Percorrer por autor "Haveric, Anja"
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- The comet assay as a tool in human biomonitoring of exposure to heavy metals: a systematic review and meta-analysisPublication . Møller, Peter; Bankoglu, Ezgi Eyluel; Stopper, Helga; Gajski, Goran; Gerić, Marko; Haveric, Anja; Azqueta, Amaya; Giovannelli, Lisa; Collins, Andrew; Ladeira, CarinaExposure to heavy metals such as lead, arsenic, and chromium is associated with genotoxicity and increased risk of cancer. In this systematic review and meta-analysis, we have assessed the effects of heavy metal exposure on levels of DNA strand breaks in leukocytes, measured by the comet assay, in human biomonitoring studies. We distinguish between traditional toxic metals (lead), semi-metals/metalloids (arsenic), transition metals (chromium), and other heavy metals. The literature search led to 66 studies, which were assessed by meta-analysis. Using standardized mean difference and 95 % confidence interval (CI), the meta-analyses show increased levels of DNA strand breaks in subjects exposed to lead (1.99, 95 % CI: 1.47, 2.51), arsenic (1.36, 95 % CI: 0.94, 1.77), chromium/welding fume (2.03, 95 % CI: 1.48, 2.57), and other heavy metals (0.81, 95 % CI: 0.45, 1.18). Subgroup analysis indicates that all studies combined from middle-income countries have a higher effect size (1.99, 95 % CI: 1.63, 2.35) than studies from high-income countries (0.81, 95 % CI: 0.37, 1.26). The lower effect size in high-income countries may be due to differences in exposure levels, related to stricter regulation of emissions or more awareness/use of personal protective equipment in the working environment. Sensitivity analysis does not unequivocally link effect size to comet assay measurement bias, inferred by insufficient information on comet assay procedures, missing assay controls, non-blinded analysis of samples, or exposure misclassification. In conclusion, this systematic review and meta-analysis shows that exposure to heavy metals - lead, arsenic, and chromium - is associated with increased levels of DNA strand breaks in human leukocytes.
- The comet assay as a tool in human biomonitoring studies: effects of confounding factorsPublication . Møller, Peter; Gajski, Goran; Gerić, Marko; Giovannelli, Lisa; Azqueta, Amaya; Haveric, Anja; Stopper, Helga; Bankoglu, Ezgi Eyluel; Collins, Andrew; Ladeira, CarinaThe comet assay is widely used in human biomonitoring studies of environmental and occupational exposures. However, it is clear from multiple studies that various types of confounding factors might affect the direct relationship between exposure and DNA damage in the comet assay. In addition to common confounders such as age, sex, and smoking, other factors considered to be important determinants for background levels of DNA damage in the comet assay include exhaustive physical exercise, chronic diseases, medical treatment, and diet. These are typically controlled in biomonitoring studies by restriction or matching of subjects. Period effects (or seasonal variation) have been observed in a relatively large number of studies. There are various putative factors, which may cause period effects, including temporal variation in solar radiation, temperature, and air pollution. The present review describes the effects of these confounding factors in measurements of DNA strand breaks by the comet assay. In general, the literature does not indicate that any confounding factor is consistently associated with an increased level of DNA damage, measured by the comet assay. In this respect, it is important to balance the need to control for confounding with the risk of introducing in the statistical analysis a variable, which is influenced by exposure and outcome (i.e. collider bias). In addition, it is important that investigators describe procedures for controlling the effect of confounding factors in the selection of subjects and statistical analysis. Care should be taken in study design and statistical analysis to avoid unwanted effects of confounding factors.
- The comet assay as a tool in human biomonitoring studies of environmental and occupational exposure to chemicals: a systematic scoping reviewPublication . Ladeira, Carina; Møller, Peter; Giovannelli, Lisa; Gajski, Goran; Haveric, Anja; Bankoglu, Ezgi Eyluel; Azqueta, Amaya; Gerić, Marko; Stopper, Helga; Cabêda, José; Tonin, Fernanda; Collins, AndrewBiomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.