at sawmill A was 0.13(0.09) mg/m 3 , while at sawmill B - 0.8(0.6) mg/m³. Likewise, the GM(GSD) for area total inhalable wood dust at sawmill A was 0.13(0.16) mg/m³ while at sawmill B - 0.54(0.55) mg/m³ .

Conclusions: Results for the majority of samples were below the OEL. Workers smoking tobacco or cigarettes should be encouraged to stop smoking since smoking, especially when associated with exposure to wood dust, may increase the risk of respiratory health symptoms.

Keywords: Wood dust; human carcinogen; occupational exposure.