No Observed Effect Level (NOEL) for Systemic Inflammation by Copper and Zinc in Welding Fumes.

: Copper and zinc containing welding fumes are able to induce systemic inflammation in healthy subjects. In this study the no observed effect levels (NOEL) for welding fumes containing either copper or zinc were assessed.Fifteen healthy male volunteers participated in an exposure. Each subject was exposed to two different concentrations of both, copper and zinc containing welding fumes. Exposure was performed in the Aachen Workplace Simulation Lab.The NOEL was found at metal concentrations between 0.2 and 0.3 mg/m for copper and between 0.8 and 1.2 mg/m for zinc.The NOEL identified in this study was about a factor of 10 higher than the German workplace threshold limit values (TLV). However, TLV in other countries was in the same range or even higher than the NOEL indicating a considerable risk for workers.

Increased Neutrophil Granulocyte and Myeloperoxidase Levels Indicate Acute Inflammation Due to the Exposure of Zinc- and Copper-Containing Welding Fumes.

OBJECTIVE: Recent studies have shown an increase of C-reactive-protein (CRP) after exposure to zinc- and copper-containing welding fumes. The objective of this study was to determine the effects of exposure to zinc- and copper-containing welding fumes on leukocytes, their subtypes, and myeloperoxidase (MPO). METHODS: Serum samples of male volunteers were examined after exposures to welding fumes in two settings: repeated exposure on 4 consecutive days for 6 hours and single exposures for different times (3, 4, 5 hours). RESULTS: Neutrophil granulocyte and MPO levels showed increases 24 hours after single and repeated exposures for 6 hours similar to CRP increases reported in literature. Overall leukocyte levels and levels of monocytes and lymphocytes were not significantly affected. CONCLUSIONS: This study indicates the involvement of neutrophil granulocytes in welding fume fever additional to mediator related effects.

The Effects of Exposure Time on Systemic Inflammation in Subjects With Exposure to Zinc- and Copper-Containing Brazing Fumes.

INTRODUCTION: Inhalation of copper and zinc containing brazing fumes (2.5 mg/m for 6 hours) is able to induce asymptomatic systemic inflammation which is supposed to be connected with an increased risk for cardiovascular disease. In this study it was investigated if inflammation can be prevented by reducing the exposure time. METHODS: A total of 15 healthy male subjects were exposed to such brazing fumes in a crossover design for 3, 4, and 5 hours in randomized order. Before and 24 hours after exposure, blood samples were taken and c-reactive protein (CRP) as marker for an acute phase reaction was measured. RESULTS: Five-hour exposure induced an increase of CRP, whereas the shorter exposure times did not result in a significant inflammatory reaction. CONCLUSIONS: Reducing daily exposure times below 5 hours is able to prevent systemic inflammatory reactions.