In vivo bioavailability of Hg and Se and their antagonistic interaction in blood-plasma, urine and hair through the ingestion of Amazonian fish and Brazil nuts by riverside communities from the Amazon region

Abstract

Toxic and non-essential for humans, mercury is a ubiquitous element in the environment. The bioavailability of methyl-Hg for humans is estimated to vary between 2% to 100%. However, several factors can influence the bioavailability of Hg in the human body, from the type of food eaten to the chemical species of Hg in the food. Intrinsic population factors, such as age and ethnicity, are also prevalent. Fish is one of the foods that present higher concentrations of Hg (methyl-Hg) once Hg is an element that undergoes biomagnification in the environment and consequently bioaccumulation in tissues. About 95% of the methyl-Hg ingested through the ingestion of fish can be absorbed in the human gastrointestinal tract. Exposure to Hg can cause impacts to the organism from stomatitis to neurological problems, even death. On the other hand, some foods such as Brazil nuts, rich in Se, can have a protective effect on the body concerning the toxicity of Hg. With the increasing concentrations of Hg in the environment, this issue is urgent, thus promoting continuous studies to review and develop new protocols on Hg exposure and intoxication. Therefore, in vivo studies are necessary to better understand exposure to Hg through food intake, in addition to Hg mitigation processes through elements such as Se. Thus, the present project aims to evaluate in vivo bioavailability of Hg (consumed through fish) and its antagonism concerning Se (consumed through Brazil nuts) in volunteers from the Brazilian Amazon, using techniques for the total determination of Hg and Se in blood, urine and hair, as well as the determination of the Hg and Se chemical species in the blood by HPLC-ICP-MS. Finally, the project will conduct environmental analysis focusing on ecotoxicology, collecting soil and water from the communities to determine Hg and Se. This project is expected to evaluate the impact of Hg and Se in food, in the human body through ingestion and in the environment in which they are disposed of this way contributing to the monitoring of public health, not only in the biological sphere but also in the environmental and feed.