Toxicity of Workplace Aluminum Particles: Insights from Earthworm (Eisenia fetida) Tests in Soil Mixtures

Abstract

Lifestyle changes have led to increasing use of alternative materials in building construction, fabrication of furniture and household appliances. Apart from the associated light weight and aesthetics, Aluminum products endure various pressures that range from climatic factors to pest attacks; hence, they are more durable than wood and other conventional materials. Activities of fabricators are widespread in many Nigerian cities and these result in traces of Aluminum particles derived from cutting, shaping and surface filing. The resulting recalcitrant dust particles can exert adverse consequences on biota. Therefore, this study examined the effects of different levels of Aluminum particles on earthworm in soil mixtures by assessing their behaviour, mobility and mortality in a five-week ecotoxicity test. Worms became sluggish after only two-week exposure and this culminated in loss of mobility and ultimately mortality in exposed organisms. Mortality of worms was highest (80 – 100%) in soil mixtures with the most proportion of Aluminum particles and decreased correspondingly with contaminant levels. However, there was no mortality of worms in soil mixtures without any Aluminum particles. Lethal concentration (LC₅₀) values of 2.564g/kg, 0.995g/kg and 0.851/kg were determined at two, four and five weeks, respectively. The results suggest that worms in the course of foraging in soil, can internalize contaminating Aluminum particles, which may lead to adverse consequences in exposed population. Considering the role of earthworms in breakdown of soil organic matter and nutrient cycling, indiscriminate disposal of Aluminum particles across various landscapes may have consequences on soil fertility, food security and sustainability.