Telomere integrity is critical for chromosomal stability. Evidence is rapidly growing that impaired telomere integrity may explain the higher risk of some diseases among specific occupations. This review aimed to assess the impact of occupational toxicants exposure on telomere length (TL) and to identify each toxicant's mechanism of action based on an integrative review of available evidence. A literature search was carried out using a set of keywords in different databases. Searches were limited to English publications from 2009 to 2019. Only studies that were using blood samples for TL measurements were included. Finally, 22 studies with a total of 5674 participants, were included. These studies included factory workers from various industries, farmers, coke-oven workers, hairdressers, traffic officers, and drivers. The toxicants were grouped into four categories, including persistent organic pollutants (7 articles), aromatic amines (9 articles), heavy metals (3 articles), and fine particulate matter (PM_2.5) (3 articles). Different effects of the same toxicant in TL were observed in various occupations. Factors such as biological characteristics of exposed individuals (especially gene variations and age), diet, lifestyle, dose, and duration of exposure might have modulatory effects on mechanisms and extent of influences of toxicants on TL. Further possible modes of actions affecting the TL are oxidative stress, telomerase expression, systemic inflammation, epigenetic modification, and genotoxicity. In conclusion, various toxicants affect TL differently, but the effect may be moderated by improving the workers’ lifestyle. The involvement of different interrelated pathways may explain the differences in TL alterations.

端粒完整性对于染色体稳定性至关重要。端粒完整性受损的证据正在迅速增长，这可能解释了特定职业中某些疾病的较高风险。这项审查旨在评估职业毒物暴露对端粒长度（TL）的影响，并基于对现有证据的综合审查，确定每种毒物的作用机制。使用不同数据库中的一组关键字进行文献搜索。搜索仅限于2009年至2019年的英文出版物。仅包括使用血液样本进行TL测量的研究。最后，纳入22项研究，共有5674名参与者。这些研究包括来自各个行业的工厂工人，农民，焦炉工人，美发师，交通官员和驾驶员。_2.5）（3条）。在各种职业中，观察到了相同毒物对TL的不同作用。诸如暴露个体的生物学特征（尤其是基因变异和年龄），饮食，生活方式，剂量和暴露持续时间等因素可能对有毒物质对TL的影响机制和影响程度具有调节作用。影响TL的其他可能作用方式是氧化应激，端粒酶表达，全身性炎症，表观遗传修饰和遗传毒性。总之，各种有毒物质对TL的影响不同，但可以通过改善工人的生活方式来减轻这种影响。不同相关途径的参与可能解释了TL改变的差异。