Toxic heavy metals in human blood in relation to certain food and environmental samples in Kerala, South India

Abstract

Toxic heavy metals such as arsenic (As), lead (Pb), and mercury (Hg) are systemic toxicants that are hazardous to human health. However, as these elements are increasing in the environment due to fast urbanization, industrialization, and chemicalized agricultural activities, accumulation of the same in human body anywhere in the world is quite interesting to global assessment of environment quality. In this connection, random examination of blood samples of human population in Kerala, South India, was carried out to assess the threat of heavy metal contamination to humans in this part of the globe, especially in relation to the amount of such metals in food and other environmental samples. Except pure vegetarians, people of Kerala consume rice as the staple food with a lot of fish. Therefore, the amount of these three heavy metals in drinking water, fish, rice, and paddy soils was done. Heavy metals in the blood were examined in relation to age, gender, and dietary habits such as frequency of fish eating or vegetarianism. Influence of dental amalgam fillings on blood mercury levels was also analyzed. Quantitative assessment of metals in samples was done by inductively coupled plasma-mass spectrometry (ICP-MS). The levels of arsenic, lead, and mercury were found well below the reference values, though diet seemed to pull them up as the amount of metals in blood showed significant differences between vegetarians and non-vegetarians. Evidence to the influence of dental amalgam fillings on blood mercury levels could not be established with the present samples.

Role of the Microbiome as the First Metal Detoxification Mechanism

“…On the other hand, toxicodynamics studies the mechanisms at the cellular or molecular level by which toxins cause damage [27]. These branches of toxicology are important to know because through toxicokinetics it is possible to prevent the metal from entering the bloodstream, its distribution can be modified and therapeutic measures can be taken to eliminate and reduce the toxic effects caused in the organism [28].…”

“…In this example, it is clear how the metal can enter via different ways, which increases the amount of metal that enters the body. However, in general, for all metals it is important to consider jointly and not in isolation: the source of exposure, the amount of toxic present, the route of entry of the toxic and the time of exposure to the toxic, since these aspects influence the magnitude of the damage that metals can cause in the organism [27,28].…”

“…As for the distribution of heavy metals, it is observed that the organic forms are rapidly distributed to the central nervous system since they can easily cross the blood-brain barrier due to their liposolubility, they are also distributed to adipose tissue and other organs with higher fat content such as liver, heart and kidneys [27]. In contrast, inorganic compounds do not pass blood-brain barrier [28]. In general, metals pass placenta, and are attached to the disulfide bonds present in the keratin of the skin, hair and nails.…”

“…Finally, heavy metals and some demethylated metabolites are eliminated primarily by urine, but they can also be eliminated by bile, feces, breast milk, skin, nails and hair [27,28]. Once the processes of absorption, distribution, metabolism and elimination of heavy metals are analyzed, it is very important to consider the pharmacokinetic changes that can occur in the most vulnerable populations who suffer from toxic effects such as children and pregnant women ( Table 1) [27].…”

Serum Selenium, Iron, Zinc, and Copper Concentrations in Renal Transplant Recipients Treated with Mycophenolate Mofetil

“…Numerous studies have examined the effect of exogenous factors-including smoking, diet, and amalgam-on heavy metal, macroelement, and microelement concentrations in various organs and tissues, including blood [3,14,32,35]. However, little is still known about the effect of various medicines, including immunosuppressive drugs, on the blood levels of these chemical elements.…”