Metal(loid) contamination in Bangladesh: a comprehensive synthesis in different landscapes with ecological and health implications.

ABSTRACT

Elevated metal(loid) concentrations in soil and foodstuffs is a significant global issue for many densely populated countries like Bangladesh, necessitating reliable estimation for sustainable management. Therefore, a comprehensive data synthesis from the published literature might help to provide a wholistic view of metal(loid) contamination in different areas in Bangladesh. This study provided a clearer view of metal(loid) contamination status and their associated ecological and health risks in different land use and ecosystems in Bangladesh. Comprehensive analyses were performed on data gathered from 143 published articles using multiple statistical techniques including meta-analysis. Considering the potential loading of metal(loid), the data were summarized under various groups, including coastal, rural, urban and industrial regions. Also, the concentrations of seven metal(loid)s, e.g., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), and arsenic (As) in soil, sediment, cereal, vegetable, fruit, surface water and groundwater were included. Results showed that the relative concentrations of metal(loid)s in comparison to the maximum permissible limit (MPL) were mostly less than one, although they varied significantly for locations and individual metal(loid). However, the normalized cumulative relative concentrations over the MPL for all seven metal(loid)s across different environmental samples were 4.75, 2.97, 1.51 and 2.79 for coastal, industrial, rural and urban areas, respectively, which was due to the higher concentration of Cd, Cr and Cu. Similar to the metal(loid) concentrations, the average of cumulative median non-cancer risks for all metal(loid)s was in the order of industrial (6.46) > urban (4.05) > rural (3.83) > coastal (2.41). This research outcome will provide a foundation for future research on metal(loid)s and will help in pertinent policy-making by the relevant authorities in Bangladesh.