Distribution and level of arsenic in selected environmental indicators

In this study, total arsenic was determined in soil, common grass (Cenchrus ciliaris), plant leaf (Dogwood; Cornus florida) and an invertebrate (Stag beetle; Rhinotia hemistictus). This was with a view of investigating its distribution and level in the environment. Samples were randomly collected from stratified sections of the study area, processed and analysed using validated acid extraction technique. Detection of arsenic was by use of ICP-OES. Percentage recovery range of 78-92% was obtained and can be adjudged acceptable for application. Overall mean concentration of arsenic ranged from 0.35 ± 0.12 to 2.52 ± 1.85 mg kg-1; 0.01 ± 0.03 to 0.34 mg kg-1; 0.02 ± 0.03 to 0.46 mg kg-1 and 0.04 ± 0.02 to 0.72 ± 0.54 mg kg-1 across sampling sections 1 to 4 for soil, grass, leaf and insect samples respectively. Arsenic was detected in all samples, however levels obtained were below prescribed toxicity limits. Samples were highly contaminated based on contamination factors of > 6. The strong correlation coefficients (> 0.9) showed association between arsenic and analysed samples while analysis of variance revealed no statistical significant difference between arsenic and samples. The study revealed widespread distribution of arsenic in analysed samples which portend serious health implications across the food chain. Key words: Pollution, trace metal, grass, arsenic, environment, health, invertebrate, Namibia.