Title:

Dust and radon levels on the west coast of Namibia - What did we learn?

Publication Year:
2020
Abstract:

The study investigated the potential for adverse health impacts from exposures to inhalable atmospheric dust and radon in the main towns along Namibia's central-western coast. An ambient air quality monitoring network was established at the end of 2016 to measure and track the inhalable dust (specifically PM10) and radon concentrations. Data collected between November 2016 and the end of December 2018 were assessed and selected PM10 samples were analysed for mineral and radionuclide content. In addition, emissions from anthropogenic sources were quantified and simulated using a regional dispersion model. Episodic dust storms associated with easterly winds are a common phenomenon during the winter months in the western part of Namibia. During such events, dust is transported over long distances westwards towards and well into the Atlantic Ocean. In view of the natural and anthropogenic nature of atmospheric dust, the study differentiated between sources of natural dust and those arising as a result of man-made processes. It was found that PM10 concentrations were, on average, higher at the coastal monitoring stations than at the stations located further inland, often exceeding the daily World Health Organisation (WHO) guideline value. Whilst high atmospheric dust concentrations were mostly associated with easterly wind conditions, sea salt was found to be a significant PM10 contributor at the coastal stations. Modelled results, which only included emissions from man-made sources, indicated that these sources contribute very little to the total PM10 concentrations measured at the coastal towns. The radiation exposure doses associated with the inhalation of atmospheric dust and radon were found to be well-below the world-wide average inhalation doses provided by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Keywords: Inhalable particulate matter, Health impacts, Radiation exposure dose, Natural and man-made emissions, Air quality management, Namibia.

Publication Title:

Atmospheric Pollution Research

Volume:
In Press
Item Type:
Journal Article
Language:
en