Speciation of trace metals in an urban tropical lake, Lake Pampulha, Brazil

摘要: Assessing the impact of urban catchment runoff on receiving waters must be addressed. Trace metal contamination represents a significant risk to environment and public health. But total concentration does not reflect trace environmental because their toxicity depends especially nature present species. Most studies address fate metals in lake tributaries or sediments. Our aim was focus seasonal variation concentrations water column order improve assessment impact. This study focuses monitoring, for 10 months including dry raining seasons, speciation Lake Pampulha. were collected at two depths middle For each sample, fractions divided into total, dissolved, inert metal. Six anthropogenic considered: cadmium, cobalt, copper, lead, nickel zinc. The results showed different behaviour column. Cadmium is under quantification limit. Speciation indicate variable bioavailability. Zinc most bioavailable (~60%). Bioavailability cobalt which highly dissolved varies with depth. Nickel bioavailability remains rather constant surface layer during period those zinc lead are more variable.