Occupational exposure to flour dust and the associated respiratory outcomes among workers at a selected flour mill in KwaZulu-Natal

Abstract

Flour dust is a hazardous substance and refers to the particles that are created when cereals or non-cereal grains are milled finely. Research shows that excessive inhalation of flour dust is linked to various adverse respiratory health effects – however, most of this research has been conducted internationally. This study aims to determine the associated respiratory outcomes with occupational exposure to flour dust, further adding to the limited South African literature in this field. The focus of this study is at a flour mill located in the Phoenix Industrial Park, Durban, KwaZulu-Natal. This is a descriptive cross-sectional study conducted at one point in time. The study sourced quantitative data. A sample size of 63 employees was selected from a total population size of 70 using the simple random sampling strategy, in which the margin of error was set at 5%. This study sought to determine the respiratory health of employees in a flour mill, to analyse retrospective spirometry data from medical records of employees at the flour mill, to identify factors contributing to increased exposure to flour dust and to determine the relationship between occupational exposure to flour dust and the associated respiratory outcomes, using retrospective spirometry data and occupational hygiene reports. This study has established a strong relationship between site of work (which determines the level of exposure to flour dust) and the prevalence of respiratory issues. Retrospective environmental monitoring reports have highlighted the departments which presented consistently high flour dust levels, namely, the milling, packing and maintenance departments. Unsurprisingly, these departments also reported a higher prevalence of breathing complications, chest tightness, rhinitis, dry cough, and conjunctivitis as well as reduced mean Forced Expiratory Value per 1 second/ Forced Vital Capacity (FEV1/FVC) values - highlighting that the department played a role in adverse respiratory effects. The Coronavirus pandemic increased mask usage, therefore, FEV1/FVC values were slightly better in 2020 when compared to those of 2019. Evidence has revealed that apart from the level of exposure to flour dust, other factors are shown to have influenced results, such as, age, Personal Protective Equipment (PPE) awareness and training, novel Coronavirus pandemic, duration of employment, smoking habits, mixing departments and a lack of a flour dust Occupational Exposure Limit (OEL).