Metal concentration in biological samples of shipyard welders: a scoping review

Welding fumes are an unavoidable by-product of welding processes and have been associated with various adverse health effects. In the shipbuilding industry, welders are potentially exposed to large amounts of welding fumes containing various metal species. For the assessment of health risks human biomonitoring (HBM) constitutes a valuable tool determining the actual internal exposure to the metal content.

This review aims to provide an overview of the current HBM data on the internal metal burden of shipyard welders, including associations with 1) ambient monitoring (AM) data, 2) welding processes, and 3) an assessment of health risks for welders based on reported HBM results.

PubMed and Web of Science were searched for HBM studies providing metal concentrations in biological samples from shipyard welders. Study characteristics, AM and HBM results, and welding processes were extracted.

Twenty-two studies were included in this review. Overall, sixteen metals were quantified in biological samples, with manganese, nickel and chromium being the most frequently analysed. In welders, metal concentrations were 1.02 to 20.6 times higher than in controls for 81 % of the HBM data, with a statistically significant difference observed in 33 % of cases. Weak associations were found between metal levels and AM results or welding processes. The limitations of using occupational exposure limits for risk assessment were discussed.

Prospective studies with a harmonised design are needed to elucidate causal relationships between welding fume exposure and systemic metal burden, and to facilitate an accurate assessment of the resulting health risks.