In male mice, exposure to very low doses of arsenic increases the number of benign or malignant tumors. The doses tested are comparable to those received by humans.
Arsenic is toxic from the lowest doses. A study published in the July edition of the journal Archives of Toxicology demonstrates the carcinogenic effects of this element in male mice. They develop more benign and malignant tumors in the lungs.
Benign tumors in females
In this study, rodents were exposed to different levels of inorganic arsenic: 50 parts per billion (ppb), 500 and 5,000. The aim was to replicate the levels to which humans are exposed. Arsenic was administered to mice via their drinking water, three weeks before reproduction and then during pregnancy and lactation. The mice underwent the same treatment when they were weaned and throughout adulthood. At the same time, the researchers observed the appearance and development of tumors.
More than half of male pups developed more benign and malignant lung tumors when exposed to 50 or 500 ppb of arsenic. In female mice, an increase in the number of benign tumors was observed only. In the group of rodents exposed to 5,000 ppb of arsenic, surprisingly, no significant increase appears.
A mostly food exhibition
In France, exposure to arsenic is limited. Since 1973, arsenical herbicides have been banned. This made it possible to reduce exposure via agricultural products. Since 2003, the dose of arsenic present in water intended for human consumption cannot exceed 10 µg / L. Despite everything, according to a report from the Health Security Agency (Anses), adults are exposed to this toxic element via drinking water and coffee, children via drinking water, milk and non-alcoholic drinks. It is also found in certain fish and agricultural foods – especially rice.
Inorganic arsenic, studied here, is known for its carcinogenic effects on humans from the lowest doses. It is a proven carcinogen since 1980, according to the criteria of the International Agency for Research on Cancer (IARC). Inhaled or absorbed by water, it causes lung, skin and bladder cancer. Most often, arsenic is ingested through water or food. Environmental contamination is also possible in several French regions where the element is highly concentrated in the subsoil: Massif-Central, Vosges and Alps.
“Although this is only one study, it adds to a growing body of evidence showing the adverse health effects of very low exposure to arsenic; this suggests that no level of arsenic appears to be safe, ”concludes Dr Linda Birnbaum, director of the National Institute of Environmental Health Sciences.
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