Assessment of Bacteria, Morphological Characteristics, and Elemental Composition of Dust Fallout

Abstract

Dust fallout can have diverse impacts ranging from major health problems to environmental concerns. It can harbour disease-causing microorganisms and toxic heavy metals, and it is therefore critical to establish the microbial and the mineral compositions of the dust fallout in a particular site and elucidate the possible related health implications for humans and the entire environment. In this study, dust fallout samples were collected from Arandis, a town in the Erongo region (Namibia), using the American Society for Testing and Materials standard method (ASTM D1739) for collection and analysis of dust fallout (settleable particulate matter). The identification of present viable bacteria was done through culturing and isolation techniques and the morphological characteristics, and the elemental composition of the dust fallout were determined using the Stereomicroscope and the X-ray fluorescence, respectively. The results showed that the most dominant bacteria contained in the fallout dust were the Bacillus species. The morphological characterisation revealed that the present particles were mixed black, brownish, greenish, and crystal particles with irregular, cubical, flocks and flake shapes. The elemental investigations indicated that the dust fallout contained Hg, As, Fe, Ni, Cr, Mn, Al and Pb occurring in varying concentrations and the status of pollution of the dust fallout ranged from low to severe concerning the inconsistent heavy metal indices that are the contamination factor, pollution load index and the enrichment factor.

Assessment of the Level of Metal(loid)s Pollution and Bioactive Compounds Screening of Anthill Soil

“…3) Health risk assessment Humans are exposed to heavy metals via several pathways. However, given that people (adults and/or teenagers) consume the aqueous extracts of this anthill soil, they are exposed to the metals and/or metalloids in the soil via ingestion route [23]. Therefore, this study focused on assessing the exposure based on the ingestion pathway in adults.…”