Workplace concentrations of particulate matter and noise levels among stone quarry and soil brick-making workers in Tanzania

Abstract

This study was conducted in 15 artisanal stone quarries (SQ) and 22 soil brick-making (SBM) sites. Specific objectives were to: (i) quantify ambient concentrations of suspended particulate matter (PM) and gaseous pollutants and noise levels at SQ and SBM workplaces; (ii) critically evaluate the potential workplace hazards, and risk factors; and (iii) analyze potential health risks to workers. Gaseous pollutants, PM, and noise levels were measured by using portable digital devices. Social demographic information of 150 workers across the study sites was collected using a questionnaire. Quantitative data were summarized and exploratorily analyzed using Stata software. This study revealed that fuel burning in the SBM releases SPM up to 10-fold and CO gas up to 14-fold above the WHO-recommended time-weighted average exposure concentrations of 16.6 µg/m3 and 0.3 mg/m3, respectively. On average hitting with a pickax in SQ areas released noise levels of about 81.01 ± 6.8 dB[A]. Overall, the SQ and SBM workers were exposed to low concentrations of PM and noise levels when the measurements were taken. Long working hours for repetitive activities in hot-sunny (27.1 ± 2.3 °C) and low outdoor humidity 23 ± 1.5%, potentially increase epidemiological risks to vulnerable individuals and enhance worker exposures to inhalable PMs. Although workplace noise exposure below the regulatory threshold of 85 dB[A] may not cause immediate hearing damage, it can have a significant impact on workers’ hearing health, cognitive performance, psychological well-being, and overall productivity. This study provides an overview of workplace conditions rather than an accurate representation of the actual worker exposure levels because personal breathing zone sampling devices were not used. This study provides baseline information for further research and can be used for evidence-based decision-making and policy formulation to safeguard worker safety and health in SQ and SBM sites in Tanzania.