Pro-inflammatory secretome of THP-1 macrophage exposed for 24 hours to welding-representative NP. THP-1 were exposed to 5 or 25 μg/cm2 NP for 24 hours. Mix is a 1:1:1:1 mixture of the four NP. Macrophage pro-inflammatory secretome was assayed by Luminex. Open bars: Control. Grey bars: 5 μg/cm2. Black bars: 25 μg/cm2. N = 6 per condition. *: p < 0.05 vs Control condition.