An international study reveals how various environmental and occupational exposures affect human DNA

An international study shows that environmental and occupationalexhibition tion to various chemical agents is associated with a significant increase in DNA breaks in human cells. The work, published in Mutation Research – Reviews in Mutation Researchresearcher, compiles and compares the results of six systematic reviews and meta-analyses previously conducted by the genotoxicology team, and, taken together, analyzes 255 programs of study on these exposures, providing a comprehensive overview of the genotoxic impact of various chemical agents.

research Dr. Amaya Azqueta, a researcher at the Biodiversity and Environment Institute BIOMA at the University of Navarra, along with an international team of specialists in toxicology Genetics and environmental health from institutions in Denmark, Croatia, Italy, Germany, Norway, Bosnia and Herzegovina, and Portugal. The team has produced an unprecedented synthesis of the evidence available on the use of the comet essay as a tool for human biomonitoring—a technique capable of detecting breaks in the DNA strands of human cells and widely used to assess the early effects of potentially genotoxic exposures.

“These damage sites can be repaired by our cells’ DNA repair systems. However, if they are not repaired or are repaired incorrectly, they can lead to mutations. For this reason, they are considered premutagenic damage sites. Mutations, unlike these initial damage sites, are permanent changes in the DNA sequence, and their presence is linked to the e development s of various diseases, including cancer. It is also important to note that not everyone has the same ability to repair DNA damage,” says Dr. Azqueta.

In total, the analysis includes data from 255 scientific programs of study , selected from a systematic review of the literature published since 2000, focusing on six major groups of exhibition: air pollution, anesthetic gases, antineoplastic drugs, heavy metals, pesticides, and volatile organic compounds. The goal was to determine whether these exposures are associated with different levels of DNA strand breaks in human leukocytes, using the essay comet assay as a tool for biomonitoring.

The results indicate that pesticides have the largest effect sizes. Volatile organic compounds, heavy metals, and anticancer drugs fall in an intermediate range, while anesthetic gases and air pollution have the smallest relative effect sizes. However, the researchers caution that this ranking should not be interpreted directly as a hierarchy of pollutant hazard levels. The exposures studied are very different from one another, and it is not possible to directly compare their doses or to establish a genotoxic potency for each substance based on these results.

The study also notes that studies conducted in middle- average -income countries generally show larger effect sizes than those conducted in high-income countries. The authors suggest that this difference could be related to both levels of exhibition and socioeconomic factors, but they caution that it is not possible to pinpoint a single explanation.

essay -comet assay enables the detection of early DNA alterations and serves as a useful tool for studying the biological effects of various exposures. However, the authors emphasize that the presence of a higher issue of DNA breaks does not necessarily mean that a person will develop a disease. The work, in which Amaya Azqueta participates, highlights both the potential of biomonitoring using essay comet assays and the need to continue making progress in standardizing procedures, assessment of exposures, and the quality of programs of study.

reference letter Bibliographic reference:
· Peter Møller, Goran Gajski, Marko Gerić, Amaya Azqueta, Lisa Giovannelli, Anja Haveric, Helga Stopper, Ezgi Eyluel Bankoglu, Andrew Collins, Carina Ladeira,“The comet assay as a tool for human biomonitoring of exposure to environmental and occupational agents” – A summary of systematic reviews and goal-analyses, *Mutation Research - Reviews in Mutation Research*, Volume 798, 2026, 108601, ISSN 1383-5742.