Reduction in welding fume and metal exposure of stainless steel welders: an example from the WELDOX study.

PURPOSE: In a plant where flux-cored arc welding was applied to stainless steel, we investigated changes in airborne and internal metal exposure following improvements of exhaust ventilation and respiratory protection. METHODS: Twelve welders were examined at a time in 2008 and in 2011 after improving health protection. Seven welders were enrolled in both surveys. Exposure measurement was performed by personal sampling of respirable welding fume inside the welding helmets during one work shift. Urine and blood samples were taken after the shift. Chromium (Cr), nickel (Ni), and manganese (Mn) were determined in air and biological samples. RESULTS: The geometric mean of respirable particles could be reduced from 4.1 mg/m(3) in 2008-0.5 mg/m(3) in 2011. Exposure to airborne metal compounds was also strongly reduced (Mn: 399 vs. 6.8 µg/m(3); Cr: 187 vs. 6.3 µg/m(3); Ni: 76 vs. 2.8 µg/m(3)), with the most striking reduction inside helmets with purified air supply. Area sampling revealed several concentrations above established or proposed exposure limits. Urinary metal concentrations were also reduced, but to a lesser extent (Cr: 14.8 vs. 4.5 µg/L; Ni: 7.9 vs. 3.1 µg/L). Although biologically regulated, the mean Mn concentration in blood declined from 12.8 to 8.9 µg/L. CONCLUSION: This intervention study demonstrated a distinct reduction in the exposure of welders using improved exhaust ventilation and welding helmets with purified air supply in the daily routine. Data from area sampling and biomonitoring indicated that the area background level may add considerably to the internal exposure.

Evidence of increased skin irritation after wet work: impact of water exposure and occlusion.

BACKGROUND: Exposure to humid environments/water and prolonged glove occlusion are both believed to cause irritant contact dermatitis. OBJECTIVES: To study the effects of different forms of wet work, especially the differences between water exposure and occlusion, by using an experimental model simulating occupational wet work. METHODS: The responses to water exposure and occlusion over multiple daily exposure periods for 7 days were compared in 73 volunteers. After the 1 week exposure, the sites were irritated with sodium lauryl sulfate (SLS). Comparison was performed via visual inspection and bioengineering methods. RESULTS: Whereas occlusion did not induce measurable alterations in skin physiology, water exposure for more than 3 hr daily caused a significant increase in transepidermal water loss (TEWL) as compared with the control areas. SLS irritation of the previously occluded and the water-exposed sites induced higher TEWL and clinical scores in a time-dependent fashion as compared with the control areas, with more pronounced reactions in the water-exposed sites than in the occluded sites. CONCLUSION: Both previous occlusion and water exposure were capable of inducing higher susceptibility to SLS irritation. Skin hydration by occlusion had a different biological effect than water exposure. Short occlusions seem to harm the skin less than water exposure for the same duration.

Assessment of mRNA and microRNA Stabilization in Peripheral Human Blood for Multicenter Studies and Biobanks.

In this study we evaluate the suitability of two methods of RNA conservation in blood samples, PAXgene and RNAlater, in combination with variable shipping conditions for their application in multicenter studies and biobanking. RNA yield, integrity, and purity as well as levels of selected mRNA and microRNA species were analyzed in peripheral human blood samples stabilized by PAXgene or RNAlater and shipped on dry ice or at ambient temperatures from the study centers to the central analysis laboratory. Both examined systems were clearly appropriate for RNA stabilization in human blood independently of the shipping conditions. The isolated RNA is characterized by good quantity and quality and well suited for downstream applications like quantitative RT-PCR analysis of mRNA and microRNA. Superior yield and integrity values were received using RNAlater. It would be reasonable to consider the production and approval of blood collection tubes prefilled with RNAlater to facilitate the use of this excellent RNA stabilization system in large studies.