Exposure to welding fumes and health effects: A systematic evaluation based on human biomonitoring analyses

Occupational exposure to heavy metals (HMs) through inhalation of welding emissions presents a serious health hazard to welders. This systematic review aimed to evaluate the concentrations of HMs in biological matrices (blood, urine, serum, and plasma) of welders, and to examine the associations between exposure to welding emissions, oxidative stress markers, and respiratory health outcomes.

A comprehensive literature search was conducted using Web of Science, Scopus, PubMed, Medline, and Embase up to September 16, 2025, based on the PECO (Population, Exposure, Comparator, and Outcomes) framework. A total of 76 studies met the inclusion criteria.

The majority of studies reported significantly higher HM levels in welders compared to control groups. A strong association was observed between metal concentrations in welding emissions and corresponding levels in biological matrices, although the strength of this relationship was occasionally diminished due to confounding variables. More than half of the included studies demonstrated elevated oxidative stress markers such as MDA and 8-OHdG in welders. However, fewer than half of the studies reported significant differences in pulmonary function parameters, with forced vital capacity (FVC) being the most frequently affected.

These findings underscore the importance of implementing protective strategies, including routine human biomonitoring and engineering controls, to mitigate HM exposure, reduce oxidative stress, and prevent related health outcomes among welders.